[PATCH 3/6] wined3d: Split clears for different size resources in ffp_blitter_clear().

[Józef Kucia]

We cannot reliably clear attachments of different sizes using a single glClear()
command. The OpenGL spec says:

  "If the attachment sizes are not all identical, the results of rendering are
  defined only within the largest area that can fit in all of the attachments.
  This area is defined as the intersection of rectangles having a lower left of
  (0, 0) and an upper right of (width, height) for each attachment. Contents of
  attachments outside this area are undefined after execution of a rendering
  command (as defined in section 2.4)."

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=46067
Signed-off-by: Józef Kucia <jkucia at codeweavers.com>
---
 dlls/wined3d/surface.c | 61 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 58 insertions(+), 3 deletions(-)

diff --git a/dlls/wined3d/surface.c b/dlls/wined3d/surface.c
index a36d010e7930..5dbac1c6aec9 100644
--- a/dlls/wined3d/surface.c
+++ b/dlls/wined3d/surface.c
@@ -2052,8 +2052,12 @@ static void ffp_blitter_clear(struct wined3d_blitter *blitter, struct wined3d_de
         unsigned int rt_count, const struct wined3d_fb_state *fb, unsigned int rect_count, const RECT *clear_rects,
         const RECT *draw_rect, DWORD flags, const struct wined3d_color *colour, float depth, DWORD stencil)
 {
+    BOOL have_previous_rect = FALSE, have_identical_size = TRUE;
     struct wined3d_rendertarget_view *view;
+    struct wined3d_fb_state tmp_fb;
+    unsigned int next_rt_count = 0;
     struct wined3d_blitter *next;
+    RECT previous_rect, rect;
     DWORD next_flags = 0;
     unsigned int i;
 
@@ -2071,6 +2075,8 @@ static void ffp_blitter_clear(struct wined3d_blitter *blitter, struct wined3d_de
             {
                 next_flags |= WINED3DCLEAR_TARGET;
                 flags &= ~WINED3DCLEAR_TARGET;
+                next_rt_count = rt_count;
+                rt_count = 0;
                 break;
             }
 
@@ -2089,11 +2095,60 @@ static void ffp_blitter_clear(struct wined3d_blitter *blitter, struct wined3d_de
     }
 
     if (flags)
-        device_clear_render_targets(device, flags & WINED3DCLEAR_TARGET ? rt_count : 0, fb, rect_count,
-                clear_rects, draw_rect, flags, colour, depth, stencil);
+    {
+        for (i = 0; i < rt_count; ++i)
+        {
+            if (!(view = fb->render_targets[i]))
+                continue;
+
+            SetRect(&rect, 0, 0, view->width, view->height);
+            IntersectRect(&rect, draw_rect, &rect);
+            if (have_previous_rect && !EqualRect(&previous_rect, &rect))
+                have_identical_size = FALSE;
+            previous_rect = rect;
+            have_previous_rect = TRUE;
+        }
+        if (flags & (WINED3DCLEAR_ZBUFFER | WINED3DCLEAR_STENCIL))
+        {
+            view = fb->depth_stencil;
+
+            SetRect(&rect, 0, 0, view->width, view->height);
+            IntersectRect(&rect, draw_rect, &rect);
+            if (have_previous_rect && !EqualRect(&previous_rect, &rect))
+                have_identical_size = FALSE;
+            previous_rect = rect;
+            have_previous_rect = TRUE;
+        }
+
+        if (have_identical_size)
+        {
+            device_clear_render_targets(device, rt_count, fb, rect_count,
+                    clear_rects, draw_rect, flags, colour, depth, stencil);
+        }
+        else
+        {
+            for (i = 0; i < rt_count; ++i)
+            {
+                if (!(view = fb->render_targets[i]))
+                    continue;
+
+                tmp_fb.render_targets[0] = view;
+                tmp_fb.depth_stencil = NULL;
+                device_clear_render_targets(device, 1, &tmp_fb, rect_count,
+                        clear_rects, draw_rect, WINED3DCLEAR_TARGET, colour, depth, stencil);
+            }
+            if (flags & (WINED3DCLEAR_ZBUFFER | WINED3DCLEAR_STENCIL))
+            {
+                tmp_fb.render_targets[0] = NULL;
+                tmp_fb.depth_stencil = fb->depth_stencil;
+                device_clear_render_targets(device, 0, &tmp_fb, rect_count,
+                        clear_rects, draw_rect, flags & ~WINED3DCLEAR_TARGET, colour, depth, stencil);
+            }
+        }
+    }
 
     if (next_flags && (next = blitter->next))
-        next->ops->blitter_clear(next, device, next_flags & WINED3DCLEAR_TARGET ? rt_count : 0, fb, rect_count,
+        next->ops->blitter_clear(next, device, next_rt_count, fb, rect_count,
                 clear_rects, draw_rect, next_flags, colour, depth, stencil);
 }
 
-- 
2.19.2