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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:
- 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:
- 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);
- }
- }