Move scanlines computations in main shader. This reduces GPU memory consumption, may improve performace and increases scanlines quality.

app/qml/ShaderTerminal.qml

@@ -23,7 +23,6 @@ import QtGraphicalEffects 1.0
 
 ShaderEffect {
     property ShaderEffectSource source
-    property ShaderEffectSource rasterizationSource
     property ShaderEffectSource bloomSource
 
     property color font_color: appSettings.font_color
@@ -54,6 +53,10 @@ ShaderEffect {
 
     property real screen_brightness: appSettings.brightness * 1.5 + 0.5
 
+    property real dispX
+    property real dispY
+    property size virtual_resolution
+
     TimeManager{
         id: timeManager
         enableTimer: terminalWindow.visible
@@ -144,8 +147,11 @@ ShaderEffect {
 
         uniform highp vec4 font_color;
         uniform highp vec4 background_color;
-        uniform highp sampler2D rasterizationSource;
-        uniform lowp float screen_brightness;" +
+        uniform lowp float screen_brightness;
+
+        uniform highp vec2 virtual_resolution;
+        uniform highp float dispX;
+        uniform highp float dispY;" +
 
         (bloom_strength !== 0 ? "
             uniform highp sampler2D bloomSource;
@@ -183,7 +189,18 @@ ShaderEffect {
                 return fract(smoothstep(-0.2, 0.0, coords.y - 3.0 * fract(time * 0.0001))) * glowing_line_strength;
             }" : "") +
 
-        "float rgb2grey(vec3 v){
+        "highp float getScanlineIntensity(vec2 coords) {
+            highp float result = 1.0;" +
+
+           (appSettings.rasterization != appSettings.no_rasterization ?
+               "result *= abs(sin(coords.y * virtual_resolution.y * "+Math.PI+"));" : "") +
+           (appSettings.rasterization == appSettings.pixel_rasterization ?
+               "result *= abs(sin(coords.x * virtual_resolution.x * "+Math.PI+"));" : "") + "
+
+           return result;
+        }
+
+        float rgb2grey(vec3 v){
             return dot(v, vec3(0.21, 0.72, 0.04));
         }" +
 
@@ -256,7 +273,9 @@ ShaderEffect {
             :
                 "vec3 finalColor = mix(background_color.rgb, font_color.rgb, greyscale_color);") +
 
-            "finalColor *= texture2D(rasterizationSource, coords).a;" +
+            "finalColor *= getScanlineIntensity(coords);
+             finalColor *= smoothstep(-dispX, 0.0, coords.x) - smoothstep(1.0, 1.0 + dispX, coords.x);
+             finalColor *= smoothstep(-dispY, 0.0, coords.y) - smoothstep(1.0, 1.0 + dispY, coords.y);" +
 
             (bloom_strength !== 0 ?
                 "vec4 bloomFullColor = texture2D(bloomSource, coords);

app/qml/TerminalContainer.qml

@@ -3,13 +3,17 @@ import QtGraphicalEffects 1.0
 
 ShaderTerminal{
     property alias title: terminal.title
-    property alias terminalSize: terminal.terminalSize
 
     id: mainShader
     opacity: appSettings.windowOpacity * 0.3 + 0.7
 
     blending: false
 
+    source: terminal.mainSource
+    dispX: (12 / width) * appSettings.window_scaling
+    dispY: (12 / height) * appSettings.window_scaling
+    virtual_resolution: terminal.virtualResolution
+
     Loader{
         id: frame
         anchors.fill: parent
@@ -22,8 +26,6 @@ ShaderTerminal{
         anchors.fill: parent
     }
 
-    source: terminal.mainSource
-
     //  EFFECTS  ////////////////////////////////////////////////////////////////
 
     Loader{
@@ -54,60 +56,64 @@ ShaderTerminal{
 
     bloomSource: bloomSourceLoader.item
 
-    ShaderEffect {
-        id: rasterizationEffect
-        width: parent.width
-        height: parent.height
-        property real outColor: 0.0
-        property real dispX: (5 / width) * appSettings.window_scaling
-        property real dispY: (5 / height) * appSettings.window_scaling
-        property size virtual_resolution: terminal.virtualResolution
+    // This shader might be useful in the future. Since we used it only for a couple
+    // of calculations is probably best to move those in the main shader. If in
+    // we will need to store another fullScreen channel this might be handy.
 
-        blending: false
+//    ShaderEffect {
+//        id: rasterizationEffect
+//        width: parent.width
+//        height: parent.height
+//        property real outColor: 0.0
+//        property real dispX: (5 / width) * appSettings.window_scaling
+//        property real dispY: (5 / height) * appSettings.window_scaling
+//        property size virtual_resolution: terminal.virtualResolution
 
-        fragmentShader:
-            "uniform lowp float qt_Opacity;" +
+//        blending: false
 
-            "varying highp vec2 qt_TexCoord0;
-             uniform highp vec2 virtual_resolution;
-             uniform highp float dispX;
-             uniform highp float dispY;
-             uniform mediump float outColor;
+//        fragmentShader:
+//            "uniform lowp float qt_Opacity;" +
 
-             highp float getScanlineIntensity(vec2 coords) {
-                 highp float result = 1.0;" +
+//            "varying highp vec2 qt_TexCoord0;
+//             uniform highp vec2 virtual_resolution;
+//             uniform highp float dispX;
+//             uniform highp float dispY;
+//             uniform mediump float outColor;
 
-                (appSettings.rasterization != appSettings.no_rasterization ?
-                    "result *= abs(sin(coords.y * virtual_resolution.y * "+Math.PI+"));" : "") +
-                (appSettings.rasterization == appSettings.pixel_rasterization ?
-                    "result *= abs(sin(coords.x * virtual_resolution.x * "+Math.PI+"));" : "") + "
+//             highp float getScanlineIntensity(vec2 coords) {
+//                 highp float result = 1.0;" +
 
-                return result;
-             }" +
+//                (appSettings.rasterization != appSettings.no_rasterization ?
+//                    "result *= abs(sin(coords.y * virtual_resolution.y * "+Math.PI+"));" : "") +
+//                (appSettings.rasterization == appSettings.pixel_rasterization ?
+//                    "result *= abs(sin(coords.x * virtual_resolution.x * "+Math.PI+"));" : "") + "
 
-            "void main() {" +
-                "highp float color = getScanlineIntensity(qt_TexCoord0);" +
+//                return result;
+//             }" +
 
-                "float distance = length(vec2(0.5) - qt_TexCoord0);" +
-                "color = mix(color, 0.0, 1.2 * distance * distance);" +
+//            "void main() {" +
+//                "highp float color = getScanlineIntensity(qt_TexCoord0);" +
 
-                "color *= outColor + smoothstep(0.00, dispX, qt_TexCoord0.x) * (1.0 - outColor);" +
-                "color *= outColor + smoothstep(0.00, dispY, qt_TexCoord0.y) * (1.0 - outColor);" +
-                "color *= outColor + (1.0 - smoothstep(1.00 - dispX, 1.00, qt_TexCoord0.x)) * (1.0 - outColor);" +
-                "color *= outColor + (1.0 - smoothstep(1.00 - dispY, 1.00, qt_TexCoord0.y)) * (1.0 - outColor);" +
+//                "float distance = length(vec2(0.5) - qt_TexCoord0);" +
+//                "color = mix(color, 0.0, 1.2 * distance * distance);" +
 
-                "gl_FragColor.a = color;" +
-            "}"
+//                "color *= outColor + smoothstep(0.00, dispX, qt_TexCoord0.x) * (1.0 - outColor);" +
+//                "color *= outColor + smoothstep(0.00, dispY, qt_TexCoord0.y) * (1.0 - outColor);" +
+//                "color *= outColor + (1.0 - smoothstep(1.00 - dispX, 1.00, qt_TexCoord0.x)) * (1.0 - outColor);" +
+//                "color *= outColor + (1.0 - smoothstep(1.00 - dispY, 1.00, qt_TexCoord0.y)) * (1.0 - outColor);" +
 
-        onStatusChanged: if (log) console.log(log) //Print warning messages
-    }
+//                "gl_FragColor.a = color;" +
+//            "}"
 
-    rasterizationSource: ShaderEffectSource{
-        id: rasterizationEffectSource
-        sourceItem: rasterizationEffect
-        hideSource: true
-        smooth: true
-        wrapMode: ShaderEffectSource.ClampToEdge
-        visible: false
-    }
+//        onStatusChanged: if (log) console.log(log) //Print warning messages
+//    }
+
+//    rasterizationSource: ShaderEffectSource{
+//        id: rasterizationEffectSource
+//        sourceItem: rasterizationEffect
+//        hideSource: true
+//        smooth: true
+//        wrapMode: ShaderEffectSource.ClampToEdge
+//        visible: false
+//    }
 }