将OpenGL ES 2.0渲染纹理转换为位图和背面

Question

我想用RenderScript模糊渲染的纹理,为此我需要将其转换为位图格式并使用它我需要将其转换回OpenGL纹理.

纹理渲染正在起作用.问题必须在某处,但我不明白为什么它不起作用.我有黑屏

  public void renderToTexture(){
    GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, fb[0]);
    GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
    GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);

    // specify texture as color attachment
    GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0, GLES20.GL_TEXTURE_2D, renderTex[0], 0);
    // attach render buffer as depth buffer
    GLES20.glFramebufferRenderbuffer(GLES20.GL_FRAMEBUFFER, GLES20.GL_DEPTH_ATTACHMENT, GLES20.GL_RENDERBUFFER, depthRb[0]);
    // check status
    int status = GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER);
    drawRender();

   Bitmap bitmap = SavePixels(0,0,texW,texH);
   //blur bitmap and get back a bluredBitmap not yet implemented
   texture = TextureHelper.loadTexture(bluredBitmap, 128);

   GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
   GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
   GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);

    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture);

    drawRender2();

}

为了创建一个位图,我从帧缓冲区读取像素,因为没有找到任何其他方法来做,但我对其他方法开放

    public static Bitmap SavePixels(int x, int y, int w, int h)
{
    int b[]=new int[w*(y+h)];
    int bt[]=new int[w*h];
    IntBuffer ib=IntBuffer.wrap(b);
    ib.position(0);
    GLES20.glReadPixels(0, 0, w, h, GLES20.GL_RGB, GLES20.GL_UNSIGNED_BYTE, ib);

    for(int i=0, k=0; i<h; i++, k++)
    {          
        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-k-1)*w+j]=pix1;
        }
    }


    Bitmap sb=Bitmap.createBitmap(bt, w, h, Bitmap.Config.ARGB_8888);
    return sb;
}

这是纹理代码的位图:

    public static int loadTexture(final Bitmap pics, int size)
{
    final int[] textureHandle = new int[1];

    GLES20.glGenTextures(1, textureHandle, 0);

    if (textureHandle[0] != 0)
    {
        // Read in the resource
        final Bitmap bitmap = pics;

        GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
        GLES20.glEnable(GLES20.GL_BLEND);

        // Bind to the texture in OpenGL
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);

        // Set filtering
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);

        // Load the bitmap into the bound texture.
         GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);

        // Recycle the bitmap, since its data has been loaded into OpenGL.
        bitmap.recycle();
    }

    if (textureHandle[0] == 0)
    {
        throw new RuntimeException("Error loading texture.");
    }

    return textureHandle[0];
}

Answer 1

您应该使用过：

GLES20.glReadPixels(0, 0, w, h, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, ib);

你的 for 循环应该将 RGBA 转换为 ARGB_8888