android - 如何从另一个位图中剪切一个位图

Question

我需要从 Bitmap2 中剪切 Bitmap1..例如，我有 Bitmap1(从 Resources drawable 解码)和 Bitmap2(也从 Resources drawable 解码)。

位图 1:

|   |
 > <
|   |

位图2:

|xxx|
|xxx|
|xxx|

我需要结果:

|xxx|
 >x<
|xxx|

谁能给我示例代码？

安卓系统。

Answer 1

您可以加载两个位图并使用 PorterDuffXfermode 和 DST_IN 来屏蔽“Bitmap2”，有点像这样:

Bitmap bitmap2 = BitmapFactory.decodeResource(getResources(), R.drawable.bitmap2);
Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.bitmap1);
Bitmap bitmap2MaskedByBitmap1 = Bitmap.createBitmap(bitmap2.getWidth(), bitmap2.getHeight(), bitmap2.getConfig());
Canvas canvas = new Canvas(bitmap2MaskedByBitmap1);

Paint paint = new Paint();
paint.setFilterBitmap(false);

canvas.drawBitmap(bitmap2, 0, 0, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
canvas.drawBitmap(bitmap1, 0, 0, paint);
bitmap2.recycle();
bitmap1.recycle();

// bitmap2MaskedByBitmap1 should now contain the desired image
// as long as your Bitmap1 mask isn't sh-t.