Android NDK OpenGL ES 2上下文初始化

Android NDK OpenGL ES 2 Context Initialization

本文关键字:上下文 初始化 ES NDK OpenGL Android      更新时间:2023-10-16

尝试使用android-ndk-r8e构建一个本地android应用程序。

代码编译良好,运行没有问题,如果构建为Java + NDK应用程序,这是一个Java接口加载.so文件,初始化OpenGL和调用。so中的方法。

然而,当作为"本机活动"编译时,在setup()函数(如下代码)之后,LogCat输出A//system/bin/app_process(27426): stack corruption detected: aborted

void Canvas::Setup ( void ) 
{ 
    // initialize OpenGL ES 2
    // Here specify the attributes of the desired configuration.
    // Below, we select an EGLConfig with at least 8 bits per color
    // component compatible with on-screen windows     
    const EGLint attribs[] =
    {
        EGL_RENDERABLE_TYPE,    EGL_OPENGL_ES2_BIT,
        EGL_RED_SIZE,           8,
        EGL_GREEN_SIZE,         8,
        EGL_BLUE_SIZE,          8,
        EGL_NONE
    };
    // ..
    // surface, window and context related data
    EGLint      w, 
                h, 
                dummy, 
                format;
    EGLConfig   config;
    EGLSurface  surface;
    EGLContext  context;
    EGLDisplay  display = eglGetDisplay( EGL_DEFAULT_DISPLAY );
    // ..
    eglInitialize(display, 0, 0);
    // get the number of matching EGL configurations
    int num_config[1];
    eglChooseConfig(display, attribs, NULL, 1, num_config);
    const int numConfigs = num_config[0];
    if (numConfigs <= 0)
    {
        //throw new IllegalArgumentException("No configs match configSpec");
    }
    // allocate then read the array of minimally matching EGL configs
    EGLConfig configs[numConfigs];
    EGLConfig current;
    eglChooseConfig(display, attribs, configs, numConfigs, num_config);
    int i = 0;
    for(; i < numConfigs; ++i)
    {
        int d = 2, s = 2, r, g, b, a;
        eglGetConfigAttrib(display, configs[i], EGL_DEPTH_SIZE, &d);
        eglGetConfigAttrib(display, configs[i], EGL_STENCIL_SIZE, &s);
        // we need at least mDepthSize and mStencilSize bits
        if (d < 1 || s < 0)
        {
            continue;
        }
        // we want an *exact* match for red/green/blue/alpha
        eglGetConfigAttrib(display, configs[i], EGL_RED_SIZE, &r);
        eglGetConfigAttrib(display, configs[i], EGL_GREEN_SIZE, &g);
        eglGetConfigAttrib(display, configs[i], EGL_BLUE_SIZE, &b);
        eglGetConfigAttrib(display, configs[i], EGL_ALPHA_SIZE, &a);
        if (r == 8 && g == 8 && b == 8 && a == 8)
        {
                        // found it, store in i
            break;
        }
    }
    surface = eglCreateWindowSurface(display, configs[i], Canvas::Engine.app->window, NULL);
    int attrib_list[] = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE };
    context = eglCreateContext(display, configs[i], EGL_NO_CONTEXT, attrib_list);

    if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE)
    {
        LOG_PRINT_ERROR("Unable to eglMakeCurrent");
    }   
    Canvas::Engine.display = display;
    Canvas::Engine.context = context;
    Canvas::Engine.surface = surface;
    Canvas::Engine.animating = true;
    eglQuerySurface(display, surface, EGL_WIDTH, &w);
    eglQuerySurface(display, surface, EGL_HEIGHT, &h);
    Canvas::Width = w;
    Canvas::Width = h;
}

下面是android_main

void android_main(struct android_app* state) 
{
    // make sure glue isn't stripped.
    app_dummy();
    // ..
    // hook to events
    memset(&Canvas::Engine, 0, sizeof(Canvas::Engine));
    state->userData = &Canvas::Engine;
    state->onAppCmd = Canvas::HandleCommand;
    state->onInputEvent = Canvas::HandleInput;
    Canvas::Engine.app = state;
    // ..

    // loop waiting for stuff to do
    while (1) 
    {
        // read all pending events.
        int ident;
        int events;
        struct android_poll_source* source;
        // If not animating, we will block forever waiting for events.
        // If animating, we loop until all events are read, then continue
        // to draw the next frame of animation.
        while ((ident=ALooper_pollAll(Canvas::Engine.animating ? 0 : -1, NULL, &events, (void**)&source)) >= 0)
        {
            // process this event.
            if (source != NULL)
            {
                source->process(state, source);
            }
            // check if we are exiting.
            if (state->destroyRequested != 0)
            {
                Canvas::Cleanup();
                return;
            }
        }
        Canvas::Render();
    }
    // ..
}

这里是我处理Android窗口命令的地方。

void Canvas::HandleCommand(struct android_app* app, int32_t cmd)
{
    switch (cmd)
    {
        case APP_CMD_INIT_WINDOW:
            // window is being shown, get it ready
                    LOG_PRINT_INFO("before setup");
            Canvas::Setup();
                    LOG_PRINT_INFO("after setup");
                    LOG_PRINT_INFO("before resize);
            Canvas::Resize(Canvas::Engine.width, Canvas::Engine.height);
                    LOG_PRINT_INFO("after resize);
        break;
        case APP_CMD_TERM_WINDOW:
            // window is being hidden or closed, clean it up
            Canvas::Cleanup();
        break;
    }
}

LogCat正确打印消息"before setup"。如果你看一下代码,它应该打印"after setup"。相反,它有时会打印"堆栈损坏检测到:中止"。其他时候,它只是简单地退出循环,即使没有代码(我写的)使它像那样返回。

我应该提到NDK代码是基于这个示例的。Java版本看起来差不多,运行也很好。

我很确定是因为这一行

surface = eglCreateWindowSurface(display, configs[i], Canvas::Engine.app->window, NULL);

您或多或少假设的问题是,在从0到numConfigs的for循环中,您寻找的配置可能在您的模拟器或设备中不可用,因此,如果您的代码从未达到该断点,那么您将基于数组之外的数据创建表面和上下文(因为在这种情况下我将是numConfigs),这反过来将解释不稳定的行为。