Android 色彩渲染(十) ComposeShader组合渲染

Android 颜色渲染(十) ComposeShader组合渲染

Android 颜色处理(十) ComposeShader组合渲染

shaderA渲染器A,Shader及其子类对象shaderB渲染器B,Shader及其子类对象mode 两种渲染器组合的模式,Xfermode对象

shaderA渲染器A,Shader及其子类对象shaderB渲染器B,Shader及其子类对象mode.两种渲染器组合的模式,ProterDuff.Mode对象

Xfermode及ProterBuff.Mode具体含义见上一篇:

Android 颜色渲染(八) PorterDuff及Xfermode详解

  ComposeShader,和AnimationSet的用法相似.是可以将两种颜色渲染器的效果进行组合:

                                            

以上图像由BimtmapShader和LinearGradient两种效果组合绘制,其中位图渲染 平铺模式使用的为镜像模式,  组合渲染使用了ProterDuff叠加模式,具体见如下代码:

MainActivity:

package com.tony.testshader;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.ComposeShader;import android.graphics.LinearGradient;import android.graphics.Paint;import android.graphics.PorterDuff;import android.graphics.Shader;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.ShapeDrawable;import android.util.AttributeSet;import android.view.View;public class ComposeShaderView extends View {Bitmap mBitmap = null;int bitwidth = 0;int bitheight = 0;Paint mPaint = null;// bitmap渲染Shader mBitmapShader = null;// 线性渐变渲染Shader mLinearGradient = null;// 混合渲染Shader mComposeShader = null;ShapeDrawable mShapeDrawable = null;public ComposeShaderView(Context context) {super(context);// 装载资源          mBitmap = ((BitmapDrawable) getResources().getDrawable(R.drawable.list_top))                  .getBitmap();          // 得到宽高          bitwidth = mBitmap.getWidth();          bitheight = mBitmap.getHeight();          // 创建BitmapShader对象          mBitmapShader = new BitmapShader(mBitmap, Shader.TileMode.MIRROR,                  Shader.TileMode.MIRROR);          // 创建LinearGradient并设置渐变颜色数组,平铺效果为镜像          mLinearGradient = new LinearGradient(0, 0, 0, 100, new int[] {                  Color.WHITE, Color.LTGRAY, Color.TRANSPARENT, Color.GREEN }, null,                  Shader.TileMode.MIRROR);                  // 混合渲染 将两个效果叠加,使用PorterDuff叠加模式         mComposeShader = new ComposeShader(mBitmapShader, mLinearGradient,  PorterDuff.Mode.MULTIPLY);          mPaint = new Paint();  }public ComposeShaderView(Context context, AttributeSet attrs) {super(context, attrs);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);   // 绘制混合渲染效果          mPaint.setShader(mComposeShader);          canvas.drawCircle(240, 360, 200, mPaint);}}