Ripple and Glitch are gone; Crt stays

The user tried them live and wants them removed entirely: the builtins,
their levels, config keys and leader paths (tR, tg), their slots in the
built-in chain, their shaders (source and prebuilt), EffectCode paths, and
on macOS their scene flags (pardes.h), the Metal kernel's coordinate warps
and the Swift pointer mapping that mirrored them. Docs say so (decision 8
in docs/render-pipeline.md); config.md documents Crt's levels, Shader and
ShaderAnimation instead.

Shared files touched: macos.zig (flags). Not touched: pardes.zig,
Messages.zig, mouse.zig, gui.zig, detached/*.

1 files changed, 9 insertions, 66 deletions

diff --git a/shaders/crt.ci.metal b/shaders/crt.ci.metal
index c7e91a7e..9159af18 100644
--- a/shaders/crt.ci.metal
+++ b/shaders/crt.ci.metal
@@ -1,7 +1,6 @@
 // Native macOS panel and scene postprocess. Panel kernels consume the core's
-// plain tracks; the final full-window kernel ports crt.frag.glsl and combines
-// CRT, ripple and glitch. Scene constants and sampling geometry stay in step
-// with GLSL, while panel easing/noise stays in step with panel_animation.zig.
+// plain tracks; the final full-window kernel is the CRT. Panel easing/noise
+// stays in step with panel_animation.zig.
 //
 // The three entry points are `extern "C" [[stitchable]]`. Both halves are
 // load-bearing: this source is compiled at runtime by
@@ -38,24 +37,6 @@ float pardesCellNoise(float2 serialParts, float colValue, float rowValue) {
     return float(x & 0xffffu) / 65535.0;
 }
 
-float2 pardesSceneUV(float2 uv, float timeSeconds, float rippleOn, float glitchOn) {
-    if (rippleOn > 0.5) {
-        float2 centered = uv - 0.5;
-        float radius = length(centered);
-        // Reversed smoothstep edges are undefined in GLSL and Metal alike.
-        float envelope = 1.0 - smoothstep(0.04, 0.72, radius);
-        float wave = sin(radius * 42.0 - timeSeconds * 5.2);
-        uv += centered / max(radius, 0.00001) * wave * envelope * 0.0032;
-    }
-    if (glitchOn > 0.5) {
-        float band = floor(uv.y * 96.0);
-        float seed = pardesNoise(float2(band, floor(timeSeconds * 13.0)));
-        float tear = smoothstep(0.955, 1.0, seed);
-        uv.x += (pardesNoise(float2(seed, band)) - 0.5) * tear * 0.020;
-    }
-    return uv;
-}
-
 float4 pardesSceneSample(
     coreimage::sampler source,
     float2 origin,
@@ -66,42 +47,13 @@ float4 pardesSceneSample(
         source.sample(source.transform(origin + uv * size)));
 }
 
-// Keep this ordering identical to crt.frag.glsl's sceneSrgb: every caller
-// supplies its own pre-warp coordinate, then ripple/glitch move that sample,
-// then glitch splits its red/blue channels around the moved center.
-float4 pardesSceneSrgb(
-    coreimage::sampler source,
-    float2 origin,
-    float2 size,
-    float2 uv,
-    float timeSeconds,
-    float rippleOn,
-    float glitchOn
-) {
-    float2 warped = pardesSceneUV(uv, timeSeconds, rippleOn, glitchOn);
-    float4 center = pardesSceneSample(source, origin, size, warped);
-    if (glitchOn <= 0.5) return center;
-
-    float band = floor(warped.y * 96.0);
-    float seed = pardesNoise(float2(band, floor(timeSeconds * 13.0)));
-    float tear = smoothstep(0.955, 1.0, seed);
-    float2 chroma = float2((0.35 + 1.25 * tear) / size.x, 0.0);
-    float4 red = pardesSceneSample(source, origin, size, warped + chroma);
-    float4 blue = pardesSceneSample(source, origin, size, warped - chroma);
-    return float4(red.r, center.g, blue.b, center.a);
-}
-
 float3 pardesSceneLinear(
     coreimage::sampler source,
     float2 origin,
     float2 size,
-    float2 uv,
-    float timeSeconds,
-    float rippleOn,
-    float glitchOn
+    float2 uv
 ) {
-    return coreimage::srgb_to_linear(pardesSceneSrgb(
-        source, origin, size, uv, timeSeconds, rippleOn, glitchOn).rgb);
+    return coreimage::srgb_to_linear(pardesSceneSample(source, origin, size, uv).rgb);
 }
 
 bool pardesInside(float2 p, float4 box) {
@@ -242,8 +194,6 @@ extern "C" [[stitchable]] float4 pardesScene(
     float timeSeconds,
     float frame,
     float crtOn,
-    float rippleOn,
-    float glitchOn,
     float2 sceneSize,
     float2 sceneOrigin,
     coreimage::destination destination
@@ -277,24 +227,18 @@ extern "C" [[stitchable]] float4 pardesScene(
     // transparent theme.
     if (crtOn > 0.5 && edge <= 0.0) return float4(0.0, 0.0, 0.0, 1.0);
 
-    float4 center = pardesSceneSrgb(
-        source, origin, size, uv, timeSeconds, rippleOn, glitchOn);
+    float4 center = pardesSceneSample(source, origin, size, uv);
     float3 scene = center.rgb;
 
-    // Ripple/glitch alone are coordinate effects. Returning the sampled sRGB
-    // values directly keeps exact theme colors exact.
+    // Without the CRT the scene passes through, exact.
     if (crtOn <= 0.5) {
         return coreimage::premultiply(float4(clamp(scene, 0.0, 1.0), center.a));
     }
 
     float3 centerLinear = coreimage::srgb_to_linear(scene);
     float2 radialChroma = cc * (chromaPx * r2) * texel;
-    float3 redSample = pardesSceneLinear(
-        source, origin, size, uv + radialChroma,
-        timeSeconds, rippleOn, glitchOn);
-    float3 blueSample = pardesSceneLinear(
-        source, origin, size, uv - radialChroma,
-        timeSeconds, rippleOn, glitchOn);
+    float3 redSample = pardesSceneLinear(source, origin, size, uv + radialChroma);
+    float3 blueSample = pardesSceneLinear(source, origin, size, uv - radialChroma);
     float3 col = float3(
         redSample.r,
         centerLinear.g,
@@ -308,8 +252,7 @@ extern "C" [[stitchable]] float4 pardesScene(
         float2(0.0, bloom.y), float2(0.0, -bloom.y)
     };
     for (uint i = 0; i < 4; i++) {
-        // Deliberately raw, like GLSL brightPass: bloom belongs to the source
-        // image and does not recursively warp through the scene effects.
+        // Deliberately raw, like GLSL brightPass.
         float4 sampleValue = pardesSceneSample(
             source, origin, size, uv + bloomOffsets[i]);
         float3 linearValue = coreimage::srgb_to_linear(sampleValue.rgb);