BookPageView.java 文件源码

/**
     * 绘制A区域右阴影
     * @param canvas
     */
    private void drawPathARightShadow(Canvas canvas, Path pathA){
        canvas.restore();
        canvas.save();

        float viewDiagonalLength = (float) Math.hypot(viewWidth, viewHeight);//view对角线长度
        int left = (int) h.x;
        int right = (int) (h.x + viewDiagonalLength*10);//需要足够长的长度
        int top;
        int bottom;

        GradientDrawable gradientDrawable;
        if (style.equals(STYLE_TOP_RIGHT)) {
            gradientDrawable = drawableRightTopRight;
            top = (int) (h.y- rPathAShadowDis /2);
            bottom = (int) h.y;
        } else {
            gradientDrawable = drawableRightLowerRight;
            top = (int) h.y;
            bottom = (int) (h.y+ rPathAShadowDis /2);
        }
        gradientDrawable.setBounds(left,top,right,bottom);

        Path mPath = new Path();
        mPath.moveTo(a.x- Math.max(rPathAShadowDis, lPathAShadowDis) /2,a.y);
//        mPath.lineTo(i.x,i.y);
        mPath.lineTo(h.x,h.y);
        mPath.lineTo(a.x,a.y);
        mPath.close();
        canvas.clipPath(pathA);
        canvas.clipPath(mPath, Region.Op.INTERSECT);

        float mDegrees = (float) Math.toDegrees(Math.atan2(a.y-h.y, a.x-h.x));
        canvas.rotate(mDegrees, h.x, h.y);
        gradientDrawable.draw(canvas);
    }