c - OpenGL 在使用使用它制作的 dll 时给出异常

Question

我正在使用 OpenGL 用 C 语言创建一个库。它只是创建一个窗口，但当我在示例程序上使用它时，它总是崩溃并给出异常:--

“抛出异常:写入访问冲突”

'“win”为 nullptr'

但是当我将它用作 header 并将其直接链接到示例程序而无需任何外部链接时，它会异常地工作。我是否错过了 OpenGL 不允许我用它制作任何库和 dll 的事情？我正在尝试用它制作自己的框架。

我也在使用 GLFW 和 GLEW。

编辑:

窗口.c:

#include "window.h"
#define GLEW_STATIC
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <stdio.h>
#include <stdlib.h>

/* Create the structures... */

struct LIB_Vector2i
{
    int x;
    int y;
};

struct LIB_Vector2f
{
    float x;
    float y;
};

struct LIB_Window
{
    LIB_String title;
    int x;
    int y;
    int width;
    int height;
    LIB_Bool fullscreen;
    GLFWwindow* window;
};

/* Start the functions here... */
LIB_Bool LIB_Initialize()
{
    return (LIB_Bool)glfwInit();
}

void LIB_SetEvents()
{
    glfwPollEvents();
}

void LIB_ClearToColor(LIB_Color color)
{
    glClearColor(color.r, color.g, color.b, color.a);
    glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
}

void LIB_SetFrameColor(LIB_Color color)
{
    glClearColor(color.r, color.g, color.b, color.a);
}

LIB_Window* LIB_CreateWindow(const LIB_String title, int x, int y, int width, int height, const LIB_Bool resizable, const LIB_Bool fullscreen)
{
    LIB_Window wind;
    wind.title = title;
    wind.x = x;
    wind.y = y;
    wind.width = width;
    wind.height = height;
    wind.fullscreen = fullscreen;

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
    glfwWindowHint(GLFW_RESIZABLE, resizable);

    GLFWwindow* window = NULL;
    if (window == NULL)
    {
        if (fullscreen == 1)
        {
            window = glfwCreateWindow(width, height, title, glfwGetPrimaryMonitor(), NULL);
        }
        else if (fullscreen == 0)
        {
            window = glfwCreateWindow(width, height, title, NULL, NULL);
        }
    }

    int screen_width, screen_height;
    glfwGetFramebufferSize(window, &screen_width, &screen_height);

    if (window == NULL)
    {
        glfwTerminate();
        return;
    }

    glfwMakeContextCurrent(window);
    glewExperimental = GL_TRUE;

    if (glewInit() != GLEW_OK)
    {
        return;
    }

    glViewport(0, 0, screen_width, screen_height);
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_BLEND);
    glEnable(GL_ALPHA_TEST);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    return &wind;
}

void LIB_GetCenterPosition(LIB_Window * window, int *x, int *y)
{
    const GLFWvidmode* mode = glfwGetVideoMode(glfwGetPrimaryMonitor());
    *x = (mode->width - window->width) / 2;
    *x = (mode->height - window->height) / 2;
}

void LIB_GetWindowFrameSize(LIB_Window * window, int *width, int *height)
{
    int screenwidth, screenheight;
    glfwGetFramebufferSize(window->window, &screenwidth, &screenheight);
    *width = screenwidth;
    *height = screenheight;
}

void LIB_GetWindowCursorPosition(LIB_Window * window, float *x, float *y)
{
    double cx, cy;
    glfwGetCursorPos(window->window, &cx, &cy);
    *x = (float)cx;
    *y = (float)cy;
}

void LIB_GetDisplaySize(int *width, int *height)
{
    const GLFWvidmode* mode = glfwGetVideoMode(glfwGetPrimaryMonitor());
    *width = mode->width;
    *height = mode->height;
}

void LIB_GetWindowPosition(LIB_Window * window, int *x, int *y)
{
    *x = window->x;
    *y=  window->y;
}

void LIB_GetWindowSize(LIB_Window * window, int *width, int *height)
{
    *width = window->width;
    *height = window->height;
}

LIB_String LIB_GetWindowTitle(LIB_Window * window)
{
    return window->title;
}

LIB_Bool LIB_IsWindowFullScreen(LIB_Window * window)
{
    return window->fullscreen;
}

LIB_Bool LIB_IsWindowOpened(LIB_Window * window)
{
    return !glfwWindowShouldClose(window->window);
}

void LIB_SwapWindowBuffers(LIB_Window * window)
{
    glfwSwapBuffers(window->window);
}

void LIB_SetWindowPosition(LIB_Window * window, int x, int y)
{
    glfwSetWindowPos(window->window, x,y);
    window->x = x;
    window->y = y;
}

void LIB_SetWindowSize(LIB_Window * window, int width, int height)
{
    glfwSetWindowSize(window->window, width, height);
    window->width = width;
    window->height = height;
}

void LIB_SetWindowTitle(LIB_Window * window, const LIB_String title)
{
    glfwSetWindowTitle(window->window, title);
    window->title = title;
}

void LIB_SetFullScreenState(LIB_Window * window, const LIB_Bool fullscreen)
{
    const GLFWvidmode* mode = glfwGetVideoMode(glfwGetPrimaryMonitor());
    if (fullscreen == LIB_FALSE)
    {
        glfwSetWindowMonitor(window->window, NULL, window->x, window->y, window->width, window->height, 60);
    }
    else if (fullscreen == LIB_TRUE)
    {
        glfwSetWindowMonitor(window->window, glfwGetPrimaryMonitor(), 0, 0, mode->width, mode->height, 60);
    }
    window->fullscreen = fullscreen;
}

void LIB_DestroyWindow(LIB_Window * window)
{
    window->title = NULL;
    window->x = 0;
    window->y = 0;
    window->width = 0;
    window->height = 0;
    free(window);
}

void LIB_Terminate()
{
    printf("LIB terminated by the user!!\n");
    glfwTerminate();
}

窗口.h:

#ifndef LIB_GRAPHICS
#define LIB_GRAPHICS

#define LIB_FALSE 0
#define LIB_TRUE 1

#define LIB_BeginRender LIB_SetEvents(); LIB_ClearToColor
#define LIB_EndRender LIB_SwapWindowBuffers

/* Define other things... */

typedef const char* LIB_String;
typedef unsigned LIB_Integer;
typedef char LIB_Char;
typedef int LIB_Bool;

/* Define the structures... */

typedef struct LIB_Window LIB_Window;

typedef struct LIB_Color
{
    int r;
    int g;
    int b;
    int a;
} LIB_Color;

#ifndef LIB_EXPORTS
#define LIB_EXPORTS _declspec(dllexport)
#else
#define LIB_EXPORTS _declspec(dllimport)
#endif

/* Constructors, destructors and other functions... */

LIB_EXPORTS LIB_Bool LIB_Initialize();
LIB_EXPORTS void LIB_SetEvents();
LIB_EXPORTS void LIB_ClearToColor(LIB_Color color);
LIB_EXPORTS void LIB_SetFrameColor(LIB_Color color);


LIB_EXPORTS LIB_Window* LIB_CreateWindow(LIB_String title, int x, int y, int width, int height, LIB_Bool resizable, LIB_Bool fullscreen);
LIB_EXPORTS void LIB_GetDisplaySize(int *width, int *height);

LIB_EXPORTS void LIB_GetCenterPosition(LIB_Window* window, int *x, int *y);
LIB_EXPORTS void LIB_GetWindowFrameSize(LIB_Window* window, int *width, int *height);
LIB_EXPORTS void LIB_GetWindowCursorPosition(LIB_Window* window, float *x, float *y);

LIB_EXPORTS void LIB_GetWindowPosition(LIB_Window* window, int *x, int *y);
LIB_EXPORTS void LIB_GetWindowSize(LIB_Window* window, int *width, int *height);
LIB_EXPORTS LIB_String LIB_GetWindowTitle(LIB_Window* window);
LIB_EXPORTS LIB_Bool LIB_IsWindowFullScreen(LIB_Window* window);
LIB_EXPORTS LIB_Bool LIB_IsWindowOpened(LIB_Window* window);
LIB_EXPORTS void LIB_SwapWindowBuffers(LIB_Window* window);

LIB_EXPORTS void LIB_SetWindowPosition(LIB_Window* window, int x, int y);
LIB_EXPORTS void LIB_SetWindowSize(LIB_Window* window, int width, int height);
LIB_EXPORTS void LIB_SetWindowTitle(LIB_Window* window, LIB_String title);
LIB_EXPORTS void LIB_SetFullScreenState(LIB_Window* window, LIB_Bool fullscreen);

LIB_EXPORTS void LIB_DestroyWindow(LIB_Window* window);


LIB_EXPORTS void LIB_Terminate();

#endif /* LIB_GRAPHICS */

Answer 1

你的代码没有任何意义。您使用 GLFWwindow* 成员声明一个 struct LIB_Window，并在 LIB_CreateWindow() 中创建一个本地 struct LIB_Window 变量您永远不会将实际窗口分配给结构成员，然后，您将地址返回到堆栈上的变量，该地址在函数离开时变得无效(并且某些代码路径仅使用return; 根本没有值。)。

此代码在 C 端完全损坏，您的问题与 DLL 或 OpenGL 无关。