From 748d2d327f6a68420462fa3dcc08ad7a01d16719 Mon Sep 17 00:00:00 2001
From: Antonis Tsiapaliokas <kok3rs@gmail.com>
Date: Thu, 12 Sep 2013 14:42:18 +0300
Subject: [PATCH] Add glSwapStrategy support

---
 kcmkwin/kwincompositing/compositing.cpp    | 42 +++++++++++++++++++++-
 kcmkwin/kwincompositing/compositing.h      |  4 ++-
 kcmkwin/kwincompositing/qml/EffectView.qml | 23 +++++++++++-
 3 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/kcmkwin/kwincompositing/compositing.cpp b/kcmkwin/kwincompositing/compositing.cpp
index 5c928a5113..62fa779e4b 100644
--- a/kcmkwin/kwincompositing/compositing.cpp
+++ b/kcmkwin/kwincompositing/compositing.cpp
@@ -95,6 +95,24 @@ bool Compositing::unredirectFullscreen() const
     return kwinConfig.readEntry("UnredirectFullscreen", false);
 }
 
+int Compositing::glSwapStrategy() const
+{
+    KConfigGroup kwinConfig(KSharedConfig::openConfig("kwinrc"), "Compositing");
+    const QString glSwapStrategyValue = kwinConfig.readEntry("GLPreferBufferSwap", "a");
+
+    if (glSwapStrategyValue == "n") {
+        return 0;
+    } else if (glSwapStrategyValue == "a") {
+        return 1;
+    } else if (glSwapStrategyValue == "e") {
+        return 2;
+    } else if (glSwapStrategyValue == "p") {
+        return 3;
+    } else if (glSwapStrategyValue == "c") {
+        return 4;
+    }
+}
+
 CompositingType::CompositingType(QObject *parent)
     : QAbstractItemModel(parent) {
 
@@ -203,8 +221,9 @@ int CompositingType::currentOpenGLType()
 }
 
 void CompositingType::syncConfig(int openGLType, int animationSpeed, int windowThumbnail, int glSclaleFilter, bool xrSclaleFilter,
-        bool unredirectFullscreen)
+        bool unredirectFullscreen, int glSwapStrategy)
 {
+    QString glSwapStrategyValue;
     QString backend;
     bool glLegacy;
     bool glCore;
@@ -233,6 +252,26 @@ void CompositingType::syncConfig(int openGLType, int animationSpeed, int windowT
             break;
     }
 
+    switch (glSwapStrategy) {
+        case 0:
+            glSwapStrategyValue = "n";
+            break;
+        case 1:
+            glSwapStrategyValue = "a";
+            break;
+        case 2:
+            glSwapStrategyValue = "e";
+            break;
+        case 3:
+            glSwapStrategyValue = "p";
+            break;
+        case 4:
+            glSwapStrategyValue = "c";
+            break;
+        default:
+            glSwapStrategyValue = "a";
+    }
+
     KConfigGroup kwinConfig(KSharedConfig::openConfig("kwinrc"), "Compositing");
     kwinConfig.writeEntry("Backend", backend);
     kwinConfig.writeEntry("GLLegacy", glLegacy);
@@ -242,6 +281,7 @@ void CompositingType::syncConfig(int openGLType, int animationSpeed, int windowT
     kwinConfig.writeEntry("GLTextureFilter", glSclaleFilter);
     kwinConfig.writeEntry("XRenderSmoothScale", xrSclaleFilter);
     kwinConfig.writeEntry("UnredirectFullscreen", unredirectFullscreen);
+    kwinConfig.writeEntry("GLPreferBufferSwap", glSwapStrategyValue);
     kwinConfig.sync();
 }
 
diff --git a/kcmkwin/kwincompositing/compositing.h b/kcmkwin/kwincompositing/compositing.h
index 5fedf69386..9229f3a32e 100644
--- a/kcmkwin/kwincompositing/compositing.h
+++ b/kcmkwin/kwincompositing/compositing.h
@@ -37,6 +37,7 @@ class Compositing : public QObject
     Q_PROPERTY(int glSclaleFilter READ glSclaleFilter CONSTANT);
     Q_PROPERTY(bool xrSclaleFilter READ xrSclaleFilter CONSTANT);
     Q_PROPERTY(bool unredirectFullscreen READ unredirectFullscreen CONSTANT);
+    Q_PROPERTY(int glSwapStrategy READ glSwapStrategy CONSTANT);
 public:
     explicit Compositing(QObject *parent = 0);
 
@@ -47,6 +48,7 @@ public:
     int glSclaleFilter() const;
     bool xrSclaleFilter() const;
     bool unredirectFullscreen() const;
+    int glSwapStrategy() const;
 
 private:
 
@@ -91,7 +93,7 @@ public:
 
     Q_INVOKABLE int currentOpenGLType();
     Q_INVOKABLE void syncConfig(int openGLType, int animationSpeed, int windowThumbnail, int glSclaleFilter, bool xrSclaleFilter,
-    bool unredirectFullscreen);
+    bool unredirectFullscreen, int glSwapStrategy);
 
 private:
     void generateCompositing();
diff --git a/kcmkwin/kwincompositing/qml/EffectView.qml b/kcmkwin/kwincompositing/qml/EffectView.qml
index 0ed1ce7726..bf7c0cc5b2 100644
--- a/kcmkwin/kwincompositing/qml/EffectView.qml
+++ b/kcmkwin/kwincompositing/qml/EffectView.qml
@@ -166,6 +166,27 @@ Item {
             onClicked: apply.enabled = true
         }
 
+        Label {
+            id: glSwapStrategyText
+            text: i18n("Tearing Prevention (VSync):")
+            anchors {
+                top: unredirectFullScreen.bottom
+                horizontalCenter: windowManagement.horizontalCenter
+                topMargin: 20
+            }
+        }
+
+        ComboBox {
+            id: glSwapStrategy
+            model: [i18n("Never"), i18n("Automatic"), i18n("Only when cheap"), i18n("Full screen repaints"), i18n("Re-use screen content")]
+            currentIndex: compositing.glSwapStrategy
+            anchors {
+                top: glSwapStrategyText.bottom
+                left: col.right
+                right: parent.right
+            }
+            onCurrentIndexChanged: apply.enabled = true;
+        }
 
         ColumnLayout {
             id: col
@@ -246,7 +267,7 @@ Item {
                 onClicked: {
                     searchModel.syncConfig();
                     apply.enabled = false;
-                    compositingType.syncConfig(openGLType.currentIndex, animationSpeed.value, windowThumbnail.currentIndex, glScaleFilter.currentIndex, xrScaleFilter.currentIndex == 1, unredirectFullScreen.checked);
+                    compositingType.syncConfig(openGLType.currentIndex, animationSpeed.value, windowThumbnail.currentIndex, glScaleFilter.currentIndex, xrScaleFilter.currentIndex == 1, unredirectFullScreen.checked, glSwapStrategy.currentIndex);
                 }
             }