使用MinGW的C中的分段错误

Question

代码可以编译，但是在运行时崩溃。

我认为是VertexShaderSource和FragmentShaderSource引起了问题，但我似乎找不到它。

几天来我一直在努力解决这个问题，非常感谢您的帮助。

如果删除以下代码行，则该程序似乎按预期运行。

GLuint RedShader = CreateShader();
glUseProgram(RedShader);

这是用于编译的命令行。

gcc -g .. \\ Source \\ main.c .. \\ Source \\ Window.c .. \\ Source \\ OpenGL.c .. \\ Source \\ Shader.c -lopengl32 -lgdi32 -o .. \\ Binary \\ Project.exe

这是GDB控制台的代码段：

程序收到信号SIGSEGV，分段故障。

0x00000000 in ?? （）

（gdb）在哪里

0x00000000 in ?? （）

.. \\ Source \\ Shader.c：5中的CreateShader中的0x00401991（VertexShaderSource = 0x26f018，> FragmentShaderSource = 0x26f014）

主（）中的0x00401432位于.. \\ Source \\ Main.c：12

这是代码：

Main.c

#include "..\Header\Window.h"
#include "..\Header\Shader.h"


int main()
{
    Project_CreateWindow("Project", 512, 512);

    float Vertices[] = {-0.5f, -0.5f, 0.0f, 0.5f, -0.5f, 0.0f, 0.0f, 0.5f, 0.0f};

    GLuint VBO;
    glGenBuffers(1, &VBO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);

    GLuint RedShader = CreateShader();
    glUseProgram(RedShader);

    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

    for(;;)
    {
        glClear(GL_COLOR_BUFFER_BIT);
        glDrawArrays(GL_TRIANGLES, 0, 3);
        Project_UpdateWindow();
    }

    glDisableVertexAttribArray(0);

    Project_DestroyWindow();

    return 0;
}

窗口

#ifndef WINDOW_HEADER
#define WINDOW_HEADER

#include <windows.h>
#include <GL\GL.h>
#include "..\Header\OpenGL.h"

void Project_CreateWindow(const char * Title, const unsigned short Width, const unsigned short Height);
void Project_DestroyWindow();
void Project_UpdateWindow();

#endif

窗口

#include "..\Header\Window.h"

static HDC DeviceContext;
static HWND Window;
static HGLRC RenderContext;

LRESULT CALLBACK EventHandler(HWND Window, UINT Message, WPARAM WordParameter, LPARAM LongParameter);

void Project_CreateWindow(const char * Title, const unsigned short Width, const unsigned short Height)
{
    WNDCLASSEX WindowClass = {sizeof(WNDCLASSEX), CS_OWNDC, EventHandler, 0, 0, GetModuleHandle(0), 0, 0, 0, 0, "WindowClass", 0};
    RegisterClassEx(&WindowClass);
    Window = CreateWindowEx(0, WindowClass.lpszClassName, Title, WS_OVERLAPPEDWINDOW, (GetSystemMetrics(SM_CXSCREEN) / 2) - (Width / 2), (GetSystemMetrics(SM_CYSCREEN) / 2) - (Height / 2), Width, Height, 0, 0, WindowClass.hInstance, 0);
    PIXELFORMATDESCRIPTOR PixelFormat = {sizeof(PIXELFORMATDESCRIPTOR), 1, PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER, PFD_TYPE_RGBA, 32, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0};
    if ((DeviceContext = GetDC(Window)) == 0)
    {
        //TODO: Device Context Creation Failed
    }
    SetPixelFormat(DeviceContext, ChoosePixelFormat(DeviceContext, &PixelFormat), &PixelFormat);
    if ((RenderContext = wglCreateContext(DeviceContext)) == 0)
    {
        //TODO: Render Context Creation Failed
    }
    if ((wglMakeCurrent(DeviceContext, RenderContext)) == 0)
    {
        //TODO: Make Context Current Failed
    }
    ShowWindow(Window, SW_SHOW);
    GetOpenGLFunctionPointers();
}

void Project_DestroyWindow()
{
    wglMakeCurrent(0, 0);
    wglDeleteContext(RenderContext);
    ReleaseDC(Window, DeviceContext);
    DestroyWindow(Window);
}

void Project_UpdateWindow()
{
    MSG Message;
    if (PeekMessage(&Message, 0, 0, 0, PM_REMOVE))
    {
        TranslateMessage(&Message);
        DispatchMessage(&Message);
    }
    SwapBuffers(DeviceContext);
}

LRESULT CALLBACK EventHandler(HWND Window, UINT Message, WPARAM WordParameter, LPARAM LongParameter)
{
    return DefWindowProc(Window, Message, WordParameter, LongParameter);
}

OpenGL.h

#ifndef OPENGL_HEADER
#define OPENGL_HEADER

#include <stddef.h.>
#include <GL\GL.h>
#include <windows.h>
#include <Wingdi.h>

#define GL_ARRAY_BUFFER                   0x8892
#define GL_STATIC_DRAW                    0x88E4
#define GL_VERTEX_SHADER                  0x8B31
#define GL_FRAGMENT_SHADER                0x8B30

typedef char GLchar;
typedef ptrdiff_t GLsizeiptr;

extern void (* glGenBuffers) (GLsizei n, GLuint *buffers);
extern void (* glBindBuffer) (GLenum target, GLuint buffer);
extern void (* glBufferData) (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
extern void (* glEnableVertexAttribArray) (GLuint index);
extern void (* glVertexAttribPointer) (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer);
extern void (* glDisableVertexAttribArray) (GLuint index);
extern GLuint (* glCreateProgram) (void);
extern GLuint (* glCreateShader) (GLenum type);
extern void (* glShaderSource) (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
extern void (* glCompileShader) (GLuint shader);
extern void (* glAttachShader) (GLuint program, GLuint shader);
extern void (* glLinkProgram) (GLuint program);
extern void (* glUseProgram) (GLuint program);

void GetOpenGLFunctionPointers();

#endif

OpenGL.c

#include "..\Header\OpenGL.h"

#include <stdio.h>

void *GetOpenGLFunctionAddress(const char *name);

void (* glGenBuffers) (GLsizei n, GLuint *buffers);
void (* glBindBuffer) (GLenum target, GLuint buffer);
void (* glBufferData) (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
void (* glEnableVertexAttribArray) (GLuint index);
void (* glVertexAttribPointer) (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer);
void (* glDisableVertexAttribArray) (GLuint index);
GLuint (* glCreateProgram) (void);
GLuint (* glCreateShader) (GLenum type);
void (* glShaderSource) (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
void (* glCompileShader) (GLuint shader);
void (* glAttachShader) (GLuint program, GLuint shader);
void (* glLinkProgram) (GLuint program);
void (* glUseProgram) (GLuint program);

void GetOpenGLFunctionPointers()
{
    glGenBuffers = (void *)GetOpenGLFunctionAddress("glGenBuffers");
    glBindBuffer = (void *)GetOpenGLFunctionAddress("glBindBuffer");
    glBufferData = (void *)GetOpenGLFunctionAddress("glBufferData");
    glEnableVertexAttribArray = (void *)GetOpenGLFunctionAddress("glEnableVertexAttribArray");
    glVertexAttribPointer = (void *)GetOpenGLFunctionAddress("glVertexAttribPointer");
    glDisableVertexAttribArray = (void *)GetOpenGLFunctionAddress("glDisableVertexAttribArray");
    glCreateProgram = (void *)GetOpenGLFunctionAddress("glCreateProgram");
    glCreateShader = (void *)GetOpenGLFunctionAddress("glCreateShader");
    glShaderSource = (void *)GetOpenGLFunctionAddress("glShaderSource");
    glCompileShader = (void *)GetOpenGLFunctionAddress("glCompileShader");
    glAttachShader = (void *)GetOpenGLFunctionAddress("glAttachShader");
    glLinkProgram = (void *)GetOpenGLFunctionAddress("glLinkProgram");
    glUseProgram = (void *)GetOpenGLFunctionAddress("glUseProgram");
}

void *GetOpenGLFunctionAddress(const char *FunctionName)
{
  void *FunctionPointer = (void *)wglGetProcAddress(FunctionName);

  if(FunctionPointer == 0 || (FunctionPointer == (void*)0x1) || (FunctionPointer == (void*)0x2) || (FunctionPointer == (void*)0x3) || (FunctionPointer == (void*)-1))
  {
        HMODULE Module = LoadLibraryA("opengl32.dll");
        FunctionPointer = (void *)GetProcAddress(Module, FunctionName);

        if(FunctionPointer == 0 || (FunctionPointer == (void*)0x1) || (FunctionPointer == (void*)0x2) || (FunctionPointer == (void*)0x3) || (FunctionPointer == (void*)-1))
        {
            printf("%s %i", "Invalid OpenGL Function Pointer, Last Error:", GetLastError());
        }
  }

  return FunctionPointer;
}

着色器

#ifndef SHADER_HEADER
#define SHADER_HEADER

#include "..\Header\OpenGL.h"

GLuint CreateShader();

#endif

着色器

    #include "..\Header\Shader.h"

GLuint CreateShader()
{
    const GLchar * VertexShaderSource  = "#version 330 core\n layout(location = 0) in vec3 vertexPosition_modelspace;\n void main(){\n gl_Position.xyz = vertexPosition_modelspace;\n gl_Position.w = 1.0;\n }";
    const GLchar * FragmentShaderSource = "#version 330 core\n out vec3 color;\n void main(){\n color = vec3(1.0f, 0.55f, 0.0f);\n }";

    GLuint ShaderProgram = glCreateProgram();

    GLuint VertexShader = glCreateShader(GL_VERTEX_SHADER);
    GLuint FragmentShader = glCreateShader(GL_FRAGMENT_SHADER);

    glShaderSource(VertexShader, 1, &VertexShaderSource, 0);
    glShaderSource(FragmentShader, 1, &FragmentShaderSource, 0);

    glCompileShader(VertexShader);
    glCompileShader(FragmentShader);

    glAttachShader(ShaderProgram, VertexShader);
    glAttachShader(ShaderProgram, FragmentShader);

    glLinkProgram(ShaderProgram);

    return ShaderProgram;
}

Answer 1

忘记通话惯例，例如

extern void (* glGenBuffers) (GLsizei n, GLuint *buffers);

应更改为：

extern void (__stdcall * glGenBuffers) (GLsizei n, GLuint *buffers);