LinearGradient线性渲染

[java]  view plain copy

 package shader.yb;

 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.LinearGradient;
 import android.graphics.Paint;
 import android.graphics.Shader;
 import android.view.View;

 /**
  * @author yubin
  * @version 2012-8-14 上午10:45:28
  **/
 public class myGameView extends View implements Runnable {
     int bitwidth = 0;
     int bitheight = 0;
     Paint mPaint = null;
     // 线性渐变渲染
     Shader mLinearGradient1 = null;
     // 线性渐变渲染
     Shader mLinearGradient2 = null;
     // 线性渐变渲染
     Shader mLinearGradient3 = null;

     public myGameView(Context context) {
         super(context);
         // 创建LinearGradient并设置渐变颜色数组
         // 第一个,第二个参数表示渐变起点 可以设置起点终点在对角等任意位置
         // 第三个,第四个参数表示渐变终点
         // 第五个参数表示渐变颜色
         // 第六个参数可以为空,表示坐标,值为0-1 new float[] {0.25f, 0.5f, 0.75f, 1 }
         // 如果这是空的，颜色均匀分布，沿梯度线。
         // 第七个表示平铺方式
         // CLAMP重复最后一个颜色至最后
         // MIRROR重复着色的图像水平或垂直方向已镜像方式填充会有翻转效果
         // REPEAT重复着色的图像水平或垂直方向
         mLinearGradient1 = new LinearGradient(0, 0, 0, 100, new int[] {
                 Color.RED, Color.GREEN, Color.BLUE, Color.WHITE }, null,
                 Shader.TileMode.CLAMP);
         mLinearGradient2 = new LinearGradient(0, 0, 0, 100, new int[] {
                 Color.RED, Color.GREEN, Color.BLUE, Color.WHITE }, null,
                 Shader.TileMode.MIRROR);
         mLinearGradient3 = new LinearGradient(0, 0, 0, 100, new int[] {
                 Color.RED, Color.GREEN, Color.BLUE, Color.WHITE }, null,
                 Shader.TileMode.REPEAT);
         mPaint = new Paint();
         new Thread(this).start();
     }

     @Override
     protected void onDraw(Canvas canvas) {
         // LinearGradient的高度只有100而绘制的矩形有200所以才会有重复
         // 如果高度两者相同clamp重复是看不出效果的
         Paint paint = new Paint();
         paint.setTextSize(20);
         paint.setColor(Color.WHITE);
         // 绘制渐变的矩形
         mPaint.setShader(mLinearGradient1);
         canvas.drawRect(0, 0, 200, 200, mPaint);
         canvas.drawText("CLAMP", 0, 200 + 20, paint);
         // 绘制渐变的矩形
         mPaint.setShader(mLinearGradient2);
         canvas.drawRect(0, 250, 200, 450, mPaint);
         canvas.drawText("MIRROR", 0, 450 + 20, paint);
         // 绘制渐变的矩形
         mPaint.setShader(mLinearGradient3);
         canvas.drawRect(0, 500, 200, 700, mPaint);
         canvas.drawText("REPEAT", 0, 700 + 20, paint);
     }

     @Override
     public void run() {
         while(!Thread.currentThread().isInterrupted()) {
             try {
                 Thread.sleep(100);
             }
             catch(Exception e) {
                 Thread.currentThread().interrupt();
             }
             postInvalidate();
         }
     }
 }