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-rw-r--r--src/physac.h198
1 files changed, 75 insertions, 123 deletions
diff --git a/src/physac.h b/src/physac.h
index cb0e3f3c..d3fdaca4 100644
--- a/src/physac.h
+++ b/src/physac.h
@@ -2,22 +2,22 @@
*
* Physac v1.0 - 2D Physics library for videogames
*
-* DESCRIPTION:
+* DESCRIPTION:
*
-* Physac is a small 2D physics engine written in pure C. The engine uses a fixed time-step thread loop
-* to simluate physics. A physics step contains the following phases: get collision information,
-* apply dynamics, collision solving and position correction. It uses a very simple struct for physic
+* Physac is a small 2D physics engine written in pure C. The engine uses a fixed time-step thread loop
+* to simluate physics. A physics step contains the following phases: get collision information,
+* apply dynamics, collision solving and position correction. It uses a very simple struct for physic
* bodies with a position vector to be used in any 3D rendering API.
-*
+*
* CONFIGURATION:
-*
+*
* #define PHYSAC_IMPLEMENTATION
* Generates the implementation of the library into the included file.
-* If not defined, the library is in header only mode and can be included in other headers
+* If not defined, the library is in header only mode and can be included in other headers
* or source files without problems. But only ONE file should hold the implementation.
*
* #define PHYSAC_STATIC (defined by default)
-* The generated implementation will stay private inside implementation file and all
+* The generated implementation will stay private inside implementation file and all
* internal symbols and functions will only be visible inside that file.
*
* #define PHYSAC_NO_THREADS
@@ -30,7 +30,7 @@
* the user (check library implementation for further details).
*
* #define PHYSAC_DEBUG
-* Traces log messages when creating and destroying physics bodies and detects errors in physics
+* Traces log messages when creating and destroying physics bodies and detects errors in physics
* calculations and reference exceptions; it is useful for debug purposes
*
* #define PHYSAC_MALLOC()
@@ -38,13 +38,21 @@
* You can define your own malloc/free implementation replacing stdlib.h malloc()/free() functions.
* Otherwise it will include stdlib.h and use the C standard library malloc()/free() function.
*
+*
+* NOTE 1: Physac requires multi-threading, when InitPhysics() a second thread is created to manage physics calculations.
+* NOTE 2: Physac requires static C library linkage to avoid dependency on MinGW DLL (-static -lpthread)
+*
+* Use the following code to compile:
+* gcc -o physac_sample.exe physac_sample.c -s $(RAYLIB_DIR)\raylib\raylib_icon -static -lraylib -lpthread \
+* -lglfw3 -lopengl32 -lgdi32 -lopenal32 -lwinmm -std=c99 -Wl,--subsystem,windows -Wl,-allow-multiple-definition
+*
* VERY THANKS TO:
* Ramón Santamaria (@raysan5)
*
*
* LICENSE: zlib/libpng
*
-* Copyright (c) 2016 Victor Fisac
+* Copyright (c) 2016-2017 Victor Fisac
*
* This software is provided "as-is", without any express or implied warranty. In no event
* will the authors be held liable for any damages arising from the use of this software.
@@ -66,7 +74,7 @@
#if !defined(PHYSAC_H)
#define PHYSAC_H
-#define PHYSAC_STATIC
+// #define PHYSAC_STATIC
// #define PHYSAC_NO_THREADS
// #define PHYSAC_STANDALONE
// #define PHYSAC_DEBUG
@@ -238,11 +246,14 @@ PHYSACDEF void ClosePhysics(void);
#include <stdlib.h> // Required for: malloc(), free(), srand(), rand()
#include <math.h> // Required for: cosf(), sinf(), fabs(), sqrtf()
+#include "raymath.h" // Required for: Vector2Add(), Vector2Subtract()
+
#if defined(_WIN32)
// Functions required to query time on Windows
int __stdcall QueryPerformanceCounter(unsigned long long int *lpPerformanceCount);
int __stdcall QueryPerformanceFrequency(unsigned long long int *lpFrequency);
-#elif defined(__linux) || defined(PLATFORM_WEB)
+#elif defined(__linux__) || defined(PLATFORM_WEB)
+ //#define _DEFAULT_SOURCE // Enables BSD function definitions and C99 POSIX compliance
#include <sys/time.h> // Required for: timespec
#include <time.h> // Required for: clock_gettime()
#include <stdint.h>
@@ -265,13 +276,13 @@ PHYSACDEF void ClosePhysics(void);
// Global Variables Definition
//----------------------------------------------------------------------------------
#if !defined(PHYSAC_NO_THREADS)
- static pthread_t physicsThreadId; // Physics thread id
+static pthread_t physicsThreadId; // Physics thread id
#endif
static unsigned int usedMemory = 0; // Total allocated dynamic memory
static bool physicsThreadEnabled = false; // Physics thread enabled state
static double currentTime = 0; // Current time in milliseconds
-#if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI) || defined(__linux) || defined(PLATFORM_WEB)
- static double baseTime = 0; // Android and RPI platforms base time
+#if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI) || defined(__linux__) || defined(PLATFORM_WEB)
+static double baseTime = 0; // Android and RPI platforms base time
#endif
static double startTime = 0; // Start time in milliseconds
static double deltaTime = 0; // Delta time used for physics steps
@@ -307,10 +318,12 @@ static void FindIncidentFace(Vector2 *v0, Vector2 *v1, PhysicsShape ref, Physics
static int Clip(Vector2 normal, float clip, Vector2 *faceA, Vector2 *faceB); // Calculates clipping based on a normal and two faces
static bool BiasGreaterThan(float valueA, float valueB); // Check if values are between bias range
static Vector2 TriangleBarycenter(Vector2 v1, Vector2 v2, Vector2 v3); // Returns the barycenter of a triangle given by 3 points
+
static void InitTimer(void); // Initializes hi-resolution timer
static double GetCurrentTime(void); // Get current time in milliseconds
static int GetRandomNumber(int min, int max); // Returns a random number between min and max (both included)
+// Math functions
static void MathClamp(double *value, double min, double max); // Clamp a value in a range
static Vector2 MathCross(float value, Vector2 vector); // Returns the cross product of a vector and a value
static float MathCrossVector2(Vector2 v1, Vector2 v2); // Returns the cross product of two vectors
@@ -318,8 +331,10 @@ static float MathLenSqr(Vector2 vector);
static float MathDot(Vector2 v1, Vector2 v2); // Returns the dot product of two vectors
static inline float DistSqr(Vector2 v1, Vector2 v2); // Returns the square root of distance between two vectors
static void MathNormalize(Vector2 *vector); // Returns the normalized values of a vector
+#if defined(PHYSAC_STANDALONE)
static Vector2 Vector2Add(Vector2 v1, Vector2 v2); // Returns the sum of two given vectors
static Vector2 Vector2Subtract(Vector2 v1, Vector2 v2); // Returns the subtract of two given vectors
+#endif
static Mat2 Mat2Radians(float radians); // Creates a matrix 2x2 from a given radians value
static void Mat2Set(Mat2 *matrix, float radians); // Set values from radians to a created matrix 2x2
@@ -361,70 +376,6 @@ PHYSACDEF PhysicsBody CreatePhysicsBodyCircle(Vector2 pos, float radius, float d
{
PhysicsBody newBody = CreatePhysicsBodyPolygon(pos, radius, PHYSAC_CIRCLE_VERTICES, density);
return newBody;
-
- /*PhysicsBody newBody = (PhysicsBody)PHYSAC_MALLOC(sizeof(PhysicsBodyData));
- usedMemory += sizeof(PhysicsBodyData);
-
- int newId = -1;
- for (int i = 0; i < PHYSAC_MAX_BODIES; i++)
- {
- int currentId = i;
-
- // Check if current id already exist in other physics body
- for (int k = 0; k < physicsBodiesCount; k++)
- {
- if (bodies[k]->id == currentId)
- {
- currentId++;
- break;
- }
- }
-
- // If it is not used, use it as new physics body id
- if (currentId == i)
- {
- newId = i;
- break;
- }
- }
-
- if (newId != -1)
- {
- // Initialize new body with generic values
- newBody->id = newId;
- newBody->enabled = true;
- newBody->position = pos;
- newBody->velocity = (Vector2){ 0 };
- newBody->force = (Vector2){ 0 };
- newBody->angularVelocity = 0;
- newBody->torque = 0;
- newBody->orient = 0;
- newBody->mass = PHYSAC_PI*radius*radius*density;
- newBody->inverseMass = ((newBody->mass != 0.0f) ? 1.0f/newBody->mass : 0.0f);
- newBody->inertia = newBody->mass*radius*radius;
- newBody->inverseInertia = ((newBody->inertia != 0.0f) ? 1.0f/newBody->inertia : 0.0f);
- newBody->staticFriction = 0;
- newBody->dynamicFriction = 0;
- newBody->restitution = 0;
- newBody->useGravity = true;
- newBody->freezeOrient = false;
- newBody->shape.type = PHYSICS_CIRCLE;
- newBody->shape.body = newBody;
- newBody->shape.radius = radius;
-
- // Add new body to bodies pointers array and update bodies count
- bodies[physicsBodiesCount] = newBody;
- physicsBodiesCount++;
-
- #if defined(PHYSAC_DEBUG)
- printf("[PHYSAC] created circle physics body id %i\n", newBody->id);
- #endif
- }
- #if defined(PHYSAC_DEBUG)
- else printf("[PHYSAC] new physics body creation failed because there is any available id to use\n");
- #endif
-
- return newBody;*/
}
// Creates a new rectangle physics body with generic parameters
@@ -461,7 +412,7 @@ PHYSACDEF PhysicsBody CreatePhysicsBodyRectangle(Vector2 pos, float width, float
// Initialize new body with generic values
newBody->id = newId;
newBody->enabled = true;
- newBody->position = pos;
+ newBody->position = pos;
newBody->velocity = (Vector2){ 0 };
newBody->force = (Vector2){ 0 };
newBody->angularVelocity = 0;
@@ -569,7 +520,7 @@ PHYSACDEF PhysicsBody CreatePhysicsBodyPolygon(Vector2 pos, float radius, int si
// Initialize new body with generic values
newBody->id = newId;
newBody->enabled = true;
- newBody->position = pos;
+ newBody->position = pos;
newBody->velocity = (Vector2){ 0 };
newBody->force = (Vector2){ 0 };
newBody->angularVelocity = 0;
@@ -802,82 +753,74 @@ PHYSACDEF int GetPhysicsBodiesCount(void)
// Returns a physics body of the bodies pool at a specific index
PHYSACDEF PhysicsBody GetPhysicsBody(int index)
{
+ PhysicsBody body = NULL;
+
if (index < physicsBodiesCount)
{
- PhysicsBody body = bodies[index];
- if (body != NULL) return body;
- else
+ body = bodies[index];
+
+ if (body == NULL)
{
#if defined(PHYSAC_DEBUG)
printf("[PHYSAC] error when trying to get a null reference physics body");
#endif
-
- return NULL;
}
}
#if defined(PHYSAC_DEBUG)
- else
- {
- printf("[PHYSAC] physics body index is out of bounds");
- return NULL;
- }
+ else printf("[PHYSAC] physics body index is out of bounds");
#endif
+
+ return body;
}
// Returns the physics body shape type (PHYSICS_CIRCLE or PHYSICS_POLYGON)
PHYSACDEF int GetPhysicsShapeType(int index)
{
+ int result = -1;
+
if (index < physicsBodiesCount)
{
PhysicsBody body = bodies[index];
- if (body != NULL) return body->shape.type;
+
+ if (body != NULL) result = body->shape.type;
#if defined(PHYSAC_DEBUG)
- else
- {
- printf("[PHYSAC] error when trying to get a null reference physics body");
- return -1;
- }
+ else printf("[PHYSAC] error when trying to get a null reference physics body");
#endif
}
#if defined(PHYSAC_DEBUG)
- else
- {
- printf("[PHYSAC] physics body index is out of bounds");
- return -1;
- }
+ else printf("[PHYSAC] physics body index is out of bounds");
#endif
+
+ return result;
}
// Returns the amount of vertices of a physics body shape
PHYSACDEF int GetPhysicsShapeVerticesCount(int index)
{
+ int result = 0;
+
if (index < physicsBodiesCount)
{
PhysicsBody body = bodies[index];
+
if (body != NULL)
{
switch (body->shape.type)
{
- case PHYSICS_CIRCLE: return PHYSAC_CIRCLE_VERTICES; break;
- case PHYSICS_POLYGON: return body->shape.vertexData.vertexCount; break;
+ case PHYSICS_CIRCLE: result = PHYSAC_CIRCLE_VERTICES; break;
+ case PHYSICS_POLYGON: result = body->shape.vertexData.vertexCount; break;
default: break;
}
}
#if defined(PHYSAC_DEBUG)
- else
- {
- printf("[PHYSAC] error when trying to get a null reference physics body");
- return 0;
- }
+ else printf("[PHYSAC] error when trying to get a null reference physics body");
#endif
}
#if defined(PHYSAC_DEBUG)
- else
- {
- printf("[PHYSAC] physics body index is out of bounds");
- return 0;
- }
+ else printf("[PHYSAC] physics body index is out of bounds");
#endif
+
+ return result;
}
// Returns transformed position of a body shape (body position + vertex transformed position)
@@ -1130,6 +1073,7 @@ static void *PhysicsLoop(void *arg)
// Physics steps calculations (dynamics, collisions and position corrections)
static void PhysicsStep(void)
{
+ // Update current steps count
stepsCount++;
// Clear previous generated collisions information
@@ -1139,6 +1083,13 @@ static void PhysicsStep(void)
if (manifold != NULL) DestroyPhysicsManifold(manifold);
}
+ // Reset physics bodies grounded state
+ for (int i = 0; i < physicsBodiesCount; i++)
+ {
+ PhysicsBody body = bodies[i];
+ body->isGrounded = false;
+ }
+
// Generate new collision information
for (int i = 0; i < physicsBodiesCount; i++)
{
@@ -1257,7 +1208,7 @@ static PhysicsManifold CreatePhysicsManifold(PhysicsBody a, PhysicsBody b)
}
if (newId != -1)
- {
+ {
// Initialize new manifold with generic values
newManifold->id = newId;
newManifold->bodyA = a;
@@ -1348,8 +1299,8 @@ static void SolvePhysicsManifold(PhysicsManifold manifold)
default: break;
}
- // Update physics body grounded state if normal direction is downside
- manifold->bodyB->isGrounded = (manifold->normal.y < 0);
+ // Update physics body grounded state if normal direction is down and grounded state is not set yet in previous manifolds
+ if (!manifold->bodyB->isGrounded) manifold->bodyB->isGrounded = (manifold->normal.y < 0);
}
// Solves collision between two circle shape physics bodies
@@ -1388,7 +1339,7 @@ static void SolveCircleToCircle(PhysicsManifold manifold)
}
// Update physics body grounded state if normal direction is down
- if (manifold->normal.y < 0) bodyA->isGrounded = true;
+ if (!bodyA->isGrounded) bodyA->isGrounded = (manifold->normal.y < 0);
}
// Solves collision between a circle to a polygon shape physics bodies
@@ -1444,7 +1395,7 @@ static void SolveCircleToPolygon(PhysicsManifold manifold)
manifold->penetration = bodyA->shape.radius - separation;
if (dot1 <= 0) // Closest to v1
- {
+ {
if (DistSqr(center, v1) > bodyA->shape.radius*bodyA->shape.radius) return;
manifold->contactsCount = 1;
@@ -1649,7 +1600,7 @@ static void IntegratePhysicsImpulses(PhysicsManifold manifold)
// Early out and positional correct if both objects have infinite mass
if (fabs(bodyA->inverseMass + bodyB->inverseMass) <= PHYSAC_EPSILON)
{
- bodyA->velocity = (Vector2){ 0 };
+ bodyA->velocity = (Vector2){ 0 };
bodyB->velocity = (Vector2){ 0 };
return;
}
@@ -1678,7 +1629,7 @@ static void IntegratePhysicsImpulses(PhysicsManifold manifold)
// Calculate impulse scalar value
float impulse = -(1.0f + manifold->restitution)*contactVelocity;
- impulse /= inverseMassSum;
+ impulse /= inverseMassSum;
impulse /= (float)manifold->contactsCount;
// Apply impulse to each physics body
@@ -1955,7 +1906,7 @@ static double GetCurrentTime(void)
time = (double)((double)currentTime/clockFrequency)*1000;
#endif
- #if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI) || defined(__linux) || defined(PLATFORM_WEB)
+ #if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI) || defined(__linux__) || defined(PLATFORM_WEB)
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
uint64_t temp = (uint64_t)ts.tv_sec*1000000000LLU + (uint64_t)ts.tv_nsec;
@@ -2033,6 +1984,7 @@ static void MathNormalize(Vector2 *vector)
vector->y *= ilength;
}
+#if defined(PHYSAC_STANDALONE)
// Returns the sum of two given vectors
static inline Vector2 Vector2Add(Vector2 v1, Vector2 v2)
{
@@ -2043,7 +1995,7 @@ static inline Vector2 Vector2Add(Vector2 v1, Vector2 v2)
static inline Vector2 Vector2Subtract(Vector2 v1, Vector2 v2)
{
return (Vector2){ v1.x - v2.x, v1.y - v2.y };
-}
+#endif
// Creates a matrix 2x2 from a given radians value
static inline Mat2 Mat2Radians(float radians)
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-06 18:11:31 +0000