erincatto/box2d

Features

• 2D Rigid Body Physics Engines - Provides a comprehensive engine for calculating realistic physical interactions, collisions, and dynamics for 2D objects.
• Collision Detection - Identifies intersections between physical shapes using continuous detection and filtering systems.
• Penetration Prevention - Generates contact constraints to stop bodies from overlapping while simulating friction and restitution.
• Body Type Definitions - Defines physical objects as dynamic, static, or kinematic to determine how they react to forces.
• Continuous Collision Detection - Prevents high-speed objects from passing through boundaries using bullet-mode marking and continuous detection.
• Physical Material Properties - Provides definitions for physical characteristics like density and friction that determine how bound shapes interact.
• Mass Property Calculation - Computes the mass, centroid, and rotational inertia for a shape to determine force reactions.
• Fixture Shape Definitions - Provides interfaces for constructing collision geometries using circles, polygons, edges, and chains.
• Mechanical Constraints - Provides tools for linking and constraining the movement of physical bodies through joints and motors.
• Mechanical Joint Constraints - Holds multiple bodies together using joints that support limits and motors to control relative motion.
• Physics World Management - Initializes the simulation environment with gravity and manages the lifecycle of all bodies and shapes.
• Deterministic State Simulation - Ensures consistent simulation results across different hardware architectures using a deterministic trigonometry implementation.
• Sequential Impulse Solvers - Uses an iterative sequential impulse solver to resolve constraints and update object velocities for physical stability.
• Time-of-Impact Interpolations - Prevents high-speed objects from passing through boundaries by calculating the exact moment of first contact.
• Force and Impulse Applications - Provides an API for applying linear forces, angular torques, and immediate impulses to rigid bodies.
• Contact Event Systems - Allows toggling reporting for hit events and sensor overlaps for specific shapes.
• Game Physics Integration - Integrates physics simulation to handle collisions, trigger sensors, and forces within a game world.
• Simulation Event Triggers - Sends notifications for body movement and contact interactions so applications can react to changes.
• Continuous Collision Detection - Uses time-of-impact interpolation to ensure fast-moving objects do not pass through each other.
• Spatial Partitioning Systems - Implements spatial partitioning to optimize collision detection by pruning distant objects using axis-aligned bounding boxes.
• Physical Body Management - Adjusts gravity scaling and damping to control movement and determine when objects enter a sleep state.
• Rigid Body Transform Management - Handles rotation and translation of objects and computes relative transformations between different coordinate frames.
• Collision Event Handlers - Collects deterministic lists of hit events after a time step to handle collision logic.
• Collision Notification Filters - Provides bitmasks and group indices to filter which physical shapes should interact or be ignored.
• Overlap Detection - Retrieves lists of shapes overlapping sensors or specific points where shapes touch.
• Ray and Shape Casting - Deno Physics detects intersections by projecting a ray or moving shape through space to find the first point of contact.
• Spatial Querying Systems - Locates objects using bounding box queries or ray casts to detect overlaps and find targets in the world.
• Degrees of Freedom Restriction - Creates physical connections that remove degrees of freedom to simulate pinned points or restricted motion.
• Collision Edge Chains - Deno Physics constructs connected line segments to create complex boundaries or terrain for objects to collide with.
• Kinematic Motion Control - Sets target transforms for kinematic bodies to calculate the necessary velocity to reach a position.
• Deterministic Calculation Utilities - Uses a custom deterministic trigonometry implementation to ensure consistent simulation results across different hardware platforms.
• Contact Pre-Solve Modifications - Intercepts collision data via a callback before the solver runs to customize or disable specific physical interactions.
• Sensor Overlap Detections - Identifies when objects enter or exit trigger areas defined as sensors to separate trigger logic from physical contact.
• Physics and Simulation - Battle-tested 2D physics for games.
• Physics Simulation - 2D physics engine for games.

Star history