canvas.drawBitmap（）仅在0时表示alpha层

BitmapFactory.decodeResource

drawBitmap()

Canvas

Canvas

BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inPreferredConfig = Config.ARGB_8888;
...
decorationTextures[1] = new 
    TextureStatic(BitmapFactory.decodeResource(resources, R.drawable.ice_1, opt));
decorationTextures[2] = new 
    TextureStatic(BitmapFactory.decodeResource(resources, R.drawable.ice_2, opt));
...
if(mTexture != null && mInPlay) {
    if(mZone != null)
        canvas.drawBitmap(mTexture.getBitmap(),
                          mScreenX + mZone.getXOffset(), 
                          mScreenY + mZone.getYOffset(), null);
    else
        canvas.drawBitmap(mTexture.getBitmap(), mScreenX, mScreenY, null);
}