added new layer input pass

shaders/feedback-highlight-accumulator/shader.json

@@ -1,18 +1,36 @@
 {
   "id": "feedback-highlight-accumulator",
   "name": "Feedback Highlight Accumulator",
-  "description": "Demonstrates shader-local feedback by accumulating only the brightest-looking parts of the image over a timed window, then resetting and starting again. The highlight selection is an approximation based on a luminance threshold rather than an exact percentile reduction.",
+  "description": "Demonstrates shader-local feedback by storing a rolling 4-frame per-pixel highlight history in RGBA and displaying only the newest 3 frames. The highlight selection is an approximation based on a luminance threshold rather than an exact percentile reduction.",
   "category": "Feedback",
-  "entryPoint": "shadeVideo",
+  "entryPoint": "buildHistory",
+  "passes": [
+    {
+      "id": "history",
+      "source": "shader.slang",
+      "entryPoint": "buildHistory",
+      "output": "historyBuffer"
+    },
+    {
+      "id": "display",
+      "source": "shader.slang",
+      "entryPoint": "displayHistory",
+      "inputs": [
+        "historyBuffer"
+      ],
+      "output": "layerOutput"
+    }
+  ],
   "feedback": {
-    "enabled": true
+    "enabled": true,
+    "writePass": "history"
   },
   "parameters": [
     {
       "id": "highlightThreshold",
       "label": "Highlight Threshold",
       "type": "float",
-      "default": 0.99,
+      "default": 0.92,
       "min": 0.5,
       "max": 1.5,
       "step": 0.001,
@@ -30,23 +48,23 @@
     },
     {
       "id": "accumulateAmount",
-      "label": "Accumulate Amount",
+      "label": "Contribution Amount",
       "type": "float",
-      "default": 0.2,
+      "default": 0.6,
       "min": 0.0,
       "max": 2.0,
       "step": 0.001,
-      "description": "How much of each bright sample gets added into the running feedback image."
+      "description": "Strength of each frame's highlight contribution before it is shifted into the rolling history."
     },
     {
       "id": "displayGain",
       "label": "Display Gain",
       "type": "float",
-      "default": 1.0,
+      "default": 2.5,
       "min": 0.0,
-      "max": 4.0,
+      "max": 8.0,
       "step": 0.01,
-      "description": "Brightness applied to the accumulated feedback when displayed."
+      "description": "Brightness applied to the sum of the most recent three stored highlight samples."
     },
     {
       "id": "baseMix",
@@ -56,17 +74,7 @@
       "min": 0.0,
       "max": 1.0,
       "step": 0.01,
-      "description": "Amount of the live source image kept under the accumulation."
-    },
-    {
-      "id": "resetSeconds",
-      "label": "Reset Seconds",
-      "type": "float",
-      "default": 10.0,
-      "min": 1.0,
-      "max": 60.0,
-      "step": 0.1,
-      "description": "Length of each accumulation window before the feedback resets."
+      "description": "Amount of the live source image kept under the recent highlight history display."
     }
   ]
 }

shaders/feedback-highlight-accumulator/shader.slang

@@ -3,29 +3,45 @@ float luminance(float3 color)
     return dot(color, float3(0.2126, 0.7152, 0.0722));
 }
 
-float currentResetPhase(float timeSeconds, float resetInterval)
+float4 buildHistory(ShaderContext context)
 {
-    float safeInterval = max(resetInterval, 0.001);
-    float cycleIndex = floor(timeSeconds / safeInterval);
-    return frac(cycleIndex * 0.5) >= 0.5 ? 1.0 : 0.0;
-}
-
-float4 shadeVideo(ShaderContext context)
-{
-    float safeResetSeconds = max(resetSeconds, 0.001);
-    float phase = currentResetPhase(context.time, safeResetSeconds);
-
     float4 previousFeedback = sampleFeedback(context.uv);
-    bool phaseMatches = context.feedbackAvailable > 0 && abs(previousFeedback.a - phase) < 0.25;
-    float3 previousAccumulation = phaseMatches ? previousFeedback.rgb : float3(0.0, 0.0, 0.0);
+    float4 previousHistory = context.feedbackAvailable > 0
+        ? previousFeedback
+        : float4(0.0, 0.0, 0.0, 0.0);
 
+    // Highlight selection is always based on the live source image only.
+    // The stored feedback never feeds back into the threshold test.
     float currentLuma = luminance(context.sourceColor.rgb);
     float thresholdWidth = max(softness, 0.0001);
     float brightMask = smoothstep(highlightThreshold - thresholdWidth, highlightThreshold + thresholdWidth, currentLuma);
 
-    float3 currentContribution = context.sourceColor.rgb * brightMask * max(accumulateAmount, 0.0);
-    float3 nextAccumulation = saturate(previousAccumulation + currentContribution);
+    // Treat RGBA as a 4-slot rolling scalar history:
+    // R = current frame, G = 1 frame ago, B = 2 frames ago, A = 3 frames ago.
+    // Each frame shifts the history forward and drops the oldest sample.
+    float currentContribution = currentLuma * brightMask * max(accumulateAmount, 0.0);
+    float4 nextHistory = float4(
+        currentContribution,
+        previousHistory.r,
+        previousHistory.g,
+        previousHistory.b
+    );
 
-    float3 displayColor = context.sourceColor.rgb * saturate(baseMix) + nextAccumulation * max(displayGain, 0.0);
-    return float4(saturate(displayColor), phase);
+    return saturate(nextHistory);
+}
+
+float4 displayHistory(ShaderContext context)
+{
+    // In the display pass, context.sourceColor is the same-frame historyBuffer
+    // produced by buildHistory().
+    float4 history = context.sourceColor;
+    float recentEnergy = history.r + history.g + history.b;
+    float3 originalColor = sampleLayerInput(context.uv).rgb;
+    float highlightBoost = recentEnergy * max(displayGain, 0.0);
+    float3 sourceHue = originalColor / max(max(originalColor.r, originalColor.g), max(originalColor.b, 0.0001));
+    float3 displayColor =
+        originalColor +
+        sourceHue * highlightBoost * 1.5;
+
+    return float4(saturate(displayColor), 1.0);
 }