Piotr Caban : ddraw: Improve GetScanLine stub so it' s usable for timing related tasks.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 5c85f96f33b71b8e8991d6ecbbafac9b1306cb4a
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=5c85f96f33b71b8e8991d6ecbbafac9b1306cb4a

Author: Piotr Caban <piotr at codeweavers.com>
Date:   Fri Apr  6 14:49:54 2012 +0200

ddraw: Improve GetScanLine stub so it's usable for timing related tasks.

---

 dlls/ddraw/ddraw.c |   19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/dlls/ddraw/ddraw.c b/dlls/ddraw/ddraw.c
index 20df445..2ef51da 100644
--- a/dlls/ddraw/ddraw.c
+++ b/dlls/ddraw/ddraw.c
@@ -1964,8 +1964,8 @@ static HRESULT WINAPI ddraw7_GetScanLine(IDirectDraw7 *iface, DWORD *Scanline)
 {
     struct ddraw *ddraw = impl_from_IDirectDraw7(iface);
     struct wined3d_display_mode mode;
-    static DWORD cur_scanline;
     static BOOL hide = FALSE;
+    DWORD time, frame_progress, lines;
 
     TRACE("iface %p, line %p.\n", iface, Scanline);
 
@@ -1982,11 +1982,20 @@ static HRESULT WINAPI ddraw7_GetScanLine(IDirectDraw7 *iface, DWORD *Scanline)
 
     /* Fake the line sweeping of the monitor */
     /* FIXME: We should synchronize with a source to keep the refresh rate */
-    *Scanline = cur_scanline++;
-    /* Assume 20 scan lines in the vertical blank */
-    if (cur_scanline >= mode.height + 20)
-        cur_scanline = 0;
 
+    /* Simulate a 60Hz display */
+    time = GetTickCount();
+    frame_progress = time & 15; /* time % (1000 / 60) */
+    if (!frame_progress)
+    {
+        *Scanline = 0;
+        return DDERR_VERTICALBLANKINPROGRESS;
+    }
+
+    /* Convert frame_progress to estimated scan line. Return any line from
+     * block determined by time. Some lines may be never returned */
+    lines = mode.height / 15;
+    *Scanline = (frame_progress - 1) * lines + time % lines;
     return DD_OK;
 }