C++ glCreateShader失败并返回0

我对glCreateShaders有问题。它总是返回0。我将Glew与SDL一起使用，每当我运行程序时，它都会显示：

0(1) : error C0000: syntax error, unexpected '}' at token "}"

Shader Shaders/colorShading.vert failed to compile!

main.cpp：

#include <iostream>
#include "MainGame.h"

int main(int argc, char** argv)
{
    MainGame maingame;
    maingame.run();

    return 0;
}

和片段着色器：

#version 130
//The fragment shader operates on each pixel in a given polygon

//This is the 3 component float vector that gets outputted to the screen
//for each pixel.
out vec3 color;

void main() {
    //Just hardcode the color to red
    color = vec3(1.0, 0.0, 1.0);
}

我不知道为什么会这样(

PS：我是glew的初学者，所以请不要用一些高级材料回答：D

编辑1: 2014年11月2日（美国人为2014年2月11日）

---

我从我使用的教程中下载了源代码，它正在运行。因此，我的代码有些问题。当我发现问题时，我将编辑帖子。

删除文件GLSLProgram.cpp中的分号，第行：

while (std::getline(vertexFile, line));

---

您遍历该文件，然后只需在空字符串fileContents中添加着色器代码的最后一行，即“}”。

您是否认为glCreateShader返回0？对我来说，您的着色器似乎没有编译。在调用glShaderSource之前，请尝试输出着色器源。@BDL我认为这将是problem@Ben产出：沙着色/着色。vert@BBPP20不是文件路径，而是实际的源。但是为什么输出文件内容会导致整个着色器？

//Used for 
#pragma once
#include <string>
#include <GL/glew.h>
//#include <SDL/SDL.h>
#include "Errors.h"


class GLSLProgram
{
public:
    GLSLProgram();
    ~GLSLProgram();

    void compileShaders(const std::string& vertextShaderFilePath, const std::string& fragmentShaderFilePath);

    void linkShaders();

    void addAttribute(const std::string&);

    void use();
    void unUse();
private:
    int _numAttributes;
    void _compileShader(const std::string&, GLuint);

    GLuint _programID;

    GLuint _vertexShaderID;
    GLuint _fragmentShaderID;
};

//Used for compiling shaders
#include "GLSLProgram.h"
#include <fstream>
#include <vector>


GLSLProgram::GLSLProgram() : _numAttributes(0), _programID(0),  _vertexShaderID(0), _fragmentShaderID(0)
{
}


GLSLProgram::~GLSLProgram()
{
}

void GLSLProgram::compileShaders(const std::string& vertexShaderFilePath, const std::string& fragmentShaderFilePath)
{
    _vertexShaderID = glCreateShader(GL_VERTEX_SHADER);
    if (_vertexShaderID == 0)
    {
        fatalError("Vertex shader failed to be created!");
        SDL_Quit();
    }

    _fragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
    if (_fragmentShaderID == 0)
    {
        fatalError("Fragment shader failed to be created!");
        SDL_Quit();
    }

    _compileShader(vertexShaderFilePath, _vertexShaderID);
    _compileShader(fragmentShaderFilePath, _fragmentShaderID);

}

void GLSLProgram::addAttribute(const std::string& attributeName)
{
    glBindAttribLocation(_programID, _numAttributes++, attributeName.c_str());
}

void GLSLProgram::use()
{
    glUseProgram(_programID);
    for (int x = 0; x < _numAttributes; x++)
    {
        glEnableVertexAttribArray(x);
    }
}

void GLSLProgram::unUse()
{
    glUseProgram(0);
    for (int x = 0; x < _numAttributes; x++)
    {
        glDisableVertexAttribArray(x);
    }
}

void GLSLProgram::linkShaders()
{
    //Vertex and fragment shaders are successfully compiled.
    //Now time to link them together into a program.
    //Get a program object.
    _programID = glCreateProgram();

    //Attach our shaders to our program
    glAttachShader(_programID, _vertexShaderID);
    glAttachShader(_programID, _fragmentShaderID);

    //Link our program
    glLinkProgram(_programID);

    //Note the different functions here: glGetProgram* instead of glGetShader*.
    GLint isLinked = 0;
    glGetProgramiv(_programID, GL_LINK_STATUS, (int *)&isLinked);
    if (isLinked == GL_FALSE)
    {
        GLint maxLength = 0;
        glGetProgramiv(_programID, GL_INFO_LOG_LENGTH, &maxLength);

        //The maxLength includes the NULL character
        std::vector<char> infoLog(maxLength);
        glGetProgramInfoLog(_programID, maxLength, &maxLength, &infoLog[0]);

        //We don't need the program anymore.
        glDeleteProgram(_programID);
        //Don't leak shaders either.
        glDeleteShader(_vertexShaderID);
        glDeleteShader(_fragmentShaderID);

        printf("%s\n", &(infoLog[0]));
        fatalError("Shaders failed to link!");
    }

    //Always detach shaders after a successful link.
    glDetachShader(_programID, _vertexShaderID);
    glDetachShader(_programID, _fragmentShaderID);
    glDeleteProgram(_programID);
    glDeleteShader(_vertexShaderID);
    glDeleteShader(_fragmentShaderID);
}

void GLSLProgram::_compileShader(const std::string &filePath, GLuint id)
{
    std::ifstream vertexFile(filePath);
    if (vertexFile.fail())
    {
        perror(filePath.c_str());
        fatalError("Failed to open " + filePath);
    }

    std::string fileContents;
    std::string line;
    while (std::getline(vertexFile, line));
    {
        fileContents += line + "\n";
    }

    vertexFile.close();

    const char *contentsPtr = fileContents.c_str();
    glShaderSource(id, 1, &contentsPtr, nullptr);
    glCompileShader(id);

    GLint isCompiled = 0;
    glGetShaderiv(id, GL_COMPILE_STATUS, &isCompiled);
    if (isCompiled == GL_FALSE)
    {
        GLint maxLength = 0;
        glGetShaderiv(id, GL_INFO_LOG_LENGTH, &maxLength);

        //The maxLength includes the NULL character
        std::vector<char> errorLog(maxLength);
        glGetShaderInfoLog(id, maxLength, &maxLength, &errorLog[0]);

        //Provide the infolog in whatever manor you deem best.
        //Exit with failure.
        glDeleteShader(id); //Don't leak the shader.

        printf("%s\n", &(errorLog[0]));
        fatalError("Shader" + filePath + "failed to compile!");
    }
}

    #version 130
//The vertex shader operates on each vertex

//input data from the VBO. Each vertex is 2 floats
in vec2 vertexPosition;

void main() 
{
    //Set the x,y position on the screen
    gl_Position.xy = vertexPosition;
    //the z position is zero since we are in 2D
    gl_Position.z = 0.0;

    //Indicate that the coordinates are normalized
    gl_Position.w = 1.0;
}

#version 130
//The fragment shader operates on each pixel in a given polygon

//This is the 3 component float vector that gets outputted to the screen
//for each pixel.
out vec3 color;

void main() {
    //Just hardcode the color to red
    color = vec3(1.0, 0.0, 1.0);
}

while (std::getline(vertexFile, line));