Do not draw sprites with backwards/empty RECTs

Previously, each backend had to guard against it, which is messy,
results in duplication, and leaves new backends open to the risk
of not guarding against it (the Wii U GX2 renderer didn't).

src/Draw.cpp

@@ -419,6 +419,10 @@ void BackupSurface(SurfaceID surf_no, const RECT *rect)
 	scaled_rect.right = rect->right * magnification;
 	scaled_rect.bottom = rect->bottom * magnification;
 
+	// Do not draw invalid RECTs
+	if (rcWork->right <= rcWork->left || rcWork->bottom <= rcWork->top)
+		return;
+
 	RenderBackend_Blit(framebuffer, &scaled_rect, surf[surf_no], scaled_rect.left, scaled_rect.top, FALSE);
 }
 
@@ -454,6 +458,10 @@ void PutBitmap3(const RECT *rcView, int x, int y, const RECT *rect, SurfaceID su
 	rcWork.right *= magnification;
 	rcWork.bottom *= magnification;
 
+	// Do not draw invalid RECTs
+	if (rcWork->right <= rcWork->left || rcWork->bottom <= rcWork->top)
+		return;
+
 	RenderBackend_Blit(surf[surf_no], &rcWork, framebuffer, x * magnification, y * magnification, TRUE);
 }
 
@@ -489,6 +497,10 @@ void PutBitmap4(const RECT *rcView, int x, int y, const RECT *rect, SurfaceID su
 	rcWork.right *= magnification;
 	rcWork.bottom *= magnification;
 
+	// Do not draw invalid RECTs
+	if (rcWork->right <= rcWork->left || rcWork->bottom <= rcWork->top)
+		return;
+
 	RenderBackend_Blit(surf[surf_no], &rcWork, framebuffer, x * magnification, y * magnification, FALSE);
 }
 
@@ -501,6 +513,10 @@ void Surface2Surface(int x, int y, const RECT *rect, int to, int from)
 	rcWork.right = rect->right * magnification;
 	rcWork.bottom = rect->bottom * magnification;
 
+	// Do not draw invalid RECTs
+	if (rcWork->right <= rcWork->left || rcWork->bottom <= rcWork->top)
+		return;
+
 	RenderBackend_Blit(surf[from], &rcWork, surf[to], x * magnification, y * magnification, TRUE);
 }
 
@@ -522,6 +538,10 @@ void CortBox(const RECT *rect, unsigned long col)
 	const unsigned char green = (col >> 8) & 0xFF;
 	const unsigned char blue = (col >> 16) & 0xFF;
 
+	// Do not draw invalid RECTs
+	if (dst_rect->right <= dst_rect->left || dst_rect->bottom <= dst_rect->top)
+		return;
+
 	RenderBackend_ColourFill(framebuffer, &dst_rect, red, green, blue);
 }
 
@@ -539,6 +559,10 @@ void CortBox2(const RECT *rect, unsigned long col, SurfaceID surf_no)
 	const unsigned char green = (col >> 8) & 0xFF;
 	const unsigned char blue = (col >> 16) & 0xFF;
 
+	// Do not draw invalid RECTs
+	if (dst_rect->right <= dst_rect->left || dst_rect->bottom <= dst_rect->top)
+		return;
+
 	RenderBackend_ColourFill(surf[surf_no], &dst_rect, red, green, blue);
 }