[reactos] 01/01: [WIN32SS][NTDDRAW] Get complexity of visible region in DxEngGetDCState (#2604)

[Oleg Dubinskiy]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=855bf46399b0f3c852250c...

commit 855bf46399b0f3c852250cccf11fb655e536be78
Author:     Oleg Dubinskiy [e-mail]
AuthorDate: Fri May 1 16:57:11 2020 +0300
Commit:     GitHub [e-mail]
CommitDate: Fri May 1 15:57:11 2020 +0200

[WIN32SS][NTDDRAW] Get complexity of visible region in DxEngGetDCState (#2604)

CORE-7733

Get the complexity of visible region in the DxEngGetDCState() function, according to its remarks.
    This implementation returns a number of rectangles that make up the region, similarly to as it done in REGION_Complexity() function:
    https://git.reactos.org/?p=reactos.git;a=blob;f=win32ss/gdi/ntgdi/region.c;h...
    It is required by MS ddraw.dll when calling win32k/dxg functions during launching DirectDraw test or any DirectX 1 - 7 apps/games.
---
 win32ss/reactx/ntddraw/dxeng.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/win32ss/reactx/ntddraw/dxeng.c b/win32ss/reactx/ntddraw/dxeng.c
index f1c681f1e3f..24cb542643e 100644
--- a/win32ss/reactx/ntddraw/dxeng.c
+++ b/win32ss/reactx/ntddraw/dxeng.c
@@ -4,6 +4,7 @@
  * FILE:             win32ss/reactx/ntddraw/dxeng.c
  * PURPOSE:          Implementation of DxEng functions
  * PROGRAMMERS:      Magnus Olsen ([e-mail])
+ *                   Oleg Dubinskiy ([e-mail])
  */

#include <win32k.h>
@@ -442,7 +443,7 @@ DxEngSetHdevData(HDEV hDev,
 * Return one of the type values
 *
 * @remarks.
-* We do not have type 2 implemented yet
+* none
 *
 *--*/
 DWORD_PTR
@@ -463,7 +464,8 @@ DxEngGetDCState(HDC hDC,
                 retVal = (DWORD_PTR) pDC->fs & DC_FLAG_FULLSCREEN;
                 break;
             case 2:
-                UNIMPLEMENTED;
+                /* Return the number of rectangles in the visible region. */
+                retVal = (DWORD_PTR) pDC->prgnRao ? pDC->prgnRao->rdh.nCount : pDC->prgnVis->rdh.nCount;
                 break;
             case 3:
             {