glGetAttribLocation在设置了多个uniform后返回-1

-1

我想创建将RGB转换为YCbCr的程序，所以我需要设置变换矩阵和向量为统一。当我多次呼叫glUniformglGetAttribLocation返回-1。这是我的代码。glGetAttribLocation在设置了多个uniform后返回-1

片段着色器

#version 410 
precision highp float; 

uniform sampler2D u_texture; 
uniform mat3 u_ycbcr_matrix; 
uniform mat3 u_ycbcr_vector; 

out vec4 color; 

in vec2 v_coord; 

void main() { 
    color = texture(u_texture, v_coord) + vec4(u_ycbcr_matrix[0], 1); 
}

C++代码

void ScreenQuad::createProgram(ShaderProgram * program, string vsPath, string fsPath){ 
shaderProgram = *program; 
shaderProgram.loadVertexShader(vsPath); 
shaderProgram.loadFragmentShader(fsPath); 
shaderProgram.link(); 

GLint attr = glGetAttribLocation(program -> getShaderProgram(), "position"); 
if (attr < 0) { 
    fprintf(stdout, "Nieprawidlowy parametr: position"); 
} 

glVertexAttribPointer(attr, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), 0); 
glEnableVertexAttribArray(attr); 

shaderProgram.use(); 
program -> setUniforms(); 
glUniform1i(glGetUniformLocation(shaderProgram.getShaderProgram(), "u_texture"), 0); 

int total = -1; 
glGetProgramiv(shaderProgram.getShaderProgram(), GL_ACTIVE_UNIFORMS, &total); 
for(int i=0; i<total; ++i) { 
    int name_len=-1, num=-1; 
    GLenum type = GL_ZERO; 
    char name[100]; 
    glGetActiveUniform(shaderProgram.getShaderProgram(), GLuint(i), sizeof(name)-1, 
         &name_len, &num, &type, name); 
    name[name_len] = 0; 
    GLuint location = glGetUniformLocation(shaderProgram.getShaderProgram(), name); 
    fprintf(stdout, "\n --- %s : %d---", name, location); 
} 

shaderPrograms.push_back(shaderProgram);} 


ShaderProgram RGB2YCbCr::setUniforms() { 
    GLuint program = getShaderProgram(); 
    fprintf(stdout, "\n+++ %d +++ \n", glGetUniformLocation(program, "u_ycbcr_matrix")); 
    glUniformMatrix3fv(glGetUniformLocation(program, "u_ycbcr_matrix"), 1, GL_FALSE, ycbcr_matrix); 

    fprintf(stdout, "\n+++ %d +++ \n", glGetUniformLocation(program, "u_ycbcr_vector")); 
    glUniform3fv(glGetUniformLocation(program, "u_ycbcr_vector"), 1, ycbcr_vector); 
};

来源

2017-10-18 Konrad Marzec

您确定'shaderProgram = * program;'正常工作吗？这似乎是对象上的副本分配调用，应该可能是不可复制的。而且你还没有调用过'glGetError'来检查错误代码。 – VTT

'GLenum a = glGetError（）; fprintf（stdout，“GL_GET_ERROR％d”，a）;'打印代码1282 –

您的着色器u_ycbcr_vector均匀，不使用它。这是由GLSL编译器和链接器完成的某种优化，它将为已声明但未使用的制服丢弃无效的位置。因此，如果您没有使用它，然后再试一次，请从着色器中移除该制服。

来源

2017-10-18 07:47:45

glGetAttribLocation在设置了多个uniform后返回-1

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