[Cocos2d]如何从GlSurfaceView创建位图

Question

如何在 Cocos2d 中截取 Glsurfaceview 的屏幕截图？我尝试使用 GLsurfaceView 编写以下代码，

    GlsurfaceView glv=CCDirector.sharedDirector().getOpenGLView();
    glv.setDrawingCacheEnabled(true);
    Bitmap bitmap=glv.getDrawingCache();

但它返回透明图像。

Answer 1

我从这个 anddev 论坛问题得到了答案，我附上了代码，希望有人能找到这个有帮助

请将此代码放入渲染器类的 onDraw 方法内启动。

public static Bitmap SavePixels(int x, int y, int w, int h, GL10 gl)
{  
    int b[]=new int[w*h];
    int bt[]=new int[w*h];
    IntBuffer ib=IntBuffer.wrap(b);
    ib.position(0);
    gl.glReadPixels(x, y, w, h, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, ib);

    /*  remember, that OpenGL bitmap is incompatible with 
        Android bitmap and so, some correction need.
     */   
    for(int i=0; i<h; i++)
    {         
        for(int j=0; j<w; j++)
        {
            int pix=b[i*w+j];
            int pb=(pix>>16)&0xff;
            int pr=(pix<<16)&0x00ff0000;
            int pix1=(pix&0xff00ff00) | pr | pb;
            bt[(h-i-1)*w+j]=pix1;
        }
    }              
    Bitmap sb=Bitmap.createBitmap(bt, w, h, true);
    return sb;
}

public static void SavePNG(int x, int y, int w, int h, String name, GL10 gl)
{
    Bitmap bmp=SavePixels(x,y,w,h,gl);
    try
    {
        FileOutputStream fos=new FileOutputStream("/sdcard/my_app/"+name);
        bmp.compress(CompressFormat.PNG, 100, fos);
        try
        {
            fos.flush();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try
        {
            fos.close();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    catch (FileNotFoundException e)
    {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }              
}

Answer 2

这是解决方案：

if (MainImageProcessingActivity.capture) {
        int width = MainImageProcessingActivity.w;
        int height = MainImageProcessingActivity.h;
        int screenshotSize = width * height;
        ByteBuffer bb = ByteBuffer.allocateDirect(screenshotSize * 4);
        bb.order(ByteOrder.nativeOrder());
        gl.glReadPixels(0, 0, width, height, GL10.GL_RGBA,
                GL10.GL_UNSIGNED_BYTE, bb);
        int pixelsBuffer[] = new int[screenshotSize];
        bb.asIntBuffer().get(pixelsBuffer);
        bb = null;
        Bitmap bitmap = Bitmap.createBitmap(width, height,
                Bitmap.Config.RGB_565);
        bitmap.setPixels(pixelsBuffer, screenshotSize - width, -width, 0,
                0, width, height);
        pixelsBuffer = null;

        short sBuffer[] = new short[screenshotSize];
        ShortBuffer sb = ShortBuffer.wrap(sBuffer);
        bitmap.copyPixelsToBuffer(sb);

        // Making created bitmap (from OpenGL points) compatible with
        // Android bitmap
        for (int i = 0; i < screenshotSize; ++i) {
            short v = sBuffer[i];
            sBuffer[i] = (short) (((v & 0x1f) << 11) | (v & 0x7e0) | ((v & 0xf800) >> 11));
        }
        sb.rewind();
        bitmap.copyPixelsFromBuffer(sb);
        MainImageProcessingActivity.captureBmp = bitmap.copy(Bitmap.Config.ARGB_8888,false);
        MainImageProcessingActivity.capture=false;
    }

将代码放在 onDrawFrame(GL10 gl) 方法下，它可以工作！