From acce0bc6f8bb86c2b53ee13a2b49098dd4c6817c Mon Sep 17 00:00:00 2001 From: sloop Date: Fri, 12 Aug 2016 22:07:56 +0800 Subject: [PATCH] Update value compute --- CustomView/Advance/[10]Matrix_Method.md | 34 +++++++++++++++---------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/CustomView/Advance/[10]Matrix_Method.md b/CustomView/Advance/[10]Matrix_Method.md index 74457a1..06160a8 100644 --- a/CustomView/Advance/[10]Matrix_Method.md +++ b/CustomView/Advance/[10]Matrix_Method.md @@ -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); - - // 构造一个matrix，x坐标缩放0.5 - Matrix matrix = new Matrix(); - matrix.setScale(0.5f, 1f); - - Log.i(TAG, "mapRadius: "+rect.toString()); - - matrix.mapRect(rect); - - Log.i(TAG, "mapRadius: "+rect.toString()); + RectF rect = new RectF(400, 400, 1000, 800); + + // 构造一个matrix + Matrix matrix = new Matrix(); + matrix.setScale(0.5f, 1f); + matrix.postSkew(1,0); + + Log.i(TAG, "mapRadius: "+rect.toString()); + + boolean result = matrix.mapRect(rect); + + 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**