Limit the zoom inside the box

plugins/MatrixVisualizer/Common/Zooming.cpp

@@ -95,6 +95,7 @@ void Zooming::move(double xStart, double xEnd, double yStart, double yEnd)
         int xEnd = (cblk->m_lcolnum - startCol) * xCoeff;
 
         xEnd = ( xEnd > x+1 ) ? xEnd : x+1;
+        float cblk_color = cblk->m_color;
 
         blok = m_matrix->m_bloktab + fbloknum;
         for (j = fbloknum; j < lbloknum; ++j, blok++)
@@ -111,11 +112,13 @@ void Zooming::move(double xStart, double xEnd, double yStart, double yEnd)
 
             yEnd = ( yEnd > y+1 ) ? yEnd : y+1;
 
+            float color = blok->m_color == -1. ? cblk_color : blok->m_color;
+
             for( m=x; m<xEnd; m++ )
-            {
-                for( n=y; n<yEnd; n++ )
                 {
-                    m_colors[m][n] = 0.0f;
+                for( n=y; n<yEnd; n++ )
+                    {
+                        m_colors[m][n] = color;
                 }
             }
         }