Android 颜色渲染(十) ComposeShader组合渲染

版权声明：本文为博主原创文章，未经博主允许不得转载。

目录(?)[+]

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);

    }

}