Add some physics handling

Engine/src/states/Game.ts

@@ -2,8 +2,10 @@ import { ContextI } from "../ContextI"
 import { segments } from "../shared/segments"
 import { StateI } from "./StateI"
 import * as PIXI from 'pixi.js'
+import * as planck from 'planck'
 import { DecorationInstance } from "../shared/decors"
-import { SpriteInstance } from "../shared/sprites"
+import { SpriteInstance, sprites } from "../shared/sprites"
+import { ShapeCircle, ShapePoints } from "../data/sprite"
 
 interface Action {
   type: string
@@ -12,6 +14,11 @@ interface Action {
 
 class Entity {
   sprite: SpriteInstance
+  body?: planck.Body
+  velocity: [number, number] = [0, 0]
+  acceleration: number = 0.5
+  maxSpeed: number = 4
+  direction: number = 0
 
   constructor(ctor: string) {
     this.sprite = new SpriteInstance(ctor)
@@ -21,17 +28,52 @@ class Entity {
     // TODO: Update sprite.
   }
 
+  get position(): [number, number] {
+    if (this.body) {
+      let p = this.body.getPosition()
+      return [p.x, p.y]
+    }
+    return [this.sprite.container.x, this.sprite.container.y]
+  }
   get x(): number {
+    if (this.body) {
+      let p = this.body.getPosition()
+      return p.x
+    }
     return this.sprite.container.x
   }
   set x(v: number) {
-    this.sprite.container.x = v
+    if (this.body) {
+      let p = this.body.getPosition()
+      this.body.setPosition(
+        planck.Vec2(
+          v,
+          p.y,
+        )
+      )
+    } else {
+      this.sprite.container.y = v
+    }
   }
   get y(): number {
+    if (this.body) {
+      let p = this.body.getPosition()
+      return p.y
+    }
     return this.sprite.container.y
   }
   set y(v: number) {
-    this.sprite.container.y = v
+    if (this.body) {
+      let p = this.body.getPosition()
+      this.body.setPosition(
+        planck.Vec2(
+          p.x,
+          v,
+        )
+      )
+    } else {
+      this.sprite.container.y = v
+    }
   }
 }
 
@@ -39,9 +81,6 @@ class PlayerEntity extends Entity {
   action?: Action
   constructor(ctor: string) {
     super(ctor)
-    this.x = 100
-    this.y = 100
-    // TODO: Hooks for key state check input, perhaps?
   }
   act(actions: Action[]) {
     this.action = actions.sort((a, b) => {
@@ -59,19 +98,33 @@ class PlayerEntity extends Entity {
       // FIXME: Use physics.
       switch(this.action.type) {
         case 'west':
-          this.x--
+          if (this.velocity[0] > -this.maxSpeed) {
+            this.velocity[0] -= this.acceleration
+          }
           break
         case 'east':
-          this.x++
+          if (this.velocity[0] < this.maxSpeed) {
+            this.velocity[0] += this.acceleration
+          }
           break
         case 'north':
-          this.y--
+          if (this.velocity[1] > -this.maxSpeed) {
+            this.velocity[1] -= this.acceleration
+          }
           break
         case 'south':
-          this.y++
+          if (this.velocity[1] < this.maxSpeed) {
+            this.velocity[1] += this.acceleration
+          }
           break
       }
     }
+    //
+    this.velocity[0] *= 0.5
+    this.velocity[1] *= 0.5
+
+    // Eh... let's manually handle velocity
+    this.body?.setLinearVelocity(planck.Vec2(this.velocity[0], this.velocity[1]))
   }
 }
 function isPlayerEntity(o: any): o is PlayerEntity {
@@ -79,6 +132,9 @@ function isPlayerEntity(o: any): o is PlayerEntity {
 }
 
 export function GameState(ctx: ContextI): StateI {
+  let world: planck.World = planck.World({
+    gravity: planck.Vec2(0, 0),
+  })
 
   let rootContainer = new PIXI.Container()
   let decorations: DecorationInstance[] = []
@@ -102,17 +158,26 @@ export function GameState(ctx: ContextI): StateI {
         di.elapsed = d.timeOffset
         di.container.x = d.x
         di.container.y = d.y
+        if (d.rotation !== 0) {
+          di.container.angle = d.rotation
+        }
         if (d.flip) {
           di.container.pivot.y = 1
           di.container.scale.y *= -1
-          di.container.position.y--
+          if (d.rotation === 0) {
+            di.container.position.y--
+          }
         }
         if (d.mirror) {
           di.container.pivot.x = 1
           di.container.scale.x *= -1
           di.container.position.x--
+          if (d.rotation !== 0) {
+            di.container.angle = -d.rotation
+            di.container.position.x++
+            di.container.position.y--
+          }
         }
-
         container.addChild(di.container)
         decorations.push(di)
       }
@@ -121,7 +186,8 @@ export function GameState(ctx: ContextI): StateI {
     }
 
     // Add bogus entity
-    addEntity(new PlayerEntity('animals.deer.animal.west.0'))
+    //addEntity(new PlayerEntity('animals.deer.animal.west.0'), 0, 0)
+    addEntity(new PlayerEntity('bogus-arrows.player.normal.e.0'), 0, 0)
 
     ctx.app.stage.addChild(rootContainer)
   }
@@ -132,7 +198,15 @@ export function GameState(ctx: ContextI): StateI {
     }
     ctx.app.stage.removeChild(rootContainer)
   }
+  let elapsed: number = 0
   let update = (delta: number) => {
+    elapsed += delta
+    // Run world sim.
+    while (elapsed >= 1/60) {
+      world.step(1/60)
+      elapsed -= 1/60
+    }
+    // Update/render.
     for (let decoration of decorations) {
       decoration.update(delta)
     }
@@ -144,17 +218,50 @@ export function GameState(ctx: ContextI): StateI {
         rootContainer.pivot.set(Math.max(rootContainer.width/6, Math.min(entity.x, rootContainer.width/3)), Math.max(rootContainer.height/6, Math.min(entity.y, rootContainer.height/3)))
       }
       entity.update(delta)
+      // I guess...
+      entity.sprite.container.x = entity.x
+      entity.sprite.container.y = entity.y
     }
   }
 
-  let addEntity = (entity: Entity) => {
+  let addEntity = (entity: Entity, x: number, y: number) => {
     if (entities.find(v=>v===entity)) return
     entities.push(entity)
     rootContainer.addChild(entity.sprite.container)
+    // I guess this is a fair enough place to create physics and add it to the entity.
+    let spriteShape = entity.sprite.getBodyShape()
+    if (spriteShape) {
+      let shape: planck.Shape|undefined
+      if (spriteShape instanceof ShapeCircle) {
+        shape = planck.Circle(planck.Vec2(spriteShape.x, spriteShape.y), spriteShape.radius)
+      } else if (spriteShape instanceof ShapePoints) {
+        shape = planck.Polygon(spriteShape.points.map(v=>planck.Vec2(v[0], v[1])))
+      }
+      if (shape !== undefined) {
+        let body = world.createDynamicBody({
+          position: planck.Vec2(entity.x, entity.y),
+          fixedRotation: true,
+        })
+        let fixture = body.createFixture({
+          shape,
+          density: 1,
+          friction: 0.9,
+          restitution: 0.05,
+        })
+        entity.body = body
+        body.setUserData(entity)
+      }
+    }
+    entity.x = x
+    entity.y = y
   }
   let removeEntity = (entity: Entity) => {
     entities = entities.filter(v=>v!==entity)
     rootContainer.removeChild(entity.sprite.container)
+    if (entity.body) {
+      world.destroyBody(entity.body)
+      entity.body = undefined
+    }
   }
 
  let desiredActions: Action[] = []