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Badlands

Collision Management

This module provides essential geometric calculations for collision detection in 2D space, particularly useful for game physics and object interaction systems. 🎮

🔢 Core Functions

getCarCorners(position: Vec2D, width: number, height: number, angle: number): Vec2D[] 📐

Calculates the four corner points of a rotated rectangular car shape. 🚘

Parameters:

  • position: Center position of the car 🎯
  • width: Width of the car’s collision box ↔️
  • height: Height of the car’s collision box ↕️
  • angle: Rotation angle in degrees 🔄

Returns: Array of 4 corner points in order:

  1. Front Left ↖️
  2. Front Right ↗️
  3. Rear Left ↙️
  4. Rear Right ↘️

Note: ⚠️ The function includes a fixed offset (+30, +15) to align the collision box with the visual representation. This should be investigated and potentially made configurable. 🔍

rayCast(from: Vec2D, to: Vec2D, corners: Vec2D[]): Vec2D | null 🔦

Performs ray casting against a polygon defined by corners. 💥

Parameters:

  • from: Starting point of the ray 🏁
  • to: Ending point of the ray 🏁
  • corners: Array of points defining the polygon 🟦

Returns: Intersection point closest to from, or null if no intersection ❌

Performance Note: ⏱️ This operation can be computationally expensive - use sparingly. 💻

lineToRectDistance(from: Vec2D, to: Vec2D, rect: Vec2D[]): number 📏

Calculates the minimum distance between a line segment and a rectangle. 📊

Parameters:

  • from: Start point of line segment 🅰️
  • to: End point of line segment 🅱️
  • rect: Array of 4 points defining rectangle corners 🟧

Returns: Minimum distance between the line segment and rectangle edges 🔢

🔧 Supporting Functions

getIntersection(from, to, p1, p2): Vec2D | null ✖️

Finds intersection point between two line segments using linear algebra. ➗

onSegment(p, q, r): boolean 📍

Determines if point q lies on segment pr. ✔️

distance(a, b): number 📐

Standard Euclidean distance between two points. 🧮

distanceToSegment(p, v, w): number 📏

Calculates distance from point p to line segment vw. 📉

🚀 Usage Examples

// Calculate car collision corners 🚗
const corners = getCarCorners(
  {x: 100, y: 100},
  50,  // width ↔️
  100, // height ↕️
  45   // angle in degrees 🔄
);


// Check ray intersection 🔦
const hitPoint = rayCast(
  {x: 0, y: 0},
  {x: 200, y: 200},
  obstacleCorners
);


// Get minimum distance to rectangle 📏
const dist = lineToRectDistance(
  {x: 50, y: 50},
  {x: 150, y: 150},
  rectCorners
);