From 1594a20b943703fb7c9ec3d8ab420248dcb1af04 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Tue, 11 Dec 2018 15:48:57 +0100
Subject: [PATCH] [dxgi] Add new functions to change the display mode of a
 monitor

---
 src/dxgi/dxgi_monitor.cpp | 84 +++++++++++++++++++++++++++++++++++++++
 src/dxgi/dxgi_monitor.h   | 35 ++++++++++++++++
 2 files changed, 119 insertions(+)

diff --git a/src/dxgi/dxgi_monitor.cpp b/src/dxgi/dxgi_monitor.cpp
index 0547a4b8..9af164ad 100644
--- a/src/dxgi/dxgi_monitor.cpp
+++ b/src/dxgi/dxgi_monitor.cpp
@@ -6,6 +6,27 @@ namespace dxvk {
   std::unordered_map<HMONITOR, DXGI_VK_MONITOR_DATA> g_monitorData;
 
 
+  uint32_t GetMonitorFormatBpp(DXGI_FORMAT Format) {
+    switch (Format) {
+      case DXGI_FORMAT_R8G8B8A8_UNORM:
+      case DXGI_FORMAT_B8G8R8A8_UNORM:
+      case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
+      case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB:
+      case DXGI_FORMAT_R10G10B10A2_UNORM:
+        return 32;
+      
+      case DXGI_FORMAT_R16G16B16A16_FLOAT:
+        return 64;
+      
+      default:
+        Logger::warn(str::format(
+          "GetMonitorFormatBpp: Unknown format: ",
+          Format));
+        return 32;
+    }
+  }
+
+
   HRESULT InitMonitorData(
           HMONITOR                hMonitor,
     const DXGI_VK_MONITOR_DATA*   pData) {
@@ -44,4 +65,67 @@ namespace dxvk {
     g_monitorMutex.unlock();
   }
   
+
+  HRESULT GetMonitorDisplayMode(
+          HMONITOR                hMonitor,
+          DWORD                   ModeNum,
+          DXGI_MODE_DESC*         pMode) {
+    ::MONITORINFOEXW monInfo;
+    monInfo.cbSize = sizeof(monInfo);
+
+    if (!::GetMonitorInfoW(hMonitor, reinterpret_cast<MONITORINFO*>(&monInfo))) {
+      Logger::err("DXGI: Failed to query monitor info");
+      return E_FAIL;
+    }
+    
+    DEVMODEW devMode = { };
+    devMode.dmSize = sizeof(devMode);
+    
+    if (!::EnumDisplaySettingsW(monInfo.szDevice, ModeNum, &devMode))
+      return DXGI_ERROR_NOT_FOUND;
+    
+    pMode->Width            = devMode.dmPelsWidth;
+    pMode->Height           = devMode.dmPelsHeight;
+    pMode->RefreshRate      = { devMode.dmDisplayFrequency, 1 };
+    pMode->Format           = DXGI_FORMAT_R8G8B8A8_UNORM_SRGB; // FIXME
+    pMode->ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_PROGRESSIVE;
+    pMode->Scaling          = DXGI_MODE_SCALING_UNSPECIFIED;
+    return S_OK;
+  }
+  
+    
+  HRESULT SetMonitorDisplayMode(
+          HMONITOR                hMonitor,
+    const DXGI_MODE_DESC*         pMode) {
+    ::MONITORINFOEXW monInfo;
+    monInfo.cbSize = sizeof(monInfo);
+
+    if (!::GetMonitorInfoW(hMonitor, reinterpret_cast<MONITORINFO*>(&monInfo))) {
+      Logger::err("DXGI: Failed to query monitor info");
+      return E_FAIL;
+    }
+    
+    DEVMODEW devMode = { };
+    devMode.dmSize       = sizeof(devMode);
+    devMode.dmFields     = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL;
+    devMode.dmPelsWidth  = pMode->Width;
+    devMode.dmPelsHeight = pMode->Height;
+    devMode.dmBitsPerPel = GetMonitorFormatBpp(pMode->Format);
+    
+    if (pMode->RefreshRate.Numerator != 0)  {
+      devMode.dmFields |= DM_DISPLAYFREQUENCY;
+      devMode.dmDisplayFrequency = pMode->RefreshRate.Numerator
+                                 / pMode->RefreshRate.Denominator;
+    }
+    
+    Logger::info(str::format("DXGI: Setting display mode: ",
+      devMode.dmPelsWidth, "x", devMode.dmPelsHeight, "@",
+      devMode.dmDisplayFrequency));
+    
+    LONG status = ::ChangeDisplaySettingsExW(
+      monInfo.szDevice, &devMode, nullptr, CDS_FULLSCREEN, nullptr);
+    
+    return status == DISP_CHANGE_SUCCESSFUL ? S_OK : DXGI_ERROR_NOT_CURRENTLY_AVAILABLE;;
+  }
+
 }
\ No newline at end of file
diff --git a/src/dxgi/dxgi_monitor.h b/src/dxgi/dxgi_monitor.h
index 2fab08c2..281d960c 100644
--- a/src/dxgi/dxgi_monitor.h
+++ b/src/dxgi/dxgi_monitor.h
@@ -19,6 +19,16 @@ namespace dxvk {
   };
 
 
+  /**
+   * \brief Queries bits per pixel for a format
+   * 
+   * The format must be a valid swap chain format.
+   * \param [in] Format The DXGI format to query
+   * \returns Bits per pixel for this format
+   */
+  uint32_t GetMonitorFormatBpp(
+          DXGI_FORMAT             Format);
+  
   /**
    * \brief Initializes monitor data
    * 
@@ -51,4 +61,29 @@ namespace dxvk {
    */
   void ReleaseMonitorData();
 
+
+  /**
+   * \brief Retrieves monitor display mode
+   *
+   * \param [in] hMonitor Monitor handle
+   * \param [in] ModeNum Mode number
+   * \param [out] Display mode properties
+   * \returns S_OK on success
+   */
+  HRESULT GetMonitorDisplayMode(
+          HMONITOR                hMonitor,
+          DWORD                   ModeNum,
+          DXGI_MODE_DESC*         pMode);
+
+  /**
+   * \brief Sets monitor display mode
+   * 
+   * \param [in] hMonitor Monitor handle
+   * \param [in] pMode Display mode properties
+   * \returns S_OK on success
+   */
+  HRESULT SetMonitorDisplayMode(
+          HMONITOR                hMonitor,
+    const DXGI_MODE_DESC*         pMode);
+
 }
\ No newline at end of file