RageSurfaceUtils::FlipVertically

stepmania/src/RageDisplay_OGL.cpp

@@ -830,17 +830,8 @@ RageSurface* RageDisplay_OGL::CreateScreenshot()
 	             GL_UNSIGNED_BYTE, image->pixels);
 	AssertNoGLError();
 
-	// flip vertically
-	int pitch = image->pitch;
-	int bytes_per_row = image->format->BytesPerPixel * width;
-	char *row = new char[bytes_per_row];
-	for( int y=0; y<wind->GetVideoModeParams().height/2; y++ )
-	{
-		memcpy( row, (char *)image->pixels + pitch * y, bytes_per_row );
-		memcpy( (char *)image->pixels + pitch * y, (char *)image->pixels + pitch * (height-1-y), bytes_per_row );
-		memcpy( (char *)image->pixels + pitch * (height-1-y), row, bytes_per_row  );
-	}
-	delete [] row;
+	RageSurfaceUtils::FlipVertically( image );
+
 	return image;
 }
 

stepmania/src/RageSurfaceUtils.cpp

@@ -950,6 +950,23 @@ void RageSurfaceUtils::ApplyHotPinkColorKey( RageSurface *&img )
 	}
 }
 
+void RageSurfaceUtils::FlipVertically( RageSurface *img )
+{
+	const int pitch = img->pitch;
+	const int bytes_per_row = img->format->BytesPerPixel * img->w;
+	char *row = new char[bytes_per_row];
+
+	for( int y=0; y < img->h/2; y++ )
+	{
+		int y2 = img->h-1-y;
+		memcpy( row, img->pixels + pitch * y, bytes_per_row );
+		memcpy( img->pixels + pitch * y, img->pixels + pitch * y2, bytes_per_row );
+		memcpy( img->pixels + pitch * y2, row, bytes_per_row  );
+	}
+
+	delete [] row;
+}
+
 /*
  * (c) 2001-2004 Glenn Maynard, Chris Danford
  * All rights reserved.

stepmania/src/RageSurfaceUtils.h

@@ -57,6 +57,7 @@ namespace RageSurfaceUtils
 	RageSurface *MakeDummySurface( int height, int width );
 
 	void ApplyHotPinkColorKey( RageSurface *&img );
+	void FlipVertically( RageSurface *img );
 };
 
 #endif