c++ - OpenGL 着色器不与着色器程序链接

Question

我正在尝试使用 GLFW/GLEW 添加着色器。

我收到着色器已加载但没有有效目标代码的错误。

这是我加载着色器的代码:

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:

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:

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，我在脚本末尾得到了这个非常奇怪的符号，每次我再次编译时都会出现另一个符号:

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.

Answer 1

您的 Load 函数很可能是问题所在:签名应显示为

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

快速修复。您在该函数中分配内存并重新分配给指针 - 您只将源加载到该地址 - 但它永远不会离开函数。

由于内存初始化为零(您是否在调试中运行它？)，编译器很可能会得到一个空字符串并且不会失败，因为这有时是可以的。但是链接器注意到实际上没有任何代码可以链接!