Add codes to prevent underflow

Change-Id: Id5d5205f587885c288744d7315ba966f0357c951

diff --git a/dali-toolkit/internal/visuals/npatch-loader.cpp b/dali-toolkit/internal/visuals/npatch-loader.cpp
index f23f1ca..8bc050f 100644 (file)
--- a/dali-toolkit/internal/visuals/npatch-loader.cpp
+++ b/dali-toolkit/internal/visuals/npatch-loader.cpp
@@ -79,10 +79,10 @@ std::size_t NPatchLoader::Load( const std::string& url, const Rect< int >& borde
     data->textureSet = mCache[ cachedIndex ]->textureSet;
 
     NinePatchImage::StretchRanges stretchRangesX;
-    stretchRangesX.PushBack( Uint16Pair( border.left, data->croppedWidth - border.right ) );
+    stretchRangesX.PushBack( Uint16Pair( border.left, ( (data->croppedWidth >= static_cast< unsigned int >( border.right )) ? data->croppedWidth - border.right : 0 ) ) );
 
     NinePatchImage::StretchRanges stretchRangesY;
-    stretchRangesY.PushBack( Uint16Pair( border.top, data->croppedHeight - border.bottom ) );
+    stretchRangesY.PushBack( Uint16Pair( border.top, ( (data->croppedHeight >= static_cast< unsigned int >( border.bottom )) ? data->croppedHeight - border.bottom : 0 ) ) );
 
     data->stretchPixelsX = stretchRangesX;
     data->stretchPixelsY = stretchRangesY;
@@ -137,10 +137,10 @@ std::size_t NPatchLoader::Load( const std::string& url, const Rect< int >& borde
       data->textureSet.SetTexture( 0u, texture );
 
       NinePatchImage::StretchRanges stretchRangesX;
-      stretchRangesX.PushBack( Uint16Pair( border.left, data->croppedWidth - border.right ) );
+      stretchRangesX.PushBack( Uint16Pair( border.left, ( (data->croppedWidth >= static_cast< unsigned int >( border.right )) ? data->croppedWidth - border.right : 0 ) ) );
 
       NinePatchImage::StretchRanges stretchRangesY;
-      stretchRangesY.PushBack( Uint16Pair( border.top, data->croppedHeight - border.bottom ) );
+      stretchRangesY.PushBack( Uint16Pair( border.top, ( (data->croppedHeight >= static_cast< unsigned int >( border.bottom )) ? data->croppedHeight - border.bottom : 0 ) ) );
 
       data->stretchPixelsX = stretchRangesX;
       data->stretchPixelsY = stretchRangesY;

diff --git a/dali-toolkit/internal/visuals/npatch/npatch-visual.cpp b/dali-toolkit/internal/visuals/npatch/npatch-visual.cpp
index da50b3e..f61848c 100755 (executable)
--- a/dali-toolkit/internal/visuals/npatch/npatch-visual.cpp
+++ b/dali-toolkit/internal/visuals/npatch/npatch-visual.cpp
@@ -570,8 +570,8 @@ void NPatchVisual::ApplyTextureAndUniforms()
       Uint16Pair stretchX = data->stretchPixelsX[ 0 ];
       Uint16Pair stretchY = data->stretchPixelsY[ 0 ];
 
-      uint16_t stretchWidth = stretchX.GetY() - stretchX.GetX();
-      uint16_t stretchHeight = stretchY.GetY() - stretchY.GetX();
+      uint16_t stretchWidth = ( stretchX.GetY() >= stretchX.GetX() ) ? stretchX.GetY() - stretchX.GetX() : 0;
+      uint16_t stretchHeight = ( stretchY.GetY() >= stretchY.GetX() ) ? stretchY.GetY() - stretchY.GetX() : 0;
 
       mImpl->mRenderer.RegisterProperty( "uFixed[0]", Vector2::ZERO );
       mImpl->mRenderer.RegisterProperty( "uFixed[1]", Vector2( stretchX.GetX(), stretchY.GetX()) );