makepad/apps/vj/resources/effects/94_ink_drop.splash
Admin f44616b2a7 makepad-vj effects: the effect renderstack, with the shaders inside the documents
The VJ's EFFECT surface is a small renderer of its own. An effect is a
`.splash` DOCUMENT — engine choice, stages, fields, parameters and now the
SHADERS THEMSELVES live in the document rather than in Rust. That is the
shape this commit introduces (dev has never seen an intermediate one): a
document is the whole effect, and the Rust side is the engine families that
documents draw with.

The engine families: particles and emitters, GPU sim swarms and fluid, static
meshes (firefly synchrony, harmonograph loom, domino liturgy), tiles, flock,
clouds, city, pipes, stock charts, an SDF raymarcher with a subclassable
`scene_sdf`, and a mountain-jet endless range with a beat-pulsed fighter.

Three things make them a system rather than a demo reel:

  - SIM FIELDS — a float simulation-texture primitive, so an engine can carry
    GPU state across frames (wind, particles, fluid) instead of being a pure
    function of the clock.
  - CONTENT COUPLING — `content:` in a document and `input0` on every engine's
    tex0, so an effect can consume the program video: drapes, backdrops,
    mirrors, billboards, chrome, frescoes, canopy, glass, silk, wall, swarm,
    pen and mosaic families all take the picture playing behind them.
  - MUSIC BINDING — shaders read the beat, so the whole library moves with the
    track rather than on its own clock.

Roughly a hundred seeded preset documents ship with it, each with a lazily
rendered animated thumbnail (rendered 4x and box-downscaled, 16-tap SSAA);
the thumbnail pass went from four minutes to eleven seconds. CONTRACT.md is
the document contract and its verify recipe; IDEAS.md is the campaign tracker.
2026-08-23 01:35:44 +02:00

74 lines
2.6 KiB
Text

// INK DROP — the STABLE-FLUIDS engine: advect, divergence, a budgeted
// jacobi pressure solve (`iters`) and projection run on a float GPU grid
// every frame; dye splats inject ON THE KICK at a per-beat hashed point,
// in a palette color that cycles per beat. The ink then genuinely FLOWS —
// filaments curl, collide and fade like drops in dark water.
{
name: "Ink Drop"
engine: "fluid"
seed: 4
grid: 176
iters: 24
force: 2.6
dissipation: 0.10
swirl: 0.35
splat: "(2.2 + pulse * 0.9) * (0.2 + 1.6*p2)"
dye_fade: 0.12
radius: 0.075
vortex: 3.2
beat_pulse: 0.4
beat_rate: 0.5
// p0 = flow-warp of the (unused) input, p1 = input mix: pure ink here.
p0: 0.0
p1: 0.0
p2: 0.5
// PERFORMANCE DIALS — WARP/MIX are the fluid engine's own p0/p1
// levers (MIX up brings the channel content through the ink, WARP
// bends it with the flow); SPLAT routes p2 through the dye splats.
dials: [
{name: "WARP", bind: "p0", default: 0.0},
{name: "MIX", bind: "p1", default: 0.0},
{name: "SPLAT", bind: "p2", default: 0.5}
]
color_bg: #x06060a
color_a: #x30c8ff
color_b: #xff3a9a
color_c: #xb0ff5a
glow: 2.6
stages: [
{kind: "bloom", threshold: 0.6, strength: 1.0, levels: 2}
]
// THE LOOK LIVES HERE. This block is not a reference to the
// engine's shader — it IS the pixel math this effect runs.
// Rewrite it and the effect looks different; everything else
// (geometry, motion, the content coupling, the beat) keeps
// working, because the block SUBCLASSES the engine shader.
// Inputs: uv, the dye and flow texels, and the base under the ink.
// Signals: self.time_beat (time, beat, phase, pulse),
// self.sig (bar, bpm, energy, dt), self.user (p0..p3),
// self.col_a/b/c/bg, self.fog (density, glow, content, -).
shader: draw.DrawVjFxFluidView {
fx_shade: fn(uv: vec2, dye: vec4, flow: vec4, base: vec3) -> vec4 {
let glow = self.u_view.x
let ink = vec3(dye.x, dye.y, dye.z) * glow
let shimmer = clamp(length(flow.xy) * 0.35, 0.0, 0.6)
let mut lit = ink + ink * shimmer
// Soft-knee tone map: color survives density; only genuinely
// dense ink approaches white.
lit = lit / (vec3(1.0, 1.0, 1.0) + lit * 0.45)
let rgb = vec3(1.0, 1.0, 1.0)
- (vec3(1.0, 1.0, 1.0) - base)
* clamp(vec3(1.0, 1.0, 1.0) - lit, vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0))
return vec4(rgb, 1.0)
}
}
}