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Update value compute

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sloop
2016-08-12 22:07:56 +08:00
parent 60ddd57d37
commit acce0bc6f8
1 changed files with 20 additions and 14 deletions
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26
CustomView/Advance/[10]Matrix_Method.md
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@@ -296,31 +296,37 @@ boolean mapRect (RectF dst, RectF src)
测量矩形变换后位置。
(1) `boolean mapRect (RectF rect)` 测量rect并将测量结果放入rect中，返回值是判断矩形(Rect)变换后是否仍为矩形。
(1) `boolean mapRect (RectF rect)` 测量rect并将测量结果放入rect中，返回值是判断矩形经过变换后是否仍为矩形。
示例：
``` java
RectF rect = new RectF(400, 400, 1000, 800);
RectF rect = new RectF(400, 400, 1000, 800);
// 构造一个matrix，x坐标缩放0.5
Matrix matrix = new Matrix();
matrix.setScale(0.5f, 1f);
// 构造一个matrix
Matrix matrix = new Matrix();
matrix.setScale(0.5f, 1f);
matrix.postSkew(1,0);
Log.i(TAG, "mapRadius: "+rect.toString());
Log.i(TAG, "mapRadius: "+rect.toString());
matrix.mapRect(rect);
boolean result = matrix.mapRect(rect);
Log.i(TAG, "mapRadius: "+rect.toString());
Log.i(TAG, "mapRadius: "+rect.toString());
Log.e(TAG, "isRect: "+ result);
```
结果：
```
RectF(400.0, 400.0, 1000.0, 800.0)
RectF(200.0, 400.0, 500.0, 800.0)
mapRadius: RectF(400.0, 400.0, 1000.0, 800.0)
mapRadius: RectF(600.0, 400.0, 1300.0, 800.0)
isRect: false
```
>
由于使用了错切，所以返回结果为false。
**4.mapVectors**