glGetAttribLocation()返回-1,但变量是统一的,如何解决？

Question

这是我的着色器'triangles.vert':

#version 430 core
layout(location = 0) in vec4 vPosition;
layout(location = 1) in vec4 vColor;
uniform mat4 vRota;

out vec4 color;

void main()
{
    color = vColor;
    gl_Position = vRota * vPosition;
}

这是C++源代码的片段:

ShaderInfo shaders[] = 
{
    { GL_VERTEX_SHADER, "triangles.vert" },
    { GL_FRAGMENT_SHADER, "triangles.frag" },
    { GL_NONE, NULL }
};

GLuint program = LoadShaders(shaders);
glUseProgram(program);

//...

int vRota_loc = glGetAttribLocation(program, "vRota");

if (vRota_loc == -1)
{
    cout << "No uniform match for 'vRota'" << endl;
}

它返回-1,但我不知道为什么.

我在着色器中做错了什么？

ps LoadShaders()是用于编译和链接着色器程序的函数.它是我正在练习的一本书的源文件.所以我认为不会有错误.

Answer 1

glGetAttribLocation用于顶点属性,即in顶点着色器中的变量(例如vPosition).你想要的glGetUniformLocation.

Answer 2

A uniform不是属性.你需要使用glGetUniformLocation

A uniform对于每个顶点是一致的,而a attribute是每个顶点.