PyOpenGL：渲染......嗯......真的
我一直在研究一个使用Python与OpenGL的项目。我之前发布了类似的问题，但我已经做了一些研究并转而使用了不推荐的函数。关注this tutorial（显然将其翻译成Python版本）我最终得到了这段代码：
import sys
import OpenGL
from OpenGL.GL import *
from OpenGL.GL.shaders import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from OpenGL.GLUT.freeglut import *
from OpenGL.arrays import vbo
import pygame
import Image
import numpy
class AClass:
def __init__(self):
self.Splash = True #There's actually more here, but it's impertinent
def TexFromPNG(self, filename):
img = Image.open(filename) # .jpg, .bmp, etc. also work
img_data = numpy.array(list(img.getdata()), 'B')
texture = glGenTextures(1)
glPixelStorei(GL_UNPACK_ALIGNMENT,1)
glBindTexture(GL_TEXTURE_2D, texture)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.size[0], img.size[1], 0, GL_RGB, GL_UNSIGNED_BYTE, img_data)
return texture
def MakeBuffer(self, target, data, size):
TempBuffer = glGenBuffers(1)
glBindBuffer(target, TempBuffer)
glBufferData(target, size, data, GL_STATIC_DRAW)
return TempBuffer
def ReadFile(self, filename):
tempfile = open(filename,'r')
source = tempfile.read()
temprfile.close()
return source
def run(self):
glutInitDisplayMode(GLUT_RGBA)
glutInitWindowSize(256,244)
self.window = glutCreateWindow("test")
glutReshapeFunc(self.reshape)
glutDisplayFunc(self.draw)
glutKeyboardFunc(self.keypress)
self.MainTex = glGenTextures(1)
self.SplashTex = self.TexFromPNG("Resources/Splash.png")
MainVertexData = numpy.array([-1,-1,1,-1,-1,1,1,1],numpy.float32)
FullWindowVertices = numpy.array([0,1,2,3],numpy.ushort)
self.MainVertexData = self.MakeBuffer(GL_ARRAY_BUFFER,MainVertexData,len(MainVertexData))
self.FullWindowVertices = self.MakeBuffer(GL_ELEMENT_ARRAY_BUFFER,FullWindowVertices,len(FullWindowVertices))
self.BaseProgram = compileProgram(compileShader(self.ReadFile("Shaders/Mainv.glsl"),
GL_VERTEX_SHADER),
compileShader(self.ReadFile("Shaders/Mainf.glsl"),
GL_FRAGMENT_SHADER))
glutMainLoop()
def reshape(self, width, height):
self.width = width
self.height = height
glutPostRedisplay()
def draw(self):
glViewport(0, 0, self.width, self.height)
glClearDepth(1)
glClearColor(0,0,0,0)
glClear(GL_COLOR_BUFFER_BIT)
glEnable(GL_TEXTURE_2D)
if self.Splash:
glUseProgram(self.BaseProgram)
pos = glGetAttribLocation(self.BaseProgram, "position")
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_2D, self.SplashTex)
glUniform1i(glGetUniformLocation(self.BaseProgram,"texture"), 0)
glBindBuffer(GL_ARRAY_BUFFER,self.MainVertexData)
glVertexAttribPointer(pos,
2,
GL_FLOAT,
GL_FALSE,
0,
numpy.array([0],numpy.uint8))
glEnableVertexAttribArray(pos)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,self.FullWindowVertices)
glDrawElements(GL_TRIANGLE_STRIP,
4,
GL_UNSIGNED_SHORT,
numpy.array([0],numpy.uint8))
glDisableVertexAttribArray(pos)
else:
glBindTexture(GL_TEXTURE_2D, self.MainTex)
glutSwapBuffers()
glutInit(sys.argv)
test = AClass()
test.run()
Shaders / Mainv.glsl和Shaders / Mainf.glsl包含：
#version 110
attribute vec2 position;
varying vec2 texcoord;
void main()
{
gl_Position = vec4(position, 0.0, 1.0);
texcoord = position * vec2(0.5) + vec2(0.5);
}
和
#version 110
uniform sampler2D texture;
varying vec2 texcoord;
void main()
{
gl_FragColor = texture2D(texture, texcoord);
}
分别
这段代码用一个（清晰的颜色）GLUT窗口给我打电话，这似乎表明它不是出于某种原因渲染我的三角形，但我不知道为什么会这样，我真的找不到任何一个例子。 PyOpenGL不使用已弃用的函数，因此我无法看到他们是否做了一些与我不同的事情。
2 个答案:
答案 0 :(得分：5)
我认为对于任何以PyOpenGL和可编程pipleline开头的人来说，这是一个有用的参考，所以我根据上面的Bethor和Josiah的评论更正了代码，并且还简化了一下（嵌入着色器）作为字符串）。这段代码适合我。它假设您在同一目录中有 test.png 。
import sys
import OpenGL
from OpenGL.GL import *
from OpenGL.GL.shaders import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from OpenGL.GLUT.freeglut import *
from OpenGL.arrays import vbo
import Image
import numpy
# vertex shader
strVS = """
attribute vec2 position;
varying vec2 texcoord;
void main()
{
gl_Position = vec4(position, 0.0, 1.0);
texcoord = position * vec2(0.5) + vec2(0.5);
}
"""
# fragment shader
strFS = """
uniform sampler2D texture;
varying vec2 texcoord;
void main()
{
gl_FragColor = texture2D(texture, texcoord);
}
"""
class AClass:
def __init__(self):
self.Splash = True #There's actually more here, but it's impertinent
def TexFromPNG(self, filename):
img = Image.open(filename) # .jpg, .bmp, etc. also work
img_data = numpy.array(list(img.getdata()), 'B')
texture = glGenTextures(1)
glPixelStorei(GL_UNPACK_ALIGNMENT,1)
glBindTexture(GL_TEXTURE_2D, texture)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.size[0], img.size[1], 0, GL_RGBA, GL_UNSIGNED_BYTE, img_data)
return texture
def MakeBuffer(self, target, data, size):
TempBuffer = glGenBuffers(1)
glBindBuffer(target, TempBuffer)
glBufferData(target, size, data, GL_STATIC_DRAW)
return TempBuffer
def run(self):
glutInitDisplayMode(GLUT_RGBA)
glutInitWindowSize(256,244)
self.window = glutCreateWindow("test")
glutReshapeFunc(self.reshape)
glutDisplayFunc(self.draw)
self.MainTex = glGenTextures(1)
self.SplashTex = self.TexFromPNG("test.png")
MainVertexData = numpy.array([-1,-1,1,-1,-1,1,1,1],numpy.float32)
FullWindowVertices = numpy.array([0,1,2,3],numpy.ushort)
self.MainVertexData = self.MakeBuffer(GL_ARRAY_BUFFER,MainVertexData,4*len(MainVertexData))
self.FullWindowVertices = self.MakeBuffer(GL_ELEMENT_ARRAY_BUFFER,FullWindowVertices,2*len(FullWindowVertices))
self.BaseProgram = compileProgram(compileShader(strVS,
GL_VERTEX_SHADER),
compileShader(strFS,
GL_FRAGMENT_SHADER))
glutMainLoop()
def reshape(self, width, height):
self.width = width
self.height = height
glutPostRedisplay()
def draw(self):
glViewport(0, 0, self.width, self.height)
glClearDepth(1)
glClearColor(0,0,0,0)
glClear(GL_COLOR_BUFFER_BIT)
glEnable(GL_TEXTURE_2D)
if self.Splash:
glUseProgram(self.BaseProgram)
pos = glGetAttribLocation(self.BaseProgram, "position")
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_2D, self.SplashTex)
glUniform1i(glGetUniformLocation(self.BaseProgram,"texture"), 0)
glBindBuffer(GL_ARRAY_BUFFER,self.MainVertexData)
glVertexAttribPointer(pos,
2,
GL_FLOAT,
GL_FALSE,
0,
None)
glEnableVertexAttribArray(pos)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,self.FullWindowVertices)
glDrawElements(GL_TRIANGLE_STRIP,
4,
GL_UNSIGNED_SHORT,
None)
glDisableVertexAttribArray(pos)
else:
glBindTexture(GL_TEXTURE_2D, self.MainTex)
glutSwapBuffers()
glutInit(sys.argv)
test = AClass()
test.run()
这是输出：
答案 1 :(得分：3)
在修复以下内容后，我设法让代码正常工作：
- glBufferData以字节为单位获取数据的大小，而不是元素：顶点数据（浮点数）需要乘以4，索引数据需要乘以2（短整数）
- 如果使用VBO（你是），glVertexAttribPointer的最后一个参数是当前绑定到ARRAY_BUFFER的目标的偏移量;在你的情况下，它应该是一个空指针，即使用pyOpenGL 时为None
- glDrawElements的行为方式相同：最后一个参数是ELEMENT_ARRAY_BUFFER的偏移量，即本例中为None
我的测试图像显示在那之后，虽然颜色是乱码。我没有尝试调试，因为用于解码png文件的选项可能特定于您的数据：）
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