WIP

engine/system/physics.ts

@@ -2,7 +2,7 @@ import type { Circle } from "#/engine/Circle.ts";
 import type { Polygon } from "#/engine/Polygon.ts";
 import { createRect, fillRect, type Rect, strokeRect } from "#/engine/Rect.ts";
 import $ from "#/engine/Scene.ts";
-import { createVector, type Vector } from "#/engine/Vector.ts";
+import { createVector, getDistance, type Vector } from "#/engine/Vector.ts";
 import { viewport } from "#/engine/Viewport.ts";
 
 export enum Shape {
@@ -42,8 +42,9 @@ export type Collision = {
 	cid: string;
 	normal: Vector;
 	position: Vector;
-	depth: 0;
-	angle: 0;
+	depth: number;
+	angle: number;
+	time: number;
 };
 
 export function createCollider(
@@ -114,13 +115,13 @@ function sweptAABB(
 	const thNear = Math.max(txNear, tyNear);
 	const thFar = Math.min(txFar, tyFar);
 
-	// thMax < 0, collision is behind a frame
-	// thMin > 1, collision is ahead a frame
+	// thFar < 0, collision is behind a frame
+	// thNear > 1, collision is ahead a frame
 	if (thFar < 0 || thNear > 1) {
 		return null;
 	}
 
-	return thNear;
+	return thNear; // -Infinity if velocity is 0
 }
 
 function collideWithCirle(
@@ -140,8 +141,10 @@ function collideWithRect(
 	velocity: Vector,
 	other: Collider,
 ) {
-	const th = sweptAABB(self, velocity, other);
-	collision.cid = th !== null ? cid : "";
+	collision.cid = cid;
+	const inflX = other.aabb.position.x - self.aabb.width;
+	const inflY = other.aabb.position.y - self.aabb.height;
+	collision.depth = getDistance(createVector(inflX, inflY), self.aabb.position);
 }
 
 function collideWithPolygon(
@@ -202,6 +205,7 @@ function createCollision(): Collision {
 		position: createVector(),
 		depth: 0,
 		angle: 0,
+		time: 0,
 	};
 }
 
@@ -228,7 +232,13 @@ export function moveAndCollide(
 		}
 
 		const other = collider.value;
+		const tHit = sweptAABB(self, velocity, other);
+		if (tHit === null) {
+			continue;
+		}
+
 		const collision = next(self.buffer);
+		collision.time = tHit;
 		switch (self.shape) {
 			case CIRCLE: {
 				circleCollide[other.shape](collision, cid, self, velocity, other);

game/entities/hero/entity.ts

@@ -1,5 +1,6 @@
 import { defineEntity } from "#/engine/Entity.ts";
 import { keyboardInput } from "#/engine/Keyboard.ts";
+import { lerp } from "#/engine/lib/lerp";
 import { pointer } from "#/engine/Pointer.ts";
 import { createRect, fillRect, strokeRect } from "#/engine/Rect.ts";
 import $ from "#/engine/Scene.ts";
@@ -36,9 +37,13 @@ const process = defineEntity("hero", {
 });
 
 process((id, delta) => {
-	const position = $<Vector>("position").get(id)!.value;
+	const positions = $<Vector>("position");
+	const position = positions.get(id)!.value;
+
+	const colliders = $<Collider>("collider");
+	const collider = colliders.get(id)!.value;
+
 	const velocity = $<Vector>("velocity").get(id)!.value;
-	const collider = $<Collider>("collider").get(id)!.value;
 
 	if (pointer.isDown) {
 		position.x = pointer.position.x;
@@ -53,11 +58,21 @@ process((id, delta) => {
 	normalize(velocity);
 	scale(velocity, speed);
 
+	let cScale = 1;
 	const collisions = moveAndCollide(id, velocity, delta);
-	// console.log(collisions);
+	for (const collision of collisions) {
+		// const _collider = colliders.get(collision.cid)!.value;
+		// const _position = positions.get(collision.cid)!.value;
+		const time = collision.time;
+		if (time === -Infinity) {
+			break;
+		}
+		cScale = Math.min(0, time - 0.001);
+		console.log(cScale);
+	}
 
-	position.x += velocity.x * delta;
-	position.y += velocity.y * delta;
+	position.x += velocity.x * delta * cScale;
+	position.y += velocity.y * delta * cScale;
 
 	velocity.x = 0;
 	velocity.y = 0;