MilkDrop fidelity: hue colour and the fixed composite as MilkDrop draws them

README.md

@@ -12,7 +12,7 @@
 [![Platform](https://img.shields.io/badge/platform-Windows%20%7C%20macOS%20%7C%20Linux-111997.svg)](#build--distribution)
 [![Electron](https://img.shields.io/badge/Electron-43-47848F.svg)](https://www.electronjs.org/)
 [![Downloads](https://img.shields.io/github/downloads/CaYatur/SoundVisualizer/total?label=downloads)](https://github.com/CaYatur/SoundVisualizer/releases)
-[![Tests](https://img.shields.io/badge/tests-2181%20passing-2ea043.svg)](#tests)
+[![Tests](https://img.shields.io/badge/tests-2184%20passing-2ea043.svg)](#tests)
 [![cayadev.com](https://img.shields.io/badge/cayadev.com-e11d2a.svg)](https://cayadev.com)
 
 </div>
@@ -255,6 +255,12 @@ that asserts the bar profile has no step in it.
   flipping. A preset that leaves out its decay or gamma gets MilkDrop's 0.98 and 2.0 instead of 0,
   and so do most other values a preset leaves out; a rotation centre of 0 stays in the corner.
   Rendered through the engine, every case matches MilkDrop's formula within 2/255.
+- **Composite shaders get the hue colour MilkDrop gives them.** MilkDrop passes every composite
+  shader four slowly drifting corner colours as `hue_shader`, whatever the preset's `fShader`
+  says; `fShader` only scales them on the fixed pipeline. The engine applied `fShader` to shaders
+  too, so about 950 presets of the corpus drew without their colour or with part of it, and the
+  corners were mirrored top to bottom. On the fixed pipeline the colour now goes through MilkDrop's
+  own draw passes, the wraparound of out-of-range colours included.
 - **Textured shapes, motion vectors, rotation matrices, mesh density, internal resolution scale,
   mouse input and preset transitions** are all implemented, and each sampler is read with the
   filtering and wrapping its name asks for (`sampler_pw_main` is point-sampled, `sampler_fc_main` is
@@ -1299,7 +1305,7 @@ npm test
 npm start -- --smoke
 ```
 
-**2181 unit tests, all passing.** They are written to check answers, not to exercise lines:
+**2184 unit tests, all passing.** They are written to check answers, not to exercise lines:
 
 - **Formulas** are checked against values derived by hand from their definitions — Viviani's curve
   staying on its sphere, the torus tube radius, Chladni's m↔n antisymmetry, every attractor

README.tr.md

@@ -12,7 +12,7 @@
 [![Platform](https://img.shields.io/badge/platform-Windows%20%7C%20macOS%20%7C%20Linux-111997.svg)](#paketleme--dağıtım)
 [![Electron](https://img.shields.io/badge/Electron-43-47848F.svg)](https://www.electronjs.org/)
 [![İndirme](https://img.shields.io/github/downloads/CaYatur/SoundVisualizer/total?label=indirme)](https://github.com/CaYatur/SoundVisualizer/releases)
-[![Test](https://img.shields.io/badge/test-2181%20geçiyor-2ea043.svg)](#testler)
+[![Test](https://img.shields.io/badge/test-2184%20geçiyor-2ea043.svg)](#testler)
 [![cayadev.com](https://img.shields.io/badge/cayadev.com-e11d2a.svg)](https://cayadev.com)
 
 </div>
@@ -248,6 +248,12 @@ profilinde basamak olmadığını doğruluyor.
   yeniden beliriyor. Sönmesini ya da gamasını yazmayan bir preset 0 yerine MilkDrop'un 0,98 ve
   2,0'ını alıyor, yazmadığı öteki değerlerin çoğu da öyle; dönme merkezi 0 ise köşede kalıyor.
   Motordan geçirilerek çizildi: her durum MilkDrop'un formülüyle 2/255 içinde aynı.
+- **Birleştirme shader'ları MilkDrop'un verdiği ton rengini alıyor.** MilkDrop her birleştirme
+  shader'ına `hue_shader` olarak dört köşede yavaşça gezinen renkler veriyor, presetin `fShader`ı
+  ne derse desin; `fShader` onları yalnız sabit yolda ölçekliyor. Motor `fShader`ı shader'lara da
+  uyguluyordu: korpustaki yaklaşık 950 preset renksiz ya da rengin bir kısmıyla çiziliyordu,
+  köşeler de dikeyde aynalanmıştı. Sabit yolda renk artık MilkDrop'un kendi çizim geçişlerinden,
+  aralık dışı renklerin sarması dahil, geçiyor.
 - **Dokulu şekiller, hareket vektörleri, dönme matrisleri, ağ sıklığı, iç çözünürlük, fare girdisi
   ve preset geçişleri** uygulandı; her sampler adının istediği süzme ve sarma ile okunuyor
   (`sampler_pw_main` noktasal, `sampler_fc_main` süzülmüş+kenetli — presetlerin %22,7'si aynı
@@ -1297,7 +1303,7 @@ npm test
 npm start -- --smoke
 ```
 
-**2181 birim testi, hepsi geçiyor.** Satır çalıştırmak için değil, cevap denetlemek için yazıldılar:
+**2184 birim testi, hepsi geçiyor.** Satır çalıştırmak için değil, cevap denetlemek için yazıldılar:
 
 - **Formüller**, tanımlarından elle türetilmiş değerlerle sınanıyor — Viviani eğrisinin küre
   üzerinde kalması, simidin boru yarıçapı, Chladni'nin m↔n antisimetrisi, her çekicinin sınırlı

ROADMAP.md

@@ -129,9 +129,9 @@ npm test
 npm start -- --smoke
 ```
 
-- **2181 unit tests, all passing** on `main`. 703 of those shipped in v3.1.0;
+- **2184 unit tests, all passing** on `main`. 703 of those shipped in v3.1.0;
   105 came with v3.1.1; 163 came with v3.1.2; 157 came with v3.1.3 — 1128 at
-  that tag — 469 more with v3.1.4, most of them from the MilkDrop work, and 584
+  that tag — 469 more with v3.1.4, most of them from the MilkDrop work, and 587
   on `main` since.
   Formulas are checked against values derived
   by hand from their definitions — Viviani's curve staying on its sphere, the
@@ -949,23 +949,24 @@ MilkDrop (#560):
   preset changes class, and rendered alone in both trees it is identical -
   that flip is the picture it inherits from the preset before it in the run,
   not this change. The legacy run is identical byte for byte.
-- **`hue_shader` only colours what the preset asked to colour** · done on
-  `main`. MilkDrop mixes the four corner colours towards white by the
-  preset's `fShader` amount, and skips them entirely below 0.001, leaving
-  white (milkdropfs.cpp:3857-3876); the default is zero (state.cpp:548). We
-  handed every preset the full colour. Of the 1,239 presets (12.0%) whose
-  composite shader reads `hue_shader`, 914 leave `fShader` at zero - their
-  picture was being tinted by a colour MilkDrop never sends - and 36 ask for
-  a partial amount. Six of those presets rendered alone in both trees all
-  differ, five of them by a lot (means of 3.6 to 26.9 of 255, up to 89% of
-  pixels past 8), and all six are identical with the fidelity switch off; on
-  the 900-preset sample no preset changes class. The same four colours then
-  reached the other half of the picture: MilkDrop draws its fixed composite
-  quad with them as vertex colours (milkdropfs.cpp:3940-3946) and we applied
-  none, so the 631 presets that have no composite shader and ask for a
-  non-zero `fShader` were missing the tint entirely. Six of them rendered
-  alone all differ (means of 0.3 to 13.0 of 255, up to 60% of pixels past 8)
-  and stay identical with the switch off.
+- **`hue_shader` gets the colour MilkDrop sends** · done on `main`,
+  corrected in #580. MilkDrop builds four corner colours every frame and uses
+  them in two ways. Every composite shader gets the full colour as
+  `hue_shader`, whatever the preset's `fShader` says - the D3D11 and the D3D9
+  code both note "since we don't know if shader uses it or not"
+  (milkdropfs.cpp:4122) - and `fShader` scales it only in the shader MilkDrop
+  writes for a preset without one. The fixed composite mixes the colours
+  towards white by `fShader`, skips them below 0.001 (milkdropfs.cpp:
+  3857-3884; the default is zero, state.cpp:548) and draws its quad with them
+  as vertex colours (3940-3946). The first version of this change (16
+  September) took the fixed composite's rule for the shaders too: with
+  fidelity on, the 914 presets whose composite shader reads `hue_shader` and
+  leaves `fShader` at zero lost their colour, and 36 got part of it. #580 gave
+  the full colour back and found the shader corners mirrored top to bottom as
+  well. The fixed composite applied no colour at all before this change; the
+  631 presets without a composite shader that ask for a non-zero `fShader`
+  got the tint here and kept it, and #580 takes its amount from the file
+  instead of per-frame values and draws it as MilkDrop does.
 - **Motion vectors sit where MilkDrop puts them and point where it points** ·
   done on `main`. Four differences in one field (milkdropfs.cpp:1172-1320):
   the count is truncated with its fraction widening the grid spacing, and the
@@ -2030,9 +2031,9 @@ rest after. No version number yet.
     was equivalent, and the branch it changed was removed. Putting back
     the old ring nouns, the " · " in mash-up names or removing the
     module's script tag each fails a test.
-- **Fidelity follow-ups (#580)** · the fixed composite, the stage rule and
-  MilkDrop's defaults are done; the other audits and the file-reading
-  differences are next.
+- **Fidelity follow-ups (#580)** · the fixed composite, the stage rule,
+  MilkDrop's defaults and the hue colour are done; the remaining defaults,
+  the other audits and the file-reading differences are next.
   - **Checked against the source.** Nullsoft's own code
     (jecassis/foo_vis_milk2 5b44cea) and, for the fixed pipeline's blend
     passes, the D3D9 code the D3D11 fork was ported from (BeatDrop
@@ -2101,34 +2102,72 @@ rest after. No version number yet.
     preset with `PSVERSION_WARP=0` was written as version 2 and drawn — so
     the mash-up rule version went from 1 to 2: a mash-up saved under the
     old rule keeps its file, and saving the recipe again writes a new one.
-  - **Found while finishing this, fixed next.** MilkDrop hands every
-    composite shader the full hue colour ("since we don't know if shader
-    uses it or not", in both the D3D11 and the D3D9 code); `fShader` scales
-    it only on the fixed path and in the shader MilkDrop writes for a
-    preset without one. The engine has applied `fShader` to preset shaders
-    too since the `hue_shader` change of 16 September, so with fidelity on
-    the 914 corpus presets that read `hue_shader` and leave `fShader` at 0
-    lost their colour, and 36 got part of it. In the shader written for a
-    composite stage with a version and no text, a partial `fShader` now
-    lands twice, in the text and in the colour; the one corpus preset with
-    such a stage has `fShader` at 0. The engine also takes the
-    amount from per-frame values: 16 presets write `fshader` in code,
-    which MilkDrop never sees, all of them with a composite shader. Some
-    keys fall back to something else when a file leaves them out. MilkDrop
-    reads a missing `wave_r`, `wave_g`, `wave_b`, `wave_x` or `wave_y` as
-    `rot`'s value at that point, which is 0, where the engine has 1, 1, 1,
-    0.5 and 0.5. Missing wave smoothing is 0.75, and the volume fade runs
-    from 0.75 to 0.95. Custom shapes default to red inside and green
-    outside. No corpus preset leaves any of these out, and neither do ours.
+  - **The hue colour, as MilkDrop gives it** (found while finishing the
+    first change). MilkDrop hands every composite shader the full hue
+    colour, and the engine had applied `fShader` there as well (see the
+    corrected #560 entry). With fidelity on, preset shaders get the full
+    colour again. Their corners were mirrored top to bottom too: MilkDrop
+    weighs them by the composite grid's screen position, with y at 1 on top
+    (plugin.cpp:1475-1490), and our translation flipped y. On the fixed
+    composite the amount is the file's `fShader`, blended linearly through a
+    transition like MilkDrop's other file values; 16 presets write `fshader`
+    in per-frame code, which MilkDrop never sees. It is no longer clamped to
+    1, and each draw's corner colour goes through `COLOR_NORM`, so the 16
+    presets with `fShader` 10 wrap into other colours as in MilkDrop. The
+    quad is interpolated as MilkDrop's two triangles, not bilinearly, and a
+    generated composite stage no longer gets a partial `fShader` twice. Echo
+    fading during a blend now looks at the new side's blended echo alpha, as
+    MilkDrop does, so the old echo fades out even when the new preset has
+    none.
+  - **Measured.** Four pure colours read back from the screen: corner 0
+    sits top right in shaders and top left on the fixed quad, as in
+    MilkDrop, and the quad's centre is the mean of corners 1 and 2. The
+    fixed composite through the engine: 72 of 72 cases within 2/255,
+    including gamma 3.7 with echo 0.5, which is eight draws; a simulation
+    that rounds after every draw, as MilkDrop's 8-bit buffer does, differs
+    from our single rounding by at most 0.6/255 in those cases. The last
+    ten of 60 frames against `main`, up to 120 presets a group:
+    - shader presets that do not read `hue_shader`: 120 of 120 identical;
+    - `fShader` at 0: 95 of 120 changed by more than 1%, and their median
+      saturation went from 0.006 to 0.150;
+    - `fShader` 1 or more, where only the corners move: 90 of 120 changed,
+      median 4.3%;
+    - partial `fShader`: 28 of 36 changed;
+    - fixed composite with `fShader` above 0.001: 30 of 120 changed,
+      median 0.5%, and 12 of the 16 at 10;
+    - fixed composite without it: rounding only, the largest mean change
+      0.36%.
+
+    On the 900-preset sample one preset moves from blown to clean (882 →
+    883 clean): it scales its picture by `hue_shader`, which was white on
+    `main`; rendered alone its brightness goes from 0.555 to 0.507 and its
+    share of pixels at full from 45.8% to 41.7%.
+    With fidelity off the fixed composite and the control group stay
+    byte-identical; presets that read `hue_shader` differ in at most 0.1%
+    of pixels by one level, the same four equal corner colours summed in
+    another order.
+  - **Next: keys that fall back to other values.** MilkDrop reads a
+    missing `wave_r`, `wave_g`, `wave_b`, `wave_x` or `wave_y` as `rot`'s
+    value at that point, which is 0, where the engine has 1, 1, 1, 0.5 and
+    0.5. Missing wave smoothing is 0.75, and the volume fade runs from 0.75
+    to 0.95. Custom shapes default to red inside and green outside. MilkDrop
+    also blends its other file-only values linearly through a transition
+    (wave scale and smoothing, the fade range, warp scale), where the engine
+    reads them from per-frame values. No corpus preset leaves any of these
+    keys out, and neither do ours.
   - **Not done yet:** the fixed warp path, the blur chain, borders and
     centre darkening, and the rest of the blend snap points; the
     file-reading differences found while building the mash-ups (a
     duplicated key, where MilkDrop reads the first occurrence and we keep
     the last; numbered code that MilkDrop stops reading at the first
     missing number; `\\` comments; integer keys holding fractions; text
     after a number; key case; indented lines — about 40 corpus presets in
-    all); the reference comparison with an external renderer, which needs
-    one installed and waits for the user's approval.
+    all); whether `uv` in preset shaders runs the way MilkDrop's does —
+    read back from the screen, our `uv.y` is 1 at the top, where MilkDrop's
+    texture coordinate is 0; sampling agrees, but a shader doing arithmetic
+    on `uv.y` may come out mirrored, which needs its own check; the
+    reference comparison with an external renderer, which needs one
+    installed and waits for the user's approval.
   - **Tests.** 14 new: the version rule and the stage choice, the two
     generated shaders (float rounding, samplers, echo, hue, flag order,
     and that they translate), echo orientation and gamma cases, the
@@ -2144,7 +2183,14 @@ rest after. No version number yet.
     check follow the new key; the mash-up tests check the part test
     against the engine's stage choice and expect `md_mix2_` ids. 36 of 36
     mutations are caught, one of them putting the mash-up rule version
-    back to 1.
+    back to 1. The hue change adds three tests — the fixed quad's two
+    triangles run through the shader's own formula, the fixed amount taken
+    from the file and not from per-frame values, and its linear blend — and
+    reworks the hue tests: preset shaders at full colour for every
+    `fShader`; the fixed amount's threshold, partial mix and no clamp; the
+    draw weights (pass counts, the 1.0001 cut, the edge below −0.999,
+    wraparound, per-corner order); the echo fade with no echo on the new
+    side; and `hueAt` not flipping y. 18 of 18 mutations are caught.
 
 ## v3.1.6 — Comprehensive video export
 

src/shared/milkdrop-shader.js

@@ -503,10 +503,16 @@
        tamamı hacim gürültüsünü veriyor; iki boyutlu aşırı yükleme yine de
        duruyor, çünkü korpus dışında bir preset 2B sampler geçirirse eskiden
        derlenen shader birden derlenmez olurdu. */
-    /* Dort kose renginin cift dogrusal karisimi. MilkDrop'un tarama sirasi
-       ekranin USTUNDEN baslıyor, bizim `uv.y` ise altta sifir: bu yuzden y
-       ters cevriliyor. Ters cevrilmezse renk gecisi dikeyde aynalanirdi. */
-    'vec3 hueAt(vec2 p){ float x = p.x; float y = 1.0 - p.y;' +
+    /* Dört köşe renginin çift doğrusal karışımı, MilkDrop'un ağırlıklarıyla
+       (milkdropfs.cpp:4146-4160; BeatDrop'un D3D9 hâli aynı): köşe 0 x·y,
+       1 (1−x)·y, 2 x·(1−y), 3 (1−x)·(1−y). x ve y birleştirme ağının
+       EKRAN konumundan geliyor ve y ekranın ÜSTÜNDE 1 — ağ `sy`yi üst
+       satırda +1 kuruyor (plugin.cpp:1475-1490) — yani 0 üst-sağ, 1 üst-sol,
+       2 alt-sağ, 3 alt-sol. Bizim `uv.y` de ekranın üstünde 1: ağın ilk
+       satırı altta, ve ekrandan geri okunarak doğrulandı. Burada
+       `1.0 - p.y` vardı ("MilkDrop'un taraması üstten başlıyor" diye) ve
+       renk geçişini dikeyde aynalıyordu (#580). */
+    'vec3 hueAt(vec2 p){ float x = p.x; float y = p.y;' +
       ' return hue_corner[0] * x * y + hue_corner[1] * (1.0 - x) * y' +
       ' + hue_corner[2] * x * (1.0 - y) + hue_corner[3] * (1.0 - x) * (1.0 - y); }',
     'vec3 tex3D(sampler3D s, vec3 uv2){ return texture(s, uv2).xyz; }',