OpenGL着色器加載失敗

Question

我遇到了着色器加載代碼的問題。讓我感到困惑的奇怪之處在於，它可能會在5次之內運行一次，但後來只有一些作品。例如，它會加載碎片着色器，但紋理將無法正常工作（它會在幾何圖形上畫出紋理的奇怪外觀）。我認爲問題出在加載代碼，所以這就是我的問題。任何人都可以發現我在下面的代碼中找不到的錯誤？

char* vs, * fs; 

vertexShaderHandle = glCreateShader(GL_VERTEX_SHADER); 
fragmentShaderHandle = glCreateShader(GL_FRAGMENT_SHADER); 

long sizeOfVShaderFile = getSizeOfFile(VERTEX_SHADER_FILE_NAME); 
long sizeOfFShaderFile = getSizeOfFile(FRAGMENT_SHADER_FILE_NAME); 

if(sizeOfVShaderFile == -1) 
{ 
    cerr << VERTEX_SHADER_FILE_NAME<<" is null! Exiting..." << endl; 
    return; 
} 
if(sizeOfFShaderFile == -1) 
{ 
    cerr << FRAGMENT_SHADER_FILE_NAME<<" is null! Exiting..." << endl; 
    return; 
} 

vs = readFile(VERTEX_SHADER_FILE_NAME); 
fs = readFile(FRAGMENT_SHADER_FILE_NAME); 

const char* vv = vs, *ff = fs; 

glShaderSource(vertexShaderHandle , 1, &vv, NULL); 

cout << "DEBUGGING SHADERS" << endl; 
cout << "VERTEX SHADER: "; 
printShaderInfoLog(vertexShaderHandle); 
cout << endl; 

glShaderSource(fragmentShaderHandle, 1, &ff, NULL); 

cout << "FRAGMENT SHADER: "; 
printShaderInfoLog(fragmentShaderHandle); 
cout << endl; 


glCompileShader(vertexShaderHandle); 

cout << "VERTEX SHADER: "; 
printShaderInfoLog(vertexShaderHandle); 
cout << endl; 

glCompileShader(fragmentShaderHandle); 

cout << "FRAGMENT SHADER: "; 
printShaderInfoLog(fragmentShaderHandle); 
cout << endl; 


programHandle = glCreateProgram(); 

cout << "DEBUGGING PROGRAM" << endl; 

glAttachShader(programHandle, vertexShaderHandle); 

printProgramInfoLog(programHandle); 

glAttachShader(programHandle, fragmentShaderHandle); 

printProgramInfoLog(programHandle); 


glLinkProgram(programHandle); 

printProgramInfoLog(programHandle); 

glUseProgram(programHandle); 

printProgramInfoLog(programHandle); 


delete[] vs; delete[] fs; 

這裏的READFILE功能：

char* readFile(const char* path) 
{ 
    unsigned int fileSize = getSizeOfFile(path); 

    char* file_data = new char[fileSize]; 

    ifstream input_stream; 

    input_stream.open(path, ios::binary); 

    input_stream.read(file_data, fileSize); 

    input_stream.close(); 
    //this is deleted at the end of the shader code 
    return file_data; 
} 

下面所有的消息是來自完全相同的可執行文件（不重建）。

這裏的第一種可能的錯誤消息：

BallGLWidget::initializeGL called 
DEBUGGING SHADERS 
VERTEX SHADER: 
FRAGMENT SHADER: 
VERTEX SHADER: ERROR: 0:17: '<' : syntax error syntax error 


FRAGMENT SHADER: 
DEBUGGING PROGRAM 
ERROR: One or more attached shaders not successfully compiled 

ERROR: One or more attached shaders not successfully compiled 

glGetError enum value: GL_NO_ERROR 

另一種可能的錯誤消息：

BallGLWidget::initializeGL called 
DEBUGGING SHADERS 
VERTEX SHADER: 
FRAGMENT SHADER: 
VERTEX SHADER: ERROR: 0:17: 'tt' : syntax error syntax error 


FRAGMENT SHADER: ERROR: 0:33: '?' : syntax error syntax error 


DEBUGGING PROGRAM 
ERROR: One or more attached shaders not successfully compiled 

ERROR: One or more attached shaders not successfully compiled 

這裏的輸出時，它的工作原理（在5或6次也許1）

BallGLWidget::initializeGL called 
DEBUGGING SHADERS 
VERTEX SHADER: 
FRAGMENT SHADER: 
VERTEX SHADER: 
FRAGMENT SHADER: 
DEBUGGING PROGRAM 
Image format is GL_RGB 
Checking textures... 
glGetError enum value: GL_NO_ERROR 

我認真地懷疑它的着色器本身，因爲他們有時候會這樣做......並且報告的錯誤是垃圾。

如果有更多的信息會有幫助，我會很樂意提供。

編輯：這裏的着色器

頂點着色器：

attribute vec2 a_v_position; 
attribute vec2 a_tex_position; 

varying vec2 tex_coord_output; 


void main() 
{ 
    tex_coord_output = a_tex_position; 

    gl_Position = vec4(a_v_position, 0.0, 1.0); 
} 

片段着色器：

varying vec2 tex_coord_output; 

uniform sampler2D ballsampler; 


void main() 
{ 
     gl_FragColor = texture2D(ballsampler, tex_coord_output); 
} 

Answer 1

您正在閱讀的文件，但據我可以看你是不是零終止文本。嘗試分配文件大小+ 1並將最後一個字符設置爲零。

Answer 2

你的問題的Getting garbage chars when reading GLSL files重複，這裏是我的answer它：

---

您使用C++，所以我建議你利用這一點。而不是讀成自分配的字符數組，我建議你讀入的std :: string：

#include <string> 
#include <fstream> 

std::string loadFileToString(char const * const fname) 
{ 
    std::ifstream ifile(fname); 
    std::string filetext; 

    while(ifile.good()) { 
     std::string line; 
     std::getline(ifile, line); 
     filetext.append(line + "\n"); 
    } 

    return filetext; 
} 

，可自動完成所有的內存分配和適當界定的 - 關鍵詞是RAII：資源分配初始化。稍後你可以上傳着色器源代碼，如

void glcppShaderSource(GLuint shader, std::string const &shader_string) 
{ 
    GLchar const *shader_source = shader_string.c_str(); 
    GLint const shader_length = shader_string.size(); 

    glShaderSource(shader, 1, &shader_source, &shader_length); 
} 

void load_shader(GLuint shaderobject, char * const shadersourcefilename) 
{ 
    glcppShaderSource(shaderobject, loadFileToString(shadersourcefilename)); 
}