The scissoring needs to take into account the window scale.
cairo_region_get_extents (clip_region, &clip_rect);
- glScissor (clip_rect.x, FLIP_Y (clip_rect.y + clip_rect.height),
- clip_rect.width, clip_rect.height);
+ glScissor (clip_rect.x * window_scale, FLIP_Y ((clip_rect.y + clip_rect.height) * window_scale),
+ clip_rect.width * window_scale, clip_rect.height * window_scale);
n_quads = 0;
n_rects = cairo_region_num_rectangles (clip_region);