gamma/contrast system reworked

apps/openmw/engine.cpp

@@ -358,6 +358,8 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     windowSettings.icon = "openmw.png";
     std::string aa = settings.getString("antialiasing", "Video");
     windowSettings.fsaa = (aa.substr(0, 4) == "MSAA") ? aa.substr(5, aa.size()-5) : "0";
+    windowSettings.gamma = Settings::Manager::getFloat("gamma", "General");
+    windowSettings.contrast = Settings::Manager::getFloat("contrast", "General");
 
     SDL_SetHint(SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS,
                 settings.getBool("minimize on focus loss", "Video") ? "1" : "0");

apps/openmw/mwrender/renderingmanager.cpp

@@ -757,6 +757,10 @@ void RenderingManager::processChangedSettings(const Settings::CategorySettingVec
             changeRes = true;
         else if (it->second == "field of view" && it->first == "General")
             mRendering.setFov(Settings::Manager::getFloat("field of view", "General"));
+        else if ((it->second == "gamma" || it->second == "contrast") && it->first == "General")
+        {
+            mRendering.setWindowGammaContrast(Settings::Manager::getFloat("gamma", "General"), Settings::Manager::getFloat("contrast", "General"));
+        }
         else if ((it->second == "texture filtering" && it->first == "General")
             || (it->second == "anisotropy" && it->first == "General"))
         {

files/mygui/openmw_settings_window.layout

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <MyGUI type="Layout" version="3.2.0">
-    <Widget type="Window" skin="MW_Window" position="0 0 400 426" layer="Windows" name="_Main">
+    <Widget type="Window" skin="MW_Window" position="0 0 400 505" layer="Windows" name="_Main">
         <Property key="MinSize" value="430 446"/>
-        <Widget type="TabControl" skin="TabControl" position="8 8 368 340" align="Stretch" name="SettingsTab">
+        <Widget type="TabControl" skin="TabControl" position="8 8 368 430" align="Stretch" name="SettingsTab">
             <Property key="ButtonAutoWidth" value="true"/>
             <Widget type="TabItem" skin="" position="4 32 360 308">
                 <Property key="Caption" value="  #{sPrefs}  "/>
@@ -214,7 +214,7 @@
             </Widget>
             <Widget type="TabItem" skin="" position="4 32 360 308">
                 <Property key="Caption" value="  #{sVideo}  "/>
-                <Widget type="TabControl" skin="TabControlInner" position="4 4 352 296" align="Stretch">
+                <Widget type="TabControl" skin="TabControlInner" position="4 4 352 390" align="Stretch">
                     <Property key="ButtonAutoWidth" value="true"/>
                     <Widget type="TabItem" skin="" position="0 28 352 268" align="Stretch">
                         <Property key="Caption" value="  Video  "/>
@@ -292,6 +292,32 @@
                             <Property key="Caption" value="#{sHigh}"/>
                             <Property key="TextAlign" value="Right"/>
                         </Widget>
+                        <Widget type="TextBox" skin="NormalText" position="0 268 329 18" align="Left Top" name="GammaText">
+                            <Property key="Caption" value="Gamma Correction"/>
+                        </Widget>
+                        <Widget type="MWScrollBar" skin="MW_HScroll" position="0 292 329 18" align="HStretch Top" name="GammaSlider">
+                            <Property key="Range" value="10000"/>
+                            <Property key="Page" value="300"/>
+                            <UserString key="SettingType" value="Slider"/>
+                            <UserString key="SettingCategory" value="General"/>
+                            <UserString key="SettingName" value="gamma"/>
+                            <UserString key="SettingValueType" value="Float"/>
+                            <UserString key="SettingMin" value="0.1"/>
+                            <UserString key="SettingMax" value="3.0"/>
+                        </Widget>
+                        <Widget type="TextBox" skin="NormalText" position="0 314 329 18" align="Left Top" name="ContrastText">
+                            <Property key="Caption" value="Contrast"/>
+                        </Widget>
+                        <Widget type="MWScrollBar" skin="MW_HScroll" position="0 336 329 18" align="HStretch Top" name="ContrastSlider">
+                            <Property key="Range" value="10000"/>
+                            <Property key="Page" value="300"/>
+                            <UserString key="SettingType" value="Slider"/>
+                            <UserString key="SettingCategory" value="General"/>
+                            <UserString key="SettingName" value="contrast"/>
+                            <UserString key="SettingValueType" value="Float"/>
+                            <UserString key="SettingMin" value="0.1"/>
+                            <UserString key="SettingMax" value="2.0"/>
+                        </Widget>
                     </Widget>
                     <Widget type="TabItem" skin="" position="0 28 352 268">
                         <Property key="Caption" value="  Detail  "/>
@@ -470,7 +496,7 @@
                 </Widget>
             </Widget>
         </Widget>
-        <Widget type="AutoSizedButton" skin="MW_Button" position="321 355 56 24" align="Right Bottom" name="OkButton">
+        <Widget type="AutoSizedButton" skin="MW_Button" position="320 440 56 24" align="Right Bottom" name="OkButton">
             <Property key="ExpandDirection" value="Left"/>
             <Property key="Caption" value="#{sOK}"/>
         </Widget>

files/settings-default.cfg

@@ -48,6 +48,8 @@ werewolf overlay = true
 [General]
 # Camera field of view
 field of view = 55
+gamma = 1.34
+contrast = 0.98
 
 # Texture filtering mode. valid values:
 # none

libs/openengine/ogre/renderer.cpp

@@ -23,6 +23,12 @@
 using namespace Ogre;
 using namespace OEngine::Render;
 
+OgreRenderer::~OgreRenderer()
+{
+    cleanup();
+    // restore system gamma ramp
+    SDL_SetWindowGammaRamp(mSDLWindow, mOldSystemGammaRamp, &mOldSystemGammaRamp[256], &mOldSystemGammaRamp[512]);
+}
 
 void OgreRenderer::cleanup()
 {
@@ -138,6 +144,8 @@ void OgreRenderer::createWindow(const std::string &title, const WindowSettings&
         helper.setWindowIcon(settings.icon);
     mWindow = helper.getWindow();
 
+    SDL_GetWindowGammaRamp(mSDLWindow, mOldSystemGammaRamp, &mOldSystemGammaRamp[256], &mOldSystemGammaRamp[512]);
+    setWindowGammaContrast(settings.gamma, settings.contrast);
 
     // create the semi-transparent black background texture used by the GUI.
     // has to be created in code with TU_DYNAMIC_WRITE_ONLY param
@@ -161,6 +169,24 @@ void OgreRenderer::createWindow(const std::string &title, const WindowSettings&
     mCamera->setAspectRatio(Real(mView->getActualWidth()) / Real(mView->getActualHeight()));
 }
 
+void OgreRenderer::setWindowGammaContrast(float gamma, float contrast)
+{
+    Uint16 red[256], green[256], blue[256];
+    for (int i = 0; i < 256; i++)
+    {
+        float k = i/256.0f;
+        k = (k - 0.5f) * contrast + 0.5f;
+        k = pow(k, 1.f/gamma);
+        k *= 256;
+        float value = k*256;
+        if (value > 65535)  value = 65535;
+        else if (value < 0) value = 0;
+
+        red[i] = green[i] = blue[i] = value;
+    }
+    SDL_SetWindowGammaRamp(mSDLWindow, red, green, blue);
+}
+
 void OgreRenderer::adjustCamera(float fov, float nearClip)
 {
     mCamera->setNearClipDistance(nearClip);

libs/openengine/ogre/renderer.hpp

@@ -42,6 +42,8 @@ namespace OEngine
             int screen;
             std::string fsaa;
             std::string icon;
+            float gamma;
+            float contrast;
         };
 
         class WindowSizeListener
@@ -67,6 +69,9 @@ namespace OEngine
             int mWindowHeight;
             bool mOutstandingResize;
 
+            // Store system gamma ramp on window creation. Restore system gamma ramp on exit
+            uint16_t mOldSystemGammaRamp[256*3];
+
         public:
             OgreRenderer()
             : mRoot(NULL)
@@ -83,7 +88,7 @@ namespace OEngine
             {
             }
 
-            ~OgreRenderer() { cleanup(); }
+            ~OgreRenderer();
 
             /** Configure the renderer. This will load configuration files and
             set up the Root and logging classes. */
@@ -95,6 +100,8 @@ namespace OEngine
             /// Create a window with the given title
             void createWindow(const std::string &title, const WindowSettings& settings);
 
+            void setWindowGammaContrast(float gamma, float contrast);
+
             /// Set up the scene manager, camera and viewport
             void adjustCamera(
                 float fov=55,                      // Field of view angle