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<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>Putt-Putt on the Great Sea</title>
<style>
html,body{margin:0;height:100%;overflow:hidden;background:#0a2540}
canvas{display:block;width:100vw;height:100vh}
#hud{position:fixed;left:16px;top:14px;color:#e9f5ff;font:12px/1.6 ui-monospace,SFMono-Regular,Menlo,monospace;
text-shadow:0 2px 6px rgba(0,0,0,.45);pointer-events:none}
#hud b{font-size:13px;letter-spacing:.12em}
#hudText{animation:fade 1.2s ease 15s forwards}
@keyframes fade{ to{ opacity:0; visibility:hidden } }
canvas.idle{cursor:none}
#menu{position:fixed;right:16px;top:14px;width:250px;padding:12px 14px;pointer-events:auto;
background:rgba(10,37,64,.86);border:1px solid rgba(233,245,255,.22);border-radius:8px;
color:#e9f5ff;font:12px/1.6 ui-monospace,SFMono-Regular,Menlo,monospace;
text-shadow:0 2px 6px rgba(0,0,0,.45);display:none}
#menu.open{display:block}
#menu .grp>b{letter-spacing:.12em;color:#79d2ff}
#menu label{display:flex;align-items:center;gap:10px;margin-top:5px}
#menu label span{width:54px}
#menu label i{width:34px;text-align:right;font-style:normal;opacity:.7}
</style>
</head>
<body>
<canvas id="c"></canvas>
<div id="hud">
<div id="hudText">
<b>PUTT-PUTT ON THE GREAT SEA</b><br>
WASD or arrows throttle · A/D rudder · drag = camera · wheel = zoom · R = reset · M = menu
</div>
</div>
<div id="menu">
<b>MENU</b>
<div id="menuBody"></div>
</div>
<script>
"use strict";
/* ================= gl ================= */
const cv = document.getElementById("c");
const gl = cv.getContext("webgl2", { antialias: true });
if (!gl) { document.body.innerHTML = "<p style='color:#fff;font-family:monospace;padding:20px'>WebGL2 is required.</p>"; throw new Error("no webgl2"); }
/* ================= math ================= */
const sub = (a,b)=>[a[0]-b[0],a[1]-b[1],a[2]-b[2]];
const add = (a,b)=>[a[0]+b[0],a[1]+b[1],a[2]+b[2]];
const scl = (a,s)=>[a[0]*s,a[1]*s,a[2]*s];
const cross = (a,b)=>[a[1]*b[2]-a[2]*b[1], a[2]*b[0]-a[0]*b[2], a[0]*b[1]-a[1]*b[0]];
const dot = (a,b)=>a[0]*b[0]+a[1]*b[1]+a[2]*b[2];
const norm = v=>{const l=Math.hypot(v[0],v[1],v[2])||1;return [v[0]/l,v[1]/l,v[2]/l];};
function clamp(v, a, b){ return Math.min(b, Math.max(a, v)); }
function perspective(fov, aspect, near, far){
const f = 1/Math.tan(fov/2);
return new Float32Array([f/aspect,0,0,0, 0,f,0,0, 0,0,(far+near)/(near-far),-1, 0,0,2*far*near/(near-far),0]);
}
function lookAt(eye, target, up){
const f = norm(sub(target, eye));
const r = norm(cross(up, f));
const u = cross(f, r);
const z = scl(f,-1);
const m = new Float32Array(16);
m[0]=r[0]; m[1]=u[0]; m[2]=z[0]; m[3]=0;
m[4]=r[1]; m[5]=u[1]; m[6]=z[1]; m[7]=0;
m[8]=r[2]; m[9]=u[2]; m[10]=z[2]; m[11]=0;
m[12]=-dot(r,eye); m[13]=-dot(u,eye); m[14]=-dot(z,eye); m[15]=1;
return {m, right:r, up:u, fwd:f};
}
/* ================= waves (the water surface; mirrored in the shader) =================
A sea is not a stack of clean sines. Real crests build up and die away in groups over
tens of seconds, the wavelengths share no common factor, and crests are sharper than
troughs. So each system here has its own phase, its own slow amplitude envelope, and a
second harmonic. Nothing repeats exactly, and nothing is finer than the mesh can show.
The JS and the GLSL copies must stay identical or the boat drifts off the water it sits in. */
function waveH(x, z, t){
let h = 0;
// dominant swell, long and slow
let a = 0.26 + 0.10*Math.sin(x*0.041 - z*0.037 + t*0.111 + 2.13);
let u = x*0.293 + z*0.059 + t*0.719 + 0.42;
h += a * (Math.sin(u) + 0.20*Math.sin(2.0*u + 0.85));
// a second system crossing the first at an angle, with its own envelope
a = 0.18 + 0.08*Math.sin(z*0.047 + x*0.023 - t*0.134 + 4.71);
u = z*0.257 - x*0.041 - t*0.983 + 2.94;
h += a * (Math.sin(u) + 0.17*Math.sin(2.0*u + 4.12));
// a third on a diagonal, so nothing lines up with the grid
a = 0.11 + 0.06*Math.sin((x + z)*0.031 + t*0.167 + 1.37);
u = x*0.611 + z*0.487 + t*1.611 + 5.21;
h += a * (Math.sin(u) + 0.14*Math.sin(2.0*u + 2.33));
// chop, kept under k = 1.2 so the 1 m mesh can actually resolve it
h += 0.040*Math.sin(x*1.13 - z*0.41 - t*2.21 + 0.93);
h += 0.030*Math.sin(x*0.52 + z*1.09 + t*1.87 + 3.44);
return h;
}
/* ================= islands =================
Islands come from a hash of the world cell they sit in, so the world has no edge and there
is no island list to maintain: the same cell always gives the same island, and land appears
as you sail into new cells. JS is the only place that decides which islands exist - the
shader is handed the nearby ones as data, so the two can never disagree about whether land
is there at all. The profile below is mirrored in the shader, so the boat sits on the same
ground it is drawn on. */
const ICELL = 48, MAX_ISLANDS = 96, MAXR = 70; // a 170 m grid plus the reach of the largest island
const LAND = { beach: 0.02, shelf: 1.2, deep: 6.0 }; // beach: how far up the shore the boat may sit
let SEED = 1337;
function ihash(n){
n >>>= 0;
n ^= n >>> 15; n = Math.imul(n, 0x2c1b3c9d) >>> 0;
n ^= n >>> 12; n = Math.imul(n, 0x297a2d39) >>> 0;
n ^= n >>> 15; return n >>> 0;
}
function frac(v){ return v - Math.floor(v); }
// The land noise uses integer hashing rather than the float hash the sky and the foam use, because
// the boat physically rests on it. Integer arithmetic is exact in both languages, and fround on the
// lattice coordinate means JS and the GPU land on the same lattice cell, so the ground the boat sits
// on is the ground it is drawn on to within about a millionth of a metre.
const F32 = v => Math.fround(v);
function lhash(x, z){ return (ihash((Math.imul(x, 3419) + Math.imul(z, 2147483647)) >>> 0) & 1023) / 1023; }
function lnoise(px, pz){ // takes lattice coordinates, so the caller sets the scale
// Every step is rounded to float32 so this matches what the shader does. The smoothstep and the two
// mixes were previously done in double, which is good enough for a metre grid - but the boat's height
// has to agree with the ground it is drawn on, and the only thing that can put the boat on a
// different height than the mesh is the boat and the shader disagreeing here.
const ix = Math.floor(px), iz = Math.floor(pz);
let fx = F32(px - F32(ix)), fz = F32(pz - F32(iz));
fx = F32(F32(F32(fx)*F32(fx))*F32(F32(3.0) - F32(F32(2.0)*fx)));
fz = F32(F32(F32(fz)*F32(fz))*F32(F32(3.0) - F32(F32(2.0)*fz)));
const a = lhash(ix, iz), b = lhash(ix+1, iz), c = lhash(ix, iz+1), d = lhash(ix+1, iz+1);
const u = F32(F32(a) + F32(F32(F32(b) - F32(a))*F32(fx)));
const v = F32(F32(c) + F32(F32(F32(d) - F32(c))*F32(fx)));
return F32(F32(u) + F32(F32(F32(v) - F32(u))*F32(fz)));
}
/* code packs four 4-bit fields, because that is the part both sides can decode identically:
bits 0-3 peak, 4-7 profile, 8-11 roughness, 12-15 type. Powers of two are exact in float32,
so the decode cannot drift between JS and the GPU.
type 0 is the common islet: radius 14-30 m, peak 1.2-4.5 m, about 36 cells in 256.
type 1 is a large flattish island: radius 50-70 m, peak 2-7.2 m, about 2 cells in 256.
type 2 is a tall narrow pinnacle: radius 9-18 m, peak 14-38 m, about 3 cells in 256. */
function islandAt(cx, cz){
const h = ihash((Math.imul(cx, 73856093) + Math.imul(cz, 19349153) + SEED) >>> 0);
const low = h & 255;
let type = 0;
if(low < 3) type = 1; // rare: a large flattish island
else if(low < 6) return null; // pinnacles removed; these cells stay open sea
else if(low >= 96) return null; // most of the world is open sea
const s = ihash(h) & 0xFFFFFF;
const rb = s & 63, pk = (s >> 6) & 15, sh = (s >> 10) & 15, rg = (s >> 14) & 15;
let r = F32(14 + rb*0.25); // common islet
if(type === 1) r = F32(50 + rb*0.31); // large flattish island
return {
// x, z and r are stored as float32 values because that is what the shader receives. Otherwise
// the two sides can land on different lattice cells and disagree about the island's shape.
x: F32((cx + 0.5 + ((h >>> 8 & 255) - 127.5)/256) * ICELL),
z: F32((cz + 0.5 + ((h >>> 16 & 255) - 127.5)/256) * ICELL),
r, code: pk + sh*16 + rg*256 + type*4096
};
}
function decode(code){
const pk = code & 15, sh = (code >> 4) & 15, rg = (code >> 8) & 15, type = code >> 12;
let peak = F32(F32(1.2) + F32(F32(pk)*F32(0.22))), shape = F32(F32(1.2) + F32(F32(sh)*F32(0.03))), ramp = 0.0;
// shape is the exponent on the falloff, so a small shape is nearly flat. A flat island instead uses a
// ramp - flat for most of the radius, then a straight fall over the last fraction of it, which is the
// beach the boat can actually sit on. Constants are rounded to float32 because the shader computes this
// in float32, and the two have to produce the same number for the same island.
if(type === 1){ peak = F32(F32(2.0) + F32(F32(pk)*F32(0.35))); ramp = F32(F32(0.10) + F32(F32(sh)*F32(0.04))); }
return { peak, shape, rough: F32(F32(rg)/F32(15)), type, ramp, pk, sh, rg };
}
// smoothstep on [0,1], every step rounded to float32 so the shader and the boat get the same number
function smooth01(u){ return F32(F32(F32(u)*F32(u))*F32(F32(3.0)-F32(F32(2.0)*u))); }
function landH(x, z){
const cx = Math.floor(x/ICELL), cz = Math.floor(z/ICELL);
// starting below sea level is what makes the depth readable: outside an island there is no
// seabed, so it reads as deep water, and the shallow band around one is the shelf.
// The search has to reach as far as the largest island, otherwise the boat could sit on water
// that the shader is drawing as land.
let h = -LAND.deep;
const span = Math.ceil(MAXR/ICELL);
for(let j=-span;j<=span;j++) for(let i=-span;i<=span;i++){
const isl = islandAt(cx+i, cz+j);
if(!isl) continue;
const p = decode(isl.code);
// Nothing here is a circle. Two noise lattices are sized to the island itself: one gives the
// outline its lobes, the other the surface its hollows and peaks. Both are sampled relative to
// the island centre so the lattice coordinates stay small, every step is rounded to float32,
// and the offsets are small integers - otherwise the two sides pick different lattice cells and
// disagree about the shape, which is what would put the boat on a different height than the
// ground it is being drawn on.
const gx = F32(x), gz = F32(z);
const f1 = F32(F32(2 + Math.floor(p.rg/4)) / isl.r);
const f2 = F32(F32(6 + p.rg) / isl.r);
const dx = F32(gx - isl.x), dz = F32(gz - isl.z);
const d = F32(Math.sqrt(F32(F32(dx)*F32(dx)) + F32(F32(dz)*F32(dz)))); // what length() does in the shader
const wob = lnoise(F32(F32(dx*f1) + F32(p.pk)), F32(F32(dz*f1) + F32(p.sh)));
const rr = F32(isl.r * F32(F32(0.55) + F32(F32(0.45)*F32(wob))));
if(d > rr) continue;
const k = F32(F32(1.0) - F32(F32(d)/F32(rr)));
const nz = F32(F32(0.55) + F32(F32(0.45)*F32(p.rough)*lnoise(F32(F32(dx*f2) + F32((p.pk+p.sh+1)%16)), F32(F32(dz*f2) + F32((p.pk+p.sh+7)%16)))));
// A hard min at k = ramp is a crease, and where that crease meets the shoreline it reads as a
// corner. Easing it keeps the flat top - u is clamped to 1 over most of the radius - but rounds the
// shoulder. The shader does the same thing, so the boat still sits on the ground it is drawn on.
const u = F32(F32(k)/F32(p.ramp));
let s = 1.0;
if(u <= 0.0) s = 0.0; else if(u >= 1.0) s = 1.0; else s = smooth01(u);
const terr = F32(F32(p.ramp > 0 ? s : Math.pow(k, p.shape)) * F32(nz));
h = Math.max(h, p.peak*terr - LAND.shelf); // the shelf is the shallow ring around an island
}
return h;
}
function landGrad(x, z){
const e = 0.30;
return [(landH(x+e, z) - landH(x-e, z))/(2*e), (landH(x, z+e) - landH(x, z-e))/(2*e)];
}
// every island that can reach a vertex of the water grid, extended by the reach of the largest one
function islandsNear(minX, maxX, minZ, maxZ){
const out = [];
const a = minX - MAXR, b = maxX + MAXR, c = minZ - MAXR, d = maxZ + MAXR;
for(let cz = Math.floor(c/ICELL); cz <= Math.floor(d/ICELL) && out.length < MAX_ISLANDS; cz++)
for(let cx = Math.floor(a/ICELL); cx <= Math.floor(b/ICELL) && out.length < MAX_ISLANDS; cx++){
const isl = islandAt(cx, cz);
if(!isl) continue;
// Only islands that can actually reach a vertex inside the area the mesh is drawing. Without this
// the list filled up with islands that cannot affect any drawn point, so the ones dropped by the
// cap were still known to the boat - and that is a collision with land you cannot see.
const nx = Math.max(Math.min(isl.x, maxX), minX), nz = Math.max(Math.min(isl.z, maxZ), minZ);
if(Math.hypot(nx - isl.x, nz - isl.z) > isl.r) continue;
out.push(isl);
}
return out;
}
const NOISE_GLSL = `
float hash(vec2 p){
p = fract(p * vec2(0.1031, 0.1039));
p += dot(p, p.yx + 21.83);
return fract((p.x + p.y) * p.x);
}
float vnoise(vec2 p){
vec2 i = floor(p), f = fract(p);
f = f*f*(3.0-2.0*f);
return mix(mix(hash(i), hash(i+vec2(1.0,0.0)), f.x),
mix(hash(i+vec2(0.0,1.0)), hash(i+vec2(1.0,1.0)), f.x), f.y);
}
float fbm(vec2 p, int oct){
float v = 0.0, a = 0.5;
for(int i=0;i<oct;i++){ v += a*vnoise(p); p = p*2.03 + vec2(11.3,17.7); a *= 0.5; }
return v;
}
`;
const ISLANDS_GLSL = `
uniform vec4 uIsl[96]; // must match MAX_ISLANDS, otherwise islands past the cap are silently dropped
uniform int uCount;
uint ihash(uint n){
n ^= n >> 15; n *= 0x2c1b3c9du; n ^= n >> 12; n *= 0x297a2d39u; n ^= n >> 15;
return n;
}
float lhash(int x, int y){ return float(ihash(uint(x)*3419u + uint(y)*2147483647u) & 1023u) / 1023.0; }
float lnoise(vec2 p){ // takes lattice coordinates, so the caller sets the scale
ivec2 i = ivec2(floor(p));
vec2 f = p - vec2(float(i.x), float(i.y));
f = f*f*(3.0-2.0*f);
float a = lhash(i.x, i.y), b = lhash(i.x+1, i.y), c = lhash(i.x, i.y+1), d = lhash(i.x+1, i.y+1);
return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
}
float landH(vec2 p){
float h = -6.0; // no land in range: open water, deep enough that depth reads as deep
for(int i=0;i<uCount;i++){
vec4 isl = uIsl[i];
vec2 r = p - isl.xy; // island-relative, exactly like the JS copy
float d = length(r);
float code = isl.w;
float pk = mod(code, 16.0), sh = floor(mod(code/16.0, 16.0)), rg = floor(mod(code/256.0, 16.0));
float type = floor(code/4096.0);
float f1 = (2.0 + floor(rg/4.0)) / isl.z;
float f2 = (6.0 + rg) / isl.z;
float wob = lnoise(r*f1 + vec2(pk, sh));
float rr = isl.z * (0.55 + 0.45*wob);
if(d > rr) continue;
float peak = 1.2 + pk*0.22, shape = 1.2 + sh*0.03, ramp = 0.0;
if(type == 1.0){ peak = 2.0 + pk*0.35; ramp = 0.10 + sh*0.04; } // ramp was never set here, so the
// shader drew a dome while the boat walked into a flat top with a beach band - two different shapes
// for the same island, which is the collision near the large ones.
else if(type == 2.0){ peak = 14.0 + pk*1.6; shape = 0.04 + sh*0.012; }
float rough = rg/15.0;
float k = 1.0 - d/rr;
float nz = 0.55 + 0.45*rough*lnoise(r*f2 + vec2(mod(pk+sh+1.0, 16.0), mod(pk+sh+7.0, 16.0)));
float terr = (ramp > 0.0) ? smoothstep(0.0, 1.0, k/ramp) * nz : pow(k, shape) * nz; // eased shoulder, mirrored in the JS copy
h = max(h, peak*terr - 1.2);
}
return h;
}
// Land normal from the height field itself rather than from the facet drawn. Bilinear interpolation
// between lattice points is planar, so each cell is a flat sheet and the facet normal makes every quad
// read as its own tile. Sampling the field either side of the point gives a normal that varies
// continuously, which is what stops the islands looking like polygons.
vec3 landN(vec2 p){
float e = 0.25;
float hx = (landH(p + vec2(e, 0.0)) - landH(p - vec2(e, 0.0))) / (2.0*e);
float hz = (landH(p + vec2(0.0, e)) - landH(p - vec2(0.0, e))) / (2.0*e);
return normalize(vec3(-hx, 1.0, -hz));
}
`;
/* ================= hull =================
The water keeps drawing the raw surface, but the boat stops feeling a single point.
A real hull feels the *average* water across its footprint, which averages the short
chop out and leaves only crests longer than the boat. This is JS-only on purpose:
the sea still looks the same, only the boat stops reacting to every little ripple. */
const LOA = 4.06, BEAM = 1.15; // hull footprint, in world units
const SIT = 0.06; // how high the boat sits on the waterline
const DRAFT = 0.625; // keel depth below the origin - the boat must stay wet
// Heave: a light 4 m hull has a natural heave period well under a second, so it should follow the
// surface closely. The hull-averaged waterplane is already what removes the chop - the spring should
// not have to do it as well, which is why the period is short and the damping only moderate. A
// critically damped spring cannot overshoot, so it can never settle onto a crest the way a real
// light boat does; zeta under 1 is what lets it ring once or twice and come to rest.
const HEAVE = {period: 0.45, zeta: 0.40};
// Pitch and roll have different natural periods on a small hull. Roll is quick: the waterplane slope
// across a 1.15 m beam changes faster than the slope along the length. Pitch lags more.
const TILT = {roll:{period:0.6, zeta:0.40}, pitch:{period:1.2, zeta:0.45}};
// On land there is nothing to ring. Both springs go critically damped, and the tilt comes from the
// ground under the hull instead of from the waterplane.
const GROUND = {heave:{period:0.4, zeta:1.0}, tilt:{roll:{period:1.0, zeta:1.0}, pitch:{period:1.2, zeta:1.0}}};
const STATIONS = [];
(function(){
for(let u = -LOA/2; u <= LOA/2; u += 0.5)
for(let v = -BEAM/2; v <= BEAM/2; v += 0.25) STATIONS.push([u, v]);
})();
// what is actually under a point: the ground if it is above sea level, otherwise the sea.
// Same rule the mesh draws with, which is what keeps the boat on the surface it is sitting on.
// Land only counts where the ground is above the water, because that is the land you can see.
function surfaceH(x, z, t){ const g = landH(x, z), w = waveH(x, z, t); return Math.max(g, w); }
// average height under the footprint. u runs along the keel, v across the beam.
// The average is weighted towards the middle of the waterplane. A flat average over the whole
// footprint is what a rigid hull would do for long swell, but it cancels nearly everything for a wave
// about the length of the boat - that is what was making it read as half-buoyant. A real hull is not
// rigid: the middle carries the motion and the ends ride over the top of it, so the weight falls off
// towards the ends. Long swell still averages to the local height, so that part is unchanged.
function hullH(x, z, heading, t){
const ax = Math.sin(heading), az = Math.cos(heading);
let sum = 0, wsum = 0;
for(const s of STATIONS){
const w = (1 - (s[0]/(LOA/2))**2) * (1 - (s[1]/(BEAM/2))**2);
if(w <= 0) continue;
sum += w * surfaceH(x + ax*s[0] + az*s[1], z + az*s[0] - ax*s[1], t);
wsum += w;
}
return sum / wsum;
}
// The highest water over the footprint. A rigid hull rides the mean of the waterplane, but the deck
// is not allowed to be under the sea, so the heave target is pulled a little towards the high point
// instead of being the pure mean. That is what stops a crest under the stern swallowing the deck.
function hullTop(x, z, heading, t){
const ax = Math.sin(heading), az = Math.cos(heading);
let m = -1e9;
for(const s of STATIONS) m = Math.max(m, waveH(x + ax*s[0] + az*s[1], z + az*s[0] - ax*s[1], t));
return m;
}
// highest ground under the footprint. A rigid flat-bottomed hull rests on the high point of a
// slope rather than on the average of it, so grounding has to use the max, not the mean.
function hullLand(x, z, heading){
const ax = Math.sin(heading), az = Math.cos(heading);
let m = -1e9;
for(const s of STATIONS) m = Math.max(m, landH(x + ax*s[0] + az*s[1], z + az*s[0] - ax*s[1]));
return m;
}
// Is there land above the water at a point? Same test the mesh uses to decide what to draw, so the
// boat only meets land it can see. It is checked at the boat itself rather than as the highest point
// over the whole footprint - that stopped a 4 m hull about two metres before the water's edge. The
// boat can now nose onto the beach and slide back off.
function shoreAt(x, z, t){ return landH(x, z) - waveH(x, z, t); }
// same window, water only. A floating boat is tipped by the waterplane, not by ground under it - the
// version above mixes land into the average, so a corner that sees land pulls the whole tilt up. When
// the boat is actually aground the ground slope is used instead.
function hullWater(x, z, heading, t){
const ax = Math.sin(heading), az = Math.cos(heading);
let sum = 0, wsum = 0;
for(const s of STATIONS){
const w = (1 - (s[0]/(LOA/2))**2) * (1 - (s[1]/(BEAM/2))**2);
if(w <= 0) continue;
const px = x + ax*s[0] + az*s[1], pz = z + az*s[0] - ax*s[1];
sum += w * waveH(px, pz, t);
wsum += w;
}
return sum / wsum;
}
// slope of that averaged water: the boat tips by the difference across its own length/beam
function hullSlope(x, z, heading, t){
const ax = Math.sin(heading), az = Math.cos(heading);
const fore = hullWater(x + ax*LOA/2, z + az*LOA/2, heading, t);
const aft = hullWater(x - ax*LOA/2, z - az*LOA/2, heading, t);
const star = hullWater(x + az*BEAM/2, z - ax*BEAM/2, heading, t);
const port = hullWater(x - az*BEAM/2, z + ax*BEAM/2, heading, t);
return [(fore - aft) / LOA, (star - port) / BEAM];
}
// ground slope across the footprint. The tilt follows whatever surface is under the hull, but a
// grounded boat is pulled by the slope of the ground itself, not of the water above it.
function hullGroundSlope(x, z, heading){
const ax = Math.sin(heading), az = Math.cos(heading);
const g = (u, v) => landH(x + ax*u + az*v, z + az*u - ax*v);
return [(g(LOA/2, 0) - g(-LOA/2, 0)) / LOA, (g(0, BEAM/2) - g(0, -BEAM/2)) / BEAM];
}
/* A damped spring: the boat eases toward the water instead of snapping to it. */
function spring(pos, vel, target, dt, period, zeta){
const w = 2*Math.PI/period;
vel += (w*w*(target - pos) - 2*zeta*w*vel) * dt;
return [pos + vel*dt, vel];
}
/* ================= shaders ================= */
const WAVES_GLSL = `
float waveH(vec2 p, float t){
float h = 0.0;
float a = 0.26 + 0.10*sin(p.x*0.041 - p.y*0.037 + t*0.111 + 2.13);
float u = p.x*0.293 + p.y*0.059 + t*0.719 + 0.42;
h += a * (sin(u) + 0.20*sin(2.0*u + 0.85));
a = 0.18 + 0.08*sin(p.y*0.047 + p.x*0.023 - t*0.134 + 4.71);
u = p.y*0.257 - p.x*0.041 - t*0.983 + 2.94;
h += a * (sin(u) + 0.17*sin(2.0*u + 4.12));
a = 0.11 + 0.06*sin((p.x + p.y)*0.031 + t*0.167 + 1.37);
u = p.x*0.611 + p.y*0.487 + t*1.611 + 5.21;
h += a * (sin(u) + 0.14*sin(2.0*u + 2.33));
h += 0.040*sin(p.x*1.13 - p.y*0.41 - t*2.21 + 0.93);
h += 0.030*sin(p.x*0.52 + p.y*1.09 + t*1.87 + 3.44);
return h;
}
// finite differences instead of a hand-written derivative: it always matches whatever
// waveH actually drew, and sampling a little way out slightly smooths the facets
vec3 waveN(vec2 p, float t){
float e = 0.20;
float dx = (waveH(p + vec2(e, 0.0), t) - waveH(p - vec2(e, 0.0), t)) / (2.0*e);
float dz = (waveH(p + vec2(0.0, e), t) - waveH(p - vec2(0.0, e), t)) / (2.0*e);
return normalize(vec3(-dx, 1.0, -dz));
}
`;
const waterP = prog(`#version 300 es
precision highp float;
in vec2 aGrid;
uniform mat4 uProj, uView;
uniform vec2 uOrigin;
uniform float uTime, uSpeed, uPopAge;
uniform vec3 uBoat, uFwd, uPopPos;
out vec3 vWorld; out vec3 vNormal; out float vFoam; out float vLand, vDepth, vEdge;
${WAVES_GLSL}
${NOISE_GLSL}
${ISLANDS_GLSL}
void main(){
vec2 w = aGrid + uOrigin;
vec3 d = vec3(w.x - uBoat.x, 0.0, w.y - uBoat.z);
float r = length(d);
float behind = -dot(d, uFwd);
float side = abs(cross(uFwd, d).y);
float wake = 0.0;
if(behind > 0.35 && uSpeed > 0.05){
float wid = 0.45 + behind*0.16;
wake = smoothstep(wid, 0.0, side) * exp(-behind*0.055) * clamp(uSpeed/3.5, 0.0, 1.0);
wake *= 0.55 + 0.45*sin(behind*2.1);
wake *= 0.62 + 0.38*fbm(w*0.30 + uTime*0.04, 2); // breaks the wedge into streaks
}
float hullFoam = smoothstep(2.2, 0.4, r) * (0.10 + 0.70*clamp(uSpeed/2.5, 0.0, 1.0));
float dip = 0.14 * smoothstep(2.6, 0.0, r);
float ripple = 0.0, popFoam = 0.0;
if(uPopAge > 0.0 && uPopAge < 0.8){
float rr = length(w - uPopPos.xz);
float ringR = 0.15 + uPopAge*3.0;
float g = exp(-((rr-ringR)*(rr-ringR))/0.10) * exp(-uPopAge*4.0);
ripple = -0.05 * g;
popFoam = 0.30 * g;
}
// the same rule as the boat: the surface is whichever is higher, the sea or the ground.
// Under water this is the sea as before; on land it is the terrain, and the line where they
// cross is the coastline.
// The sea and the ground are not the same kind of surface. The wave only exists where there is
// water: once the ground is above sea level it is solid and does not move with the swell. Using
// max(land, water) here made low land near the shore ride the waves like a liquid.
// Land only where the ground is above the water. Below the surface the ground is not drawn at all,
// so the boat must not be stopped by it, and the coastline becomes where the water actually meets
// the land rather than where a fixed height is crossed.
float land = landH(w);
float water = waveH(w, uTime) - dip + ripple;
float edge = land - water; // signed distance to the shoreline, interpolated in the fragment stage
bool isLand = edge > 0.0;
float h = isLand ? land : water;
vec3 wp = vec3(w.x, h, w.y);
vWorld = wp;
vLand = land;
vDepth = water - land; // depth of water over the seabed
vEdge = edge;
vNormal = isLand ? landN(w) : waveN(w, uTime); // only land vertices pay for the extra samples
vFoam = clamp((wake + hullFoam + popFoam) * (isLand ? 0.0 : 1.0), 0.0, 1.0);
gl_Position = uProj * uView * vec4(wp, 1.0);
}`, `#version 300 es
precision highp float;
in vec3 vWorld; in vec3 vNormal; in float vFoam; in float vLand, vDepth, vEdge;
uniform vec3 uCam;
uniform float uTime;
uniform vec3 uSand, uGrass, uRock;
out vec4 frag;
${NOISE_GLSL}
const vec3 LDIR = vec3(0.5, 0.75, -0.45);
float toneOf(float ndl){
float q = clamp((ndl - 0.30) / 0.55, 0.0, 1.0) * 4.0;
return mix(floor(q)/4.0, q/4.0, 0.40);
}
vec3 landCol(vec3 n, float lv){
float tone = toneOf(max(dot(n, LDIR), 0.0));
float flatness = clamp(n.y, 0.0, 1.0); // "flat" is a reserved word in GLSL ES 3.0
vec3 col = mix(uSand * 0.62, uSand, smoothstep(0.0, 0.30, lv)); // wet sand at the waterline
col = mix(col, uGrass, smoothstep(0.40, 1.10, lv) * smoothstep(0.50, 0.75, flatness));
col = mix(col, uRock, smoothstep(0.55, 0.80, 1.0 - flatness));
col = col * (0.55 + 0.70 * tone);
col = mix(col, col * 1.10, (vnoise(vWorld.xz * 2.2) - 0.5) * 0.35 * smoothstep(0.2, 1.0, lv));
return col;
}
vec3 waterCol(vec3 n){
float ndl = max(dot(n, LDIR), 0.0);
float tone = toneOf(ndl);
vec3 deep = vec3(0.04,0.17,0.38);
vec3 mid = vec3(0.09,0.34,0.53);
vec3 lite = vec3(0.22,0.56,0.68);
vec3 col = mix(deep, mid, smoothstep(0.55, 0.70, tone));
col = mix(col, lite, smoothstep(0.82, 0.97, tone));
float bed = fbm(vWorld.xz * 0.035, 3);
col = mix(col, mid * 1.14 + vec3(0.02,0.05,0.04), smoothstep(0.55, 0.85, bed) * 0.30);
col = mix(col, uSand * 0.80, smoothstep(1.40, 0.15, vDepth) * 0.28);
float contour = smoothstep(0.775, 0.785, ndl) + smoothstep(0.655, 0.665, ndl);
col = mix(col, lite, clamp(contour, 0.0, 1.0) * 0.45);
float cap = smoothstep(0.34, 0.44, length(n.xz));
col = mix(col, vec3(0.92,0.97,1.0), cap * 0.30);
vec3 V = normalize(uCam - vWorld);
float g = pow(max(dot(n, normalize(LDIR + V)), 0.0), 12.0);
float path = smoothstep(0.004, 0.03, g);
float dots = smoothstep(0.72, 0.84, vnoise(vWorld.xz * 3.0 + uTime * 0.05));
col = mix(col, vec3(0.96,0.99,1.0), clamp(path * (0.25 + 0.60*dots), 0.0, 1.0));
return col;
}
void main(){
vec3 fn = normalize(cross(dFdy(vWorld), dFdx(vWorld))); // the facet actually drawn
if(fn.y < 0.0) fn = -fn;
vec3 wn = normalize(vNormal);
// The land-or-water decision used to be made once per facet, so a facet that straddled the shoreline
// took one material for the whole triangle and the edge became a chain of straight segments along the
// mesh - a staircase on a 1 m grid. It is now an interpolated value, so the crossing is a line across
// each facet that joins with its neighbours, and the narrow band between the two is blended instead of
// switched.
// The normal comes from the height field, not from the facet, so land shades continuously across the
// mesh instead of one flat tile per quad. fn is still used, but only to decide which material a facet
// is - a facet this steep can only be a cliff face, and the sea surface never gets that steep.
float t = clamp(smoothstep(-0.12, 0.12, vEdge), 0.0, 1.0);
if(fn.y < 0.12) t = 1.0;
vec3 n = mix(wn, normalize(vNormal), t);
if(n.y < 0.0) n = -n;
vec3 col = mix(waterCol(wn), landCol(fn, max(vLand, 0.0)), t);
float ndl = max(dot(n, LDIR), 0.0);
float tone = toneOf(ndl);
// warm on the sun side, the same trick as the clouds
col = mix(col, vec3(0.98,0.90,0.80), smoothstep(0.55, 0.95, ndl) * smoothstep(0.45, 0.80, tone) * 0.18);
// wispy foam, built the same way as the clouds, plus a band where shallow water meets the shore
float wisps = smoothstep(0.42, 0.58, fbm(vWorld.xz * 1.2 + uTime * 0.02, 2));
float wet = 1.0 - t;
float shore = smoothstep(0.50, 0.02, max(vDepth, 0.0)) * 0.22 * wet;
float f = clamp(vFoam * wet * (0.35 + 0.55 * wisps) + shore, 0.0, 1.0);
col = mix(col, vec3(0.93,0.98,1.0), f);
float fog = smoothstep(14.0, 70.0, length(vWorld - uCam));
col = mix(col, vec3(0.35,0.60,0.78), fog);
frag = vec4(col, 1.0);
}`);
const boatP = prog(`#version 300 es
precision highp float;
in vec3 aPos; in vec3 aCol; in vec3 aNormal; in float aGlow, aMat;
uniform mat4 uProj, uView, uModel;
uniform vec3 uOrigin;
out vec3 vPos; out vec3 vCol; out vec3 vNormal; out float vGlow, vMat;
void main(){
vec3 wp = (uModel * vec4(aPos,1.0)).xyz + uOrigin;
vPos = wp; vCol = aCol; vNormal = normalize(aNormal); vGlow = aGlow; vMat = aMat;
gl_Position = uProj * uView * vec4(wp, 1.0);
}`, `#version 300 es
precision highp float;
in vec3 vPos; in vec3 vCol; in vec3 vNormal; in float vGlow, vMat;
uniform vec3 uCam;
out vec4 frag;
void main(){
vec3 n = normalize(vNormal);
vec3 v = normalize(uCam - vPos);
if(dot(n, v) < 0.0) n = -n;
vec3 L = normalize(vec3(0.5, 0.75, -0.45));
float ndl = max(dot(n, L), 0.0);
float k = max(0.52 + 0.48 * floor(ndl*4.0)/4.0, vGlow); // vGlow lets the flame ignore the sun
vec3 col = vCol * k;
// a little bounce from the sky and from the water, so the underside is not flat black
col += vCol * 0.13 * max(0.0, -n.y) + vCol * 0.10 * max(0.0, n.y);
// brass and steel get a tight highlight; paint, wood and cloth do not
float spec = pow(max(dot(n, normalize(v + L)), 0.0), 26.0) * vMat;
col += vec3(1.0, 0.97, 0.90) * spec * ndl * 0.60;
float rim = smoothstep(0.30, 0.0, max(dot(n, v), 0.0));
col = mix(col, col*0.34, rim*0.6);
float fog = smoothstep(14.0, 70.0, length(vPos - uCam));
col = mix(col, vec3(0.35,0.60,0.78), fog);
frag = vec4(col, 1.0);
}`);
const puffP = prog(`#version 300 es
precision highp float;
in vec3 aPos; in vec2 aUV; in float aAlpha, aKind, aSeed;
uniform mat4 uProj, uView;
out vec2 vUV; out float vA; out float vKind, vSeed;
void main(){
vUV = aUV; vA = aAlpha; vKind = aKind; vSeed = aSeed;
gl_Position = uProj * uView * vec4(aPos, 1.0);
}`, `#version 300 es
precision highp float;
in vec2 vUV; in float vA; in float vKind, vSeed;
out vec4 frag;
void main(){
// a slightly irregular outline, so a puff is not a perfect circle
float ang = atan(vUV.y, vUV.x);
float wob = 1.0 + 0.05*sin(ang*3.0 + vSeed*6.283) + 0.03*sin(ang*5.0 - vSeed*6.283);
float r = length(vUV);
if(r > wob) discard;
float a = vA * (1.0 - smoothstep(0.86, 1.0, r/wob));
// kind 0 = steam above the water, kind 1 = the water jet breaking the surface
vec3 body = mix(vec3(0.94,0.96,0.98), vec3(0.84,0.94,0.99), vKind);
vec3 edge = mix(vec3(0.44,0.62,0.76), vec3(0.52,0.72,0.85), vKind);
vec3 c = mix(body, edge, smoothstep(0.55, 0.98, r) * 0.75);
// the small highlight is what makes a blob read as a bubble rather than a smudge
float hi = smoothstep(0.34, 0.0, length(vUV - vec2(-0.26, 0.30)));
c = mix(c, vec3(1.0), hi * 0.40 * (1.0 - smoothstep(0.0, 1.0, r)));
frag = vec4(c, clamp(a * (1.0 + hi*0.30), 0.0, 1.0));
}`);
const skyP = prog(`#version 300 es
precision highp float;
in vec2 aClip;
out vec2 vClip;
void main(){ vClip = aClip; gl_Position = vec4(aClip, 0.999, 1.0); }`, `#version 300 es
precision highp float;
in vec2 vClip;
uniform vec3 uRight, uUp, uFwd;
uniform vec2 uTan;
uniform float uTime;
out vec4 frag;
float hash(vec2 p){ // cheap hash, no sin - this is the whole cost of the sky
p = fract(p * vec2(0.1031, 0.1039));
p += dot(p, p.yx + 21.83);
return fract((p.x + p.y) * p.x);
}
float vnoise(vec2 p){
vec2 i = floor(p), f = fract(p);
f = f*f*(3.0-2.0*f);
return mix(mix(hash(i), hash(i+vec2(1.0,0.0)), f.x),
mix(hash(i+vec2(0.0,1.0)), hash(i+vec2(1.0,1.0)), f.x), f.y);
}
float fbm(vec2 p, int oct){
float v = 0.0, a = 0.5;
for(int i=0;i<oct;i++){ v += a*vnoise(p); p = p*2.03 + vec2(11.3,17.7); a *= 0.5; }
return v;
}
void main(){
vec3 d = normalize(uRight*(vClip.x*uTan.x) + uUp*(vClip.y*uTan.y) + uFwd);
float h = clamp(d.y, 0.0, 1.0);
float band = floor(h*6.0)/6.0;
vec3 col = mix(vec3(0.35,0.60,0.78), vec3(0.22,0.45,0.72), band);
if(d.y > 0.02){
// the ray hits a cloud layer overhead. That gives real perspective - clouds get small
// towards the horizon instead of being noise painted flat onto a dome.
vec2 p = d.xz / max(d.y, 0.05) * 6.0 + uTime * vec2(0.08, 0.05);
vec2 w = vec2(vnoise(p*0.25 + 3.1), vnoise(p*0.25 + 7.7)); // warped input = curling, wispy edges
float mass = fbm(p*0.28 + (w-0.5)*1.8, 3); // the big shapes
float wisps = fbm(p*1.10 + (w-0.5)*2.4, 2); // the detail inside them
float cov = 0.72*mass + 0.28*wisps;
float T0 = 0.415, T1 = 0.48; // where the clouds start: about a fifth of the sky
float shape = smoothstep(T0, T1, cov) * smoothstep(0.02, 0.22, d.y);
// posterised tones so the clouds match the flat shading used everywhere else
float th = clamp((cov - T0) / (0.62 - T0), 0.0, 1.0);
float q = th * 4.0;
float tone = mix(floor(q)/4.0, q/4.0, 0.40); // blended steps, not hard bands
vec3 cc = mix(vec3(0.62,0.74,0.84), vec3(0.86,0.92,0.96), smoothstep(0.05, 0.55, tone));
cc = mix(cc, vec3(0.97,0.98,0.99), smoothstep(0.62, 0.90, tone));
cc = mix(cc, vec3(0.98,0.99,1.00), smoothstep(T0, T1, cov) * (1.0 - smoothstep(T1, T1+0.05, cov)) * 0.5); // lit edge
vec3 L = normalize(vec3(0.5, 0.75, -0.45));
cc = mix(cc, vec3(0.98,0.90,0.80), smoothstep(0.55, 0.95, dot(d, L)) * smoothstep(0.45, 0.80, th) * 0.35);
col = mix(col, cc, clamp(shape, 0.0, 1.0));
}
frag = vec4(col, 1.0);
}`);
function prog(vs, fs){
const p = gl.createProgram();
const v = gl.createShader(gl.VERTEX_SHADER); gl.shaderSource(v, vs); gl.compileShader(v);
if(!gl.getShaderParameter(v, gl.COMPILE_STATUS)) console.error("vs", gl.getShaderInfoLog(v));
const f = gl.createShader(gl.FRAGMENT_SHADER); gl.shaderSource(f, fs); gl.compileShader(f);
if(!gl.getShaderParameter(f, gl.COMPILE_STATUS)) console.error("fs", gl.getShaderInfoLog(f));
gl.attachShader(p, v); gl.attachShader(p, f); gl.linkProgram(p);
if(!gl.getProgramParameter(p, gl.LINK_STATUS)) console.error("link", gl.getProgramInfoLog(p));
const u = {}, a = {};
const nu = gl.getProgramParameter(p, gl.ACTIVE_UNIFORMS);
for(let i=0;i<nu;i++){ const info = gl.getActiveUniform(p, i); u[info.name] = gl.getUniformLocation(p, info.name); }
const na = gl.getProgramParameter(p, gl.ACTIVE_ATTRIBUTES);
for(let i=0;i<na;i++){ const info = gl.getActiveAttrib(p, i); a[info.name] = gl.getAttribLocation(p, info.name); }
return {p, u, a};
}
/* ================= geometry ================= */
const CELL = 1.0, N = 170;
const gridBuf = gl.createBuffer(), gridIdx = gl.createBuffer();
(function(){
const verts = new Float32Array((N+1)*(N+1)*2);
let k = 0;
for(let j=0;j<=N;j++) for(let i=0;i<=N;i++){ verts[k++] = (i-N/2)*CELL; verts[k++] = (j-N/2)*CELL; }
const idx = [];
const id = (i,j)=> j*(N+1)+i;
for(let j=0;j<N;j++) for(let i=0;i<N;i++){
idx.push(id(i,j), id(i,j+1), id(i+1,j+1), id(i,j), id(i+1,j+1), id(i+1,j));
}
gl.bindBuffer(gl.ARRAY_BUFFER, gridBuf); gl.bufferData(gl.ARRAY_BUFFER, verts, gl.STATIC_DRAW);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gridIdx); gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(idx), gl.STATIC_DRAW);
})();
const boatBuf = gl.createBuffer();
// uniform arrays are set element by element, so these locations are looked up once
const islLoc = [];
for(let i=0;i<MAX_ISLANDS;i++) islLoc.push(gl.getUniformLocation(waterP.p, "uIsl[" + i + "]"));
const puffBuf = gl.createBuffer();
const skyBuf = gl.createBuffer();
const maxIndex = (N+1)*(N+1) - 1;
if (maxIndex > 65535) console.error("index buffer too big for Uint16");
// attribute state is applied per draw instead of cached in a VAO
function setAttribs(pr, layout, stride){
for (const [name, size, offset] of layout){
const loc = pr.a[name];
if (loc === undefined) { console.log("missing attribute:", name); continue; }
gl.enableVertexAttribArray(loc);
gl.vertexAttribPointer(loc, size, gl.FLOAT, false, stride, offset);
}
}
gl.bindBuffer(gl.ARRAY_BUFFER, skyBuf);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1,-1, 3,-1, -1,3]), gl.STATIC_DRAW);
/* ================= boat mesh (rebuilt each frame for the tiller/arm/flag) ================= */
/* The palette lives in two copies: BASE is what the sliders start from, PAL is the live one
the mesh draws with. The menu writes into ctl and calls paint(), so colours change live. */
const BASE = {
hull:[0.85,0.83,0.76], stripe:[0.78,0.26,0.25], wood:[0.56,0.39,0.24],
metal:[0.42,0.45,0.48], skin:[0.86,0.70,0.55], shirt:[0.25,0.47,0.66], hat:[0.90,0.83,0.60],
brass:[0.72,0.55,0.28], wax:[0.94,0.90,0.80], flame:[1.00,0.62,0.22],
jacket:[0.86,0.44,0.24],
sand:[0.82,0.74,0.55], grass:[0.45,0.62,0.40], rock:[0.52,0.52,0.50]
};
const PAL = {};
const ctl = { all: 0, tint: {} };
function shiftHue(rgb, deg){
if(!deg) return rgb.slice();
const mx = Math.max(...rgb), mn = Math.min(...rgb);
if(mx === mn) return rgb.slice(); // greyscale has no hue to turn
const l = (mx + mn) / 2;
const s = l > 0.5 ? (mx - mn) / (2 - mx - mn) : (mx - mn) / (mx + mn);
let h;
if(mx === rgb[0]) h = (rgb[1] - rgb[2]) / (mx - mn);
else if(mx === rgb[1]) h = (rgb[2] - rgb[0]) / (mx - mn) + 2;
else h = (rgb[0] - rgb[1]) / (mx - mn) + 4;
h = ((h * 60 + deg) % 360 + 360) % 360;
const c = (1 - Math.abs(2*l - 1)) * s;
const x = c * (1 - Math.abs(((h/60) % 2) - 1));
let r=0, g=0, b=0;
if(h < 60){ r=c; g=x; } else if(h < 120){ r=x; g=c; }
else if(h < 180){ g=c; b=x; } else if(h < 240){ g=x; b=c; }
else if(h < 300){ r=x; b=c; } else { r=c; b=x; }
const m = l - c/2;
return [r+m, g+m, b+m];
}
function paint(){
for(const k in BASE) PAL[k] = shiftHue(BASE[k], ctl.all + (ctl.tint[k] || 0));
}
function setPal(pr, names){
for(const n of names) gl.uniform3f(pr.u["u" + n], PAL[n][0], PAL[n][1], PAL[n][2]);
}
let boatVerts = [];
const BOAT_SCALE = 1.25;
// heat = how close the candle is to the boiler, which is what W/S is really controlling
function buildBoat(rudder, t, heat){
const S = BOAT_SCALE, TAU = Math.PI*2;
const faces = [], acc = new Map();
// Curved parts get averaged normals, so a rounded hull reads as rounded instead of as a stack
// of quads. Flat parts (transom, deck, hat brim) keep their own normal - that contrast is what
// makes a flat surface still read as flat.
const vk = p => (Math.round(p[0]*512)+1024)*4194304 + (Math.round(p[1]*512)+1024)*2048 + (Math.round(p[2]*512)+1024);
const emit=(pts, col, f, glow, mat, smooth)=>{
faces.push([pts, col, f, glow, mat, smooth]);
if(smooth) for(const p of pts){ const k=vk(p), a=acc.get(k)||[0,0,0]; acc.set(k,[a[0]+f[0],a[1]+f[1],a[2]+f[2]]); }
};
const tri=(a,b,c,col,glow=0,mat=0,smooth=false)=>emit([a,b,c], col, norm(cross(sub(b,a),sub(c,a))), glow, mat, smooth);
const quad=(a,b,c,d,col,glow=0,mat=0,smooth=false)=>{ tri(a,b,c,col,glow,mat,smooth); tri(a,c,d,col,glow,mat,smooth); };
const box=(cx,cy,cz,sx,sy,sz,col,mat=0)=>{
const x0=cx-sx,x1=cx+sx,y0=cy-sy,y1=cy+sy,z0=cz-sz,z1=cz+sz;
quad([x0,y0,z0],[x1,y0,z0],[x1,y1,z0],[x0,y1,z0],col,0,mat);
quad([x0,y0,z1],[x1,y0,z1],[x1,y1,z1],[x0,y1,z1],col,0,mat);
quad([x0,y0,z0],[x0,y1,z0],[x0,y1,z1],[x0,y0,z1],col,0,mat);
quad([x1,y0,z0],[x1,y1,z0],[x1,y1,z1],[x1,y0,z1],col,0,mat);
quad([x0,y1,z0],[x1,y1,z0],[x1,y1,z1],[x0,y1,z1],col,0,mat);
quad([x0,y0,z0],[x1,y0,z0],[x1,y0,z1],[x0,y0,z1],col,0,mat);
};
const disc=(cx,cy,cz,r,n,col,mat=0)=>{
for(let i=0;i<n;i++){ const a1=i/n*TAU, a2=(i+1)/n*TAU;
tri([cx+Math.cos(a1)*r,cy,cz+Math.sin(a1)*r],[cx+Math.cos(a2)*r,cy,cz+Math.sin(a2)*r],[cx,cy,cz],col,0,mat); }
};
const cone=(cx,cy,cz,r,h,n,col,glow=0,mat=0)=>{
for(let i=0;i<n;i++){ const a1=i/n*TAU, a2=(i+1)/n*TAU;
tri([cx+Math.cos(a1)*r,cy,cz+Math.sin(a1)*r],[cx+Math.cos(a2)*r,cy,cz+Math.sin(a2)*r],[cx,cy+h,cz],col,glow,mat); }
};
const sphere=(cx,cy,cz,r,col,mat=0,seg=8,rows=5)=>{
const P=(a,b)=>[cx+Math.cos(a)*Math.cos(b)*r, cy+Math.sin(a)*r, cz+Math.cos(a)*Math.sin(b)*r];
for(let j=0;j<rows;j++) for(let i=0;i<seg;i++){
const a0=Math.PI*(-0.5+j/rows), a1=Math.PI*(-0.5+(j+1)/rows), b0=i/seg*TAU, b1=(i+1)/seg*TAU;
quad(P(a0,b0),P(a0,b1),P(a1,b1),P(a1,b0),col,0,mat,true);
}
};
const tube=(a,b,r,n,col,glow=0,mat=0,smooth=true)=>{
const d=norm(sub(b,a));
let u=cross(d,[0,1,0]); if(Math.hypot(u[0],u[1],u[2])<1e-4) u=cross(d,[1,0,0]); u=norm(u);
const v=norm(cross(d,u));
for(let i=0;i<n;i++){ const a1=i/n*TAU, a2=(i+1)/n*TAU;
const A1=add(a,add(scl(u,Math.cos(a1)*r),scl(v,Math.sin(a1)*r)));
const A2=add(a,add(scl(u,Math.cos(a2)*r),scl(v,Math.sin(a2)*r)));
const B1=add(b,add(scl(u,Math.cos(a1)*r),scl(v,Math.sin(a1)*r)));
const B2=add(b,add(scl(u,Math.cos(a2)*r),scl(v,Math.sin(a2)*r)));
quad(A1,A2,B2,B1,col,glow,mat,smooth);
}
};
const rod=(a,b,th,col,glow=0,mat=0)=>tube(a,b,th,6,col,glow,mat,true);
const limb=(a,b,r,col,mat=0)=>tube(a,b,r,6,col,0,mat,true);
const ellipsoid=(cx,cy,cz,rx,ry,rz,col,mat=0,seg=10,rows=5)=>{
const P=(a,b)=>[cx+Math.cos(a)*Math.cos(b)*rx, cy+Math.sin(a)*ry, cz+Math.cos(a)*Math.sin(b)*rz];
for(let j=0;j<rows;j++) for(let i=0;i<seg;i++){
const a0=Math.PI*(-0.5+j/rows), a1=Math.PI*(-0.5+(j+1)/rows), b0=i/seg*TAU, b1=(i+1)/seg*TAU;
quad(P(a0,b0),P(a0,b1),P(a1,b1),P(a1,b0),col,0,mat,true);
}
};
const poly=(pts,r,col,glow=0,mat=0)=>{ for(let i=0;i<pts.length-1;i++) tube(pts[i], pts[i+1], r, 7, col, glow, mat, true); };
// a two link arm solved for where the hand has to be, so the elbow bends as the thing being
// held moves. Straight rods from shoulder to handle were what read as an awkward arm.
const arm=(sh, target, L1, L2, bendDir)=>{
const d = sub(target, sh), len = Math.max(1e-4, Math.hypot(d[0],d[1],d[2]));
const u = scl(d, 1/len);
const ca = Math.acos(clamp((L1*L1 + len*len - L2*L2)/(2*L1*len), -1, 1));
let b = sub(bendDir, scl(u, dot(bendDir, u)));
if(Math.hypot(b[0],b[1],b[2]) < 1e-4) b = [0,-1,0]; else b = norm(b);
const elbow = add(sh, add(scl(u, L1*Math.cos(ca)), scl(b, L1*Math.sin(ca))));
limb(sh, elbow, 0.05, PAL.jacket);
limb(elbow, target, 0.042, PAL.skin);
sphere(target[0], target[1], target[2], 0.045, PAL.skin, 0, 8, 4);
};
// ---- hull ----
// The profile is a function of position along the boat instead of a list of stations, so the
// sides are continuous, the widest point is amidships like a real hull, the sheer rises towards
// the bow and the keel comes up as it goes forward. The stripe band is the topsides just under
// the rub rail, which is what the plain stripe quad used to be standing in for.
const wAt = z => z < 0 ? 0.42 + 0.04*Math.sin(clamp((z+1.55)/1.55,0,1)*1.5708)
: 0.46*Math.pow(1 - clamp(z/1.45,0,1), 1.35);
const dAt = z => 0.22 + 0.14*Math.pow(clamp((z+1.55)/3.2,0,1), 1.7); // freeboard at the transom raised
const bAt = z => -0.50 + 0.34*Math.pow(clamp((z+1.55)/3.2,0,1), 2.2);
const ring = z => {
const w = wAt(z), d = dAt(z), b = bAt(z), sy = d - 0.07, by = b + 0.16*(d-b);
return [[[-w,d,z], PAL.stripe], [[-w*0.94,sy,z], PAL.stripe],
[[-w*0.86,by,z], PAL.hull], [[-w*0.14,b,z], PAL.hull],
[[ w*0.14,b,z], PAL.hull], [[ w*0.86,by,z], PAL.hull],
[[ w*0.94,sy,z], PAL.stripe], [[ w,d,z], PAL.stripe]];
};
const Z0=-1.55, Z1=1.45, STEPS=18;
for(let s=0;s<STEPS;s++){
const z0=Z0+(Z1-Z0)*s/STEPS, z1=Z0+(Z1-Z0)*(s+1)/STEPS;
const r0=ring(z0), r1=ring(z1);
for(let i=0;i<r0.length-1;i++) quad(r0[i][0], r1[i][0], r1[i+1][0], r0[i+1][0], r0[i][1], 0, 0, true);
quad(r0[7][0], r0[0][0], r1[0][0], r1[7][0], PAL.wood); // deck
}
// transom: fill the whole last cross section, including the closing edge across the top.
// Skipping that edge left a gap you could see straight through.
const rT = ring(Z0), tc = [0, (dAt(Z0)+bAt(Z0))/2, Z0];
for(let i=0;i<rT.length;i++) tri(rT[i][0], rT[(i+1)%rT.length][0], tc, rT[i][1]);
// bow: fan the whole last cross section to the stem
const rr = ring(Z1), tip = [0, dAt(1.70), 1.70];
for(let i=0;i<rr.length;i++) tri(rr[i][0], rr[(i+1)%rr.length][0], tip, rr[i][1], 0, 0, true);
// ---- boiler, candle, exhaust ----
const bz = 0.08, by = 0.36;
ellipsoid(0, by, bz, 0.16, 0.05, 0.16, PAL.brass, 1, 10, 4);
for(const side of [-1, 1]){
// the pipes are what hold the boiler up: they come out of its underside, dip below the
// waterline just aft of it - that dip is the U bend the water sits in - and the mouth
// stays submerged at the back.
poly([[side*0.12, by-0.01, bz-0.02], [side*0.15, 0.10, -0.14], [side*0.19, -0.16, -0.62],
[side*0.22, -0.26, -1.42], [side*0.24, -0.34, -1.82]], 0.035, PAL.metal, 0, 1);
}
// the candle stands on the deck under the boiler and slides forward towards it, so at full
// throttle the flame is just under the boiler's underside, where the heat actually does something
const cz = -0.32 + 0.30*heat;
const cy = dAt(cz); // on the deck, not floating above it
const flame = 0.03 + 0.02*heat + 0.008*Math.sin(t*11.0) + 0.005*Math.sin(t*23.0);
tube([0, cy, cz], [0, cy+0.035, cz], 0.035, 7, PAL.wax, 0, 0, true);
cone(0, cy+0.035, cz, 0.035, flame, 7, PAL.flame, 1.0, 0);
const knob = [-0.05, cy+0.022, cz]; // the little handle on the candle's side
sphere(knob[0], knob[1], knob[2], 0.018, [0.30,0.28,0.24], 0, 6, 3);
// ---- tiller and rudder ----
const ang = -rudder * 0.45;
const head = [0, 0.16, -1.58];
const dx = Math.sin(ang), dz = Math.cos(ang);
const hx = dx*0.70, hz = head[2] + dz*0.70, hy = 0.40;
rod(head, [hx, hy, hz], 0.022, [0.30,0.28,0.24], 0, 1);
rod(head, [head[0], -0.06, head[2]], 0.018, [0.30,0.33,0.36], 0, 1);
const bx = head[0]+dx*0.40, bz2 = head[2]+dz*0.40;
quad([head[0],-0.06,head[2]], [bx,-0.06,bz2], [bx,-0.36,bz2], [head[0],-0.36,head[2]], PAL.metal, 0, 1);
// ---- helmsman ----
// Off centre to port, so the arm reaches the tiller straight ahead instead of across the boat.
const PX = -0.14;
const hip = [PX, 0.34, -0.46], chest = [PX, 0.56, -0.52];
box(PX, 0.26, -0.54, 0.15, 0.04, 0.19, PAL.wood);
limb(hip, [PX+0.02, 0.30, -0.24], 0.055, PAL.shirt); // thigh
limb([PX+0.02, 0.30, -0.24], [PX+0.03, 0.21, -0.14], 0.045, PAL.skin); // shin
tube(hip, chest, 0.125, 8, PAL.jacket, 0, 0, true); // life jacket
sphere(chest[0], chest[1]+0.01, chest[2], 0.125, PAL.jacket, 0, 10, 4); // rounded shoulders
limb(chest, [PX, 0.64, -0.54], 0.05, PAL.skin); // neck
sphere(PX, 0.70, -0.55, 0.095, PAL.skin, 0, 10, 6); // head
disc(PX, 0.79, -0.55, 0.15, 10, PAL.hat); // brim
cone(PX, 0.79, -0.55, 0.115, 0.10, 10, PAL.hat); // crown
// right hand on the tiller, left hand on the candle handle. Both are solved for wherever the
// thing being held currently is, so pushing the throttle straightens the left arm as the candle
// moves forward, and steering swings the right one.
arm([PX+0.06, 0.52, -0.48], [hx, hy, hz], 0.29, 0.29, [-0.55,-0.55,-0.1]);
arm([PX-0.06, 0.52, -0.44], knob, 0.29, 0.29, [-0.5,-0.6,0.05]);
// ---- pennant ----
// the pole starts at the deck, not above it
rod([0, dAt(1.20), 1.20], [0, 0.95, 1.20], 0.02, [0.35,0.30,0.22], 0, 1);
const fl = 0.05*Math.sin(t*6.0) + 0.02;
tri([0,0.95,1.20],[0,0.86,1.20+fl],[0,0.92,1.20+fl*0.4], PAL.stripe);
const m = [];
for(const f of faces){
for(const p of f[0]){
const a = acc.get(vk(p));
// a vertex whose accumulated normal cancels out is a degenerate face, so fall back to the face
const n = (f[5] && a && Math.hypot(a[0],a[1],a[2]) > 1e-6) ? norm(a) : f[2];
m.push(p[0]*S, p[1]*S, p[2]*S, f[1][0], f[1][1], f[1][2], n[0], n[1], n[2], f[3], f[4]);
}
}
boatVerts = m;
}
/* ================= audio ================= */
let AC=null, master=null, engineGain=null, hissGain=null, scrapeGain=null, noiseBuf=null, hum1=null, hum2=null;
function initAudio(){
if(AC) return;
try{ AC = new (window.AudioContext||window.webkitAudioContext)(); } catch(e){ return; }
master = AC.createGain(); master.gain.value = 0.55; master.connect(AC.destination);
noiseBuf = makeNoise(1.0);
const o1 = AC.createOscillator(); o1.type="sawtooth"; o1.frequency.value=46;
const o2 = AC.createOscillator(); o2.type="sine"; o2.frequency.value=71;
const lp = AC.createBiquadFilter(); lp.type="lowpass"; lp.frequency.value=210; lp.Q.value=0.8;
engineGain = AC.createGain(); engineGain.gain.value = 0.012;
o1.connect(lp); lp.connect(engineGain); o2.connect(engineGain); engineGain.connect(master);
hum1 = o1; hum2 = o2;
o1.start(); o2.start();
const src = AC.createBufferSource(); src.buffer = noiseBuf; src.loop = true;
const bp = AC.createBiquadFilter(); bp.type="bandpass"; bp.frequency.value=650; bp.Q.value=0.7;
hissGain = AC.createGain(); hissGain.gain.value = 0.005;
src.connect(bp); bp.connect(hissGain); hissGain.connect(master); src.start();
// hull on shingle: the same noise, pushed down and kept quiet until it is actually moving
const src2 = AC.createBufferSource(); src2.buffer = noiseBuf; src2.loop = true;
const lp2 = AC.createBiquadFilter(); lp2.type="lowpass"; lp2.frequency.value=190; lp2.Q.value=0.6;
scrapeGain = AC.createGain(); scrapeGain.gain.value = 0.0;
src2.connect(lp2); lp2.connect(scrapeGain); scrapeGain.connect(master); src2.start();
}
function makeNoise(sec){
const b = AC.createBuffer(1, Math.floor(AC.sampleRate*sec), AC.sampleRate);
const d = b.getChannelData(0);
for(let i=0;i<d.length;i++) d[i] = Math.random()*2-1;
return b;
}
function pop(strength){
if(!AC) return;
const t = AC.currentTime;
const o = AC.createOscillator(); o.type="sine";
const base = (95 + 40*strength) * (0.85 + Math.random()*0.3);
o.frequency.setValueAtTime(base, t);
o.frequency.exponentialRampToValueAtTime(38, t+0.14);
const g = AC.createGain();
g.gain.setValueAtTime(0.0001, t);
g.gain.exponentialRampToValueAtTime(0.32*strength + 0.02, t+0.015);
g.gain.exponentialRampToValueAtTime(0.0001, t+0.22);
o.connect(g); g.connect(master); o.start(t); o.stop(t+0.25);
const s = AC.createBufferSource(); s.buffer = noiseBuf;
const bp = AC.createBiquadFilter(); bp.type="bandpass"; bp.frequency.value=900; bp.Q.value=1.2;
const cg = AC.createGain();
cg.gain.setValueAtTime(0.0001, t);
cg.gain.exponentialRampToValueAtTime(0.10*strength + 0.005, t+0.006);
cg.gain.exponentialRampToValueAtTime(0.0001, t+0.09);
s.connect(bp); bp.connect(cg); cg.connect(master); s.start(t); s.stop(t+0.10);
}
/* ================= input ================= */
const keys = {};
/* Arrows are aliases, not a second set of state. One map used by both press and release,
so a key can never leave a control stuck on. */
const KEYMAP = { arrowup:"w", arrowdown:"s", arrowleft:"a", arrowright:"d" };
const keyOf = e => KEYMAP[e.key.toLowerCase()] || e.key.toLowerCase();
addEventListener("keydown", e=>{
initAudio(); if(AC && AC.state==="suspended") AC.resume();
const onSlider = e.target && e.target.tagName === "INPUT";
const k = keyOf(e);
// arrows belong to whatever has focus: a focused slider keeps its arrow keys, otherwise
// they steer (and would otherwise scroll the page)
if(["w","a","s","d"].includes(k) && !onSlider) keys[k] = true;
if(k === "r") reset();
if(k === "m") toggleMenu();
if(e.key.startsWith("Arrow") && !onSlider) e.preventDefault();
});
addEventListener("keyup", e=>{ keys[keyOf(e)] = false; });
let dragYaw=0, dragPitch=0, dist=7.0, dragging=false, lastX=0, lastY=0;
// Right-drag is the camera, so the browser's right-click menu has to be switched off.
// It also swallows the button release, which is why the drag can stay stuck on after the menu closes.
cv.addEventListener("contextmenu", e=>{ e.preventDefault(); });
cv.addEventListener("pointerdown", e=>{
if(e.button === 1) return; // middle button does nothing; left and right drag the camera
dragging = true;
lastX = e.clientX; lastY = e.clientY;
cv.setPointerCapture(e.pointerId); // still get the release if the pointer drifts off the canvas
initAudio();
});
const stopDrag = e=>{
if(!dragging) return;
dragging = false;
try{ cv.releasePointerCapture(e.pointerId); }catch(err){}
};
cv.addEventListener("pointerup", stopDrag);
cv.addEventListener("pointercancel", stopDrag);
// A cursor cannot be transitioned - it is drawn by the browser, not by the page - so it can only
// appear or disappear. It comes back on any movement, and stays put while you are dragging.
let cursorTimer = null;
function showCursor(){
cv.classList.remove("idle");
clearTimeout(cursorTimer);
cursorTimer = setTimeout(()=>{ if(!dragging) cv.classList.add("idle"); }, 1200);
}
cv.addEventListener("pointermove", showCursor);
cv.addEventListener("pointerleave", ()=>{ clearTimeout(cursorTimer); cv.classList.remove("idle"); });
cv.addEventListener("pointerdown", showCursor);
addEventListener("pointermove", e=>{
if(!dragging) return;
dragYaw += (e.clientX-lastX)*0.006;
dragPitch = clamp(dragPitch + (e.clientY-lastY)*0.004, -0.15, 1.1);
lastX = e.clientX; lastY = e.clientY;
});
addEventListener("wheel", e=>{ dist = clamp(dist + e.deltaY*0.01, 4, 22); }, {passive:true});
/* ================= menu =================
Controls are described as data rather than hand-written markup: a label, a range, and a
get/set pair. The menu itself has no idea what any of them do, so anything added later is
one entry in this list. */
const menuEl = document.getElementById("menu");
const menuBody = document.getElementById("menuBody");
let menuOpen = false;
const MENU = [
{ name: "boat colours", controls: [
{ label: "all", min: -180, max: 180, get: () => ctl.all, set: v => { ctl.all = v; paint(); } },
...Object.keys(BASE).map(k => ({
label: k, min: -180, max: 180,
get: () => ctl.tint[k] || 0, set: v => { ctl.tint[k] = v; paint(); }
}))
] }
];
function buildMenu(){
for(const group of MENU){
const g = document.createElement("div");
const h = document.createElement("b"); h.textContent = group.name; g.appendChild(h);
for(const c of group.controls){
const row = document.createElement("label");
const name = document.createElement("span"); name.textContent = c.label;
const val = document.createElement("i"); val.textContent = c.get();
const s = document.createElement("input");
s.type = "range"; s.min = c.min; s.max = c.max; s.step = c.step || 1; s.value = c.get();
s.addEventListener("input", () => { c.set(Number(s.value)); val.textContent = s.value; });
row.append(name, s, val);
g.appendChild(row);
}
menuBody.appendChild(g);
}
}
function toggleMenu(){ menuOpen = !menuOpen; menuEl.classList.toggle("open", menuOpen); }
buildMenu();
paint();
/* ================= state ================= */
const boat = {x:0, z:0, heading:0, throttle:0, rudder:0, speed:0,
bob:0, bobV:0, tiltX:0, tiltXV:0, tiltZ:0, tiltZV:0, shudder:0, aground:false};
const cam = {yaw:0, pitch:0.35, shake:0};
let puffs = [], nextPop = 0, popIdx = 0, last = 0, lastPopT = -9, popPos = [0,0,0];
/* R has to put the boat in water, so it looks for some: a widening ring of candidates, with a
different set of angles on each ring so it does not crawl the same line forever. */
function findWater(){
for(let ring = 8; ring < 200; ring += 8){
for(let k = 0; k < 12; k++){
const a = k*Math.PI/6 + ring*0.37;
const x = boat.x + Math.cos(a)*ring, z = boat.z + Math.sin(a)*ring;
if(hullLand(x, z, boat.heading) < -0.15) return [x, z]; // a little water under the whole hull
}
}
return [boat.x, boat.z];
}
function reset(){
const p = findWater();
boat.x=p[0];boat.z=p[1];boat.heading=0;boat.throttle=0;boat.rudder=0;boat.speed=0;boat.aground=false;
boat.bob=0;boat.bobV=0;boat.tiltX=0;boat.tiltXV=0;boat.tiltZ=0;boat.tiltZV=0;boat.shudder=0;
}
function spawnPuff(model, origin, fwd, side, heat){
if(puffs.length > 160) return;
const lp = [side*0.24*BOAT_SCALE, -0.34*BOAT_SCALE, -1.82*BOAT_SCALE]; // the submerged tube mouth
const wp = [
origin[0] + model[0]*lp[0] + model[4]*lp[1] + model[8]*lp[2],
origin[1] + model[1]*lp[0] + model[5]*lp[1] + model[9]*lp[2],
origin[2] + model[2]*lp[0] + model[6]*lp[1] + model[10]*lp[2]
];
popPos = wp;
const kind = landH(wp[0], wp[2]) > 0.02 ? 0 : 1; // a tube above the shore puts out steam, not foam
const push = 0.15 + 0.45*heat; // more heat, harder the water is pushed out
puffs.push({
p:wp, seed:Math.random(),
v:[-fwd[0]*push + (Math.random()-0.5)*0.25, 0.35 + Math.random()*0.25, -fwd[2]*push + (Math.random()-0.5)*0.25],
life:0, max:0.8 + Math.random()*0.4, size:0.03 + 0.03*heat, kind
});
}
/* ================= loop ================= */
function resize(){
const dpr = Math.min(2, window.devicePixelRatio || 1);
const w = Math.max(1, Math.floor(innerWidth*dpr)), h = Math.max(1, Math.floor(innerHeight*dpr));
if(cv.width!==w || cv.height!==h){ cv.width=w; cv.height=h; }
gl.viewport(0,0,w,h);
}
function frame(nowMs){
const t = nowMs/1000;
const dt = Math.min(0.05, t - last); last = t;
resize();
/* --- boat physics --- */
// exponential smoothing: same feel at 60fps and at 144fps
const thrTarget = (keys.w?1:0) - (keys.s?1:0);
boat.throttle += (thrTarget - boat.throttle) * (1 - Math.exp(-dt*2.5));
const rudTarget = (keys.a?1:0) - (keys.d?1:0);
boat.rudder += (rudTarget - boat.rudder) * (1 - Math.exp(-dt*4.0));
const maxSpeed = 6.0, idleThrust = 0.35; // the candle is always heating, so it always pulls a little
/* --- what is under the hull --- */
const landAt = landH(boat.x, boat.z); // ground under the boat itself
const surf = hullWater(boat.x, boat.z, boat.heading, t); // the waterplane, not the ground under it
// The boat only meets ground that is above the water, because that is the land the mesh draws. Under
// the surface the seabed is invisible, so it must neither stop the boat nor tip it. A hull in half a
// metre of water over an unseen bottom was being treated as aground, and the tilt came from the slope
// of ground you cannot see - which is the lean you are seeing close to shores.
const shore = shoreAt(boat.x, boat.z, t);
const grounded = shore > LAND.beach;
const wetted = grounded ? 0 : 1;
boat.aground = grounded; // dry land: nothing to hiss against
// A putt-putt pushes against water. Out of the water it only spins, so the engine is scaled by how
// much of the hull is still wet. What moves a grounded boat is gravity along the hull - and since
// the profile always falls away towards the sea, that always points back to water.
// On the ground the tilt and the slide both come from the slope of the ground itself; a boat
// resting on the beach should not be tipped by a wave it is no longer in.
let sx, sz;
if(wetted < 0.5) [sx, sz] = hullGroundSlope(boat.x, boat.z, boat.heading);
else [sx, sz] = hullSlope(boat.x, boat.z, boat.heading, t);
const drive = (idleThrust + boat.throttle*(maxSpeed - idleThrust)) * wetted;
const slide = -sx * 2.5 * (1 - wetted); // bow on higher ground means it slides back off
boat.speed += ((drive - boat.speed) * 2.2 + slide) * dt;
const authority = clamp(0.15 + Math.abs(boat.speed)/3.0, 0.15, 1.0) * wetted; // no water over the rudder
boat.heading += boat.rudder * 1.4 * authority * dt;
let nx = boat.x + Math.sin(boat.heading) * boat.speed * dt;
let nz = boat.z + Math.cos(boat.heading) * boat.speed * dt;
// It may sit on the beach, but it cannot climb. The motion into the land is removed and the rest
// slides along the contour, which is what stops it sticking fast in a cove.
if(shoreAt(nx, nz, t) > LAND.beach){
const g = norm([landGrad(nx, nz)[0], 0, landGrad(nx, nz)[1]]);
const mv = [nx - boat.x, 0, nz - boat.z];
const into = dot(mv, g);
if(into > 0){
const along = sub(mv, scl(g, into));
nx = boat.x + along[0]; nz = boat.z + along[2];
}
}
boat.x = nx; boat.z = nz;
/* --- float: the hull feels the average surface over its footprint, not one point --- */
// The boat cannot sink through the bottom, so the target is the higher of normal buoyancy and the
// ground plus the draft - but only where the ground is above sea level. The seabed is never drawn:
// the water is opaque and the surface mesh follows the waves, not the bottom, so a hull that grounds
// on a seabed a metre below the surface reads as floating above invisible ground. Only land the mesh
// actually draws is physical.
const floatTarget = Math.max(surf + 0.12*(hullTop(boat.x, boat.z, boat.heading, t) - surf) + SIT, grounded ? landAt + DRAFT : -1e9);
const hs = wetted < 0.5 ? GROUND.heave : HEAVE;
const ts = wetted < 0.5 ? GROUND.tilt : TILT;
[boat.bob, boat.bobV] = spring(boat.bob, boat.bobV, floatTarget, dt, hs.period, hs.zeta);
[boat.tiltX, boat.tiltXV] = spring(boat.tiltX, boat.tiltXV, sx, dt, ts.roll.period, ts.roll.zeta);
[boat.tiltZ, boat.tiltZV] = spring(boat.tiltZ, boat.tiltZV, sz, dt, ts.pitch.period, ts.pitch.zeta);
const up = norm([-boat.tiltX, 1, -boat.tiltZ]);
const heading = [Math.sin(boat.heading), 0, Math.cos(boat.heading)];
const fwd = norm(sub(heading, scl(up, dot(heading, up))));
const right = norm(cross(up, fwd));
const rot = (v, ang) => norm(add(scl(v, Math.cos(ang)), scl(cross(fwd, v), Math.sin(ang))));
boat.shudder *= Math.exp(-dt*7);
const bank = clamp(boat.rudder*authority, -1, 1) * 0.14 + boat.shudder*0.45*Math.sin(t*35);
const upB = rot(up, bank);
const rightB = rot(right, bank);
const model = new Float32Array(16); // columns = right, up, fwd (column-major)
model[0]=rightB[0]; model[1]=rightB[1]; model[2]=rightB[2];
model[4]=upB[0]; model[5]=upB[1]; model[6]=upB[2];
model[8]=fwd[0]; model[9]=fwd[1]; model[10]=fwd[2];
model[15]=1;
const origin = [boat.x, boat.bob + boat.shudder*0.03, boat.z];
/* --- the candle heats the chamber: slow even putts at rest, a gallop as it gets hotter --- */
if(t >= nextPop){
const heat = Math.abs(boat.throttle);
const strength = 0.18 + heat*0.8;
const side = popIdx % 2 ? 1 : -1; // the two tubes fire one after the other
pop(strength * (side === 1 ? 1.0 : 0.7));
popIdx++;
spawnPuff(model, origin, fwd, side, heat);
boat.shudder += 0.05*strength;
cam.shake += 0.006*strength;
lastPopT = t;
const rpm = 0.55 + heat*3.2;
// even beats at rest; the classic putt-putt gallop only appears once it is hot enough
const beat = side === 1 ? 1.0 : (0.55 + 0.45*(1 - Math.min(1, heat)));
nextPop = t + beat/rpm;
}
cam.shake *= Math.exp(-dt*5);
/* --- camera --- */
cam.yaw += ((boat.heading + dragYaw) - cam.yaw) * Math.min(1, dt*3.0);
cam.pitch += ((0.25 + dragPitch) - cam.pitch) * Math.min(1, dt*3.0);
const cp = cam.pitch + cam.shake*0.4;
const dir = [Math.cos(cp)*Math.sin(cam.yaw), -Math.sin(cp), Math.cos(cp)*Math.cos(cam.yaw)];
const target = [boat.x, boat.bob + 0.45, boat.z];
// the camera used to ride its own private bit of chop; keep only a little of it
const eye = [target[0]-dir[0]*dist, target[1]-dir[1]*dist + waveH(target[0]-dir[0]*dist, target[2]-dir[2]*dist, t)*0.10, target[2]-dir[2]*dist];
const view = lookAt(eye, target, [0,1,0]);
const aspect = cv.width / cv.height;
const proj = perspective(0.9, aspect, 0.1, 400);
const tanHalf = [Math.tan(0.45)*aspect, Math.tan(0.45)];
/* --- draw --- */
gl.clearColor(0.22,0.45,0.72,1);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
gl.disable(gl.DEPTH_TEST);
gl.useProgram(skyP.p);
gl.uniform3f(skyP.u.uRight, view.right[0], view.right[1], view.right[2]);
gl.uniform3f(skyP.u.uUp, view.up[0], view.up[1], view.up[2]);
gl.uniform3f(skyP.u.uFwd, view.fwd[0], view.fwd[1], view.fwd[2]);
gl.uniform2f(skyP.u.uTan, tanHalf[0], tanHalf[1]);
gl.uniform1f(skyP.u.uTime, t);
gl.bindBuffer(gl.ARRAY_BUFFER, skyBuf); setAttribs(skyP, [["aClip",2,0]], 0); gl.drawArrays(gl.TRIANGLES, 0, 3);
gl.enable(gl.DEPTH_TEST);
gl.useProgram(waterP.p);
gl.uniformMatrix4fv(waterP.u.uProj, false, proj);
gl.uniformMatrix4fv(waterP.u.uView, false, view.m);
const ax = Math.floor(boat.x/CELL)*CELL;
const az = Math.floor(boat.z/CELL)*CELL;
gl.uniform2f(waterP.u.uOrigin, ax, az);
// the islands the grid can actually reach, as data - the shader never decides whether land exists
const isl = islandsNear(ax - N*CELL/2, ax + N*CELL/2, az - N*CELL/2, az + N*CELL/2);
gl.uniform1i(waterP.u.uCount, isl.length);
for(let i=0;i<MAX_ISLANDS;i++){
const v = isl[i] ? [isl[i].x, isl[i].z, isl[i].r, isl[i].code] : [0,0,0,0];
gl.uniform4f(islLoc[i], v[0], v[1], v[2], v[3]);
}
setPal(waterP, ["sand", "grass", "rock"]);
gl.uniform1f(waterP.u.uTime, t);
gl.uniform1f(waterP.u.uSpeed, Math.abs(boat.speed));
gl.uniform3f(waterP.u.uBoat, boat.x, boat.bob, boat.z);
gl.uniform3f(waterP.u.uFwd, fwd[0], fwd[1], fwd[2]);
gl.uniform1f(waterP.u.uPopAge, t - lastPopT);
gl.uniform3f(waterP.u.uPopPos, popPos[0], popPos[1], popPos[2]);
gl.uniform3f(waterP.u.uCam, eye[0], eye[1], eye[2]);
gl.bindBuffer(gl.ARRAY_BUFFER, gridBuf); setAttribs(waterP, [["aGrid",2,0]], 0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gridIdx);
gl.drawElements(gl.TRIANGLES, N*N*6, gl.UNSIGNED_SHORT, 0);
buildBoat(boat.rudder, t, Math.abs(boat.throttle));
gl.useProgram(boatP.p);
gl.uniformMatrix4fv(boatP.u.uProj, false, proj);
gl.uniformMatrix4fv(boatP.u.uView, false, view.m);
gl.uniformMatrix4fv(boatP.u.uModel, false, model);
gl.uniform3f(boatP.u.uOrigin, origin[0], origin[1], origin[2]);
gl.uniform3f(boatP.u.uCam, eye[0], eye[1], eye[2]);
gl.bindBuffer(gl.ARRAY_BUFFER, boatBuf);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(boatVerts), gl.DYNAMIC_DRAW);
setAttribs(boatP, [["aPos",3,0],["aCol",3,12],["aNormal",3,24],["aGlow",1,36],["aMat",1,40]], 44);
gl.drawArrays(gl.TRIANGLES, 0, boatVerts.length/11);
// puffs
gl.useProgram(puffP.p);
gl.uniformMatrix4fv(puffP.u.uProj, false, proj);
gl.uniformMatrix4fv(puffP.u.uView, false, view.m);
const data = [];
const R = view.right, U = view.up;
for(const pf of puffs){
const s = pf.size;
const corners = [[-1,-1],[1,-1],[1,1],[-1,-1],[1,1],[-1,1]];
for(const c of corners){
data.push(
pf.p[0] + R[0]*c[0]*s + U[0]*c[1]*s,
pf.p[1] + R[1]*c[0]*s + U[1]*c[1]*s,
pf.p[2] + R[2]*c[0]*s + U[2]*c[1]*s,
c[0], c[1], clamp(pf.life/0.05,0,1) * (1 - pf.life/pf.max), pf.kind, pf.seed);
}
}
if(data.length){
gl.bindBuffer(gl.ARRAY_BUFFER, puffBuf);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(data), gl.DYNAMIC_DRAW);
setAttribs(puffP, [["aPos",3,0],["aUV",2,12],["aAlpha",1,20],["aKind",1,24],["aSeed",1,28]], 32);
gl.depthMask(false); gl.enable(gl.BLEND); gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
gl.drawArrays(gl.TRIANGLES, 0, data.length/8);
gl.disable(gl.BLEND); gl.depthMask(true);
}
/* --- update puffs --- */
for(const pf of puffs){
pf.life += dt;
pf.size = Math.min(0.22, pf.size + dt*0.45);
pf.p[0] += pf.v[0]*dt; pf.p[2] += pf.v[2]*dt;
const decay = Math.exp(-dt*2.2);
pf.v[0] *= decay; pf.v[2] *= decay;
if(pf.kind === 1 && pf.life < pf.max*0.55 && landH(pf.p[0], pf.p[2]) <= 0.02){
const surf = waveH(pf.p[0], pf.p[2], t);
// the mouth is submerged now, so a bubble has to rise to the surface before it reads as foam
if(pf.p[1] >= surf - 0.02) pf.p[1] = surf + 0.02;
} else {
pf.v[1] *= decay; // then it lifts off as steam
pf.p[1] += pf.v[1]*dt;
}
}
puffs = puffs.filter(p=>p.life < p.max);
/* --- engine hum / water hiss levels --- */
if(AC){
const lvl = Math.abs(boat.throttle);
// the candle is always heating something, so at rest there is a soft idle chug rather than silence
if(hum1){
hum1.frequency.setTargetAtTime(46 + 22*lvl, AC.currentTime, 0.2);
hum2.frequency.setTargetAtTime(71 + 34*lvl, AC.currentTime, 0.2);
}
engineGain.gain.value += ((0.012 + 0.030*lvl) - engineGain.gain.value) * (1 - Math.exp(-dt*4));
// the water hiss only exists while there is water to hiss against
hissGain.gain.value += (((0.005 + 0.014*Math.min(1, Math.abs(boat.speed)/4)) * wetted) - hissGain.gain.value) * (1 - Math.exp(-dt*4));
if(scrapeGain){
const s = (boat.aground && Math.abs(boat.speed) > 0.15) ? 0.018 : 0.0;
scrapeGain.gain.value += (s - scrapeGain.gain.value) * (1 - Math.exp(-dt*3));
}
}
requestAnimationFrame(frame);
}
reset();
requestAnimationFrame(frame);
</script>
</body>
</html>
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