Annotations

shaders/singularity/shader.slang

@@ -20,6 +20,8 @@ float4 shadeVideo(ShaderContext context)
 	float2 p = (fragCoord + fragCoord - resolution) / resolution.y / safeScale;
 	p -= center + float2(sin(seed * 6.2831853), cos(seed * 6.2831853)) * 0.035;
 
+	// Build a skewed coordinate system around an offset "black hole" so the
+	// waves pinch and stretch instead of staying radially symmetric.
 	float iterator = 0.2;
 	float2 diagonal = normalize(float2(-1.0 + seed * 0.5, 1.0 - seed * 0.35));
 	float2 blackholeCenter = p - iterator * diagonal;
@@ -30,6 +32,8 @@ float4 shadeVideo(ShaderContext context)
 	float2 v = singularitySpiral(c, time, iterator);
 	float2 waves = float2(0.0001, 0.0001);
 
+	// Iterative sine feedback creates the accretion texture; the iterator value
+	// also damps later steps to keep the pattern stable.
 	for (; iterator < 9.0; iterator += 1.0)
 	{
 		waves += 1.0 + sin(v);
@@ -40,6 +44,8 @@ float4 shadeVideo(ShaderContext context)
 	float disk = 2.0 + diskRadius * diskRadius * (0.25 * safeTightness) - diskRadius;
 	float centerDarkness = 0.5 + 1.0 / max(dot(c, c), 0.0001);
 	float rim = 0.025 + abs(length(p) - safeRingRadius) * safeTightness;
+	// Exponential falloff turns the accumulated wave field into bright rims and
+	// a darker center without hard thresholds.
 	float4 redBlueGradient = exp(c.x * float4(0.6, -0.4, -1.0, 0.0) * colorShift);
 	float4 waveColor = waves.xyyx;