Add shutter length effect, fix bug when opening a project using vector display, separate glow and ambient light effects, improve range of glow slider

Source/visualiser/LineFragmentShader.glsl

@@ -9,7 +9,6 @@ uniform float uSize;
 uniform float uIntensity;
 uniform vec2 uOffset;
 uniform vec2 uScale;
-uniform float uScreenOverlay;
 uniform float uFishEye;
 uniform sampler2D uScreen;
 varying float vSize;

Source/visualiser/LineVertexShader.glsl

@@ -7,6 +7,7 @@ uniform float uSize;
 uniform float uNEdges;
 uniform float uFadeAmount;
 uniform float uIntensity;
+uniform float uShutterLength;
 uniform float uGain;
 attribute vec3 aStart, aEnd;
 attribute float aIdx;
@@ -56,17 +57,20 @@ void main () {
         uvl.w = aStartBrightness;
     }
     // `side` corresponds to shift to the "right" or "left"
-    float side = (mod(idx, 2.0)-0.5)*2.0;
+    float side = (mod(idx, 2.0) - 0.5) * 2.0;
     uvl.y = side * vSize;
     
-    uvl.w *= intensity * mix(1.0-uFadeAmount, 1.0, floor(aIdx / 4.0 + 0.5)/uNEdges);
+    float intensityScale = floor(aIdx / 4.0 + 0.5)/uNEdges;
+    float avgIntensityScale = floor((uNEdges / 2.0) / 4.0 + 0.5)/uNEdges;
+    float shutterLength = clamp(uShutterLength, 0.0, 1.0);
+    float adjustedIntensity = mix(intensityScale, avgIntensityScale, shutterLength);
+    float intensityFade = mix(1.0 - uFadeAmount, 1.0, adjustedIntensity);
+    
+    uvl.w *= intensity * intensityFade;
                              
     vec4 pos = vec4((current+(tang*dir+norm*side)*vSize)*uInvert,0.0,1.0);
     gl_Position = pos;
-    vTexCoord = 0.5*pos.xy+0.5;
-    //float seed = floor(aIdx/4.0);
-    //seed = mod(sin(seed*seed), 7.0);
-    //if (mod(seed/2.0, 1.0)<0.5) gl_Position = vec4(10.0);
+    vTexCoord = 0.5 * pos.xy + 0.5;
 }
 
 )";

Source/visualiser/OutputFragmentShader.glsl

@@ -65,7 +65,7 @@ void main() {
     // r components have grid; g components do not.
     vec4 screen = texture2D(uTexture3, vTexCoord);
     vec4 tightGlow = texture2D(uTexture1, linePos);
-    vec4 scatter = texture2D(uTexture2, linePos) + (1.0 - uRealScreen) * max(uAmbient - 0.35, 0.0);
+    vec4 scatter = texture2D(uTexture2, linePos);
     
     if (uRealScreen > 0.5) {
         vec4 reflection = texture2D(uTexture4, vTexCoord);
@@ -73,8 +73,14 @@ void main() {
         scatter += max4(screenGlow * reflection * max(1.0 - 0.5 * uAmbient, 0.0), vec4(0.0));
     }
     
-    float light = line.r + uGlow * 1.5 * screen.g * screen.g * tightGlow.r;
-    light += uGlow * 0.3 * scatter.g * (2.0 + 1.0 * screen.g + 0.5 * screen.r);
+    // making the range of the glow slider more useful
+    float glow = 1.05 * pow(uGlow, 1.5);
+    float light = line.r + glow * 1.5 * screen.g * screen.g * tightGlow.r;
+    float scatterScalar = 0.3 * (2.0 + 1.0 * screen.g + 0.5 * screen.r);
+    light += glow * scatter.g * scatterScalar;
+    // add ambient light to graticule
+    light += (1.0 - uRealScreen) * max(uAmbient - 0.35, 0.0) * scatterScalar;
+    
     float tlight = 1.0-pow(2.0, -uExposure*light);
     float tlight2 = tlight * tlight * tlight;
     gl_FragColor.rgb = mix(uColour, vec3(1.0), 0.3+tlight2*tlight2*uOverexposure) * tlight;

Source/visualiser/VisualiserComponent.cpp

@@ -1091,8 +1091,11 @@ void VisualiserComponent::drawLine(const std::vector<float>& xPoints, const std:
     setOffsetAndScale(lineShader.get());
     
 #if SOSCI_FEATURES
-    lineShader->setUniform("uScreenOverlay", (GLfloat) screenOverlay);
     lineShader->setUniform("uFishEye", screenOverlay == ScreenOverlay::VectorDisplay ? VECTOR_DISPLAY_FISH_EYE : 0.0f);
+    lineShader->setUniform("uShutterLength", (GLfloat) settings.getShutterLength());
+#else
+    lineShader->setUniform("uFishEye", 0.0f);
+    lineShader->setUniform("uShutterLength", 0.0f);
 #endif
 
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vertexIndexBuffer);

Source/visualiser/VisualiserComponent.h

@@ -240,7 +240,7 @@ private:
     juce::OpenGLShaderProgram* currentShader;
     
     float fadeAmount;
-    ScreenOverlay screenOverlay = ScreenOverlay::MAX;
+    ScreenOverlay screenOverlay = ScreenOverlay::INVALID;
     
     const double RESAMPLE_RATIO = 6.0;
     double sampleRate = -1;

Source/visualiser/VisualiserSettings.h

@@ -11,6 +11,7 @@
 #include "../audio/StereoEffect.h"
 
 enum class ScreenOverlay : int {
+    INVALID = -1,
     Empty = 1,
     Graticule = 2,
     Smudged = 3,
@@ -177,6 +178,14 @@ public:
             VERSION_HINT, 0.0, -1.0, 1.0
         ),
     });
+    std::shared_ptr<Effect> shutterLengthEffect = std::make_shared<Effect>(
+        new EffectParameter(
+            "Shutter Length",
+            "Controls the percentage of time the camera shutter is open over a frame. This can be beneficial when the drawing frequency and frame rate are in sync.",
+            "shutterLength",
+            VERSION_HINT, 0.0, 0.0, 1.0
+        )
+    );
 #endif
 
     std::shared_ptr<Effect> persistenceEffect = std::make_shared<Effect>(
@@ -285,6 +294,7 @@ public:
         screenSaturationEffect,
         screenHueEffect,
         overexposureEffect,
+        shutterLengthEffect,
 #endif
     };
     std::vector<std::shared_ptr<Effect>> audioEffects = {
@@ -395,6 +405,10 @@ public:
     bool isGoniometer() {
         return parameters.goniometer->getBoolValue();
     }
+    
+    double getShutterLength() {
+        return parameters.shutterLengthEffect->getActualValue();
+    }
 #endif
     
     double getFocus() {
@@ -465,6 +479,7 @@ private:
 #if SOSCI_FEATURES
             std::make_shared<EffectComponent>(*parameters.afterglowEffect),
             std::make_shared<EffectComponent>(*parameters.overexposureEffect),
+            std::make_shared<EffectComponent>(*parameters.shutterLengthEffect),
 #else
             std::make_shared<EffectComponent>(*parameters.ambientEffect),
 #endif