使用PyOpenGL渲染带纹理的矩形

Question

我正在使用PyOpenGL开发一个项目,我正在尝试让OpenGL呈现一种启动画面.我决定的解决方案是绘制纹理2D矩形.不幸的是,似乎无论我做什么,都没有画出任何东西,我只是得到一个黑色的屏幕(所以我想有些东西被绘制,否则它将是一个透明的窗口,但它绝对不是我想要的).这是我班级的相关代码:

class ClassThing:
    def __init__(self):
        self.Splash = True
        glutInit(sys.argv)

    def TexFromPNG(self, filename):
        img = Image.open(filename)
        img_data = numpy.array(list(img.getdata()), numpy.uint8)

        texture = glGenTextures(1)
        glPixelStorei(GL_UNPACK_ALIGNMENT,1)
        glBindTexture(GL_TEXTURE_2D, texture)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)
        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_RGB, img.size[0], img.size[1], 0, GL_RGB, GL_UNSIGNED_BYTE, img_data)
        return texture

    def run(self):
        glutInitDisplayMode(GLUT_RGBA)

        glutInitWindowSize(256,224)
        self.window = glutCreateWindow("GL")
        glutDisplayFunc(self.draw)

        glClearColor(0,0,0,0)
        glEnable(GL_TEXTURE_2D)
        glEnable(GL_VERTEX_ARRAY)

        self.MainTex = glGenTextures(1)
        self.SplashTex = self.TexFromPNG("Resources/Splash.png")

        glutMainLoop()

    def draw(self):
        glClear(GL_COLOR_BUFFER_BIT)
        glLoadIdentity()
        if self.Splash:
            glBindTexture(GL_TEXTURE_2D, self.SplashTex)
        else:
            glBindTexture(GL_TEXTURE_2D, self.MainTex)

        glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
        glTexParameter(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER)
        Varray = numpy.array([[0,0],[0,256],[224,256],[224,0]],numpy.uint16)
        glVertexPointer(2,GL_SHORT,0,Varray)
        indices = [0,1,2,3]
        glDrawElements(GL_QUADS,1,GL_UNSIGNED_SHORT,indices)

        glFlush()
thing = ClassThing()
thing.run()

就像我说的那样,只是用一个全黑屏幕给我打网.感觉我可能缺少某种初始化或启用,但我不知道还需要启用什么.

顺便说一下,显然glVertexPointer已被弃用,如果没有它,我将如何运行glDrawElements？是否有某种顶点生成可以做类似于纹理生成或什么？

Answer 1

您还需要提供纹理坐标，否则 OpenGL 不知道如何将纹理映射到您的四边形 \xe2\x80\x94 您也可以使用自动纹理坐标生成，但在您的情况下，仅指定坐标更简单。此外还需要指定视口和投影

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class ClassThing:\n    def __init__(self):\n        self.Splash = True\n\n    def TexFromPNG(self, filename):\n        img = Image.open(filename)\n        img_data = numpy.array(list(img.getdata()), numpy.uint8)\n\n        texture = glGenTextures(1)\n        glPixelStorei(GL_UNPACK_ALIGNMENT,1)\n        glBindTexture(GL_TEXTURE_2D, texture)\n\n        # Texture parameters are part of the texture object, so you need to \n        # specify them only once for a given texture object.\n        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)\n        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)\n        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)\n        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)\n        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img.size[0], img.size[1], 0, GL_RGB, GL_UNSIGNED_BYTE, img_data)\n        return texture\n\n    def run(self):\n        glutInitDisplayMode(GLUT_RGBA)\n\n        glutInitWindowSize(256,224)\n        self.window = glutCreateWindow("GL")\n        glutReshapeFunc(self.reshape)\n        glutDisplayFunc(self.draw)\n\n        self.MainTex = glGenTextures(1)\n        self.SplashTex = self.TexFromPNG("Resources/Splash.png")\n\n        glutMainLoop()\n\n    def reshape(self, width, height):\n        self.width = width\n        self.height = height\n        glutPostRedisplay();\n\n    def draw(self):\n        glViewport(0, 0, self.width, self.height)\n\n        glClearDepth(1) # just for completeness\n        glClearColor(0,0,0,0)\n        glClear(GL_COLOR_BUFFER_BIT)\n\n        glMatrixMode(GL_PROJECTION)\n        glLoadIdentity()\n        glOrtho(0, 1, 0, 1, -1, 1)\n\n        glMatrixMode(GL_MODELVIEW);\n        glLoadIdentity()\n\n        if self.Splash:\n            glBindTexture(GL_TEXTURE_2D, self.SplashTex)\n        else:\n            glBindTexture(GL_TEXTURE_2D, self.MainTex)\n\n        # it\'s a good idea to enable state right before you need it\n        # there\'s no such thing like global state intialization in\n        # OpenGL\n        glEnable(GL_TEXTURE_2D)\n        # vertex arrays must be enabled using glEnableClientState\n        glEnableClientState(GL_VERTEX_ARRAY)\n        glEnableClientState(GL_TEXTURE_COORD_ARRAY)\n\n        Varray = numpy.array([[0,0],[0,1],[1,1],[1,0]],numpy.float)\n        glVertexPointer(2,GL_FLOAT,0,Varray)\n        glTexCoordPointer(2,GL_FLOAT,0,Varray)\n        indices = [0,1,2,3]\n        glDrawElements(GL_QUADS,1,GL_UNSIGNED_SHORT,indices)\n\n        # This implies a glFinish, which includes a glFlush\n        glutSwapBuffers() \n\n# GLUT initialization in program global, so initialize it on\n# the process level. It might be \nglutInit(sys.argv)\n\nthing = ClassThing()\nthing.run()\n

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