Android 颜色渲染(十) ComposeShader组合渲染

转自：http://blog.csdn.net/t12x3456/article/details/10366131

Android 颜色处理(十) ComposeShader组合渲染

public ComposeShader(Shader shaderA,Shader shaderB, Xfermode mode)

Parameters

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

public ComposeShader(Shader shaderA,Shader shaderB, PorterDuff.Mode mode)

Parameters

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:

[java] view
plain copy

package com.tony.testshader;

import android.os.Bundle;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.view.Menu;

import android.widget.SeekBar;

import android.widget.SeekBar.OnSeekBarChangeListener;

public class MainActivity extends Activity implements OnSeekBarChangeListener{

private SweepGradientView sweepGradientView;

private ComposeShaderView composeShaderView;

private SeekBar seekbar;

private PorterDuffView porterDuffView;

private int currentId;

private WaterRipplesView waterRipplesView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

composeShaderView = new ComposeShaderView(this);

setContentView(composeShaderView);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

}

ComposeShaderView:

[java] view
plain copy

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);

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

// 绘制混合渲染效果

mPaint.setShader(mComposeShader);

canvas.drawCircle(240, 360, 200, mPaint);

}

}