2

我开始开发 OpenGL 3（我已经习惯了 1，所以这是一个很大的变化），并且我使用 SDL 作为我的窗口/图像/声音/事件框架。我有以下代码（取自 opengl.org 并稍作修改）：

#include <stdio.h>
#include <stdlib.h>
/* If using gl3.h */
/* Ensure we are using opengl's core profile only */
#define GL3_PROTOTYPES 1
#include <OpenGL/gl3.h>

#include <SDL2/SDL.h>
#define PROGRAM_NAME "Tutorial1"

/* A simple function that prints a message, the error code returned by SDL,
 * and quits the application */
void sdldie(const char *msg)
{
    printf("%s: %s\n", msg, SDL_GetError());
    SDL_Quit();
    exit(1);
}


void checkSDLError(int line = -1)
{
#ifndef NDEBUG
    const char *error = SDL_GetError();
    if (*error != '\0')
    {
        printf("SDL Error: %s\n", error);
        if (line != -1)
            printf(" + line: %i\n", line);
        SDL_ClearError();
    }
#endif
}

void render(SDL_Window* win){
    glClearColor(1.0,0.0,0.0,1.0);
    glClear ( GL_COLOR_BUFFER_BIT );
    SDL_GL_SwapWindow(win);
}


/* Our program's entry point */
int main(int argc, char *argv[])
{
    SDL_Window *mainwindow; /* Our window handle */
    SDL_GLContext maincontext; /* Our opengl context handle */

    if (SDL_Init(SDL_INIT_VIDEO) < 0) /* Initialize SDL's Video subsystem */
    sdldie("Unable to initialize SDL"); /* Or die on error */

    /* Request opengl 3.2 context.
     * SDL doesn't have the ability to choose which profile at this time of writing,
     * but it should default to the core profile */
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);

    /* Turn on double buffering with a 24bit Z buffer.
     * You may need to change this to 16 or 32 for your system */
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);

    /* Create our window centered at 512x512 resolution */
    mainwindow = SDL_CreateWindow(PROGRAM_NAME, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                              512, 512, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN);
    if (!mainwindow) /* Die if creation failed */
        sdldie("Unable to create window");

    checkSDLError(__LINE__);

    /* Create our opengl context and attach it to our window */
    maincontext = SDL_GL_CreateContext(mainwindow);
    checkSDLError(__LINE__);


    /* This makes our buffer swap syncronized with the monitor's vertical refresh */
    SDL_GL_SetSwapInterval(1);

    render(mainwindow);
    SDL_Delay(2000);

    /* Delete our opengl context, destroy our window, and shutdown SDL */
    SDL_GL_DeleteContext(maincontext);
    SDL_DestroyWindow(mainwindow);
    SDL_Quit();

    return 0;
}

这很好用。但如果我改变这一行：

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);

对此：

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);

所以它使用 OpenGL 3.3 而不是 3.2，EXC_BAD_ACCES每次调用 OpenGL 都会出错。我确实想使用 OpenGL 3.3。我的电脑：MacBook Pro 视网膜 2012 年末 Mac OS X Mountain Lion Intel i7 2.7 GHz Intel HD 4000 NVidia GeForce G

任何人都知道这是 OS X 错误、SDL 错误还是我的代码有问题？（我知道 SDL 代码可能不是最好的，但它最初是 SDL 1.2 代码）

4

2 回答 2

9

因为 OSX 只有最高 3.2的opengl 功能。

如果您执行SDL_GetError，它会告诉您出了什么问题。

编辑：OSX Mavericks (10.9) 现在支持 4.1。

于 2013-08-10T15:56:17.560 回答
1

OpenGL 3.3 和 + 目前在 OSX 上不可用。

然而 OpenGL 4.1 将在最新的 OSX 10.9 Mavericks 上可用...敬请期待 :)

于 2013-08-14T07:04:29.207 回答