Invert custom viewport y position when suitable

Author: sonninnos

gfx/video_driver.c

@@ -2141,6 +2141,9 @@ void video_viewport_get_scaled_aspect2(struct video_viewport *vp,
          x                 = custom_vp->x;
          y                 = custom_vp->y;
 
+         if (!y_down)
+            y = -y;
+
          padding_x         = vp_width - custom_vp->width;
          padding_y         = vp_height - custom_vp->height;
 
@@ -2476,6 +2479,9 @@ void video_viewport_get_scaled_integer(struct video_viewport *vp,
          x         = custom_vp->x;
          y         = custom_vp->y;
 
+         if (!y_down)
+            y = -y;
+
          padding_x = width - custom_vp->width;
          padding_y = height - custom_vp->height;