Make the burn-in look more like the real thing.

Exponential decay instead of linear.

.github/workflows/appimage.yml

@@ -0,0 +1,98 @@
+name: "ci"
+
+on:
+  push:
+    tags: "**"
+  workflow_dispatch:
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  appimage:
+    runs-on: ubuntu-18.04
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        submodules: true
+
+    - name: Install dependencies
+      run: |
+        sudo add-apt-repository -y ppa:beineri/opt-qt-5.15.2-bionic
+        sudo apt-get update -qq
+        sudo apt-get install -y \
+        build-essential make wget libgl1-mesa-dev \
+        qt515declarative qt515graphicaleffects \
+        qt515quickcontrols qt515quickcontrols2
+
+    - name: Download QT appimage builder
+      run: |
+        wget -c -O linuxdeployqt.AppImage \
+        https://github.com/probonopd/linuxdeployqt/releases/download/continuous/linuxdeployqt-continuous-x86_64.AppImage
+        chmod a+x linuxdeployqt.AppImage
+
+    - name: Build project
+      run: |
+        source /opt/qt*/bin/qt*-env.sh && \
+        qmake -v && \
+        qmake CONFIG+=release PREFIX=/usr && \
+        make -j$(nproc)
+
+    - name: Install to appdir
+      run: |
+        source /opt/qt*/bin/qt*-env.sh && \
+        make INSTALL_ROOT=appdir -j$(nproc) install
+
+    - name: Extract version number
+      run: |
+        # Extract version for linuxdeployqt to name the file. Use the tag as
+        # release name but remove prefix.
+        echo "VERSION=$(echo '${{ github.ref }}' | sed 's;.*/;;')" >> $GITHUB_ENV
+
+    - name: Build appimage directory
+      run: |
+        mkdir -p \
+        appdir/usr/bin \
+        appdir/usr/lib \
+        appdir/usr/share/applications \
+        appdir/usr/share/metainfo \
+        appdir/usr/share/icons/hicolor/128x128/apps
+
+        cp cool-retro-term appdir/usr/bin/
+        cp cool-retro-term.desktop appdir/usr/share/applications/
+        cp packaging/appdata/cool-retro-term.appdata.xml appdir/usr/share/metainfo/
+        cp app/icons/128x128/cool-retro-term.png appdir/usr/share/icons/hicolor/128x128/apps/
+        cp -r ./app/qml appdir/usr/
+        # Workaround for https://github.com/probonopd/linuxdeployqt/issues/78
+        cp -r ./qmltermwidget/QMLTermWidget appdir/usr/qml/
+
+        find appdir | sort
+
+    - name: Build appimage
+      run: |
+        source /opt/qt*/bin/qt*-env.sh && \
+        ./linuxdeployqt.AppImage appdir/usr/share/applications/cool-retro-term.desktop \
+        -verbose=1 -appimage \
+        -qmldir=./app/qml/ \
+        -qmldir=./qmltermwidget/
+      env:
+        # Unset environment variables
+        QTDIR:
+        QT_PLUGIN_PATH:
+        LD_LIBRARY_PATH:
+
+    - name: Upload release
+      uses: softprops/action-gh-release@v1
+      with:
+        body: appimage release
+        files: ./**/Cool_Retro_Term-*-x86_64.AppImage
+
+    - name: Clean up
+      if: always()
+      run: |
+        find appdir -executable -type f -exec ldd {} \; | grep " => /usr" | cut -d " " -f 2-3 | sort | uniq
+        make clean
+        rm -rf appdir

app/qml/ApplicationSettings.qml

@@ -32,7 +32,7 @@ QtObject {
     readonly property real maximumFontScaling: 2.50
 
     readonly property real minBurnInFadeTime: 160
-    readonly property real maxBurnInFadeTime: 1600
+    readonly property real maxBurnInFadeTime: 160000
 
     property bool isMacOS: Qt.platform.os === "osx"
 

app/qml/BurnInEffect.qml

@@ -29,8 +29,8 @@ Loader {
     property real lastUpdate: 0
     property real prevLastUpdate: 0
 
-    property real burnIn: appSettings.burnIn
+    property real burnIn: appSettings.burnIn;
-    property real burnInFadeTime: 1 / Utils.lint(_minBurnInFadeTime, _maxBurnInFadeTime, burnIn)
+    property real burnInFadeTime: (1 / Utils.lint(_minBurnInFadeTime, _maxBurnInFadeTime, burnIn))*64
     property real _minBurnInFadeTime: appSettings.minBurnInFadeTime
     property real _maxBurnInFadeTime: appSettings.maxBurnInFadeTime
 
@@ -146,9 +146,8 @@ Loader {
                     float prevMask = accColor.a;
                     float currMask = rgb2grey(txtColor);
 
-                    highp float blurDecay = clamp((lastUpdate - prevLastUpdate) * burnInTime, 0.0, 1.0);
+                    highp float blurDecay = clamp(pow(0.5, burnInTime * (lastUpdate - prevLastUpdate)), 0.0, 1.0);
-                    blurDecay = max(0.0, blurDecay - prevMask);
+                    vec3 blurColor = accColor.rgb * vec3(blurDecay);
-                    vec3 blurColor = accColor.rgb - vec3(blurDecay);
                     vec3 color = max(blurColor, txtColor);
 
                     gl_FragColor = vec4(color, currMask);

app/qml/ShaderTerminal.qml

@@ -302,8 +302,8 @@ Item {
 
                  (burnIn !== 0 ? "
                      vec4 txt_blur = texture2D(burnInSource, staticCoords);
-                     float blurDecay = clamp((time - burnInLastUpdate) * burnInTime, 0.0, 1.0);
+                     float blurDecay = clamp(pow(0.5, burnInTime * (time - burnInLastUpdate)), 0.0, 1.0);
-                     vec3 burnInColor = 0.65 * (txt_blur.rgb - vec3(blurDecay));
+                     vec3 burnInColor = txt_blur.rgb * vec3(blurDecay);
                      txt_color = max(txt_color, convertWithChroma(burnInColor));"
                  : "") +