Fix invisible torch flames (halo hid them); thin wisp of torch smoke

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/particles.rs

@@ -25,6 +25,7 @@ pub const FLASH: u8 = 8; // expanding fireball
 pub const RING: u8 = 9; // shock wave
 pub const SPLASH: u8 = 10; // liquid droplets, bounce on the river surface
 pub const BURNING_ARROW: u8 = 11; // arrow drifting on lava until it burns up (vx, vy = its direction)
+pub const WISP: u8 = 12; // torch smoke: a small pixel that rises in a gentle wave and fades
 
 // projectile styles (Fx::style)
 pub const ST_PLAIN: u8 = 0;
@@ -210,6 +211,13 @@ impl Game {
                     p.h += p.vh * dt;
                 }
                 FLASH | RING => {}
+                WISP => {
+                    // rises and sways a little from side to side
+                    p.h += p.vh * dt;
+                    let sway = (p.t * 3.0 + p.vx * 50.0).sin() * 0.06 * dt;
+                    p.x += sway;
+                    p.y += sway * 0.6;
+                }
                 BURNING_ARROW => {
                     // drifts slowly with the lava
                     p.x += p.vx * 0.05 * dt;
@@ -400,13 +408,16 @@ impl Game {
     fn spawn_torch_smoke(&mut self, dt: f32) {
         let spots: Vec<(f32, f32, f32)> = self.torches.iter().filter(|t| self.map.shown(t.wall)).map(|t| (t.pos().0, t.pos().1, t.flame_h())).collect();
         for (x, y, fh) in spots {
-            if self.parts.len() >= PARTS_MAX - 100 {
+            // torch smoke takes at most half of the particles: explosions and splashes come first
+            if self.parts.len() >= PARTS_MAX / 2 {
                 break;
             }
-            if self.vrng.f() < 1.1 * dt {
-                let v = ((self.vrng.f() - 0.5) * 0.08, (self.vrng.f() - 0.5) * 0.08, 0.32 + self.vrng.f() * 0.12);
-                let life = 1.8 + self.vrng.f() * 0.6;
-                self.part(SMOKE, (x, y, fh + 0.28), v, life, abgr(70, 62, 58), 0.05);
+            if self.vrng.f() < 3.0 * dt {
+                // vx only seeds the sway (see WISP in the update)
+                let v = (self.vrng.f(), 0.0, 0.3 + self.vrng.f() * 0.1);
+                let life = 1.2 + self.vrng.f() * 0.5;
+                let size = 0.025 + self.vrng.f() * 0.012;
+                self.part(WISP, (x, y, fh + 0.3), v, life, abgr(150, 140, 132), size);
             }
             if self.vrng.f() < 0.25 * dt {
                 let v = ((self.vrng.f() - 0.5) * 0.3, (self.vrng.f() - 0.5) * 0.3, 0.9);

src/render3d.rs

@@ -2698,7 +2698,6 @@ fn draw_torch_stand(x: f32, z: f32) {
 // sway and flicker; a soft halo around it (the smoke comes from particles.rs)
 fn draw_torch_flame((x, z): (f32, f32), base: f32, k: f32, t: f32) {
     let flick = 0.8 + 0.2 * (t * 13.0 + k * 2.1).sin() + 0.1 * (t * 29.0 + k * 0.7).sin();
-    draw_sphere(vec3(x, base + 0.1, z), 0.24 * flick, None, Color::new(1.0, 0.55, 0.15, 0.16));
     let n = 6;
     for i in 0..n {
         let f = i as f32 / (n - 1) as f32;
@@ -2713,6 +2712,9 @@ fn draw_torch_flame((x, z): (f32, f32), base: f32, k: f32, t: f32) {
         };
         draw_cube(vec3(x + sway, h, z + sway2), Vec3::splat(size), None, Color::new(c.x, c.y, c.z, 0.95 - f * 0.4));
     }
+    // the halo last: the glow material writes depth, so anything drawn after it inside the
+    // sphere would be hidden
+    draw_sphere(vec3(x, base + 0.1, z), 0.24 * flick, None, Color::new(1.0, 0.55, 0.15, 0.16));
 }
 
 // particles that glow (embers, sparks, smoke, flashes, shock waves)
@@ -2774,6 +2776,10 @@ fn draw_parts_glow(g: &Game) {
         let life = (p.t / p.max).clamp(0.0, 1.0);
         let at = vec3(p.x, p.h, p.y);
         match p.kind {
+            WISP => {
+                // a thin thread of smoke: small pixels that fade, they do not grow
+                draw_cube(at, Vec3::splat(p.size), None, Color::new(c.r, c.g, c.b, 0.55 * (1.0 - life)));
+            }
             EMBER | SPARK | MOTE | SPLASH => {
                 let s = p.size * (1.0 - life * 0.6);
                 draw_cube(at, Vec3::splat(s), None, Color::new(c.r, c.g, c.b, 1.0 - life * life));