Layer stacking

shaders/vhs/shader.json

@@ -67,6 +67,33 @@
       "min": 0.0,
       "max": 0.5,
       "step": 0.01
+    },
+    {
+      "id": "bloomAmount",
+      "label": "Bloom",
+      "type": "float",
+      "default": 0.18,
+      "min": 0.0,
+      "max": 0.6,
+      "step": 0.01
+    },
+    {
+      "id": "fadeAmount",
+      "label": "Fade",
+      "type": "float",
+      "default": 0.22,
+      "min": 0.0,
+      "max": 0.75,
+      "step": 0.01
+    },
+    {
+      "id": "noiseAmount",
+      "label": "Noise",
+      "type": "float",
+      "default": 0.055,
+      "min": 0.0,
+      "max": 0.2,
+      "step": 0.005
     }
   ]
 }

shaders/vhs/shader.slang

@@ -39,6 +39,38 @@ float3 yiq2rgb(float3 c)
 	);
 }
 
+float noiseHash(float2 p)
+{
+	return frac(sin(dot(p, float2(127.1, 311.7))) * 43758.5453123);
+}
+
+float3 chromaSpeckle(float2 uv, float framecount)
+{
+	float2 coarseUv = floor(uv);
+	float r = noiseHash(coarseUv + float2(framecount * 19.0, framecount * 11.0));
+	float g = noiseHash(coarseUv + float2(framecount * 23.0 + 17.0, framecount * 7.0 + 31.0));
+	float b = noiseHash(coarseUv + float2(framecount * 13.0 + 47.0, framecount * 29.0 + 9.0));
+	return float3(r, g, b) - 0.5;
+}
+
+float3 softBloom(float2 uv, float2 outputResolution, float radius)
+{
+	float2 pixel = 1.0 / max(outputResolution, float2(1.0, 1.0));
+	float2 dx = float2(pixel.x * radius, 0.0);
+	float2 dy = float2(0.0, pixel.y * radius);
+
+	float3 sum = sampleVideo(frac(uv)).rgb * 0.28;
+	sum += sampleVideo(frac(uv + dx)).rgb * 0.14;
+	sum += sampleVideo(frac(uv - dx)).rgb * 0.14;
+	sum += sampleVideo(frac(uv + dy)).rgb * 0.14;
+	sum += sampleVideo(frac(uv - dy)).rgb * 0.14;
+	sum += sampleVideo(frac(uv + dx + dy)).rgb * 0.075;
+	sum += sampleVideo(frac(uv + dx - dy)).rgb * 0.075;
+	sum += sampleVideo(frac(uv - dx + dy)).rgb * 0.075;
+	sum += sampleVideo(frac(uv - dx - dy)).rgb * 0.075;
+	return sum;
+}
+
 float3 blurVhs(float2 uv, float d, int sampleCount)
 {
 	float3 sum = float3(0.0, 0.0, 0.0);
@@ -107,6 +139,26 @@ float4 shadeVideo(ShaderContext context)
 	float halationMask = smoothstep(0.45, 1.0, halationLuma) * halationAmount;
 	color += halationSource * float3(1.0, 0.38, 0.24) * halationMask * 0.35;
 
+	float3 bloomSource = softBloom(context.uv, context.outputResolution, 2.0 + smear * 2.5);
+	float bloomLuma = dot(bloomSource, float3(0.299, 0.587, 0.114));
+	float bloomMask = smoothstep(0.32, 1.0, bloomLuma) * bloomAmount;
+	color = lerp(color, bloomSource, bloomAmount * 0.18);
+	color += bloomSource * float3(1.0, 0.96, 0.92) * bloomMask * 0.24;
+
+	float2 noiseUv = context.uv * context.outputResolution * float2(0.55, 1.1);
+	float3 speckle = chromaSpeckle(noiseUv, framecount);
+	float luma = dot(color, float3(0.299, 0.587, 0.114));
+	float noiseMask = lerp(0.65, 1.0, 1.0 - saturate(luma));
+	float3 chromaNoise = float3(speckle.x * 1.1, speckle.y * 0.45, speckle.z * 1.2);
+	color += chromaNoise * noiseAmount * noiseMask;
+	color.rg = lerp(color.rg, float2(color.r, color.g) + speckle.xy * noiseAmount * 0.18, 0.35);
+	color.b = lerp(color.b, color.b + speckle.z * noiseAmount * 0.22, 0.45);
+
+	float3 grayscale = float3(luma, luma, luma);
+	color = lerp(color, grayscale, fadeAmount * 0.18);
+	color = color * (1.0 - fadeAmount * 0.08) + float3(0.055, 0.055, 0.065) * fadeAmount;
+	color = lerp(color, softBloom(context.uv, context.outputResolution, 1.0 + smear), fadeAmount * 0.12);
+
 	float vignetteBase = context.uv.x * (1.0 - context.uv.x) * context.uv.y * (1.0 - context.uv.y);
 	float vignette = saturate(pow(vignetteBase * 16.0, 0.22));
 	color *= lerp(1.0 - vignetteAmount, 1.0, vignette);