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社区首页 >问答首页 >glGetAttribLocation导致无效操作

glGetAttribLocation导致无效操作
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Stack Overflow用户
提问于 2018-06-12 04:18:53
回答 1查看 585关注 0票数 1

我试图用pyopengl和pygame的python制作一个月球的模型/模拟。我在.obj文件中使用了一个开源的月球3d模型,并试图将其合并到我的代码中。但是由于某些原因,出现了一个错误,标记为

位置:GLError(错误= 1282,描述=b‘无效操作’,baseOperation = glGetAttribLocation,cArguments = (6,b‘位置\x00’)

我的实现被分成不同的类(如OOP),但下面列出了主要的类,即着色器、月亮类和我使用该程序的类。OBJ加载器直接来自官方pygame网站。

顶点着色器

#version 330
layout (location = 0) in vec3 position;
layout (location = 1) in vec3 newColor;
layout (location = 2) in vec2 verTexCoord;
out vec3 color;
out vec2 fragTexCoord;
// other methods like scaling, rotation
void main(){
    vec4 pos = vec4(position, 1.0);
    // apply translation, rotation and scaling 
    gl_Position = pos;
    fragTexCoord = verTexCoord;
    color = newColor;
}

片段着色器

#version 330
in vec3 color;
in vec2 fragCoord;
out vec4 outColor;
uniform sampler2D ourTexture;
void main(){
    outColor = texture2D(ourTexture, fragCoord);
}

月亮

from objloader import *
class Moon(Shape):
    def __init__(self):
        Shape.__init__(self)
        self.obj = OBJ("Moon\moon.obj", swapyz=True)
        self.drawing_type = GL_POLYGON
        self.setup_shaders()
        self.setup_buffers()
    def setup_shaders(self):
        # Get and Compile the shaders here
        self.program = glCreateProgram()
        glAttachShader(self.program, vertexShader)
        glAttachShader(self.program, fragmentShader)
        glLinkProgram(self.program)

    def setup_buffers(self):
        self.vao = glGenVertexArrays(1)
        self.vbo = glGenBuffers(1)
        v = []
        # buildlist will give a list that contains the moons vertices including the texture coordinates. 
        v = self.buildList(self.obj)
        self.vertexes = np.stack(v)
        self.vertex_length = len(self.vertexes)
        glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
        glBufferData(GL_ARRAY_BUFFER, self.vertexes.nbytes, self.vertexes, GL_STATIC_DRAW)
        glBindVertexArray(self.vao)
        # This is the line the error occurs at.
        positionLocation = glGetAttribLocation(self.program, "position")

不是必需的,但这里是Shape类和绘制文本所在的函数(它位于与Shape不同的类中)。

class Shape():
    def __init__(self):
        self.vao = None
        self.vbo = None
        self.program = None
        self.vertexes = None
        self.drawing_type = None
        self.vertex_length = None

绘图函数

def draw(self):
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    for shape in self.shapes:
        glUseProgram(shape.program)
        glBindVertexArray(shape.vao)
        glDrawArrays(shape.drawing_type, 0, shape.vertex_length)
        glBindVertexArray(0)
EN

回答 1

Stack Overflow用户

回答已采纳

发布于 2018-06-12 04:28:58

由于程序对象self.program未正确链接,glGetAttribLocation显示无效操作错误。

该程序未链接,因为顶点着色器的输出变量与片段着色器的输入变量不匹配。

顶点着色器:

out vec3 color;
out vec2 fragTexCoord;

片段着色器:

in vec3 color;
in vec2 fragCoord;

像这样更改片段着色器,以解决此问题:

#version 330

in vec3 color;
in vec2 fragTexCoord; // "fragTexCoord" insted of "fragCoord"

out vec4 outColor;
uniform sampler2D ourTexture;
void main(){
    outColor = texture2D(ourTexture, fragTexCoord); 
}

请注意,glGetProgramiv( self.program, GL_LINK_STATUS )可以检查程序对象是否链接成功

glLinkProgram( self.program )
if not glGetProgramiv( self.__prog, GL_LINK_STATUS ):
    print( 'link error:' )
    print( glGetProgramInfoLog( self.__prog ) )

为了完整性,glGetShaderiv( shaderObj, GL_COMPILE_STATUS )可以检查着色器对象是否已成功编译

glCompileShader( shaderObj )
if not glGetShaderiv( shaderObj, GL_COMPILE_STATUS ):
    print( 'compile error:' )
    print( glGetShaderInfoLog( shaderObj ) )
票数 1
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页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/50805413

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