From 37c2bb3985c5724e9c3d00472f6f3419d65266d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herv=C3=A9=20Poussineau?= <hpoussin@reactos.org>
Date: Sun, 8 May 2022 21:56:00 +0200
Subject: [PATCH] [WIN32SS] Handle panning in LDEVOBJ_bProbeAndCaptureDevmode

- search a graphic mode corresponding to real screen resolution (not virtual panning one)
- when capturing the selected mode, copy from input the virtual panning resolution
- when searching the best mode, also try without panning
---
 win32ss/gdi/eng/ldevobj.c | 53 +++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 7 deletions(-)

diff --git a/win32ss/gdi/eng/ldevobj.c b/win32ss/gdi/eng/ldevobj.c
index cb6a8bbbe32..43c0e0fdf94 100644
--- a/win32ss/gdi/eng/ldevobj.c
+++ b/win32ss/gdi/eng/ldevobj.c
@@ -688,6 +688,14 @@ LDEVOBJ_bGetClosestMode(
     if (LDEVOBJ_bProbeAndCaptureDevmode(pGraphicsDevice, RequestedMode, pSelectedMode, FALSE))
         return TRUE;
 
+    /* Remove panning (if specified) */
+    if (RequestedMode->dmFields & (DM_PANNINGWIDTH | DM_PANNINGHEIGHT))
+    {
+        RequestedMode->dmFields &= ~(DM_PANNINGWIDTH | DM_PANNINGHEIGHT);
+        if (LDEVOBJ_bProbeAndCaptureDevmode(pGraphicsDevice, RequestedMode, pSelectedMode, FALSE))
+            return TRUE;
+    }
+
     /* Fall back to first mode */
     WARN("Fall back to first available mode\n");
     *pSelectedMode = pGraphicsDevice->pDevModeList[0].pdm;
@@ -718,21 +726,36 @@ LDEVOBJ_bProbeAndCaptureDevmode(
     else
     {
         /* Search if requested mode exists */
+        DWORD dmPelsWidth = RequestedMode->dmPelsWidth;
+        DWORD dmPelsHeight = RequestedMode->dmPelsHeight;
+        DWORD dmFields = RequestedMode->dmFields;
+
+        if (dmFields & DM_PANNINGWIDTH)
+        {
+            dmFields |= DM_PELSWIDTH;
+            dmPelsWidth = RequestedMode->dmPanningWidth;
+        }
+        if (dmFields & DM_PANNINGHEIGHT)
+        {
+            dmFields |= DM_PELSHEIGHT;
+            dmPelsHeight = RequestedMode->dmPanningHeight;
+        }
+
         for (i = 0; i < pGraphicsDevice->cDevModes; i++)
         {
             pdmCurrent = pGraphicsDevice->pDevModeList[i].pdm;
 
             /* Compare asked DEVMODE fields
              * Only compare those that are valid in both DEVMODE structs */
-            dwFields = pdmCurrent->dmFields & RequestedMode->dmFields;
+            dwFields = pdmCurrent->dmFields & dmFields;
 
             /* For now, we only need those */
             if ((dwFields & DM_BITSPERPEL) &&
                 (pdmCurrent->dmBitsPerPel != RequestedMode->dmBitsPerPel)) continue;
             if ((dwFields & DM_PELSWIDTH) &&
-                (pdmCurrent->dmPelsWidth != RequestedMode->dmPelsWidth)) continue;
+                (pdmCurrent->dmPelsWidth != dmPelsWidth)) continue;
             if ((dwFields & DM_PELSHEIGHT) &&
-                (pdmCurrent->dmPelsHeight != RequestedMode->dmPelsHeight)) continue;
+                (pdmCurrent->dmPelsHeight != dmPelsHeight)) continue;
             if ((dwFields & DM_DISPLAYFREQUENCY) &&
                 (pdmCurrent->dmDisplayFrequency != RequestedMode->dmDisplayFrequency)) continue;
 
@@ -743,10 +766,10 @@ LDEVOBJ_bProbeAndCaptureDevmode(
         if (!pdmSelected)
         {
             WARN("Requested mode not found (%dx%dx%d %d Hz)\n",
-                RequestedMode->dmFields & DM_PELSWIDTH ? RequestedMode->dmPelsWidth : 0,
-                RequestedMode->dmFields & DM_PELSHEIGHT ? RequestedMode->dmPelsHeight : 0,
-                RequestedMode->dmFields & DM_BITSPERPEL ? RequestedMode->dmBitsPerPel : 0,
-                RequestedMode->dmFields & DM_DISPLAYFREQUENCY ? RequestedMode->dmDisplayFrequency : 0);
+                dmFields & DM_PELSWIDTH ? dmPelsWidth : 0,
+                dmFields & DM_PELSHEIGHT ? dmPelsHeight : 0,
+                dmFields & DM_BITSPERPEL ? RequestedMode->dmBitsPerPel : 0,
+                dmFields & DM_DISPLAYFREQUENCY ? RequestedMode->dmDisplayFrequency : 0);
             return FALSE;
         }
     }
@@ -762,6 +785,22 @@ LDEVOBJ_bProbeAndCaptureDevmode(
                   (PVOID)((ULONG_PTR)pdmSelected + pdmSelected->dmSize),
                   pdmSelected->dmDriverExtra);
 
+    if (!bSearchClosestMode)
+    {
+        if (RequestedMode->dmFields & DM_PANNINGWIDTH)
+        {
+            pdm->dmFields |= DM_PANNINGWIDTH;
+            pdm->dmPanningWidth = pdm->dmPelsWidth;
+            pdm->dmPelsWidth = RequestedMode->dmPelsWidth;
+        }
+        if (RequestedMode->dmFields & DM_PANNINGHEIGHT)
+        {
+            pdm->dmFields |= DM_PANNINGHEIGHT;
+            pdm->dmPanningHeight = pdm->dmPelsHeight;
+            pdm->dmPelsHeight = RequestedMode->dmPelsHeight;
+        }
+    }
+
     *pSelectedMode = pdm;
     return TRUE;
 }