98 lines
7.2 KiB
C
98 lines
7.2 KiB
C
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#define PHYSAC_MAX_BODIES 64 // Maximum number of physic bodies supported
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#define PHYSAC_MAX_MANIFOLDS 4096 // Maximum number of physic bodies interactions (64x64)
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#define PHYSAC_MAX_VERTICES 24 // Maximum number of vertex for polygons shapes
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#define PHYSAC_DEFAULT_CIRCLE_VERTICES 24 // Default number of vertices for circle shapes
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typedef enum PhysicsShapeType { PHYSICS_CIRCLE = 0, PHYSICS_POLYGON } PhysicsShapeType;
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// Previously defined to be used in PhysicsShape struct as circular dependencies
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typedef struct PhysicsBodyData *PhysicsBody;
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// Matrix2x2 type (used for polygon shape rotation matrix)
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typedef struct Matrix2x2 {
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float m00;
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float m01;
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float m10;
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float m11;
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} Matrix2x2;
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typedef struct PhysicsVertexData {
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unsigned int vertexCount; // Vertex count (positions and normals)
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Vector2 positions[PHYSAC_MAX_VERTICES]; // Vertex positions vectors
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Vector2 normals[PHYSAC_MAX_VERTICES]; // Vertex normals vectors
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} PhysicsVertexData;
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typedef struct PhysicsShape {
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PhysicsShapeType type; // Shape type (circle or polygon)
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PhysicsBody body; // Shape physics body data pointer
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PhysicsVertexData vertexData; // Shape vertices data (used for polygon shapes)
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float radius; // Shape radius (used for circle shapes)
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Matrix2x2 transform; // Vertices transform matrix 2x2
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} PhysicsShape;
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typedef struct PhysicsBodyData {
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unsigned int id; // Unique identifier
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bool enabled; // Enabled dynamics state (collisions are calculated anyway)
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Vector2 position; // Physics body shape pivot
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Vector2 velocity; // Current linear velocity applied to position
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Vector2 force; // Current linear force (reset to 0 every step)
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float angularVelocity; // Current angular velocity applied to orient
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float torque; // Current angular force (reset to 0 every step)
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float orient; // Rotation in radians
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float inertia; // Moment of inertia
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float inverseInertia; // Inverse value of inertia
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float mass; // Physics body mass
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float inverseMass; // Inverse value of mass
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float staticFriction; // Friction when the body has not movement (0 to 1)
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float dynamicFriction; // Friction when the body has movement (0 to 1)
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float restitution; // Restitution coefficient of the body (0 to 1)
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bool useGravity; // Apply gravity force to dynamics
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bool isGrounded; // Physics grounded on other body state
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bool freezeOrient; // Physics rotation constraint
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PhysicsShape shape; // Physics body shape information (type, radius, vertices, transform)
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} PhysicsBodyData;
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typedef struct PhysicsManifoldData {
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unsigned int id; // Unique identifier
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PhysicsBody bodyA; // Manifold first physics body reference
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PhysicsBody bodyB; // Manifold second physics body reference
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float penetration; // Depth of penetration from collision
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Vector2 normal; // Normal direction vector from 'a' to 'b'
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Vector2 contacts[2]; // Points of contact during collision
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unsigned int contactsCount; // Current collision number of contacts
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float restitution; // Mixed restitution during collision
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float dynamicFriction; // Mixed dynamic friction during collision
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float staticFriction; // Mixed static friction during collision
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} PhysicsManifoldData, *PhysicsManifold;
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PHYSACDEF void InitPhysics(void); // Initializes physics system
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PHYSACDEF void UpdatePhysics(void); // Update physics system
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PHYSACDEF void ResetPhysics(void); // Reset physics system (global variables)
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PHYSACDEF void ClosePhysics(void); // Close physics system and unload used memory
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PHYSACDEF void SetPhysicsTimeStep(double delta); // Sets physics fixed time step in milliseconds. 1.666666 by default
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PHYSACDEF void SetPhysicsGravity(float x, float y); // Sets physics global gravity force
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// Physic body creation/destroy
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PHYSACDEF PhysicsBody CreatePhysicsBodyCircle(Vector2 pos, float radius, float density); // Creates a new circle physics body with generic parameters
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PHYSACDEF PhysicsBody CreatePhysicsBodyRectangle(Vector2 pos, float width, float height, float density); // Creates a new rectangle physics body with generic parameters
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PHYSACDEF PhysicsBody CreatePhysicsBodyPolygon(Vector2 pos, float radius, int sides, float density); // Creates a new polygon physics body with generic parameters
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PHYSACDEF void DestroyPhysicsBody(PhysicsBody body); // Destroy a physics body
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// Physic body forces
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PHYSACDEF void PhysicsAddForce(PhysicsBody body, Vector2 force); // Adds a force to a physics body
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PHYSACDEF void PhysicsAddTorque(PhysicsBody body, float amount); // Adds an angular force to a physics body
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PHYSACDEF void PhysicsShatter(PhysicsBody body, Vector2 position, float force); // Shatters a polygon shape physics body to little physics bodies with explosion force
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PHYSACDEF void SetPhysicsBodyRotation(PhysicsBody body, float radians); // Sets physics body shape transform based on radians parameter
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// Query physics info
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PHYSACDEF PhysicsBody GetPhysicsBody(int index); // Returns a physics body of the bodies pool at a specific index
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PHYSACDEF int GetPhysicsBodiesCount(void); // Returns the current amount of created physics bodies
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PHYSACDEF int GetPhysicsShapeType(int index); // Returns the physics body shape type (PHYSICS_CIRCLE or PHYSICS_POLYGON)
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PHYSACDEF int GetPhysicsShapeVerticesCount(int index); // Returns the amount of vertices of a physics body shape
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PHYSACDEF Vector2 GetPhysicsShapeVertex(PhysicsBody body, int vertex); // Returns transformed position of a body shape (body position + vertex transformed position)
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