Settings optin for old burinin version. It seems to be working better on osx.

app/qml/ApplicationSettings.qml

@@ -33,6 +33,9 @@ QtObject{
     readonly property real minimumFontScaling: 0.25
     readonly property real maximumFontScaling: 2.50
 
+    readonly property real minBurnInFadeTime: 160
+    readonly property real maxBurnInFadeTime: 1600
+
     // GENERAL SETTINGS ///////////////////////////////////////////////////////
 
     property int x: 100
@@ -52,7 +55,9 @@ QtObject{
     property bool verbose: false
 
     property real bloomQuality: 0.5
+
     property real burnInQuality: 0.5
+    property bool useFastBurnIn: Qt.platform.os === "osx" ? false : true
 
     onWindowScalingChanged: handleFontChanged();
 
@@ -202,7 +207,8 @@ QtObject{
             bloomQuality: bloomQuality,
             burnInQuality: burnInQuality,
             useCustomCommand: useCustomCommand,
-            customCommand: customCommand
+            customCommand: customCommand,
+            useFastBurnIn: useFastBurnIn
         }
         return stringify(settings);
     }
@@ -288,6 +294,8 @@ QtObject{
 
         useCustomCommand = settings.useCustomCommand !== undefined ? settings.useCustomCommand : useCustomCommand
         customCommand = settings.customCommand !== undefined ? settings.customCommand : customCommand
+
+        useFastBurnIn = settings.useFastBurnIn !== undefined ? settings.useFastBurnIn : useFastBurnIn;
     }
 
     function loadProfileString(profileString){

app/qml/BurnInEffect.qml

@@ -13,10 +13,12 @@ Loader {
     property real delay: (1.0 / appSettings.fps) * 1000
     property real burnIn: appSettings.burnIn
     property real burnInFadeTime: 1 / Utils.lint(_minBurnInFadeTime, _maxBurnInFadeTime, burnIn)
-    property real _minBurnInFadeTime: 160
+    property real _minBurnInFadeTime: appSettings.minBurnInFadeTime
-    property real _maxBurnInFadeTime: 1600
+    property real _maxBurnInFadeTime: appSettings.maxBurnInFadeTime
 
-    active: appSettings.burnIn !== 0
+    active: appSettings.useFastBurnIn && appSettings.burnIn !== 0
+
+    anchors.fill: parent
 
     function completelyUpdate() {
         prevLastUpdate = lastUpdate;
@@ -33,16 +35,6 @@ Loader {
     sourceComponent: Item {
         property alias source: burnInEffectSource
 
-        property int burnInScaling: scaleTexture * appSettings.burnInQuality
-
-        width: appSettings.lowResolutionFont
-               ? kterminal.totalWidth * Math.max(1, burnInScaling)
-               : kterminal.totalWidth * scaleTexture * appSettings.burnInQuality
-
-        height: appSettings.lowResolutionFont
-                ? kterminal.totalHeight * Math.max(1, burnInScaling)
-                : kterminal.totalHeight * scaleTexture * appSettings.burnInQuality
-
         ShaderEffectSource {
             id: burnInEffectSource
 
@@ -88,7 +80,6 @@ Loader {
             property real prevLastUpdate: burnInEffect.prevLastUpdate
 
             anchors.fill: parent
-
             blending: false
 
             fragmentShader:

app/qml/PreprocessedTerminal.qml

@@ -33,6 +33,7 @@ Item{
 
     property ShaderEffectSource mainSource: kterminalSource
     property BurnInEffect burnInEffect: burnInEffect
+    property SlowBurnIn slowBurnInEffect: slowBurnInEffect
     property real fontWidth: 1.0
     property real screenScaling: 1.0
     property real scaleTexture: 1.0
@@ -227,7 +228,26 @@ Item{
         sourceRect: Qt.rect(-kterminal.margin, -kterminal.margin, kterminal.totalWidth, kterminal.totalHeight)
     }
 
-    BurnInEffect {
+    Item {
-        id: burnInEffect
+        id: burnInContainer
+
+        property int burnInScaling: scaleTexture * appSettings.burnInQuality
+
+        width: Math.round(appSettings.lowResolutionFont
+               ? kterminal.totalWidth * Math.max(1, burnInScaling)
+               : kterminal.totalWidth * scaleTexture * appSettings.burnInQuality)
+
+        height: Math.round(appSettings.lowResolutionFont
+                ? kterminal.totalHeight * Math.max(1, burnInScaling)
+                : kterminal.totalHeight * scaleTexture * appSettings.burnInQuality)
+
+
+        BurnInEffect {
+            id: burnInEffect
+        }
+
+        SlowBurnIn {
+            id: slowBurnInEffect
+        }
     }
 }

app/qml/SettingsAdvancedTab.qml

@@ -133,6 +133,12 @@ Tab{
                     }
                 }
                 SizedLabel{text: Math.round(burnInSlider.value * 100) + "%"}
+                CheckBox{
+                    Layout.columnSpan: 2
+                    text: qsTr("Burnin optimization (Might display timing artifacts)")
+                    checked: appSettings.useFastBurnIn
+                    onCheckedChanged: appSettings.useFastBurnIn = checked
+                }
             }
         }
     }

app/qml/ShaderTerminal.qml

@@ -24,6 +24,7 @@ import QtGraphicalEffects 1.0
 import "utils.js" as Utils
 
 Item {
+    property SlowBurnIn slowBurnInEffect
     property ShaderEffectSource source
     property BurnInEffect burnInEffect
     property ShaderEffectSource bloomSource
@@ -56,9 +57,16 @@ Item {
          property real horizontalSync: appSettings.horizontalSync
          property real horizontalSyncStrength: Utils.lint(0.05, 0.35, horizontalSync)
          property real glowingLine: appSettings.glowingLine * 0.2
-         property real burnIn: appSettings.burnIn
+
+         // Fast burnin properties
+         property real burnIn: appSettings.useFastBurnIn ? appSettings.burnIn : 0
          property real burnInLastUpdate: burnInEffect.lastUpdate
          property real burnInTime: burnInEffect.burnInFadeTime
+
+         // Slow burnin properties
+         property real slowBurnIn: appSettings.useFastBurnIn ? 0 : appSettings.burnIn
+         property ShaderEffectSource slowBurnInSource: slowBurnInEffect.source
+
          property real jitter: appSettings.jitter
          property size jitterDisplacement: Qt.size(0.007 * jitter, 0.002 * jitter)
          property real shadowLength: 0.25 * screenCurvature * Utils.lint(0.50, 1.5, ambientLight)
@@ -162,6 +170,8 @@ Item {
                  uniform sampler2D burnInSource;
                  uniform highp float burnInLastUpdate;
                  uniform highp float burnInTime;" : "") +
+             (slowBurnIn !== 0 ? "
+                 uniform sampler2D slowBurnInSource;" : "") +
              (staticNoise !== 0 ? "
                  uniform highp float staticNoise;" : "") +
              (((staticNoise !== 0 || jitter !== 0)
@@ -292,6 +302,11 @@ Item {
                      txt_color = max(txt_color, convertWithChroma(burnInColor));"
                  : "") +
 
+                 (slowBurnIn !== 0 ? "
+                     vec4 txt_blur = texture2D(slowBurnInSource, staticCoords);
+                     txt_color = max(txt_color, convertWithChroma(txt_blur.rgb * txt_blur.a));
+                 " : "") +
+
                   "txt_color += fontColor.rgb * vec3(color);" +
 
                  "vec3 finalColor = txt_color;" +

app/qml/SlowBurnIn.qml

@@ -0,0 +1,122 @@
+import QtQuick 2.0
+
+import "utils.js" as Utils
+
+Loader {
+    property ShaderEffectSource source: item ? item.source : null
+
+    active: !appSettings.useFastBurnIn && appSettings.burnIn !== 0
+
+    anchors.fill: parent
+
+    sourceComponent: Item {
+        property alias source: burnInSourceEffect
+
+        property int burnInScaling: scaleTexture * appSettings.burnInQuality
+
+        ShaderEffectSource {
+            property bool updateBurnIn: false
+            property real burnIn: appSettings.burnIn
+            property real fps: appSettings.fps !== 0 ? appSettings.fps : 60
+            property real burnInFadeTime: Utils.lint(minBurnInFadeTime, maxBurnInFadeTime, burnIn)
+            property real burnInCoefficient: 1000 / (fps * burnInFadeTime)
+            property real minBurnInFadeTime: appSettings.minBurnInFadeTime
+            property real maxBurnInFadeTime: appSettings.maxBurnInFadeTime
+
+            id: burnInSourceEffect
+
+            anchors.fill: parent
+
+            sourceItem: burnInEffect
+            recursive: true
+            live: false
+            hideSource: true
+            wrapMode: kterminalSource.wrapMode
+
+            visible: false
+
+            function restartBlurSource(){
+                livetimer.restart();
+            }
+
+            // This updates the burnin synched with the timer.
+            Connections {
+                target: burnInSourceEffect.updateBurnIn ? timeManager : null
+                ignoreUnknownSignals: false
+                onTimeChanged: {
+                    burnInSourceEffect.scheduleUpdate();
+                }
+            }
+
+            Timer{
+                id: livetimer
+
+                // The interval assumes 60 fps. This is the time needed burnout a white pixel.
+                // We multiply 1.1 to have a little bit of margin over the theoretical value.
+                // This solution is not extremely clean, but it's probably the best to avoid measuring fps.
+
+                interval: burnInSourceEffect.burnInFadeTime * 1.1
+                running: true
+                onTriggered: burnInSourceEffect.updateBurnIn = false;
+            }
+            Connections{
+                target: kterminal
+                onImagePainted:{
+                    burnInSourceEffect.scheduleUpdate();
+                    burnInSourceEffect.updateBurnIn = true;
+                    livetimer.restart();
+                }
+            }
+            // Restart blurred source settings change.
+            Connections{
+                target: appSettings
+                onBurnInChanged: burnInSourceEffect.restartBlurSource();
+                onTerminalFontChanged: burnInSourceEffect.restartBlurSource();
+                onRasterizationChanged: burnInSourceEffect.restartBlurSource();
+                onBurnInQualityChanged: burnInSourceEffect.restartBlurSource();
+            }
+            Connections {
+                target: kterminalScrollbar
+                onOpacityChanged: burnInSourceEffect.restartBlurSource();
+            }
+
+            ShaderEffect {
+                id: burnInEffect
+
+                property variant txt_source: kterminalSource
+                property variant blurredSource: burnInSourceEffect
+                property real burnInCoefficient: burnInSourceEffect.burnInCoefficient
+
+                anchors.fill: parent
+                blending: false
+
+                fragmentShader:
+                    "#ifdef GL_ES
+                    precision mediump float;
+                #endif\n" +
+
+                "uniform lowp float qt_Opacity;" +
+                "uniform lowp sampler2D txt_source;" +
+
+                "varying highp vec2 qt_TexCoord0;
+             uniform lowp sampler2D blurredSource;
+             uniform highp float burnInCoefficient;" +
+
+                "float max3(vec3 v) {
+                     return max (max (v.x, v.y), v.z);
+                }" +
+
+                "void main() {" +
+                    "vec2 coords = qt_TexCoord0;" +
+                    "vec3 origColor = texture2D(txt_source, coords).rgb;" +
+                    "vec3 blur_color = texture2D(blurredSource, coords).rgb - vec3(burnInCoefficient);" +
+                    "vec3 color = min(origColor + blur_color, max(origColor, blur_color));" +
+
+                    "gl_FragColor = vec4(color, max3(color - origColor));" +
+                "}"
+
+                onStatusChanged: if (log) console.log(log) //Print warning messages
+            }
+        }
+    }
+}

app/qml/TerminalContainer.qml

@@ -12,6 +12,7 @@ ShaderTerminal {
 
     source: terminal.mainSource
     burnInEffect: terminal.burnInEffect
+    slowBurnInEffect: terminal.slowBurnInEffect
     virtual_resolution: terminal.virtualResolution
 
     TimeManager{

app/qml/resources.qrc

@@ -43,5 +43,6 @@
         <file>BurnInEffect.qml</file>
         <file>fonts/modern-terminus/TerminusTTF-4.46.0.ttf</file>
         <file>NewTerminalFrame.qml</file>
+        <file>SlowBurnIn.qml</file>
     </qresource>
 </RCC>