glsl Samouczek
Rozpoczęcie pracy z glsl
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Uwagi
Ta sekcja zawiera przegląd tego, czym jest glsl i dlaczego deweloper może chcieć z niego korzystać.
Powinien również wymieniać wszelkie duże tematy w glsl i link do powiązanych tematów. Ponieważ Dokumentacja dla glsl jest nowa, może być konieczne utworzenie początkowych wersji tych pokrewnych tematów.
Wersje
Język cieniowania OpenGL
| Wersja GLSL | Wersja OpenGL | Preprocesor Shadera | Data wydania |
|---|---|---|---|
| 1.10 | 2.0 | #wersja 110 | 2004-09-07 |
| 1.20 | 2.1 | #wersja 120 | 2006-07-02 |
| 1,30 | 3.0 | #wersja 130 | 2008-08-11 |
| 1,40 | 3.1 | #wersja 140 | 24.03.2009 |
| 1,50 | 3.2 | #wersja 150 | 2009-08-03 |
| 3,30 | 3.3 | #wersja 330 | 2010-02-12 |
| 4.00 | 4.0 | #wersja 400 | 2010-03-11 |
| 4.10 | 4.1 | #wersja 410 | 2010-07-26 |
| 4.20 | 4.2 | #wersja 420 | 08.08.2011 |
| 4,30 | 4.3 | #version 430 | 06.08.2012 |
| 4,40 | 4.4 | #wersja 440 | 2013-07-22 |
| 4.50 | 4.5 | #wersja 450 | 2014-08-11 |
Język cieniowania OpenGL ES
| Wersja GLSL ES | Wersja OpenGL ES | Preprocesor Shadera | Data wydania |
|---|---|---|---|
| 1,00 ES | 2.0 | #wersja 100 | 2007-03-05 |
| 3,00 ES | 3.0 | #version 300 es | 06.08.2012 |
| 3.10 ES | 3.1 | #version 310 es | 17.03.2014 |
| 3,20 ES | 3.2 | #version 320 es | 2015-08-10 |
Instalacja lub konfiguracja
Szczegółowe instrukcje dotyczące konfigurowania lub instalowania glsl.
Pierwszy program do cieniowania GLSL OGL 4.0
Prosty program cieniujący OGL 4.0 GLSL z pozycją wierzchołka i atrybutem koloru. Program jest wykonywany za pomocą skryptu phyton. Aby uruchomić skrypt, PyOpenGL musi być zainstalowany.
Program do cieniowania składa się co najmniej z modułu cieniującego wierzchołki i modułu cieniującego fragmant (z wyjątkiem programów cieniujących komputer). Pierwszy stopień modułu cieniującego to moduł cieniujący wierzchołek, a ostatni stopień modułu cieniującego to moduł cieniujący fragmenty (w międzyczasie możliwe są opcjonalne dalsze etapy, które nie są tutaj dalej opisane).
Moduł cieniujący wierzchołków
first.vet
Moduł cieniujący wierzchołki przetwarza wierzchołki i powiązane atrybuty określone przez polecenie rysowania. Moduł cieniujący wierzchołki przetwarza wierzchołki ze strumienia wejściowego i może nim manipulować w dowolny pożądany sposób. Moduł cieniujący wierzchołki odbiera jeden pojedynczy wierzchołek ze strumienia wejściowego i generuje jeden pojedynczy wierzchołek do wyjściowego strumienia wierzchołków.
W naszym przykładzie rysujemy pojedynczy trójkąt, więc moduł cieniujący wierzchołek jest wykonywany 3 razy, raz dla każdego punktu narożnego trójkąta. W tym przypadku dane wejściowe do modułu cieniującego wierzchołek to pozycja wierzchołka in vec3 inPos i atrybut koloru in vec3 inCol . Atrybuty kolorów są przekazywane do następnego etapu modułu cieniującego ( out vec3 vertCol ).
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inCol;
out vec3 vertCol;
void main()
{
vertCol = inCol;
gl_Position = vec4( inPos, 1.0 );
}
Moduł cieniujący fragmenty
first.frag
W tym przykładzie moduł cieniujący fragment następuje bezpośrednio po module cieniującym wierzchołek. Pozycje i atrybuty wierzchołków są interpolowane w obrębie każdej powierzchni dla każdego fragmentu. Moduł cieniujący fragmenty jest wykonywany raz dla każdego fragmentu w całym trójkącie i otrzymuje atrybut koloru z modułu cieniującego fragmentu. Po narysowaniu trójkąta atrybut koloru interpolowany jest według współrzędnych barycentrycznych fragmentu na podstawie narysowanego trójkąta.
#version 400
in vec3 vertCol;
out vec4 fragColor;
void main()
{
fragColor = vec4( vertCol, 1.0 );
}
Skrypt phyton
Skrypt Pythona służy tylko do kompilacji, łączenia i uruchamiania programu cieniującego oraz do rysowania geometrii. Można go trywialnie przepisać w C lub cokolwiek innego. Nie jest to część tej dokumentacji, na którą należy zwrócić największą uwagę.
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
from sys import *
from array import array
# draw event
def OnDraw():
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glBindVertexArray( vaObj )
glDrawArrays( GL_TRIANGLES, 0, 3 )
glutSwapBuffers()
# read vertex shader program
with open( 'first.vert', 'r' ) as vertFile:
vertCode = vertFile.read()
print( '\nvertex shader code:' )
print( vertCode )
# read fragment shader program
with open( 'first.frag', 'r' ) as fragFile:
fragCode = fragFile.read()
print( '\nfragment shader code:' )
print( fragCode )
# initialize glut
glutInit()
# create window
wndW = 800
wndH = 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define triangle data
posData = [ -0.636, -0.45, 0.0, 0.636, -0.45, 0.0, 0.0, 0.9, 0.0 ]
colData = [ 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0, 1.0 ]
posAr = array( "f", posData )
colAr = array( "f", colData )
# create buffers
posBuffer = glGenBuffers(1)
glBindBuffer( GL_ARRAY_BUFFER, posBuffer )
glBufferData( GL_ARRAY_BUFFER, posAr.tostring(), GL_STATIC_DRAW )
colBuffer = glGenBuffers(1)
glBindBuffer( GL_ARRAY_BUFFER, colBuffer )
glBufferData( GL_ARRAY_BUFFER, colAr.tostring(), GL_STATIC_DRAW )
# create vertex array opject
vaObj = glGenVertexArrays( 1 )
glBindVertexArray( vaObj )
glEnableVertexAttribArray( 0 )
glEnableVertexAttribArray( 1 )
glBindBuffer( GL_ARRAY_BUFFER, posBuffer )
glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 0, None )
glBindBuffer( GL_ARRAY_BUFFER, colBuffer )
glVertexAttribPointer( 1, 3, GL_FLOAT, GL_FALSE, 0, None )
# compile vertex shader
vertShader = glCreateShader( GL_VERTEX_SHADER )
glShaderSource( vertShader, vertCode )
glCompileShader( vertShader )
result = glGetShaderiv( vertShader, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( vertShader ) )
sys.exit()
# compile fragment shader
fragShader = glCreateShader( GL_FRAGMENT_SHADER )
glShaderSource( fragShader, fragCode )
glCompileShader( fragShader )
result = glGetShaderiv( fragShader, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( fragShader ) )
sys.exit()
# link shader program
shaderProgram = glCreateProgram()
glAttachShader( shaderProgram, vertShader )
glAttachShader( shaderProgram, fragShader )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
# start main loop
glutMainLoop()
Wykorzystanie macierzy modelu, widoku i projekcji w OGL 4.0 GLSL
Prosty program cieniujący OGL 4.0 GLSL, który pokazuje użycie modelu, widoku i macierzy projekcji. Program jest wykonywany za pomocą skryptu phyton. Aby uruchomić skrypt, PyOpenGL i NumPy muszą być zainstalowane.
Macierz projekcji: Macierz projekcji opisuje mapowanie kamery otworkowej z punktów 3D na świecie do punktów 2D rzutni. W tym przykładzie używamy macierzy projekcji o polu widzenia 90 stopni.
Macierz widoków: Macierz widoków określa pozycję oka i kierunek patrzenia na scenę. W tym przykładzie poruszamy się wokół sceny, zachowując kierunek patrzenia na środek sceny.
Macierz modelu: Macierz modelu określa położenie i względny rozmiar obiektu w scenie. W tym przykładzie macierze modelu przesuwają obiekty w górę i w dół.
Moduł cieniujący wierzchołków
mvp.vet
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inCol;
out vec3 vertCol;
uniform mat4 projectionMat44;
uniform mat4 viewMat44;
uniform mat4 modelMat44;
void main()
{
vertCol = inCol;
vec4 modolPos = modelMat44 * vec4( inPos, 1.0 );
vec4 viewPos = viewMat44 * modolPos;
gl_Position = projectionMat44 * viewPos;
}
Moduł cieniujący fragmenty
mvp.frag
#version 400
in vec3 vertCol;
out vec4 fragColor;
void main()
{
fragColor = vec4( vertCol, 1.0 );
}
Skrypt phyton
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
# draw event
def OnDraw():
currentTime = time()
# set up projection matrix
prjMat = perspective( 90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = Translate( np.matrix(np.identity(4), copy=False, dtype='float32'), np.array( [0.0, 0.0, -8.0] ) )
viewMat = RotateView( viewMat, [10.0, CalcAng( currentTime, 10.0 ), 0.0] )
# set up tetrahedron model matrix
tetModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
tetModelMat = RotateX( tetModelMat, -90.0 )
tetModelMat = Scale( tetModelMat, np.repeat( 2.0, 3 ) )
tetModelMat = Translate( tetModelMat, np.array( [-2.0, 0.0, CalcMove(currentTime, 6.0, [-1.0, 1.0])] ) )
# set up icosahedron model matrix
icoModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
icoModelMat = RotateX( icoModelMat, -90.0 )
icoModelMat = Scale( icoModelMat, np.repeat( 2.0, 3 ) )
icoModelMat = Translate( icoModelMat, np.array( [2.0, 0.0, CalcMove(currentTime, 6.0, [1.0, -1.0])] ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
# draw tetrahedron
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, tetModelMat )
glBindVertexArray( tetVAObj )
glDrawElements(GL_TRIANGLES, len(tetIndices), GL_UNSIGNED_INT, tetIndices)
# draw tetrahedron
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, icoModelMat )
glBindVertexArray( icoVAObj )
glDrawArrays( GL_TRIANGLES, 0, len(icoPosData) )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array opject
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define tetrahedron vertex array opject
sin120 = 0.8660254
tetPposData = [ 0.0, 0.0, 1.0, 0.0, -sin120, -0.5, sin120 * sin120, 0.5 * sin120, -0.5, -sin120 * sin120, 0.5 * sin120, -0.5 ]
tetColData = [ 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, ]
tetIndices = [ 0, 1, 2, 0, 2, 3, 0, 3, 1, 1, 3, 2 ]
tetVAObj = CreateVAO( [ (3, tetPposData), (3, tetColData) ] )
tetInxArr = np.array( tetIndices, dtype='uint' )
# define icosahedron vertex array opject
icoPts = [
[ 0.000, 0.000, 1.000], [ 0.894, 0.000, 0.447], [ 0.276, 0.851, 0.447], [-0.724, 0.526, 0.447],
[-0.724, -0.526, 0.447], [ 0.276, -0.851, 0.447], [ 0.724, 0.526, -0.447], [-0.276, 0.851, -0.447],
[-0.894, 0.000, -0.447], [-0.276, -0.851, -0.447], [ 0.724, -0.526, -0.447], [ 0.000, 0.000, -1.000] ]
icoCol = [ [1.0, 0.0, 0.0], [0.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0] ]
icoIndices = [
2, 0, 1, 3, 0, 2, 4, 0, 3, 5, 0, 4, 1, 0, 5, 11, 7, 6, 11, 8, 7, 11, 9, 8, 11, 10, 9, 11, 6, 10,
1, 6, 2, 2, 7, 3, 3, 8, 4, 4, 9, 5, 5, 10, 1, 2, 6, 7, 3, 7, 8, 4, 8, 9, 5, 9, 10, 1, 10, 6 ]
icoPosData = []
for inx in icoIndices:
for inx_s in range(0, 3):
icoPosData.append( icoPts[inx][inx_s] )
icoColData = []
for inx in range(0, len(icoPosData) // 9):
inx_col = inx % len(icoCol)
for inx_p in range(0, 3):
for inx_s in range(0, 3):
icoColData.append( icoCol[inx_col][inx_s] )
icoVAObj = CreateVAO( [ (3, icoPosData), (3, icoColData) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'mvp.vert', GL_VERTEX_SHADER ),
CompileShader( 'mvp.frag', GL_FRAGMENT_SHADER )
] )
projectionMatLocation = glGetUniformLocation(shaderProgram, "projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "modelMat44")
# start main loop
startTime = time()
glutMainLoop()
Umieść teksturę na modelu i użyj matrycy tekstur w OGL 4.0 GLSL
Prosty program cieniujący OGL 4.0 GLSL, który pokazuje, jak mapować teksturę 2D na siatce. Program jest wykonywany za pomocą skryptu phyton. Aby uruchomić skrypt, PyOpenGL i NumPy muszą być zainstalowane.
Macierz tekstur określa sposób odwzorowywania tekstury na siatce. Manipulując matrycą tekstur, teksturę można przesuwać, skalować i obracać.
Moduł cieniujący wierzchołków
tex.vert
#wersja 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec2 inTex;
out vec2 vertTex;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
uniform mat4 u_textureMat44;
void main()
{
vertTex = ( u_textureMat44 * vec4( inTex, 0.0, 1.0 ) ).st;
vec4 modolPos = u_modelMat44 * vec4( inPos, 1.0 );
vec4 viewPos = u_viewMat44 * modolPos;
gl_Position = u_projectionMat44 * viewPos;
}
Moduł cieniujący fragmenty
tex.frag
#version 400
in vec2 vertTex;
out vec4 fragColor;
uniform sampler2D u_texture;
void main()
{
vec4 texCol = texture( u_texture, vertTex.st );
fragColor = vec4( texCol.rgb, 1.0 );
}
Skrypt phyton
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
# draw event
def OnDraw():
currentTime = time()
# set up projection matrix
prjMat = perspective( 90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = Translate( np.matrix(np.identity(4), copy=False, dtype='float32'), np.array( [0.0, 0.0, -15.0] ) )
viewMat = RotateView( viewMat, [30.0, CalcAng( currentTime, 60.0 ), 0.0] )
# set up tetrahedron model matrix
cubeModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
cubeModelMat = RotateX( cubeModelMat, -90.0 )
cubeModelMat = Scale( cubeModelMat, np.repeat( 5.0, 3 ) )
# set up texture matrix
texMat = np.matrix(np.identity(4), copy=False, dtype='float32')
deltaT = Fract( (currentTime - startTime) / 28.0 ) * 28.0
if deltaT < 7.0 or deltaT >= 21.0:
texMat = Scale( texMat, np.repeat( CalcMove(currentTime, 7.0, [1.0, 2.0]), 3 ) )
if deltaT >= 7.0 and deltaT < 14.0 or deltaT >= 21.0:
transAng = math.radians( CalcAng(currentTime, 7.0) )
texMat = Translate( texMat, np.array( [math.sin(transAng)*0.5, math.cos(transAng)*0.5-0.5, 0.0] ) )
if deltaT >= 14.0:
texMat = RotateZ( texMat, CalcAng(currentTime, 7.0) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
glUniformMatrix4fv( textureMatLocation, 1, GL_FALSE, texMat )
glUniform1i( textureLocation, 0 )
# draw cube
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, cubeModelMat )
glBindVertexArray( cubeVAObj )
glDrawElements(GL_TRIANGLES, len(cubeIndices), GL_UNSIGNED_INT, cubeIndices)
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define cube vertex array opject
icoPts = [
[-1.0, -1.0, 1.0], [ 1.0, -1.0, 1.0], [ 1.0, 1.0, 1.0], [-1.0, 1.0, 1.0],
[-1.0, -1.0, -1.0], [ 1.0, -1.0, -1.0], [ 1.0, 1.0, -1.0], [-1.0, 1.0, -1.0] ]
cubePosData = []
for inx in [ 0, 1, 2, 3, 1, 5, 6, 2, 5, 4, 7, 6, 4, 0, 3, 7, 3, 2, 6, 7, 1, 0, 4, 5 ]:
for inx_s in range(0, 3): cubePosData.append( icoPts[inx][inx_s] )
cubeTexData = []
for inx in range(0, 6):
for texCoord in [-0.5, -0.5, 0.5, -0.5, 0.5, 0.5, -0.5, 0.5]: cubeTexData.append( texCoord )
icoCol = [ [1.0, 0.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0] ]
cubeIndices = []
for inx in range(0, 6):
for inx_s in [0, 1, 2, 0, 2, 3]: cubeIndices.append( inx * 4 + inx_s )
cubeVAObj = CreateVAO( [ (3, cubePosData), (2, cubeTexData) ] )
cubeInxArr = np.array( cubeIndices, dtype='uint' )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'python/ogl4tex/tex.vert', GL_VERTEX_SHADER ),
CompileShader( 'python/ogl4tex/tex.frag', GL_FRAGMENT_SHADER )
] )
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "u_viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "u_modelMat44")
textureMatLocation = glGetUniformLocation(shaderProgram, "u_textureMat44")
textureLocation = glGetUniformLocation(shaderProgram, "u_texture")
# create texture
texCX, texCY = 128, 128
texPlan = np.zeros( texCX * texCY * 4, dtype=np.uint8 )
for inx_x in range(0, texCX):
for inx_y in range(0, texCY):
val_x = math.sin( math.pi * 6.0 * inx_x / texCX )
val_y = math.sin( math.pi * 6.0 * inx_y / texCY )
inx_tex = inx_y * texCX * 4 + inx_x * 4
texPlan[inx_tex + 0] = int( 128 + 127 * val_x )
texPlan[inx_tex + 1] = 63
texPlan[inx_tex + 2] = int( 128 + 127 * val_y )
texPlan[inx_tex + 3] = 255
glActiveTexture( GL_TEXTURE0 )
texObj = glGenTextures( 1 )
glBindTexture( GL_TEXTURE_2D, texObj )
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texCX, texCY, 0, GL_RGBA, GL_UNSIGNED_BYTE, texPlan)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
# start main loop
startTime = time()
glutMainLoop()
Korzystanie z bloku interfejsu i jednolitego bloku: model oświetlenia Cook-Torrance w OGL 4.0 GLSL
Prosty program cieniujący OGL 4.0 GLSL, który pokazuje użycie bloku interfejsu i jednolitego bloku w implementacji modelu oświetlenia mikropacet Cook-Torrance. Program jest wykonywany za pomocą skryptu phyton. Aby uruchomić skrypt, PyOpenGL i NumPy muszą być zainstalowane.
Blok interfejsu to grupa zmiennych wejściowych, wyjściowych, jednolitych lub buforów pamięci GLSL. Mundurze Blockis jest blok interfejsu z kwalifikatorem przechowywania uniform .
Moduł cieniujący wierzchołków
ibub.vert
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNV;
layout (location = 2) in vec3 inCol;
out TVertexData
{
vec3 pos;
vec3 nv;
vec3 col;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_modelViewMat44;
uniform mat3 u_normalMat33;
void main()
{
vec4 viewPos = u_modelViewMat44 * vec4( inPos, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
outData.nv = u_normalMat33 * normalize( inNV );
outData.col = inCol;
gl_Position = u_projectionMat44 * viewPos;
}
Moduł cieniujący fragmenty
ibub.frag
#version 400
in TVertexData
{
vec3 pos;
vec3 nv;
vec3 col;
} inData;
out vec4 fragColor;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
vec3 CookTorrance( vec3 esPt, vec3 esPtNV, vec3 col, vec4 specularTint, float roughness, float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
vec3 reflVector = normalize( reflect( -esVLight, esPtNV ) );
float VdotR = dot( esVEye, reflVector );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Cook-Torrance fresnel
float theta = HdotL;
float n = (1.0 + sqrt(fresnel0)) / (1.0 - sqrt(fresnel0));
float g = sqrt( n*n + theta * theta + 1.0 );
float gc = g + theta;
float g_c = g - theta;
float q = (gc * theta - 1.0) / (g_c * theta + 1.0);
float fresnel = 0.5 * (g_c * g_c) / (gc * gc) * (1.0 + q * q);
// Gaussian distribution
float psi = acos( VdotR );
float distribution = max( 0.0, HdotL * exp( - psi * psi / m2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float brdf_spec = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
float k_specular = brdf_spec;
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb
+ max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
+ max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
void main()
{
vec3 lightCol = CookTorrance( inData.pos, inData.nv, inData.col, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( lightCol, 1.0 );
}
Skrypt phyton
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = Translate( np.matrix(np.identity(4), copy=False, dtype='float32'), np.array( [0.0, 0.0, -12.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-3.0, -2.0, -1.0, 0.0], viewMat) )
# set up tetrahedron model matrix
tetModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: tetModelMat = RotateY( tetModelMat, comeraRotAng )
tetModelMat = RotateX( tetModelMat, -90.0 )
tetModelMat = Scale( tetModelMat, np.repeat( 2.4, 3 ) )
tetModelMat = Translate( tetModelMat, np.array( [0.0, dist, 0.0] ) )
tetModelMat = RotateY( tetModelMat, CalcAng( currentTime, 20.0 ) )
tetModelMat = RotateX( tetModelMat, CalcAng( currentTime, 9.0 ) )
# set up icosahedron model matrix
icoModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: icoModelMat = RotateY( icoModelMat, comeraRotAng )
icoModelMat = RotateX( icoModelMat, -90.0 )
icoModelMat = Scale( icoModelMat, np.repeat( 2.0, 3 ) )
icoModelMat = Translate( icoModelMat, np.array( [dist * -sin120, dist * -0.5, 0.0] ) )
icoModelMat = RotateY( icoModelMat, CalcAng( currentTime, 20.0 ) )
icoModelMat = RotateX( icoModelMat, CalcAng( currentTime, 11.0 ) )
# set up cube model matrix
cubeModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: cubeModelMat = RotateY( cubeModelMat, comeraRotAng )
cubeModelMat = RotateX( cubeModelMat, -90.0 )
cubeModelMat = Scale( cubeModelMat, np.repeat( 1.6, 3 ) )
cubeModelMat = Translate( cubeModelMat, np.array( [dist * sin120, dist * -0.5, 0.0] ) )
cubeModelMat = RotateY( cubeModelMat, CalcAng( currentTime, 20.0 ) )
cubeModelMat = RotateX( cubeModelMat, CalcAng( currentTime, 13.0 ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
lightSourceBuffer.BindToTarget()
# draw tetrahedron
tetMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, tetModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( tetVAObj )
glDrawArrays( GL_TRIANGLES, 0, len(tetPosData) )
# draw icosahedron
icoMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, icoModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( icoVAObj )
glDrawArrays( GL_TRIANGLES, 0, len(icoPosData) )
# draw cube
cubeMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, cubeModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( cubeVAObj )
glDrawElements(GL_TRIANGLES, len(cubeIndices), GL_UNSIGNED_INT, cubeIndices)
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
self.size = 0
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets [self.namemap[uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA [3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define tetrahedron vertex array opject
tetPts = [ (0.0, 0.0, 1.0), (0.0, -sin120, -0.5), (sin120 * sin120, 0.5 * sin120, -0.5), (-sin120 * sin120, 0.5 * sin120, -0.5) ]
tetCol = [ [1.0, 0.0, 0.0], [1.0, 1.0, 0.0], [0.0, 0.0, 1.0], [0.0, 1.0, 0.0], ]
tetInxdices = [ 0, 1, 2, 0, 2, 3, 0, 3, 1, 1, 3, 2 ]
tetPosData = []
for inx in tetInxdices: AddToBuffer( tetPosData, tetPts[inx] )
tetNVData = []
for inx_nv in range(0, len(tetInxdices) // 3):
nv = [0.0, 0.0, 0.0]
for inx_p in range(0, 3):
for inx_s in range(0, 3): nv[inx_s] += tetPts[ tetInxdices[inx_nv*3 + inx_p] ][inx_s]
AddToBuffer( tetNVData, nv, 3 )
tetColData = []
for inx_col in range(0, len(tetInxdices) // 3): AddToBuffer( tetColData, tetCol[inx_col % len(tetCol)], 3 )
tetVAObj = CreateVAO( [ (3, tetPosData), (3, tetNVData), (3, tetColData) ] )
# define icosahedron vertex array opject
icoPts = [
( 0.000, 0.000, 1.000), ( 0.894, 0.000, 0.447), ( 0.276, 0.851, 0.447), (-0.724, 0.526, 0.447),
(-0.724, -0.526, 0.447), ( 0.276, -0.851, 0.447), ( 0.724, 0.526, -0.447), (-0.276, 0.851, -0.447),
(-0.894, 0.000, -0.447), (-0.276, -0.851, -0.447), ( 0.724, -0.526, -0.447), ( 0.000, 0.000, -1.000) ]
icoCol = [ [1.0, 0.0, 0.0], [0.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0] ]
icoIndices = [
2, 0, 1, 3, 0, 2, 4, 0, 3, 5, 0, 4, 1, 0, 5, 11, 7, 6, 11, 8, 7, 11, 9, 8, 11, 10, 9, 11, 6, 10,
1, 6, 2, 2, 7, 3, 3, 8, 4, 4, 9, 5, 5, 10, 1, 2, 6, 7, 3, 7, 8, 4, 8, 9, 5, 9, 10, 1, 10, 6 ]
icoPosData = []
for inx in icoIndices: AddToBuffer( icoPosData, icoPts[inx] )
icoNVData = []
for inx in icoIndices: AddToBuffer( icoNVData, icoPts[inx] )
#for inx_nv in range(0, len(icoIndices) // 3):
# nv = [0.0, 0.0, 0.0]
# for inx_p in range(0, 3):
# for inx_s in range(0, 3): nv[inx_s] += icoPts[ icoIndices[inx_nv*3 + inx_p] ][inx_s]
# AddToBuffer( icoNVData, nv, 3 )
icoColData = []
for inx_col in range(0, len(icoIndices) // 3): AddToBuffer( icoColData, icoCol[inx_col % len(icoCol)], 3 )
icoVAObj = CreateVAO( [ (3, icoPosData), (3, icoNVData), (3, icoColData) ] )
# define cube vertex array opject
cubePts = [
(-1.0, -1.0, 1.0), ( 1.0, -1.0, 1.0), ( 1.0, 1.0, 1.0), (-1.0, 1.0, 1.0),
(-1.0, -1.0, -1.0), ( 1.0, -1.0, -1.0), ( 1.0, 1.0, -1.0), (-1.0, 1.0, -1.0) ]
cubeCol = [ [1.0, 0.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0] ]
cubeHlpInx = [ 0, 1, 2, 3, 1, 5, 6, 2, 5, 4, 7, 6, 4, 0, 3, 7, 3, 2, 6, 7, 1, 0, 4, 5 ]
cubePosData = []
for inx in cubeHlpInx: AddToBuffer( cubePosData, cubePts[inx] )
cubeNVData = []
for inx_nv in range(0, len(cubeHlpInx) // 4):
nv = [0.0, 0.0, 0.0]
for inx_p in range(0, 4):
for inx_s in range(0, 3): nv[inx_s] += cubePts[ cubeHlpInx[inx_nv*4 + inx_p] ][inx_s]
AddToBuffer( cubeNVData, nv, 4 )
cubeColData = []
for inx_col in range(0, 6):
AddToBuffer( cubeColData, cubeCol[inx_col % len(cubeCol)], 4 )
cubeIndices = []
for inx in range(0, 6):
for inx_s in [0, 1, 2, 0, 2, 3]: cubeIndices.append( inx * 4 + inx_s )
cubeVAObj = CreateVAO( [ (3, cubePosData), (3, cubeNVData), (3, cubeColData) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'ibub.vert', GL_VERTEX_SHADER ),
CompileShader( 'ibub.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
modelViewMatLocation = glGetUniformLocation(shaderProgram, "u_modelViewMat44")
normalMatLocation = glGetUniformLocation(shaderProgram, "u_normalMat33")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.1, 0.1, 0.1, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.4, 0.4, 0.4, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
tetMaterialBuffer = UniformBlockBuffer(ubMaterial)
tetMaterialBuffer.BindDataFloat(b'u_roughness', [0.3])
tetMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.5])
tetMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 1.0, 1.0, 0.7])
icoMaterialBuffer = UniformBlockBuffer(ubMaterial)
icoMaterialBuffer.BindDataFloat(b'u_roughness', [0.1])
icoMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.2])
icoMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 1.0, 1.0, 0.7])
cubeMaterialBuffer = UniformBlockBuffer(ubMaterial)
cubeMaterialBuffer.BindDataFloat(b'u_roughness', [0.5])
cubeMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.3])
cubeMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 1.0, 1.0, 0.7])
# start main loop
startTime = time()
glutMainLoop()
Tworzenie geometrii za pomocą modułu do cieniowania geometrii w OGL 4.0 GLSL
Prosty program cieniujący OGL 4.0 GLSL, który pokazuje użycie modułów cieniujących geometrię. Program jest wykonywany za pomocą skryptu phyton. Aby uruchomić skrypt, PyOpenGL i NumPy muszą być zainstalowane.
W tym przykładzie cała geometria (walec) jest generowana w module cieniującym geometrię.
Moduł cieniujący wierzchołków
geo.vert
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNormal;
layout (location = 2) in vec3 inTangent;
out TVertexData
{
mat3 orientationMat;
} outData;
void main()
{
vec3 normal = normalize( inNormal );
vec3 tangent = normalize( inTangent );
vec3 binormal = cross( tangent, normal );
outData.orientationMat = mat3( normal, cross( binormal, normal ), binormal );
gl_Position = vec4( inPos, 1.0 );
}
Moduł cieniujący geometrię
geo.geo
#version 400
layout( invocations = 3 ) in;
layout( points ) in;
layout( triangle_strip, max_vertices = 160 ) out;
in TVertexData
{
mat3 orientationMat;
} inData[];
out TGeometryData
{
vec3 pos;
vec3 nv;
vec3 col;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
void NewVertex( in vec3 pt, in mat4 transMat )
{
vec4 viewPos = transMat * vec4( pt, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
EmitVertex();
}
const int circumferenceTile = 36;
void main()
{
vec4 origin = gl_in[0].gl_Position;
origin /= origin.w;
mat4 orintationMat = mat4( vec4( inData[0].orientationMat[0], 0.0 ),
vec4( inData[0].orientationMat[1], 0.0 ),
vec4( inData[0].orientationMat[2], 0.0 ),
origin );
mat4 modelViewMat = u_viewMat44 * u_modelMat44 * orintationMat;
mat3 normalMat = mat3( modelViewMat );
outData.col = vec3( 0.5, 0.7, 0.6 );
if ( gl_InvocationID == 0 ) // top of the cylinder
{
outData.nv = normalMat * vec3(0.0, 0.0, 1.0);
vec2 prevPt = vec2( 0.0, 1.0 );
for ( int inx = 1; inx <= circumferenceTile; inx += 2 )
{
float ang1 = 2.0 * 3.14159 * float(inx) / float(circumferenceTile);
float ang2 = 2.0 * 3.14159 * float(inx+1) / float(circumferenceTile);
vec2 actPt1 = vec2( sin(ang1), cos(ang1) );
vec2 actPt2 = vec2( sin(ang2), cos(ang2) );
NewVertex( vec3(prevPt.xy, 1.0), modelViewMat );
NewVertex( vec3(actPt1.xy, 1.0), modelViewMat );
NewVertex( vec3(0.0, 0.0, 1.0), modelViewMat );
NewVertex( vec3(actPt2.xy, 1.0), modelViewMat );
EndPrimitive();
prevPt = actPt2;
}
}
if ( gl_InvocationID == 1 ) // bottom of the cylinder
{
outData.nv = normalMat * vec3(0.0, 0.0, -1.0);
vec2 prevPt = vec2( 0.0, 1.0 );
for ( int inx = circumferenceTile-1; inx >= 0; inx -= 2 )
{
float ang1 = 2.0 * 3.14159 * float(inx) / float(circumferenceTile);
float ang2 = 2.0 * 3.14159 * float(inx-1) / float(circumferenceTile);
vec2 actPt1 = vec2( sin(ang1), cos(ang1) );
vec2 actPt2 = vec2( sin(ang2), cos(ang2) );
NewVertex( vec3(prevPt.xy, -1.0), modelViewMat );
NewVertex( vec3(actPt1.xy, -1.0), modelViewMat );
NewVertex( vec3(0.0, 0.0, -1.0), modelViewMat );
NewVertex( vec3(actPt2.xy, -1.0), modelViewMat );
EndPrimitive();
prevPt = actPt2;
}
}
if ( gl_InvocationID == 2 ) // hull of the cylinder
{
vec2 prevPt = vec2( 0.0, 1.0 );
for ( int inx = 1; inx <= circumferenceTile; ++ inx )
{
float ang = 2.0 * 3.14159 * float(inx) / float(circumferenceTile);
vec2 actPt = vec2( sin(ang), cos(ang) );
outData.nv = normalMat * vec3(prevPt, 0.0);
NewVertex( vec3(prevPt.xy, -1.0), modelViewMat );
outData.nv = normalMat * vec3(actPt, 0.0);
NewVertex( vec3(actPt.xy, -1.0), modelViewMat );
outData.nv = normalMat * vec3(prevPt, 0.0);
NewVertex( vec3(prevPt.xy, 1.0), modelViewMat );
outData.nv = normalMat * vec3(actPt, 0.0);
NewVertex( vec3(actPt.xy, 1.0), modelViewMat );
prevPt = actPt;
}
EndPrimitive();
}
}
Moduł cieniujący fragmenty
geo.frag
#version 400
in TGeometryData
{
vec3 pos;
vec3 nv;
vec3 col;
} inData;
out vec4 fragColor;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
float Fresnel_Schlick( float theta )
{
float m = clamp( 1.0 - theta, 0.0, 1.0 );
float m2 = m * m;
return m2 * m2 * m; // pow( m, 5.0 )
}
vec3 LightModel( vec3 esPt, vec3 esPtNV, vec3 col, vec4 specularTint, float roughness, float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Schlick approximation
float fresnel = fresnel0 + ( 1.0 - fresnel0 ) * Fresnel_Schlick( HdotL );
// Beckmann distribution
float distribution = max( 0.0, exp( ( NdotH2 - 1.0 ) / ( m2 * NdotH2 ) ) / ( 3.14159265 * m2 * NdotH2 * NdotH2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float k_specular = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb +
max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
void main()
{
vec3 lightCol = LightModel( inData.pos, inData.nv, inData.col, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( clamp( lightCol, 0.0, 1.0 ), 1.0 );
}
Skrypt phyton
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = np.matrix(np.identity(4), copy=False, dtype='float32')
viewMat = Translate( viewMat, np.array( [0.0, 0.0, -12.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-0.1, 1.0, -5.0, 0.0], viewMat) )
# set up the model matrix
modelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: modelMat = RotateY( modelMat, comeraRotAng )
modelMat = Scale( modelMat, np.repeat( 4, 3 ) )
#modelMat = Translate( modelMat, np.array( [0.0, 0.0, 1.0] ) )
#modelMat = RotateY( modelMat, CalcAng( currentTime, 20.0 ) )
modelMat = RotateX( modelMat, CalcAng( currentTime, 9.0 ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
lightSourceBuffer.BindToTarget()
# draw point
materialBuffer.BindToTarget()
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, modelMat )
glBindVertexArray( pointVAObj )
glDrawArrays( GL_POINTS, 0, 1 )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_GEOMETRY_SHADER: 'geometry', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets [self.namemap[uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA [3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define location vertex array opject
pointVAObj = CreateVAO( [ (3, [0.0, 0.0, 0.0] ), (3, [0.0, 0.0, -1.0]), (3, [1.0, 0.0, 0.0]) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'geo.vert', GL_VERTEX_SHADER ),
CompileShader( 'geo.geo', GL_GEOMETRY_SHADER ),
CompileShader( 'geo.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "u_viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "u_modelMat44")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
materialBuffer = UniformBlockBuffer(ubMaterial)
materialBuffer.BindDataFloat(b'u_roughness', [0.5])
materialBuffer.BindDataFloat(b'u_fresnel0', [0.2])
materialBuffer.BindDataFloat(b'u_specularTint',[1.0, 0.5, 0.5, 0.8])
# start main loop
startTime = time()
glutMainLoop()
Przełączanie geometrii i reprezentacji powierzchni za pomocą podprogramów w OGL 4.0 GLSL
Prosty program cieniujący OGL 4.0 GLSL, który pokazuje podprogramy modułu cieniującego. Program jest wykonywany za pomocą skryptu phyton. Aby uruchomić skrypt, PyOpenGL i NumPy muszą być zainstalowane.
Podprogramy przełączają się między różnymi geometriami generowanymi w module cieniującym geometrię i zmieniają reprezentację powierzchni.
Moduł cieniujący wierzchołków
subr.vert
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNormal;
layout (location = 2) in vec3 inTangent;
out TVertexData
{
mat3 orientationMat;
} outData;
void main()
{
vec3 normal = normalize( inNormal );
vec3 tangent = normalize( inTangent );
vec3 binormal = cross( tangent, normal );
outData.orientationMat = mat3( normal, cross( binormal, normal ), binormal );
gl_Position = vec4( inPos, 1.0 );
}
Moduł cieniujący geometrię
subr.geo
#version 400
layout( points ) in;
layout( triangle_strip, max_vertices = 512 ) out;
in TVertexData
{
mat3 orientationMat;
} inData[];
out TGeometryData
{
vec3 pos;
vec3 nv;
vec2 tex;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
uniform mat4 u_textureMat44;
void SetTextureCoord( in vec2 tecCoord )
{
vec4 tex = u_textureMat44 * vec4( tecCoord, 0.0, 1.0 );
outData.tex = tex.xy;
}
void NewVertex( in vec3 pt, in mat4 transMat )
{
vec4 viewPos = transMat * vec4( pt, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
EmitVertex();
}
void NewVertexAndTex( in vec3 pt, in mat4 transMat )
{
SetTextureCoord( pt.xy * 0.5 + 0.5 );
NewVertex( pt, transMat );
}
void NewVertexNvTex( in vec3 pt, in mat4 transMat, in vec3 nv, in vec2 tex )
{
outData.nv = nv;
SetTextureCoord( tex );
vec4 viewPos = transMat * vec4( pt, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
EmitVertex();
}
subroutine void TShape( in mat4 );
subroutine uniform TShape su_shape;
void main()
{
vec4 origin = gl_in[0].gl_Position;
origin /= origin.w;
mat4 orintationMat = mat4( vec4( inData[0].orientationMat[0], 0.0 ),
vec4( inData[0].orientationMat[1], 0.0 ),
vec4( inData[0].orientationMat[2], 0.0 ),
origin );
mat4 modelMat = u_modelMat44 * orintationMat;
su_shape( modelMat );
}
subroutine(TShape) void DrawSphere( in mat4 modelMat )
{
const int circumferenceTile = 18;
const int layersTile = 11;
mat4 modelViewMat = u_viewMat44 * modelMat;
mat3 normalMat = mat3( modelViewMat );
float preStepLay = 0.0;
vec2 prePtLay = vec2( 0.0, -1.0 );
for ( int inxLay = 1; inxLay <= layersTile; ++ inxLay )
{
float stepLay = float(inxLay) / float(layersTile);
float angLay = 3.14159 * stepLay;
vec2 ptLay = vec2( sin(angLay), -cos(angLay) );
float preStepCir = 0.0;
vec2 prePtCir = vec2( 0.0, 1.0 );
for ( int inxCir = 0; inxCir <= circumferenceTile; ++ inxCir )
{
float stepCir = float(inxCir) / float(circumferenceTile);
float angCir = 2.0 * 3.14159 * stepCir;
vec2 ptCir = vec2( sin(angCir), cos(angCir) );
if ( inxLay == 1 )
{
if ( inxCir >= 0 )
{
vec3 pt1 = vec3( ptLay.x * prePtCir.x, ptLay.x * prePtCir.y, ptLay.y );
vec3 pt2 = vec3( 0.0, 0.0, -1.0 );
vec3 pt3 = vec3( ptLay.x * ptCir.x, ptLay.x * ptCir.y, ptLay.y );
NewVertexNvTex( pt1, modelViewMat, normalMat * pt1, vec2( preStepCir * 2.0, stepLay ) );
NewVertexNvTex( pt2, modelViewMat, normalMat * pt2, vec2( preStepCir + stepCir, preStepLay ) );
NewVertexNvTex( pt3, modelViewMat, normalMat * pt3, vec2( stepCir * 2.0, stepLay ) );
EndPrimitive();
}
}
else if ( inxLay == layersTile )
{
if ( inxCir > 0 )
{
vec3 pt1 = vec3( prePtLay.x * prePtCir.x, prePtLay.x * prePtCir.y, prePtLay.y );
vec3 pt2 = vec3( prePtLay.x * ptCir.x, prePtLay.x * ptCir.y, prePtLay.y );
vec3 pt3 = vec3( 0.0, 0.0, 1.0 );
NewVertexNvTex( pt1, modelViewMat, normalMat * pt1, vec2( preStepCir * 2.0, preStepLay ) );
NewVertexNvTex( pt2, modelViewMat, normalMat * pt2, vec2( stepCir * 2.0, preStepLay ) );
NewVertexNvTex( pt3, modelViewMat, normalMat * pt3, vec2( preStepCir + stepCir, stepLay ) );
EndPrimitive();
}
}
else
{
vec3 pt1 = vec3( prePtLay.x * ptCir.x, prePtLay.x * ptCir.y, prePtLay.y );
vec3 pt2 = vec3( ptLay.x * ptCir.x, ptLay.x * ptCir.y, ptLay.y );
NewVertexNvTex( pt1, modelViewMat, normalMat * pt1, vec2( stepCir * 2.0, preStepLay ) );
NewVertexNvTex( pt2, modelViewMat, normalMat * pt2, vec2( stepCir * 2.0, stepLay ) );
}
preStepCir = stepCir;
prePtCir = ptCir;
}
if ( inxLay > 1 && inxLay < layersTile )
EndPrimitive();
preStepLay = stepLay;
prePtLay = ptLay;
}
}
subroutine(TShape) void DrawTorus( in mat4 modelMat )
{
const int circumferenceTile = 12;
const int layersTile = 18;
const float torusRad = 0.8;
const float ringRad = 0.4;
mat4 modelViewMat = u_viewMat44 * modelMat;
mat3 normalMat = mat3( modelViewMat );
float preStepLay = 0.0;
mat4 prePosMat;
for ( int inxLay = 0; inxLay <= layersTile; ++ inxLay )
{
float stepLay = float(inxLay) / float(layersTile);
float angLay = 2.0 * 3.14159 * stepLay;
mat4 posMat = mat4(
vec4( cos(angLay), sin(angLay), 0.0, 0.0 ),
vec4( sin(angLay), cos(angLay), 0.0, 0.0 ),
vec4( 0.0, 0.0, 1.0, 0.0 ),
vec4( cos(angLay) * torusRad, sin(angLay) * torusRad, 0.0, 1.0 ) );
for ( int inxCir = 0; inxLay > 0 && inxCir <= circumferenceTile; ++ inxCir )
{
float stepCir = float(inxCir) / float(circumferenceTile);
float angCir = 2.0 * 3.14159 * stepCir;
vec2 ptCir = vec2( sin(angCir), cos(angCir) );
vec4 tempPt = vec4( ptCir.x * ringRad, 0.0, ptCir.y * ringRad, 1.0 );
vec4 pt1 = prePosMat * tempPt;
vec4 pt2 = posMat * tempPt;
NewVertexNvTex( pt1.xyz, modelViewMat, normalMat * normalize(pt1.xyz - prePosMat[3].xyz), vec2(stepCir, preStepLay*2.0) );
NewVertexNvTex( pt2.xyz, modelViewMat, normalMat * normalize(pt2.xyz - posMat[3].xyz), vec2(stepCir, stepLay*2.0) );
}
EndPrimitive();
preStepLay = stepLay;
prePosMat = posMat;
}
}
Moduł cieniujący fragmenty
subr.frag
#version 400
in TGeometryData
{
vec3 pos;
vec3 nv;
vec2 tex;
} inData;
out vec4 fragColor;
uniform sampler2D u_texture;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_color;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
subroutine vec4 TSurface( void );
subroutine uniform TSurface su_surface;
float Fresnel_Schlick( in float theta );
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 );
void main()
{
vec4 fragCol = su_surface();
vec3 lightCol = LightModel( inData.pos, inData.nv, fragCol.rgb, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( clamp( lightCol, 0.0, 1.0 ), fragCol.a );
}
subroutine(TSurface) vec4 SurfaceColor( void )
{
return u_color;
}
subroutine(TSurface) vec4 SurfaceTexture( void )
{
return texture( u_texture, inData.tex.st );
}
float Fresnel_Schlick( in float theta )
{
float m = clamp( 1.0 - theta, 0.0, 1.0 );
float m2 = m * m;
return m2 * m2 * m; // pow( m, 5.0 )
}
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Schlick approximation
float fresnel = fresnel0 + ( 1.0 - fresnel0 ) * Fresnel_Schlick( HdotL );
// Beckmann distribution
float distribution = max( 0.0, exp( ( NdotH2 - 1.0 ) / ( m2 * NdotH2 ) ) / ( 3.14159265 * m2 * NdotH2 * NdotH2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float k_specular = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb +
max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
Skrypt phyton
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = np.matrix(np.identity(4), copy=False, dtype='float32')
viewMat = Translate( viewMat, np.array( [0.0, 0.0, -14.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-1.0, -1.0, -5.0, 0.0], viewMat) )
# set up model matrices
modelMat = []
for inx in range(0, 2):
modelMat.append( np.matrix(np.identity(4), copy=False, dtype='float32') )
if not rotateCamera: modelMat[inx] = RotateY( modelMat[inx], comeraRotAng )
modelMat[0] = Scale( modelMat[0], np.repeat( 3, 3 ) )
modelMat[0] = Translate( modelMat[0], np.array( [0.0, 0.0, -2.0] ) )
modelMat[0] = RotateY( modelMat[0], CalcAng( currentTime, 23.0 ) )
modelMat[0] = RotateX( modelMat[0], CalcAng( currentTime, 13.0 ) )
modelMat[1] = Scale( modelMat[1], np.repeat( 3, 3 ) )
modelMat[1] = Translate( modelMat[1], np.array( [0.0, 0.0, 2.0] ) )
modelMat[1] = RotateY( modelMat[1], CalcAng( currentTime, 17.0 ) )
modelMat[1] = RotateX( modelMat[1], CalcAng( currentTime, 9.0 ) )
# set up texture matrix
texMat = np.matrix(np.identity(4), copy=False, dtype='float32')
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
glUniformMatrix4fv( textureMatLocation, 1, GL_FALSE, texMat )
glUniform1i( textureLocation, 0 )
lightSourceBuffer.BindToTarget()
# draw points
glBindVertexArray( pointVAObj )
for inx in range(0, 2):
# set up geometry shader subroutine
shape = 1 if inx==0 else 0 # 0: sphere, 1: torus
glUniformSubroutinesuiv(GL_GEOMETRY_SHADER, 1, np.array( [shape], dtype='uint' ))
# set up fragment shader subroutine
surfaceKind = inx # 0: color, 1: texture
glUniformSubroutinesuiv(GL_FRAGMENT_SHADER, 1, np.array( [surfaceKind], dtype='uint' ))
materialBuffer[inx].BindToTarget()
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, modelMat[inx] )
glDrawArrays( GL_POINTS, 0, 1 )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_GEOMETRY_SHADER: 'geometry', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets[self.namemap [uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA[3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define location vertex array opject
pointVAObj = CreateVAO( [ (3, [0.0, 0.0, 0.0] ), (3, [0.0, 0.0, 1.0]), (3, [1.0, 0.0, 0.0]) ] )
# create texture
texCX, texCY = 128, 128
texPlan = np.zeros( texCX * texCY * 4, dtype=np.uint8 )
for inx_x in range(0, texCX):
for inx_y in range(0, texCY):
val_x = math.sin( math.pi * 6.0 * inx_x / texCX )
val_y = math.sin( math.pi * 6.0 * inx_y / texCY )
inx_tex = inx_y * texCX * 4 + inx_x * 4
texPlan[inx_tex + 0] = int( 128 + 127 * val_x )
texPlan[inx_tex + 1] = 63
texPlan[inx_tex + 2] = int( 128 + 127 * val_y )
texPlan[inx_tex + 3] = 255
glActiveTexture( GL_TEXTURE0 )
texObj = glGenTextures( 1 )
glBindTexture( GL_TEXTURE_2D, texObj )
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texCX, texCY, 0, GL_RGBA, GL_UNSIGNED_BYTE, texPlan)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'python/ogl4subr/subr.vert', GL_VERTEX_SHADER ),
CompileShader( 'python/ogl4subr/subr.geo', GL_GEOMETRY_SHADER ),
CompileShader( 'python/ogl4subr/subr.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "u_viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "u_modelMat44")
textureMatLocation = glGetUniformLocation(shaderProgram, "u_textureMat44")
textureLocation = glGetUniformLocation(shaderProgram, "u_texture")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
materialBuffer = [ UniformBlockBuffer(ubMaterial), UniformBlockBuffer(ubMaterial) ]
materialBuffer[0].BindDataFloat(b'u_roughness', [0.45])
materialBuffer[0].BindDataFloat(b'u_fresnel0', [0.45])
materialBuffer[0].BindDataFloat(b'u_color', [0.5, 0.7, 0.6, 1.0])
materialBuffer[0].BindDataFloat(b'u_specularTint',[1.0, 0.5, 0.5, 0.8])
materialBuffer[1].BindDataFloat(b'u_roughness', [0.4])
materialBuffer[1].BindDataFloat(b'u_fresnel0', [0.4])
materialBuffer[1].BindDataFloat(b'u_color', [0.7, 0.5, 0.6, 1.0])
materialBuffer[1].BindDataFloat(b'u_specularTint',[0.5, 1.0, 0.5, 0.8])
# start main loop
startTime = time()
glutMainLoop()
Zmiana geometrii za pomocą shaderów teselacyjnych w OGL 4.0 GLSL
Prosty program cieniujący OGL 4.0 GLSL, który pokazuje, jak dodać szczegóły do modułu cieniującego mozaikowania do geometrii. Program jest wykonywany za pomocą skryptu python. Aby uruchomić skrypt, PyOpenGL i NumPy muszą być zainstalowane.
Podstawową siatką w tym przykładzie jest dwudziestościan, który składa się z 20 trójkątów. Moduł cieniujący teselacji określa, w jaki sposób każdy trójkąt jest podzielony na zestaw wielu małych części. Podczas mozaikowania trójkąta generowane dane są współrzędnymi barycentrycznymi opartymi na oryginalnym trójkącie. Moduł cieniujący oceny teselacji generuje nową geometrię z danych uzyskanych w ten sposób. W tym przykładzie każdy trójkąt otrzymuje szczyt pośrodku, który unosi się na zewnątrz od środka icosadera. W ten sposób generowana jest znacznie bardziej złożona geometria niż oryginalny dwudziestościan.
Moduł cieniujący wierzchołków
tess.vert
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNV;
out TVertexData
{
vec3 pos;
vec3 nv;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_modelViewMat44;
uniform mat3 u_normalMat33;
void main()
{
vec4 viewPos = u_modelViewMat44 * vec4( inPos, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
outData.nv = u_normalMat33 * normalize( inNV );
gl_Position = u_projectionMat44 * viewPos;
}
Moduł cieniujący kontroli Tesselacji
tess.tctrl
#version 400
layout( vertices=3 ) out;
in TVertexData
{
vec3 pos;
vec3 nv;
} inData[];
out TVertexData
{
vec3 pos;
vec3 nv;
} outData[];
void main()
{
outData[gl_InvocationID].pos = inData[gl_InvocationID].pos;
outData[gl_InvocationID].nv = inData[gl_InvocationID].nv;
if ( gl_InvocationID == 0 )
{
gl_TessLevelOuter[0] = 10.0;
gl_TessLevelOuter[1] = 10.0;
gl_TessLevelOuter[2] = 10.0;
gl_TessLevelInner[0] = 10.0;
}
}
Moduł cieniujący oceny teselacji
tess.teval
#version 400
layout(triangles, equal_spacing, ccw) in;
in TVertexData
{
vec3 pos;
vec3 nv;
} inData[];
out TTessData
{
vec3 pos;
vec3 nv;
float height;
} outData;
uniform mat4 u_projectionMat44;
void main()
{
float sideLen[3] = float[3]
(
length( inData[1].pos - inData[0].pos ),
length( inData[2].pos - inData[1].pos ),
length( inData[0].pos - inData[2].pos )
);
float s = ( sideLen[0] + sideLen[1] + sideLen[2] ) / 2.0;
float rad = sqrt( (s - sideLen[0]) * (s - sideLen[1]) * (s - sideLen[2]) / s );
vec3 cpt = ( inData[0].pos + inData[1].pos + inData[2].pos ) / 3.0;
vec3 pos = inData[0].pos * gl_TessCoord.x + inData[1].pos * gl_TessCoord.y + inData[2].pos * gl_TessCoord.z;
vec3 nv = normalize( inData[0].nv * gl_TessCoord.x + inData[1].nv * gl_TessCoord.y + inData[2].nv * gl_TessCoord.z );
float cptDist = length( cpt - pos );
float sizeRelation = 1.0 - min( rad, cptDist ) / rad;
float height = pow( sizeRelation, 2.0 );
outData.pos = pos + nv * height * rad;
outData.nv = mix( nv, normalize( pos - cpt ), height );
outData.height = height;
gl_Position = u_projectionMat44 * vec4( outData.pos, 1.0 );
}
Moduł cieniujący fragmenty
tess.frag
#version 400
in TTessData
{
vec3 pos;
vec3 nv;
float height;
} inData;
out vec4 fragColor;
uniform sampler2D u_texture;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_color;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
float Fresnel_Schlick( in float theta );
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 );
void main()
{
vec3 col = mix( u_color.rgb, vec3( 1.0, 1.0, 1.0 ), inData.height );
vec3 lightCol = LightModel( inData.pos, inData.nv, col, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( clamp( lightCol, 0.0, 1.0 ), 1.0 );
}
float Fresnel_Schlick( in float theta )
{
float m = clamp( 1.0 - theta, 0.0, 1.0 );
float m2 = m * m;
return m2 * m2 * m; // pow( m, 5.0 )
}
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Schlick approximation
float fresnel = fresnel0 + ( 1.0 - fresnel0 ) * Fresnel_Schlick( HdotL );
// Beckmann distribution
float distribution = max( 0.0, exp( ( NdotH2 - 1.0 ) / ( m2 * NdotH2 ) ) / ( 3.14159265 * m2 * NdotH2 * NdotH2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float k_specular = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb +
max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
Skrypt w języku Python
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = np.matrix(np.identity(4), copy=False, dtype='float32')
viewMat = Translate( viewMat, np.array( [0.0, 0.0, -12.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-1.0, -1.0, -5.0, 0.0], viewMat) )
# set up icosahedron model matrix
icoModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: icoModelMat = RotateY( icoModelMat, comeraRotAng )
icoModelMat = Scale( icoModelMat, np.repeat( 5, 3 ) )
icoModelMat = RotateY( icoModelMat, CalcAng( currentTime, 17.0 ) )
icoModelMat = RotateX( icoModelMat, CalcAng( currentTime, 13.0 ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
lightSourceBuffer.BindToTarget()
# draw icosahedron
icoMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, icoModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( icoVAObj )
glPatchParameteri( GL_PATCH_VERTICES, 3 )
glDrawArrays( GL_PATCHES, 0, len(icoPosData) )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_GEOMETRY_SHADER: 'geometry', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# link shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets[self.namemap [uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA[3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define icosahedron vertex array opject
icoPts = [
( 0.000, 0.000, 1.000), ( 0.894, 0.000, 0.447), ( 0.276, 0.851, 0.447), (-0.724, 0.526, 0.447),
(-0.724, -0.526, 0.447), ( 0.276, -0.851, 0.447), ( 0.724, 0.526, -0.447), (-0.276, 0.851, -0.447),
(-0.894, 0.000, -0.447), (-0.276, -0.851, -0.447), ( 0.724, -0.526, -0.447), ( 0.000, 0.000, -1.000) ]
icoCol = [ [1.0, 0.0, 0.0], [0.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0] ]
icoIndices = [
2, 0, 1, 3, 0, 2, 4, 0, 3, 5, 0, 4, 1, 0, 5, 11, 7, 6, 11, 8, 7, 11, 9, 8, 11, 10, 9, 11, 6, 10,
1, 6, 2, 2, 7, 3, 3, 8, 4, 4, 9, 5, 5, 10, 1, 2, 6, 7, 3, 7, 8, 4, 8, 9, 5, 9, 10, 1, 10, 6 ]
icoPosData = []
for inx in icoIndices: AddToBuffer( icoPosData, icoPts[inx] )
icoNVData = []
for inx_nv in range(0, len(icoIndices) // 3):
nv = [0.0, 0.0, 0.0]
for inx_p in range(0, 3):
for inx_s in range(0, 3): nv[inx_s] += icoPts[ icoIndices[inx_nv*3 + inx_p] ][inx_s]
AddToBuffer( icoNVData, nv, 3 )
icoVAObj = CreateVAO( [ (3, icoPosData), (3, icoNVData) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'tess.vert', GL_VERTEX_SHADER ),
CompileShader( 'tess.tctrl', GL_TESS_CONTROL_SHADER ),
CompileShader( 'tess.teval', GL_TESS_EVALUATION_SHADER ),
CompileShader( 'tess.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
modelViewMatLocation = glGetUniformLocation(shaderProgram, "u_modelViewMat44")
normalMatLocation = glGetUniformLocation(shaderProgram, "u_normalMat33")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
icoMaterialBuffer = UniformBlockBuffer(ubMaterial)
icoMaterialBuffer.BindDataFloat(b'u_roughness', [0.45])
icoMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.4])
icoMaterialBuffer.BindDataFloat(b'u_color', [0.6, 0.5, 0.8, 1.0])
icoMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 0.5, 0.5, 0.8])
# start main loop
startTime = time()
glutMainLoop()
Modified text is an extract of the original Stack Overflow Documentation
Licencjonowany na podstawie CC BY-SA 3.0
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