Unload burnin effect when not in use.

app/qml/BurnInEffect.qml

@@ -2,10 +2,10 @@ import QtQuick 2.0
 
 import "utils.js" as Utils
 
-Item {
+Loader {
     id: burnInEffect
 
-    readonly property alias source: burnInEffectSource
+    property ShaderEffectSource source: item ? item.source : null
 
     property real lastUpdate: 0
     property real prevLastUpdate: 0
@@ -16,10 +16,12 @@ Item {
     property real _minBurnInFadeTime: 160
     property real _maxBurnInFadeTime: 1600
 
+    active: appSettings.burnIn !== 0
+
     function completelyUpdate() {
         prevLastUpdate = lastUpdate;
         lastUpdate = timeManager.time;
-        burnInEffectSource.scheduleUpdate();
+        item.source.scheduleUpdate();
     }
 
     function restartBlurSource(){
@@ -28,40 +30,8 @@ Item {
         completelyUpdate()
     }
 
-    ShaderEffectSource {
-        id: burnInEffectSource
-
-        sourceItem: burnInShaderEffect
-        live: false
-        recursive: true
-        hideSource: true
-        wrapMode: kterminalSource.wrapMode
-
-        format: ShaderEffectSource.RGBA
-
-        visible: false
-
-        Connections {
-            target: kterminal
-            onImagePainted: completelyUpdate()
-        }
-        // Restart blurred source settings change.
-        Connections{
-            target: appSettings
-            onBurnInChanged: burnInEffect.restartBlurSource();
-            onTerminalFontChanged: burnInEffect.restartBlurSource();
-            onRasterizationChanged: burnInEffect.restartBlurSource();
-            onBurnInQualityChanged: burnInEffect.restartBlurSource();
-        }
-
-        Connections {
-            target: kterminalScrollbar
-            onOpacityChanged: burnInEffect.restartBlurSource()
-        }
-    }
-
-    ShaderEffect {
-        id: burnInShaderEffect
+    sourceComponent: Item {
+        property alias source: burnInEffectSource
 
         property int burnInScaling: scaleTexture * appSettings.burnInQuality
 
@@ -73,54 +43,94 @@ Item {
                 ? kterminal.height * Math.max(1, burnInScaling)
                 : kterminal.height * scaleTexture * appSettings.burnInQuality
 
-        property variant txt_source: kterminalSource
-        property variant burnInSource: burnInEffectSource
-        property real burnInTime: burnInFadeTime
-        property alias lastUpdate: burnInEffect.lastUpdate
-        property alias prevLastUpdate: burnInEffect.prevLastUpdate
+        ShaderEffectSource {
+            id: burnInEffectSource
 
-        blending: false
+            anchors.fill: parent
 
-        fragmentShader:
-            "#ifdef GL_ES
-                    precision mediump float;
-                #endif\n" +
+            sourceItem: burnInShaderEffect
+            live: false
+            recursive: true
+            hideSource: true
+            wrapMode: kterminalSource.wrapMode
 
-            "uniform lowp float qt_Opacity;" +
-            "uniform lowp sampler2D txt_source;" +
+            format: ShaderEffectSource.RGBA
 
-            "varying highp vec2 qt_TexCoord0;
+            visible: false
 
-             uniform lowp sampler2D burnInSource;
-             uniform highp float burnInTime;
-
-             uniform highp float lastUpdate;
-
-             uniform highp float prevLastUpdate;" +
-
-            "float max3(vec3 v) {
-                 return max (max (v.x, v.y), v.z);
-            }" +
-
-            "void main() {
-                vec2 coords = qt_TexCoord0;
-
-                vec3 txtColor = texture2D(txt_source, coords).rgb * 0.70;
-                vec4 accColor = texture2D(burnInSource, coords);
-
-                float prevMask = accColor.a;
-                float currMask = 1.0 - max3(txtColor);
-
-                highp float blurDecay = prevMask * clamp((lastUpdate - prevLastUpdate) * burnInTime, 0.0, 1.0);
-                vec3 blurColor = accColor.rgb - vec3(blurDecay);
-
-                blurColor = clamp(blurColor, vec3(0.0), vec3(1.0));
-                vec3 color = max(blurColor, txtColor);
-
-                gl_FragColor = vec4(color, currMask);
+            Connections {
+                target: kterminal
+                onImagePainted: completelyUpdate()
+            }
+            // Restart blurred source settings change.
+            Connections{
+                target: appSettings
+                onBurnInChanged: burnInEffect.restartBlurSource();
+                onTerminalFontChanged: burnInEffect.restartBlurSource();
+                onRasterizationChanged: burnInEffect.restartBlurSource();
+                onBurnInQualityChanged: burnInEffect.restartBlurSource();
             }
-        "
 
-        onStatusChanged: if (log) console.log(log) //Print warning messages
+            Connections {
+                target: kterminalScrollbar
+                onOpacityChanged: burnInEffect.restartBlurSource()
+            }
+        }
+
+        ShaderEffect {
+            id: burnInShaderEffect
+
+            property variant txt_source: kterminalSource
+            property variant burnInSource: burnInEffectSource
+            property real burnInTime: burnInFadeTime
+            property real lastUpdate: burnInEffect.lastUpdate
+            property real prevLastUpdate: burnInEffect.prevLastUpdate
+
+            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 burnInSource;
+                 uniform highp float burnInTime;
+
+                 uniform highp float lastUpdate;
+
+                 uniform highp float prevLastUpdate;" +
+
+                "float max3(vec3 v) {
+                     return max (max (v.x, v.y), v.z);
+                }" +
+
+                "void main() {
+                    vec2 coords = qt_TexCoord0;
+
+                    vec3 txtColor = texture2D(txt_source, coords).rgb * 0.5;
+                    vec4 accColor = texture2D(burnInSource, coords);
+
+                    float prevMask = accColor.a;
+                    float currMask = 1.0 - max3(txtColor);
+
+                    highp float blurDecay = prevMask * clamp((lastUpdate - prevLastUpdate) * burnInTime, 0.0, 1.0);
+                    vec3 blurColor = accColor.rgb - vec3(blurDecay);
+
+                    blurColor = clamp(blurColor, vec3(0.0), vec3(1.0));
+                    vec3 color = max(blurColor, txtColor);
+
+                    gl_FragColor = vec4(color, currMask);
+                }
+            "
+
+            onStatusChanged: if (log) console.log(log) //Print warning messages
+        }
     }
 }