sw_engien renderer: ++safety

+exceptional handling for the drawing region.

diff --git a/src/lib/sw_engine/tvgSwRenderer.cpp b/src/lib/sw_engine/tvgSwRenderer.cpp
index 61c9156..70c7768 100644 (file)
--- a/src/lib/sw_engine/tvgSwRenderer.cpp
+++ b/src/lib/sw_engine/tvgSwRenderer.cpp
@@ -53,6 +53,8 @@ struct SwTask : Task
         region.y = bbox.min.y > 0 ? bbox.min.y : 0;
         region.w = bbox.max.x - region.x;
         region.h = bbox.max.y - region.y;
+        if (region.w < 0) region.w = 0;
+        if (region.h < 0) region.h = 0;
 
         return region;
     }