 const mixColors = (backColors, fronRgba) => {
                        const mixedColors = [];
                        for (let i = 0; i < backColors.length; i += 4) {
                            const mixedColor = mixColor(backColors.subarray(i, i + 4), fronRgba);
                            mixedColor.forEach(item => mixedColors.push(item));
                        }
                        return mixedColors;
                    };

                    // 非透明色的个数
                    const n