获取图片倒影效果

获取图片倒影效果

/**
     * 获取传入图片的倒影
     * 
     * @param originalImage 原始图片
     * @param reflectionGap 原始图片与倒影图片的间距
     * @param percentage     倒影是原图的高度的百分比 . 0< percentage < 1 
     * @param onlyReflect      true, 只返回倒影图片，倒影有蒙板效果; 
     *                         false, 返回原图 + 间距 + 倒影(从上到下的顺序), 间距和倒影都有蒙板效果
     * @return Bitmap;
     */
    public static Bitmap createReflectionImageWithOrigin(Bitmap originalImage, int reflectionGap, float percentage, boolean onlyReflect){ 
        
        int width = originalImage.getWidth(); 
        int height = originalImage.getHeight(); 
        int preHeight = (int)(height * percentage); 
        
        Matrix matrix = new Matrix(); 
        matrix.preScale(1, -1); // 图片矩阵变换（从低部向顶部的倒影）

        Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, (height - preHeight), width, preHeight, matrix, false); // 截取原图下半部分

        Bitmap reflectionBitmp = Bitmap.createBitmap(width, preHeight, Config.ARGB_8888);
        
        Canvas canvas = new Canvas(reflectionBitmp);// 绘制倒影图 
        Paint defaultPaint = new Paint();
        canvas.drawRect(0, height / 5, width, height / 5, defaultPaint);
        canvas.drawBitmap(reflectionImage, 0, 0, null);
        
        //给倒影图片添加遮罩效果
        Paint paint = new Paint(); 
        LinearGradient shader = new LinearGradient(0, 0, 0, reflectionBitmp.getHeight(), 0x70ffffff, 0x00ffffff, TileMode.CLAMP); 
        paint.setShader(shader); // 线性渐变效果
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); // 倒影遮罩效果
        canvas.drawRect(0, 0, width, reflectionBitmp.getHeight(), paint); // 绘制倒影的阴影效果
        
        Bitmap tempReflectionBitmap = reflectionBitmp;
        
        if (! onlyReflect) {
            tempReflectionBitmap = Bitmap.createBitmap(width, (height + preHeight), Config.ARGB_8888); // 创建倒影图片
            canvas = new Canvas(tempReflectionBitmap);// 绘制倒影图（原图 + 间距 + 倒影） 
            canvas.drawBitmap(originalImage, 0, 0, null); // 绘制原图
            canvas.drawRect(0, height,width,height + reflectionGap, defaultPaint);  // 绘制原图与倒影的间距
            canvas.drawRect(0, height, width, height + reflectionGap, paint); // 绘制间距的阴影效果
            canvas.drawBitmap(reflectionBitmp, 0, height + reflectionGap, null); // 绘制倒影图
        }
        
        return tempReflectionBitmap; 
    }