android TileMode效果 水波纹效果 环形渐变

TileMode是一个枚举类，位于android.graphics.Shader类里面

android源码

    public enum TileMode {
        /**
         * replicate the edge color if the shader draws outside of its
         * original bounds
         */
        CLAMP   (0),
        /**
         * repeat the shader‘s image horizontally and vertically
         */
        REPEAT  (1),
        /**
         * repeat the shader‘s image horizontally and vertically, alternating
         * mirror images so that adjacent images always seam
         */
        MIRROR  (2);

        TileMode(int nativeInt) {
            this.nativeInt = nativeInt;
        }
        final int nativeInt;
    }

今天主要测试这几个属性的效果。先将部分测试代码贴出来：

    private void drawTextRadial(Canvas canvas, RectF rectF) {
        canvas.save();

        float centerX = rectF.centerX();
        float centerY = rectF.centerY();
        float radius = rectF.height();
        RadialGradient gradient = new RadialGradient(centerX, centerY, radius, Color.GREEN, Color.RED, TileMode.CLAMP); 

        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStyle(Paint.Style.FILL);
        paint.setTextSize(TEXTSIZE);
        paint.setFakeBoldText(true);
        paint.setShader(gradient);
        canvas.drawText(mText, rectF.left, rectF.bottom, paint);

        canvas.restore();
    }

CLAMP看意思是 如果超出规定的区域就重复边缘的效果，看效果：

REPEAT的意思是 在竖直和水平方向上重复，看效果：

MIRROR的意思是 在竖直和水平方向上重复，交替的显示（翻译的貌似不对）看效果：