feat: birch

app/assets.ts

@@ -1,6 +1,7 @@
 import type { Texture } from "../engine/render/Texture"
 import barkUrl from "../assets/bark.png"
 import beeUrl from "../assets/bee.png"
+import birchUrl from "../assets/birch.png"
 import crateUrl from "../assets/crate.png"
 import floorUrl from "../assets/floor.png"
 import flowerUrl from "../assets/flower.png"
@@ -16,6 +17,7 @@ export type Textures = {
   floor: Texture
   grass: Texture
   bark: Texture
+  birch: Texture
   leaf: Texture
   needle: Texture
   rock: Texture
@@ -29,10 +31,11 @@ export type Textures = {
 
 /** Load every game texture up front. Call once before starting the loop. */
 export async function loadTextures(): Promise<Textures> {
-  const [floor, grass, bark, leaf, needle, rock, flower, wall, crate, npc, frog, bee] = await Promise.all([
+  const [floor, grass, bark, birch, leaf, needle, rock, flower, wall, crate, npc, frog, bee] = await Promise.all([
     loadTexture(floorUrl),
     loadTexture(grassUrl),
     loadTexture(barkUrl),
+    loadTexture(birchUrl),
     loadTexture(leafUrl),
     loadTexture(needleUrl),
     loadTexture(rockUrl),
@@ -43,7 +46,7 @@ export async function loadTextures(): Promise<Textures> {
     loadTexture(frogUrl),
     loadTexture(beeUrl),
   ])
-  return { floor, grass, bark, leaf, needle, rock, flower, wall, crate, npc, frog, bee }
+  return { floor, grass, bark, birch, leaf, needle, rock, flower, wall, crate, npc, frog, bee }
 }
 
 function loadTexture(url: string): Promise<Texture> {

app/level.ts

@@ -35,6 +35,9 @@ export type Chunk = {
   maxZ: number
   grass: Mesh
   bark: Mesh
+  /** Birch trunks (white bark texture) -- separate mesh since a draw is one mesh +
+   *  one texture, and silver birch bark can't share the brown oak/spruce bark. */
+  birchBark: Mesh
   leaf: Mesh
   needle: Mesh
   rock: Mesh
@@ -42,8 +45,9 @@ export type Chunk = {
   flowers: Mesh
   /** Cheap low-poly impostors of the same trees/boulders, drawn instead of the
    *  full meshes once the chunk is past `config.lodDistance` (renderScene). Same
-   *  textures as bark/leaf/needle/rock. Bushes/flowers have no far version. */
+   *  textures as bark/birch/leaf/needle/rock. Bushes/flowers have no far version. */
   barkFar: Mesh
+  birchBarkFar: Mesh
   leafFar: Mesh
   needleFar: Mesh
   rockFar: Mesh
@@ -231,21 +235,27 @@ function buildChunks(trees: Tree[], boulders: Boulder[], bushes: Bush[], flowers
       const z1 = z0 + cell
       const grass = mesh()
       const bark = mesh()
+      const birchBark = mesh()
       const leaf = mesh()
       const needle = mesh()
       const rock = mesh()
       const flowerMesh = mesh()
       const barkFar = mesh()
+      const birchBarkFar = mesh()
       const leafFar = mesh()
       const needleFar = mesh()
       const rockFar = mesh()
       Terrain.patch(TERRAIN, grass, x0, z0, x1, z1, TERRAIN_SUBDIV, TERRAIN_SUBDIV, GROUND_UV)
       for (const tree of trees) {
         if (inCell(tree.position, x0, z0, x1, z1)) {
-          const foliage = tree.kind === "oak" ? leaf : needle
-          const foliageFar = tree.kind === "oak" ? leafFar : needleFar
-          Tree.build(tree, bark, foliage)
-          Tree.build(tree, barkFar, foliageFar, "impostor")
+          // Birch trunks go to their own white-bark mesh; oak + birch share the oak
+          // leaf foliage, spruce keeps its needles.
+          const trunk = tree.kind === "birch" ? birchBark : bark
+          const trunkFar = tree.kind === "birch" ? birchBarkFar : barkFar
+          const foliage = tree.kind === "spruce" ? needle : leaf
+          const foliageFar = tree.kind === "spruce" ? needleFar : leafFar
+          Tree.build(tree, trunk, foliage)
+          Tree.build(tree, trunkFar, foliageFar, "impostor")
         }
       }
       for (const boulder of boulders) {
@@ -265,11 +275,11 @@ function buildChunks(trees: Tree[], boulders: Boulder[], bushes: Bush[], flowers
           Flower.build(flower, flowerMesh)
         }
       }
-      const b = bounds([grass, bark, leaf, needle, rock, flowerMesh])
+      const b = bounds([grass, bark, birchBark, leaf, needle, rock, flowerMesh])
       if (b === null) {
         continue
       }
-      chunks.push({ ...b, grass, bark, leaf, needle, rock, flowers: flowerMesh, barkFar, leafFar, needleFar, rockFar })
+      chunks.push({ ...b, grass, bark, birchBark, leaf, needle, rock, flowers: flowerMesh, barkFar, birchBarkFar, leafFar, needleFar, rockFar })
     }
   }
   return chunks
@@ -320,7 +330,8 @@ function placeTrees(colliders: Aabb[]): Tree[] {
     if (Math.max(Math.abs(x), Math.abs(z)) < TERRAIN.inner + 3) {
       continue
     }
-    const kind = rand() < 0.5 ? "oak" : "spruce"
+    const roll = rand()
+    const kind = roll < 0.4 ? "oak" : roll < 0.72 ? "spruce" : "birch"
     const growth = 0.08 + rand() * 0.92
     const position = { x, y: Terrain.height(TERRAIN, x, z), z }
     trees.push({ kind, position, growth, seed: (rand() * 0xFFFFFFFF) | 0 })

app/main.ts

@@ -161,8 +161,8 @@ async function main(): Promise<void> {
       t += c.grass.indices.length + c.flowers.indices.length
       const far = chunkFar(c, cam.position, config.lodDistance)
       t += far
-        ? c.barkFar.indices.length + c.leafFar.indices.length + c.needleFar.indices.length + c.rockFar.indices.length
-        : c.bark.indices.length + c.leaf.indices.length + c.needle.indices.length + c.rock.indices.length
+        ? c.barkFar.indices.length + c.birchBarkFar.indices.length + c.leafFar.indices.length + c.needleFar.indices.length + c.rockFar.indices.length
+        : c.bark.indices.length + c.birchBark.indices.length + c.leaf.indices.length + c.needle.indices.length + c.rock.indices.length
     }
     return (t / 3) | 0
   }

app/renderScene.ts

@@ -104,11 +104,13 @@ export function renderBand(
     if (chunkFar(c, camera.position, config.lodDistance)) {
       Rasterizer.draw(fb, c.rockFar, tx.rock, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.barkFar, tx.bark, viewProj, config, true, y0, y1)
+      Rasterizer.draw(fb, c.birchBarkFar, tx.birch, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.leafFar, tx.leaf, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.needleFar, tx.needle, viewProj, config, true, y0, y1)
     } else {
       Rasterizer.draw(fb, c.rock, tx.rock, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.bark, tx.bark, viewProj, config, true, y0, y1)
+      Rasterizer.draw(fb, c.birchBark, tx.birch, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.leaf, tx.leaf, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.needle, tx.needle, viewProj, config, true, y0, y1)
       Rasterizer.draw(fb, c.flowers, tx.flower, viewProj, config, false, y0, y1)