From 29e5dbeb065a13d555370dc0c093ac99aeda2323 Mon Sep 17 00:00:00 2001
From: Jared Miller <jared@smell.flowers>
Date: Wed, 11 Mar 2026 13:52:03 -0400
Subject: [PATCH] Extend draw tools to support material palette

Replace bit-flag draw modes with direct material ID painting. draw.frag
now writes the material ID float directly instead of toggling individual
cell flag bits. ScreenScene drops the PointerState enum in favor of
numeric material IDs from constants.ts, and adds Digit1/Digit2 bindings
for sand and dirt.
---
 src/scenes/DrawScene.ts   |  2 +-
 src/scenes/ScreenScene.ts | 36 ++++++++++++++++++++++--------------
 src/shaders/draw.frag     | 24 ++++++------------------
 3 files changed, 29 insertions(+), 33 deletions(-)

diff --git a/src/scenes/DrawScene.ts b/src/scenes/DrawScene.ts
index 41ded5d..b2edcb7 100644
--- a/src/scenes/DrawScene.ts
+++ b/src/scenes/DrawScene.ts
@@ -18,7 +18,7 @@ export default class DrawScene extends AbstractScene {
             uniforms: {
                 tWorld: { value: null },
                 pointerPosition: { value: new THREE.Vector2() },
-                drawMode: { value: 0 },
+                drawMode: { value: -1 },
                 brushRadius: { value: 0 },
             },
             vertexShader,
diff --git a/src/scenes/ScreenScene.ts b/src/scenes/ScreenScene.ts
index a4ea054..40bc485 100644
--- a/src/scenes/ScreenScene.ts
+++ b/src/scenes/ScreenScene.ts
@@ -1,5 +1,13 @@
 import * as THREE from "three";
 import Config from "../Config";
+import {
+    MAT_AIR,
+    MAT_DIRT,
+    MAT_FOOD,
+    MAT_HOME,
+    MAT_ROCK,
+    MAT_SAND,
+} from "../constants";
 import type Renderer from "../Renderer";
 import fragmentShaderAnts from "../shaders/ants.frag";
 import vertexShaderAnts from "../shaders/ants.vert";
@@ -7,21 +15,13 @@ import fragmentShaderGround from "../shaders/screenWorld.frag";
 import vertexShaderGround from "../shaders/screenWorld.vert";
 import AbstractScene from "./AbstractScene";
 
-enum PointerState {
-    None,
-    Food,
-    Home,
-    Obstacle,
-    Erase,
-}
-
 export default class ScreenScene extends AbstractScene {
     public readonly camera: THREE.OrthographicCamera;
     public readonly material: THREE.ShaderMaterial;
     public ants!: THREE.InstancedMesh;
     public readonly groundMaterial: THREE.ShaderMaterial;
     public readonly pointerPosition: THREE.Vector2 = new THREE.Vector2();
-    public drawMode: PointerState = PointerState.None;
+    public drawMode: number = -1;
     // zoom stored in Config.cameraZoom
     private isPointerDown: boolean = false;
     public renderWidth: number = 1;
@@ -148,26 +148,34 @@ export default class ScreenScene extends AbstractScene {
         window.addEventListener("keydown", (e) => {
             switch (e.code) {
                 case "KeyQ": {
-                    this.drawMode = PointerState.Home;
+                    this.drawMode = MAT_HOME;
                     break;
                 }
                 case "KeyW": {
-                    this.drawMode = PointerState.Food;
+                    this.drawMode = MAT_FOOD;
                     break;
                 }
                 case "KeyE": {
-                    this.drawMode = PointerState.Obstacle;
+                    this.drawMode = MAT_ROCK;
                     break;
                 }
                 case "KeyR": {
-                    this.drawMode = PointerState.Erase;
+                    this.drawMode = MAT_AIR;
+                    break;
+                }
+                case "Digit1": {
+                    this.drawMode = MAT_SAND;
+                    break;
+                }
+                case "Digit2": {
+                    this.drawMode = MAT_DIRT;
                     break;
                 }
             }
         });
 
         window.addEventListener("keyup", () => {
-            this.drawMode = PointerState.None;
+            this.drawMode = -1;
         });
     }
 
diff --git a/src/shaders/draw.frag b/src/shaders/draw.frag
index 483942e..bae8c11 100644
--- a/src/shaders/draw.frag
+++ b/src/shaders/draw.frag
@@ -13,24 +13,12 @@ uniform float brushRadius;
 void main()	{
     vec4 lastState = texture(tWorld, vUv);
 
-    int cellData = int(lastState.x);
-    int isFood = cellData & 1;
-    int isHome = (cellData & 2) >> 1;
-    int isObstacle = (cellData & 4) >> 2;
+    float materialId = lastState.x;
 
-    if (distance(pointerPosition, vUv) < brushRadius / WORLD_SIZE) {
-        if (drawMode == 1.) {
-            isFood = 1;
-        } else if (drawMode == 2.) {
-            isHome = 1;
-        } else if (drawMode == 3.) {
-            isObstacle = 1;
-        } else if (drawMode == 4.) {
-            isFood = 0;
-            isHome = 0;
-            isObstacle = 0;
-        }
+    // drawMode >= 0 means painting that material ID; -1 means not drawing
+    if (drawMode >= 0. && distance(pointerPosition, vUv) < brushRadius / WORLD_SIZE) {
+        materialId = drawMode;
     }
 
-    FragColor = vec4(float(isFood + (isHome << 1) + (isObstacle << 2)), lastState.yzw);
-}
\ No newline at end of file
+    FragColor = vec4(materialId, lastState.yzw);
+}