OpenGL着色器不与着色器程序链接 [英] OpenGL shaders don't link with shader program

问题描述

我正在尝试使用GLFW/GLEW添加着色器.

I am trying to add shaders with GLFW/GLEW.

我收到一个错误信息，指出着色器已加载，但是它们没有有效的目标代码.

I am getting an error that the shaders are loaded but they don't have valid object code.

这是我用于加载着色器的代码:

This is the code I have for loading the shaders:

class SHADER {
public:

void LoadShaders(const char *vertexFile, const char *fragmentFile);

char *vertexShader;
char *fragmentShader;

private:

int Load(const char *filename, char*&shaderSource);
fstream file;
};

int SHADER::Load(const char *filename, char *&shaderSource) {
file.open(filename, ios::in);
if(file.is_open()) {
    file.tellg();
    file.seekg(0,ios::end);
    unsigned long len = file.tellg();
    file.seekg(ios::beg);

    if(len == 0 ) {
        return -2;
    } else {
        shaderSource = new char[len + 1];
        file.read(shaderSource,len);
        file.close();
        printf("%s\n",shaderSource);
    }
} else {
    return -1;
}
return 0;
}

void SHADER::LoadShaders(const char *vertexFile, const char *fragmentFile) {
int resultVertex = this->Load(vertexFile, vertexShader);
int resultFragment = this->Load(fragmentFile, fragmentShader);
if(resultVertex ==0 && resultFragment ==0) {
    printf("Shaders loaded succesfully.\n");
}
if(resultVertex == -2) {
    printf("VertexShader is empty!\n");
}
if(resultFragment == -2) {
    printf("FragmentShader is empty!\n");
}
if(resultVertex == -1) {
    printf("Unable to load VertexShader!\n");
}
if(resultFragment == -1) {
    printf("Unable to load FragmentShader!\n");
}
}

这是初始化着色器的代码:

This is the code for initializing the shaders:

SHADER Shaders;
GLhandleARB vertexShader, fragmentShader, shaderProgram;

Shaders.LoadShaders("vertexShader.vert","fragmentShader.frag");

const char* vertTemp = Shaders.vertexShader;
vertexShader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
glShaderSourceARB(vertexShader, 1, &vertTemp, NULL);
glCompileShaderARB(vertexShader);
traceShaderInfoLog(vertexShader);

const char* fragTemp = Shaders.fragmentShader;
fragmentShader = glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
glShaderSourceARB(fragmentShader, 1, &fragTemp, NULL);
glCompileShaderARB(fragmentShader);
traceShaderInfoLog(fragmentShader);

delete[] Shaders.vertexShader;
delete[] Shaders.fragmentShader;

shaderProgram = glCreateProgramObjectARB();
glAttachObjectARB(shaderProgram,vertexShader);
glAttachObjectARB(shaderProgram,fragmentShader);
glLinkProgramARB(shaderProgram);
traceProgramInfoLog(shaderProgram);

glUseProgramObjectARB(shaderProgram);

这是vertexShader.vert和fragmentShader.frag:

This is vertexShader.vert and fragmentShader.frag:

void main(){
gl_Position = ftransform();
}
void main(){
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}

这是我在打印日志时遇到的错误，我在脚本的末尾得到了这个确实很奇怪的符号，这是我每次再次编译另一个符号时的情况:

And this is the error I get when I print the log, I get this really weird symbol at the end of the scripts which is every time I compile again another symbol:

void main(){
    //gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
    gl_Position = ftransform();
}┘
void main(){
    gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}♣
Shaders loaded succesfully.
Vertex shader was successfully compiled to run on hardware.

Fragment shader failed to compile with the following errors:
ERROR: 0:3: error(#132) Syntax error: '<' parse error
ERROR: error(#273) 1 compilation errors.  No code generated

Fragment shader(s) were not successfully compiled before glLinkProgram() was called.
Link failed.

推荐答案

您的Load函数很可能是问题所在:签名应读取

Your Load function is most likely the problem: the signature should read

int SHADER::Load(const char *filename, char *&shaderSource) // Note the &

快速修复.您正在该函数中分配内存，然后重新分配给指针-您仅将源加载到该地址-但这永远不会离开该函数.

for a quick fix. You're allocating the memory in that function and reassigning to the pointer - you only load the source to that address - but that never leaves the function.

由于内存初始化为零(您是否在调试中运行此程序)，编译器很可能会得到一个空字符串，并且不会失败，因为有时还可以.但是链接器会注意到实际上没有任何要链接的代码！

The compiler most likely gets an empty string due to memory being zero initialized (are you running this in debug?) and doesn't fail because that's sometimes okay. But the linker notices that there's not really any code to link!

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