cars: distribute lights by density and scale point size with render resolution

vendor/clouds3d.js

@@ -3345,7 +3345,7 @@ var CAR_M_DASH = carMetres(CAR_TUN.dashM || 620);
 // density sits below the motorway peak and the gaussian falloff shapes it
 // further by distance to the nearest motorway.
 var CAR_M_SPEED = 0.055 * CAR_SPEED, CAR_M_DENS = 0.85 * CAR_DENS;
-var CAR_B_DASH = CAR_M_DASH * 1.15, CAR_B_SPEED = 0.017 * CAR_SPEED, CAR_B_DENS = 1.0 * CAR_DENS;
+var CAR_B_DASH = CAR_M_DASH * 2.8, CAR_B_SPEED = 0.017 * CAR_SPEED, CAR_B_DENS = 0.75 * CAR_DENS;
 var carGeo = null;         // { motorway: packedChains, secondary: packedChains }
 var carVboM = null, carCountM = 0;
 var carVboB = null, carCountB = 0;
@@ -4284,16 +4284,15 @@ function buildCarGeometry(chainsM, chainsB, ts, cfg, places) {
     // spreadKm is the sigma of the motorway distribution.
     function densScale(x, z) {
         var st = settleAt(x, z);
-        if (!distField) return Math.min(1, 0.72 + 0.45 * st);
+        if (!distField) return Math.min(1, 0.16 + 0.84 * st);
         var i = Math.max(0, Math.min(ts.gw - 1, Math.round((x + ts.halfX) / ts.s)));
         var j = Math.max(0, Math.min(ts.gh - 1, Math.round((ts.halfY - z) / ts.s)));
         var d = distField[j * ts.gw + i] * ts.s;      // world units to a motorway
         var t = d / cfg.CAR_SIGMA;
         var mw = cfg.CAR_FLOOR + (1 - cfg.CAR_FLOOR) * Math.exp(-t * t);
-        // Flat enough that a side road 60 km from the A-net still carries
+        // Side roads are sparse unless they are near the A-net or a town.
-        // clearly visible traffic; the motorway gaussian only adds a modest
+        // Motorways/settlements get the bulk; remote secondary roads stay faint.
-        // boost on top instead of dominating the whole field.
+        return Math.min(1, 0.12 + 0.58 * mw + 0.62 * st);
-        return Math.min(1, 0.72 + 0.28 * mw + 0.45 * st);
     }
     function build(polys, withField, dash) {
         var li, i, segs = 0, totalLen = 0;
@@ -4315,7 +4314,7 @@ function buildCarGeometry(chainsM, chainsB, ts, cfg, places) {
         // shorter than the spacing still gets a vehicle), so the capacity
         // must count both - otherwise a network of many short side roads
         // overflows the buffer and the tail of it is silently dropped.
-        var pArr = new Float32Array((Math.ceil(totalLen / dash) + polys.length + 2) * 20);
+        var pArr = new Float32Array((Math.ceil(totalLen / (dash * 0.55)) + polys.length + 2) * 20);
         var pi = 0, pn = 0;
         for (li = 0; li < polys.length; li++) {
             var pts = polys[li];
@@ -4337,7 +4336,7 @@ function buildCarGeometry(chainsM, chainsB, ts, cfg, places) {
                 var ya = terrainH(ts, a.x, a.z) * cfg.ELEV_SCALE_UNITS + CAR_Y;
                 var yb = terrainH(ts, b.x, b.z) * cfg.ELEV_SCALE_UNITS + CAR_Y;
                 var dens = withField ? densScale((a.x + b.x) / 2, (a.z + b.z) / 2)
-                    : Math.min(1, 0.55 + 0.65 * settleAt((a.x + b.x) / 2, (a.z + b.z) / 2));
+                    : Math.min(1, 0.88 + 0.25 * settleAt((a.x + b.x) / 2, (a.z + b.z) / 2));
                 verts[vi++] = a.x + nx; verts[vi++] = ya; verts[vi++] = a.z + nz;
                 verts[vi++] = a.d; verts[vi++] = 1; verts[vi++] = tx; verts[vi++] = tz; verts[vi++] = dens;
                 verts[vi++] = a.x - nx; verts[vi++] = ya; verts[vi++] = a.z - nz;
@@ -4355,7 +4354,8 @@ function buildCarGeometry(chainsM, chainsB, ts, cfg, places) {
                     var f = next - acc;
                     if (f < 0) f = 0;
                     var qx = a.x + dx * f, qz = a.z + dz * f;
-                    if (inView(qx, qz) && pi + 20 <= pArr.length) {
+                    var slotWeight = withField ? Math.max(0.12, Math.min(1.25, (dens - 0.10) / 0.72)) : 1.18;
+                    if (inView(qx, qz) && pi + 20 <= pArr.length && slotWeight > 0.14) {
                         // one shared slide phase per chain: every vehicle of
                         // a chain moves in lockstep, so a wrap lands exactly
                         // on the slot the neighbour just left - continuous
@@ -4375,7 +4375,7 @@ function buildCarGeometry(chainsM, chainsB, ts, cfg, places) {
                         pArr[pi++] = clen;
                         pn++;
                     }
-                    next += dash;
+                    next += dash / slotWeight;
                 }
                 acc += L;
             }
@@ -6457,6 +6457,7 @@ window.clouds3dRender = function(target) {
     // aircraft): the mean over the per-light thresholds.
     var carNight = lightFactor(window.__currentSunAlt || 0);
     if (carProg && (carVboM || carVboB) && carNight > 0.01) {
+        var carPxScale = Math.max(0.45, Math.min(1.25, gl.drawingBufferHeight / 1080));
         var tCurve = Math.max(0, Math.min(1, (carNight - 0.10) / 0.40));
         tCurve = tCurve * tCurve * (3 - 2 * tCurve);   // smoothstep
         // rush-hour shaping: busy evening/early morning, quiet 23:00-04:00
@@ -6494,7 +6495,7 @@ window.clouds3dRender = function(target) {
         gl.uniform1f(carUniforms.night, carNight);
         // dot radius the light needs per unit distance to still reach
         // CAR_MIN_PX diameter (0.5774 = tan(fovY/2) of the 60 deg vertical fov)
-        gl.uniform1f(carUniforms.grow, CAR_BAND_PX * 0.5774 / gl.drawingBufferHeight);
+        gl.uniform1f(carUniforms.grow, CAR_BAND_PX * carPxScale * 0.5774 / gl.drawingBufferHeight);
         gl.uniform1f(carUniforms.halfW, CAR_W);
         gl.uniform1f(carUniforms.bright, CAR_BAND_BRIGHT);
         gl.uniform1f(carUniforms.fadeA, CAR_FADE_A);
@@ -6574,14 +6575,14 @@ window.clouds3dRender = function(target) {
                 // world units covered by one pixel at unit distance:
                 // 2*tan(fovY/2)/H = 1.1547/H for the 60 deg vertical fov
                 gl.uniform1f(carPtsUniforms.laneW, CAR_LANE_W);
-                gl.uniform1f(carPtsUniforms.lanePx, CAR_LANE_PX);
+                gl.uniform1f(carPtsUniforms.lanePx, CAR_LANE_PX * carPxScale);
                 // world units covered by one pixel at unit distance:
                 // 2*tan(fovY/2)/H = 1.1547/H for the 60 deg vertical fov
                 gl.uniform1f(carPtsUniforms.pxW, 1.1547 / gl.drawingBufferHeight);
                 gl.uniform1f(carPtsUniforms.traffic, CAR_TRAFFIC);
-                gl.uniform1f(carPtsUniforms.minPx, CAR_MIN_PX);
+                gl.uniform1f(carPtsUniforms.minPx, CAR_MIN_PX * carPxScale);
-                gl.uniform1f(carPtsUniforms.maxPx, CAR_MAX_PX);
+                gl.uniform1f(carPtsUniforms.maxPx, CAR_MAX_PX * carPxScale);
-                gl.uniform1f(carPtsUniforms.boost, CAR_BOOST);
+                gl.uniform1f(carPtsUniforms.boost, CAR_BOOST * carPxScale);
                 gl.uniform1f(carPtsUniforms.bright, CAR_BRIGHT);
                 gl.uniform1f(carPtsUniforms.fadeA, CAR_FADE_A);
                 gl.uniform1f(carPtsUniforms.fadeB, CAR_FADE_B);