            const y = finalRect[1];
            const width = finalRect[2];
            const height = finalRect[3];

            clipCtx.fillStyle = 遮罩颜色;

            const topMaskHeight = y;
            const leftMaskWidth = x;
            const rightMaskWidth = cw - (x + width);
            const bottomMaskHeight = ch - (y + height);

            clipCtx.fillRect(0, 0, cw, topMaskHeight);
            clipCtx.fillRect(0, y, leftMaskWidth, height);
            clipCtx.fillRect(x + width, y, rightM