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Merge pull request #131 from victorfisac/develop 

Physac 1.0 module completed
pull/132/head
Ray vor 8 Jahren
committed von GitHub
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d1a5374ac4 1b0996fb0b
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d5d1305bc0
5 geänderte Dateien mit 493 neuen und 396 gelöschten Zeilen
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  1. +2
    -1
      .gitignore
  2. +8
    -6
      examples/physics_basic_rigidbody.c
  3. +8
    -4
      examples/physics_forces.c
  4. BIN
      src/external/pthread/pthreadGC2.dll
  5. +475
    -385
      src/physac.h

+ 2
- 1
.gitignore Datei anzeigen

@ -72,4 +72,5 @@ src/libraylib.bc
# external libraries DLLs
!src/external/glfw3/lib/win32/glfw3.dll
!src/external/openal_soft/lib/win32/OpenAL32.dll
!src/external/OculusSDK/LibOVR/LibOVRRT32_1.dll
!src/external/OculusSDK/LibOVR/LibOVRRT32_1.dll
!src/external/pthread/pthreadGC2.dll

+ 8
- 6
examples/physics_basic_rigidbody.c Datei anzeigen

@ -5,6 +5,10 @@
* This example has been created using raylib 1.5 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*
* Compile example using:
* cmd /c IF NOT EXIST pthreadGC2.dll copy C:\raylib\raylib\src\external\pthread\pthreadGC2.dll $(CURRENT_DIRECTORY) /Y
*
* Copyright (c) 2016 Victor Fisac and Ramon Santamaria (@raysan5)
*
********************************************************************************************/
@ -25,7 +29,6 @@ int main()
int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib [physac] example - basic rigidbody");
InitPhysics((Vector2){ 0.0f, -9.81f/2 }); // Initialize physics module
// Debug variables
@ -60,11 +63,9 @@ int main()
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
UpdatePhysics(); // Update all created physic objects
//----------------------------------------------------------------------------------
// Check rectangle movement inputs
if (IsKeyDown('W') && rectangle->rigidbody.isGrounded) rectangle->rigidbody.velocity.y = JUMP_VELOCITY;
if (IsKeyPressed('W')) rectangle->rigidbody.velocity.y = JUMP_VELOCITY;
if (IsKeyDown('A')) rectangle->rigidbody.velocity.x = -MOVE_VELOCITY;
else if (IsKeyDown('D')) rectangle->rigidbody.velocity.x = MOVE_VELOCITY;
@ -111,6 +112,8 @@ int main()
// Draw help message
DrawText("Use WASD to move rectangle and ARROWS to move square", screenWidth/2 - MeasureText("Use WASD to move rectangle and ARROWS to move square", 20)/2, screenHeight*0.075f, 20, LIGHTGRAY);
DrawFPS(10, 10);
EndDrawing();
//----------------------------------------------------------------------------------
}
@ -118,7 +121,6 @@ int main()
// De-Initialization
//--------------------------------------------------------------------------------------
ClosePhysics(); // Unitialize physics (including all loaded objects)
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------

+ 8
- 4
examples/physics_forces.c Datei anzeigen

@ -5,6 +5,11 @@
* This example has been created using raylib 1.5 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
* NOTE: This example requires raylib module [rlgl]
*
* Compile example using:
* cmd /c IF NOT EXIST pthreadGC2.dll copy C:\raylib\raylib\src\external\pthread\pthreadGC2.dll $(CURRENT_DIRECTORY) /Y
*
* Copyright (c) 2016 Victor Fisac and Ramon Santamaria (@raysan5)
*
********************************************************************************************/
@ -27,7 +32,6 @@ int main()
int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib [physac] example - forces");
InitPhysics((Vector2){ 0.0f, -9.81f/2 }); // Initialize physics module
// Global variables
@ -69,7 +73,6 @@ int main()
{
// Update
//----------------------------------------------------------------------------------
UpdatePhysics(); // Update all created physic objects
// Update mouse position value
mousePosition = GetMousePosition();
@ -166,7 +169,9 @@ int main()
// Draw help messages
DrawText("Use LEFT MOUSE BUTTON to apply a force", screenWidth/2 - MeasureText("Use LEFT MOUSE BUTTON to apply a force", 20)/2, screenHeight*0.075f, 20, LIGHTGRAY);
DrawText("Use R to reset objects position", screenWidth/2 - MeasureText("Use R to reset objects position", 20)/2, screenHeight*0.875f, 20, GRAY);
DrawText("Use R to reset objects position", screenWidth/2 - MeasureText("Use R to reset objects position", 20)/2, screenHeight*0.875f, 20, GRAY);
DrawFPS(10, 10);
EndDrawing();
//----------------------------------------------------------------------------------
@ -175,7 +180,6 @@ int main()
// De-Initialization
//--------------------------------------------------------------------------------------
ClosePhysics(); // Unitialize physics module
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------

BIN
src/external/pthread/pthreadGC2.dll Datei anzeigen


+ 475
- 385
src/physac.h Datei anzeigen

@ -15,6 +15,10 @@
* 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
* The generated implementation won't include pthread library and user must create a secondary thread to call PhysicsThread().
* It is so important that the thread where PhysicsThread() is called must not have v-sync or any other CPU limitation.
*
* #define PHYSAC_STANDALONE
* Avoid raylib.h header inclusion in this file. Data types defined on raylib are defined
* internally in the library and input management and drawing functions must be provided by
@ -27,12 +31,16 @@
*
* LIMITATIONS:
*
* // TODO.
* - There is a limit of 256 physic objects.
* - Physics behaviour can be unexpected using bounciness or friction values out of 0.0f - 1.0f range.
* - The module is limited to 2D axis oriented physics.
* - Physics colliders must be rectangle or circle shapes (there is not a custom polygon collider type).
*
* VERSIONS:
*
* 1.0 (09-Jun-2016) Module names review and converted to header-only.
* 0.9 (23-Mar-2016) Complete module redesign, steps-based for better physics resolution.
* 1.0 (14-Jun-2016) New module defines and fixed some delta time calculation bugs.
* 0.9 (09-Jun-2016) Module names review and converted to header-only.
* 0.8 (23-Mar-2016) Complete module redesign, steps-based for better physics resolution.
* 0.3 (13-Feb-2016) Reviewed to add PhysicObjects pool.
* 0.2 (03-Jan-2016) Improved physics calculations.
* 0.1 (30-Dec-2015) Initial release.
@ -146,7 +154,7 @@ typedef struct PhysicBodyData {
// Module Functions Declaration
//----------------------------------------------------------------------------------
PHYSACDEF void InitPhysics(Vector2 gravity); // Initializes pointers array (just pointers, fixed size)
PHYSACDEF void UpdatePhysics(); // Update physic objects, calculating physic behaviours and collisions detection
PHYSACDEF void* PhysicsThread(void *arg); // Physics calculations thread function
PHYSACDEF void ClosePhysics(); // Unitialize all physic objects and empty the objects pool
PHYSACDEF PhysicBody CreatePhysicBody(Vector2 position, float rotation, Vector2 scale); // Create a new physic body dinamically, initialize it and add to pool
@ -177,12 +185,26 @@ PHYSACDEF Rectangle TransformToRectangle(Transform transform);
#endif
#include <math.h> // Required for: cos(), sin(), abs(), fminf()
#include <stdint.h> // Required for typedef unsigned long long int uint64_t, used by hi-res timer
#ifndef PHYSAC_NO_THREADS
#include <pthread.h> // Required for: pthread_create()
#endif
#if defined(PLATFORM_DESKTOP)
// 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(PLATFORM_ANDROID) || defined(PLATFORM_RPI)
#include <sys/time.h> // Required for: timespec
#include <time.h> // Required for: clock_gettime()
#endif
//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
#define MAX_PHYSIC_BODIES 256 // Maximum available physic bodies slots in bodies pool
#define PHYSICS_STEPS 64 // Physics update steps per frame for improved collision-detection
#define PHYSICS_TIMESTEP 0.016666 // Physics fixed time step (1/fps)
#define PHYSICS_ACCURACY 0.0001f // Velocity subtract operations round filter (friction)
#define PHYSICS_ERRORPERCENT 0.001f // Collision resolve position fix
@ -195,6 +217,9 @@ PHYSACDEF Rectangle TransformToRectangle(Transform transform);
//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
static bool physicsThreadEnabled = false; // Physics calculations thread exit control
static uint64_t baseTime; // Base time measure for hi-res timer
static double currentTime, previousTime; // Used to track timmings
static PhysicBody physicBodies[MAX_PHYSIC_BODIES]; // Physic bodies pool
static int physicBodiesCount; // Counts current enabled physic bodies
static Vector2 gravityForce; // Gravity force
@ -202,6 +227,9 @@ static Vector2 gravityForce; // Gravity f
//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
static void UpdatePhysics(double deltaTime); // Update physic objects, calculating physic behaviours and collisions detection
static void InitTimer(void); // Initialize hi-resolution timer
static double GetCurrentTime(void); // Time measure returned are microseconds
static float Vector2DotProduct(Vector2 v1, Vector2 v2); // Returns the dot product of two Vector2
static float Vector2Length(Vector2 v); // Returns the length of a Vector2
@ -215,392 +243,20 @@ PHYSACDEF void InitPhysics(Vector2 gravity)
// Initialize physics variables
physicBodiesCount = 0;
gravityForce = gravity;
}
// Update physic objects, calculating physic behaviours and collisions detection
PHYSACDEF void UpdatePhysics()
{
// Reset all physic objects is grounded state
for (int i = 0; i < physicBodiesCount; i++) physicBodies[i]->rigidbody.isGrounded = false;
for (int steps = 0; steps < PHYSICS_STEPS; steps++)
{
for (int i = 0; i < physicBodiesCount; i++)
{
if (physicBodies[i]->enabled)
{
// Update physic behaviour
if (physicBodies[i]->rigidbody.enabled)
{
// Apply friction to acceleration in X axis
if (physicBodies[i]->rigidbody.acceleration.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else if (physicBodies[i]->rigidbody.acceleration.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else physicBodies[i]->rigidbody.acceleration.x = 0.0f;
// Apply friction to acceleration in Y axis
if (physicBodies[i]->rigidbody.acceleration.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else if (physicBodies[i]->rigidbody.acceleration.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else physicBodies[i]->rigidbody.acceleration.y = 0.0f;
// Apply friction to velocity in X axis
if (physicBodies[i]->rigidbody.velocity.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else if (physicBodies[i]->rigidbody.velocity.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else physicBodies[i]->rigidbody.velocity.x = 0.0f;
// Apply friction to velocity in Y axis
if (physicBodies[i]->rigidbody.velocity.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else if (physicBodies[i]->rigidbody.velocity.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS;
else physicBodies[i]->rigidbody.velocity.y = 0.0f;
// Apply gravity to velocity
if (physicBodies[i]->rigidbody.applyGravity)
{
physicBodies[i]->rigidbody.velocity.x += gravityForce.x/PHYSICS_STEPS;
physicBodies[i]->rigidbody.velocity.y += gravityForce.y/PHYSICS_STEPS;
}
// Apply acceleration to velocity
physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.acceleration.x/PHYSICS_STEPS;
physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.acceleration.y/PHYSICS_STEPS;
// Apply velocity to position
physicBodies[i]->transform.position.x += physicBodies[i]->rigidbody.velocity.x/PHYSICS_STEPS;
physicBodies[i]->transform.position.y -= physicBodies[i]->rigidbody.velocity.y/PHYSICS_STEPS;
}
// Update collision detection
if (physicBodies[i]->collider.enabled)
{
// Update collider bounds
physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform);
// Check collision with other colliders
for (int k = 0; k < physicBodiesCount; k++)
{
if (physicBodies[k]->collider.enabled && i != k)
{
// Resolve physic collision
// NOTE: collision resolve is generic for all directions and conditions (no axis separated cases behaviours)
// and it is separated in rigidbody attributes resolve (velocity changes by impulse) and position correction (position overlap)
// 1. Calculate collision normal
// -------------------------------------------------------------------------------------------------------------------------------------
// Define collision contact normal, direction and penetration depth
Vector2 contactNormal = { 0.0f, 0.0f };
Vector2 direction = { 0.0f, 0.0f };
float penetrationDepth = 0.0f;
switch (physicBodies[i]->collider.type)
{
case COLLIDER_RECTANGLE:
{
switch (physicBodies[k]->collider.type)
{
case COLLIDER_RECTANGLE:
{
// Check if colliders are overlapped
if (CheckCollisionRecs(physicBodies[i]->collider.bounds, physicBodies[k]->collider.bounds))
{
// Calculate direction vector from i to k
direction.x = (physicBodies[k]->transform.position.x + physicBodies[k]->transform.scale.x/2) - (physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2);
direction.y = (physicBodies[k]->transform.position.y + physicBodies[k]->transform.scale.y/2) - (physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2);
// Define overlapping and penetration attributes
Vector2 overlap;
// Calculate overlap on X axis
overlap.x = (physicBodies[i]->transform.scale.x + physicBodies[k]->transform.scale.x)/2 - abs(direction.x);
// SAT test on X axis
if (overlap.x > 0.0f)
{
// Calculate overlap on Y axis
overlap.y = (physicBodies[i]->transform.scale.y + physicBodies[k]->transform.scale.y)/2 - abs(direction.y);
// SAT test on Y axis
if (overlap.y > 0.0f)
{
// Find out which axis is axis of least penetration
if (overlap.y > overlap.x)
{
// Point towards k knowing that direction points from i to k
if (direction.x < 0.0f) contactNormal = (Vector2){ -1.0f, 0.0f };
else contactNormal = (Vector2){ 1.0f, 0.0f };
// Update penetration depth for position correction
penetrationDepth = overlap.x;
}
else
{
// Point towards k knowing that direction points from i to k
if (direction.y < 0.0f) contactNormal = (Vector2){ 0.0f, 1.0f };
else contactNormal = (Vector2){ 0.0f, -1.0f };
// Update penetration depth for position correction
penetrationDepth = overlap.y;
}
}
}
}
} break;
case COLLIDER_CIRCLE:
{
if (CheckCollisionCircleRec(physicBodies[k]->transform.position, physicBodies[k]->collider.radius, physicBodies[i]->collider.bounds))
{
// Calculate direction vector between circles
direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2;
direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2;
// Calculate closest point on rectangle to circle
Vector2 closestPoint = { 0.0f, 0.0f };
if (direction.x > 0.0f) closestPoint.x = physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width;
else closestPoint.x = physicBodies[i]->collider.bounds.x;
if (direction.y > 0.0f) closestPoint.y = physicBodies[i]->collider.bounds.y + physicBodies[i]->collider.bounds.height;
else closestPoint.y = physicBodies[i]->collider.bounds.y;
// Check if the closest point is inside the circle
if (CheckCollisionPointCircle(closestPoint, physicBodies[k]->transform.position, physicBodies[k]->collider.radius))
{
// Recalculate direction based on closest point position
direction.x = physicBodies[k]->transform.position.x - closestPoint.x;
direction.y = physicBodies[k]->transform.position.y - closestPoint.y;
float distance = Vector2Length(direction);
// Calculate final contact normal
contactNormal.x = direction.x/distance;
contactNormal.y = -direction.y/distance;
// Calculate penetration depth
penetrationDepth = physicBodies[k]->collider.radius - distance;
}
else
{
if (abs(direction.y) < abs(direction.x))
{
// Calculate final contact normal
if (direction.y > 0.0f)
{
contactNormal = (Vector2){ 0.0f, -1.0f };
penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y - physicBodies[k]->collider.radius);
}
else
{
contactNormal = (Vector2){ 0.0f, 1.0f };
penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y + physicBodies[k]->collider.radius);
}
}
else
{
// Calculate final contact normal
if (direction.x > 0.0f)
{
contactNormal = (Vector2){ 1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[k]->transform.position.x + physicBodies[k]->collider.radius - physicBodies[i]->collider.bounds.x);
}
else
{
contactNormal = (Vector2){ -1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width - physicBodies[k]->transform.position.x - physicBodies[k]->collider.radius);
}
}
}
}
} break;
}
} break;
case COLLIDER_CIRCLE:
{
switch (physicBodies[k]->collider.type)
{
case COLLIDER_RECTANGLE:
{
if (CheckCollisionCircleRec(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->collider.bounds))
{
// Calculate direction vector between circles
direction.x = physicBodies[k]->transform.position.x + physicBodies[i]->transform.scale.x/2 - physicBodies[i]->transform.position.x;
direction.y = physicBodies[k]->transform.position.y + physicBodies[i]->transform.scale.y/2 - physicBodies[i]->transform.position.y;
// Calculate closest point on rectangle to circle
Vector2 closestPoint = { 0.0f, 0.0f };
if (direction.x > 0.0f) closestPoint.x = physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width;
else closestPoint.x = physicBodies[k]->collider.bounds.x;
if (direction.y > 0.0f) closestPoint.y = physicBodies[k]->collider.bounds.y + physicBodies[k]->collider.bounds.height;
else closestPoint.y = physicBodies[k]->collider.bounds.y;
// Check if the closest point is inside the circle
if (CheckCollisionPointCircle(closestPoint, physicBodies[i]->transform.position, physicBodies[i]->collider.radius))
{
// Recalculate direction based on closest point position
direction.x = physicBodies[i]->transform.position.x - closestPoint.x;
direction.y = physicBodies[i]->transform.position.y - closestPoint.y;
float distance = Vector2Length(direction);
// Calculate final contact normal
contactNormal.x = direction.x/distance;
contactNormal.y = -direction.y/distance;
// Calculate penetration depth
penetrationDepth = physicBodies[k]->collider.radius - distance;
}
else
{
if (abs(direction.y) < abs(direction.x))
{
// Calculate final contact normal
if (direction.y > 0.0f)
{
contactNormal = (Vector2){ 0.0f, -1.0f };
penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y - physicBodies[i]->collider.radius);
}
else
{
contactNormal = (Vector2){ 0.0f, 1.0f };
penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y + physicBodies[i]->collider.radius);
}
}
else
{
// Calculate final contact normal and penetration depth
if (direction.x > 0.0f)
{
contactNormal = (Vector2){ 1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[i]->transform.position.x + physicBodies[i]->collider.radius - physicBodies[k]->collider.bounds.x);
}
else
{
contactNormal = (Vector2){ -1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width - physicBodies[i]->transform.position.x - physicBodies[i]->collider.radius);
}
}
}
}
} break;
case COLLIDER_CIRCLE:
{
// Check if colliders are overlapped
if (CheckCollisionCircles(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->transform.position, physicBodies[k]->collider.radius))
{
// Calculate direction vector between circles
direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x;
direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y;
// Calculate distance between circles
float distance = Vector2Length(direction);
// Check if circles are not completely overlapped
if (distance != 0.0f)
{
// Calculate contact normal direction (Y axis needs to be flipped)
contactNormal.x = direction.x/distance;
contactNormal.y = -direction.y/distance;
}
else contactNormal = (Vector2){ 1.0f, 0.0f }; // Choose random (but consistent) values
}
} break;
default: break;
}
} break;
default: break;
}
// Update rigidbody grounded state
if (physicBodies[i]->rigidbody.enabled)
{
if (contactNormal.y < 0.0f) physicBodies[i]->rigidbody.isGrounded = true;
}
// 2. Calculate collision impulse
// -------------------------------------------------------------------------------------------------------------------------------------
// Calculate relative velocity
Vector2 relVelocity = { 0.0f, 0.0f };
relVelocity.x = physicBodies[k]->rigidbody.velocity.x - physicBodies[i]->rigidbody.velocity.x;
relVelocity.y = physicBodies[k]->rigidbody.velocity.y - physicBodies[i]->rigidbody.velocity.y;
// Calculate relative velocity in terms of the normal direction
float velAlongNormal = Vector2DotProduct(relVelocity, contactNormal);
// Dot not resolve if velocities are separating
if (velAlongNormal <= 0.0f)
{
// Calculate minimum bounciness value from both objects
float e = fminf(physicBodies[i]->rigidbody.bounciness, physicBodies[k]->rigidbody.bounciness);
// Calculate impulse scalar value
float j = -(1.0f + e)*velAlongNormal;
j /= 1.0f/physicBodies[i]->rigidbody.mass + 1.0f/physicBodies[k]->rigidbody.mass;
// Calculate final impulse vector
Vector2 impulse = { j*contactNormal.x, j*contactNormal.y };
// Calculate collision mass ration
float massSum = physicBodies[i]->rigidbody.mass + physicBodies[k]->rigidbody.mass;
float ratio = 0.0f;
// Apply impulse to current rigidbodies velocities if they are enabled
if (physicBodies[i]->rigidbody.enabled)
{
// Calculate inverted mass ration
ratio = physicBodies[i]->rigidbody.mass/massSum;
// Apply impulse direction to velocity
physicBodies[i]->rigidbody.velocity.x -= impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
physicBodies[i]->rigidbody.velocity.y -= impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
}
if (physicBodies[k]->rigidbody.enabled)
{
// Calculate inverted mass ration
ratio = physicBodies[k]->rigidbody.mass/massSum;
// Apply impulse direction to velocity
physicBodies[k]->rigidbody.velocity.x += impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
physicBodies[k]->rigidbody.velocity.y += impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
}
// 3. Correct colliders overlaping (transform position)
// ---------------------------------------------------------------------------------------------------------------------------------
// Calculate transform position penetration correction
Vector2 posCorrection;
posCorrection.x = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.x;
posCorrection.y = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.y;
// Fix transform positions
if (physicBodies[i]->rigidbody.enabled)
{
// Fix physic objects transform position
physicBodies[i]->transform.position.x -= 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.x;
physicBodies[i]->transform.position.y += 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.y;
// Update collider bounds
physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform);
if (physicBodies[k]->rigidbody.enabled)
{
// Fix physic objects transform position
physicBodies[k]->transform.position.x += 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.x;
physicBodies[k]->transform.position.y -= 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.y;
// Update collider bounds
physicBodies[k]->collider.bounds = TransformToRectangle(physicBodies[k]->transform);
}
}
}
}
}
}
}
}
}
#ifndef PHYSAC_NO_THREADS // NOTE: if defined, user will need to create a thread for PhysicsThread function manually
// Create physics thread
pthread_t tid;
pthread_create(&tid, NULL, &PhysicsThread, NULL);
#endif
}
// Unitialize all physic objects and empty the objects pool
PHYSACDEF void ClosePhysics()
{
// Exit physics thread loop
physicsThreadEnabled = false;
// Free all dynamic memory allocations
for (int i = 0; i < physicBodiesCount; i++) PHYSAC_FREE(physicBodies[i]);
@ -716,9 +372,71 @@ PHYSACDEF Rectangle TransformToRectangle(Transform transform)
return (Rectangle){transform.position.x, transform.position.y, transform.scale.x, transform.scale.y};
}
// Physics calculations thread function
PHYSACDEF void* PhysicsThread(void *arg)
{
// Initialize thread loop state
physicsThreadEnabled = true;
// Initialize hi-resolution timer
InitTimer();
// Physics update loop
while (physicsThreadEnabled)
{
currentTime = GetCurrentTime();
double deltaTime = (double)(currentTime - previousTime);
previousTime = currentTime;
// Delta time value needs to be inverse multiplied by physics time step value (1/target fps)
UpdatePhysics(deltaTime/PHYSICS_TIMESTEP);
}
return NULL;
}
//----------------------------------------------------------------------------------
// Module specific Functions Definition
//----------------------------------------------------------------------------------
// Initialize hi-resolution timer
static void InitTimer(void)
{
#if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI)
struct timespec now;
if (clock_gettime(CLOCK_MONOTONIC, &now) == 0) // Success
{
baseTime = (uint64_t)now.tv_sec*1000000000LLU + (uint64_t)now.tv_nsec;
}
#endif
previousTime = GetCurrentTime(); // Get time as double
}
// Time measure returned are microseconds
static double GetCurrentTime(void)
{
double time;
#if defined(PLATFORM_DESKTOP)
unsigned long long int clockFrequency, currentTime;
QueryPerformanceFrequency(&clockFrequency);
QueryPerformanceCounter(&currentTime);
time = (double)((double)currentTime/(double)clockFrequency);
#endif
#if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI)
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
uint64_t temp = (uint64_t)ts.tv_sec*1000000000LLU + (uint64_t)ts.tv_nsec;
time = (double)(temp - baseTime)*1e-9;
#endif
return time;
}
// Returns the dot product of two Vector2
static float Vector2DotProduct(Vector2 v1, Vector2 v2)
@ -739,4 +457,376 @@ static float Vector2Length(Vector2 v)
return result;
}
// Update physic objects, calculating physic behaviours and collisions detection
static void UpdatePhysics(double deltaTime)
{
for (int i = 0; i < physicBodiesCount; i++)
{
if (physicBodies[i]->enabled)
{
// Update physic behaviour
if (physicBodies[i]->rigidbody.enabled)
{
// Apply friction to acceleration in X axis
if (physicBodies[i]->rigidbody.acceleration.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x -= physicBodies[i]->rigidbody.friction*deltaTime;
else if (physicBodies[i]->rigidbody.acceleration.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x += physicBodies[i]->rigidbody.friction*deltaTime;
else physicBodies[i]->rigidbody.acceleration.x = 0.0f;
// Apply friction to acceleration in Y axis
if (physicBodies[i]->rigidbody.acceleration.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y -= physicBodies[i]->rigidbody.friction*deltaTime;
else if (physicBodies[i]->rigidbody.acceleration.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y += physicBodies[i]->rigidbody.friction*deltaTime;
else physicBodies[i]->rigidbody.acceleration.y = 0.0f;
// Apply friction to velocity in X axis
if (physicBodies[i]->rigidbody.velocity.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x -= physicBodies[i]->rigidbody.friction*deltaTime;
else if (physicBodies[i]->rigidbody.velocity.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.friction*deltaTime;
else physicBodies[i]->rigidbody.velocity.x = 0.0f;
// Apply friction to velocity in Y axis
if (physicBodies[i]->rigidbody.velocity.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y -= physicBodies[i]->rigidbody.friction*deltaTime;
else if (physicBodies[i]->rigidbody.velocity.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.friction*deltaTime;
else physicBodies[i]->rigidbody.velocity.y = 0.0f;
// Apply gravity to velocity
if (physicBodies[i]->rigidbody.applyGravity)
{
physicBodies[i]->rigidbody.velocity.x += gravityForce.x*deltaTime;
physicBodies[i]->rigidbody.velocity.y += gravityForce.y*deltaTime;
}
// Apply acceleration to velocity
physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.acceleration.x*deltaTime;
physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.acceleration.y*deltaTime;
// Apply velocity to position
physicBodies[i]->transform.position.x += physicBodies[i]->rigidbody.velocity.x*deltaTime;
physicBodies[i]->transform.position.y -= physicBodies[i]->rigidbody.velocity.y*deltaTime;
}
// Update collision detection
if (physicBodies[i]->collider.enabled)
{
// Update collider bounds
physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform);
// Check collision with other colliders
for (int k = 0; k < physicBodiesCount; k++)
{
if (physicBodies[k]->collider.enabled && i != k)
{
// Resolve physic collision
// NOTE: collision resolve is generic for all directions and conditions (no axis separated cases behaviours)
// and it is separated in rigidbody attributes resolve (velocity changes by impulse) and position correction (position overlap)
// 1. Calculate collision normal
// -------------------------------------------------------------------------------------------------------------------------------------
// Define collision contact normal, direction and penetration depth
Vector2 contactNormal = { 0.0f, 0.0f };
Vector2 direction = { 0.0f, 0.0f };
float penetrationDepth = 0.0f;
switch (physicBodies[i]->collider.type)
{
case COLLIDER_RECTANGLE:
{
switch (physicBodies[k]->collider.type)
{
case COLLIDER_RECTANGLE:
{
// Check if colliders are overlapped
if (CheckCollisionRecs(physicBodies[i]->collider.bounds, physicBodies[k]->collider.bounds))
{
// Calculate direction vector from i to k
direction.x = (physicBodies[k]->transform.position.x + physicBodies[k]->transform.scale.x/2) - (physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2);
direction.y = (physicBodies[k]->transform.position.y + physicBodies[k]->transform.scale.y/2) - (physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2);
// Define overlapping and penetration attributes
Vector2 overlap;
// Calculate overlap on X axis
overlap.x = (physicBodies[i]->transform.scale.x + physicBodies[k]->transform.scale.x)/2 - abs(direction.x);
// SAT test on X axis
if (overlap.x > 0.0f)
{
// Calculate overlap on Y axis
overlap.y = (physicBodies[i]->transform.scale.y + physicBodies[k]->transform.scale.y)/2 - abs(direction.y);
// SAT test on Y axis
if (overlap.y > 0.0f)
{
// Find out which axis is axis of least penetration
if (overlap.y > overlap.x)
{
// Point towards k knowing that direction points from i to k
if (direction.x < 0.0f) contactNormal = (Vector2){ -1.0f, 0.0f };
else contactNormal = (Vector2){ 1.0f, 0.0f };
// Update penetration depth for position correction
penetrationDepth = overlap.x;
}
else
{
// Point towards k knowing that direction points from i to k
if (direction.y < 0.0f) contactNormal = (Vector2){ 0.0f, 1.0f };
else contactNormal = (Vector2){ 0.0f, -1.0f };
// Update penetration depth for position correction
penetrationDepth = overlap.y;
}
}
}
}
} break;
case COLLIDER_CIRCLE:
{
if (CheckCollisionCircleRec(physicBodies[k]->transform.position, physicBodies[k]->collider.radius, physicBodies[i]->collider.bounds))
{
// Calculate direction vector between circles
direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2;
direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2;
// Calculate closest point on rectangle to circle
Vector2 closestPoint = { 0.0f, 0.0f };
if (direction.x > 0.0f) closestPoint.x = physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width;
else closestPoint.x = physicBodies[i]->collider.bounds.x;
if (direction.y > 0.0f) closestPoint.y = physicBodies[i]->collider.bounds.y + physicBodies[i]->collider.bounds.height;
else closestPoint.y = physicBodies[i]->collider.bounds.y;
// Check if the closest point is inside the circle
if (CheckCollisionPointCircle(closestPoint, physicBodies[k]->transform.position, physicBodies[k]->collider.radius))
{
// Recalculate direction based on closest point position
direction.x = physicBodies[k]->transform.position.x - closestPoint.x;
direction.y = physicBodies[k]->transform.position.y - closestPoint.y;
float distance = Vector2Length(direction);
// Calculate final contact normal
contactNormal.x = direction.x/distance;
contactNormal.y = -direction.y/distance;
// Calculate penetration depth
penetrationDepth = physicBodies[k]->collider.radius - distance;
}
else
{
if (abs(direction.y) < abs(direction.x))
{
// Calculate final contact normal
if (direction.y > 0.0f)
{
contactNormal = (Vector2){ 0.0f, -1.0f };
penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y - physicBodies[k]->collider.radius);
}
else
{
contactNormal = (Vector2){ 0.0f, 1.0f };
penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y + physicBodies[k]->collider.radius);
}
}
else
{
// Calculate final contact normal
if (direction.x > 0.0f)
{
contactNormal = (Vector2){ 1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[k]->transform.position.x + physicBodies[k]->collider.radius - physicBodies[i]->collider.bounds.x);
}
else
{
contactNormal = (Vector2){ -1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width - physicBodies[k]->transform.position.x - physicBodies[k]->collider.radius);
}
}
}
}
} break;
}
} break;
case COLLIDER_CIRCLE:
{
switch (physicBodies[k]->collider.type)
{
case COLLIDER_RECTANGLE:
{
if (CheckCollisionCircleRec(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->collider.bounds))
{
// Calculate direction vector between circles
direction.x = physicBodies[k]->transform.position.x + physicBodies[i]->transform.scale.x/2 - physicBodies[i]->transform.position.x;
direction.y = physicBodies[k]->transform.position.y + physicBodies[i]->transform.scale.y/2 - physicBodies[i]->transform.position.y;
// Calculate closest point on rectangle to circle
Vector2 closestPoint = { 0.0f, 0.0f };
if (direction.x > 0.0f) closestPoint.x = physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width;
else closestPoint.x = physicBodies[k]->collider.bounds.x;
if (direction.y > 0.0f) closestPoint.y = physicBodies[k]->collider.bounds.y + physicBodies[k]->collider.bounds.height;
else closestPoint.y = physicBodies[k]->collider.bounds.y;
// Check if the closest point is inside the circle
if (CheckCollisionPointCircle(closestPoint, physicBodies[i]->transform.position, physicBodies[i]->collider.radius))
{
// Recalculate direction based on closest point position
direction.x = physicBodies[i]->transform.position.x - closestPoint.x;
direction.y = physicBodies[i]->transform.position.y - closestPoint.y;
float distance = Vector2Length(direction);
// Calculate final contact normal
contactNormal.x = direction.x/distance;
contactNormal.y = -direction.y/distance;
// Calculate penetration depth
penetrationDepth = physicBodies[k]->collider.radius - distance;
}
else
{
if (abs(direction.y) < abs(direction.x))
{
// Calculate final contact normal
if (direction.y > 0.0f)
{
contactNormal = (Vector2){ 0.0f, -1.0f };
penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y - physicBodies[i]->collider.radius);
}
else
{
contactNormal = (Vector2){ 0.0f, 1.0f };
penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y + physicBodies[i]->collider.radius);
}
}
else
{
// Calculate final contact normal and penetration depth
if (direction.x > 0.0f)
{
contactNormal = (Vector2){ 1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[i]->transform.position.x + physicBodies[i]->collider.radius - physicBodies[k]->collider.bounds.x);
}
else
{
contactNormal = (Vector2){ -1.0f, 0.0f };
penetrationDepth = fabs(physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width - physicBodies[i]->transform.position.x - physicBodies[i]->collider.radius);
}
}
}
}
} break;
case COLLIDER_CIRCLE:
{
// Check if colliders are overlapped
if (CheckCollisionCircles(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->transform.position, physicBodies[k]->collider.radius))
{
// Calculate direction vector between circles
direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x;
direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y;
// Calculate distance between circles
float distance = Vector2Length(direction);
// Check if circles are not completely overlapped
if (distance != 0.0f)
{
// Calculate contact normal direction (Y axis needs to be flipped)
contactNormal.x = direction.x/distance;
contactNormal.y = -direction.y/distance;
}
else contactNormal = (Vector2){ 1.0f, 0.0f }; // Choose random (but consistent) values
}
} break;
default: break;
}
} break;
default: break;
}
// Update rigidbody grounded state
if (physicBodies[i]->rigidbody.enabled) physicBodies[i]->rigidbody.isGrounded = (contactNormal.y < 0.0f);
// 2. Calculate collision impulse
// -------------------------------------------------------------------------------------------------------------------------------------
// Calculate relative velocity
Vector2 relVelocity = { 0.0f, 0.0f };
relVelocity.x = physicBodies[k]->rigidbody.velocity.x - physicBodies[i]->rigidbody.velocity.x;
relVelocity.y = physicBodies[k]->rigidbody.velocity.y - physicBodies[i]->rigidbody.velocity.y;
// Calculate relative velocity in terms of the normal direction
float velAlongNormal = Vector2DotProduct(relVelocity, contactNormal);
// Dot not resolve if velocities are separating
if (velAlongNormal <= 0.0f)
{
// Calculate minimum bounciness value from both objects
float e = fminf(physicBodies[i]->rigidbody.bounciness, physicBodies[k]->rigidbody.bounciness);
// Calculate impulse scalar value
float j = -(1.0f + e)*velAlongNormal;
j /= 1.0f/physicBodies[i]->rigidbody.mass + 1.0f/physicBodies[k]->rigidbody.mass;
// Calculate final impulse vector
Vector2 impulse = { j*contactNormal.x, j*contactNormal.y };
// Calculate collision mass ration
float massSum = physicBodies[i]->rigidbody.mass + physicBodies[k]->rigidbody.mass;
float ratio = 0.0f;
// Apply impulse to current rigidbodies velocities if they are enabled
if (physicBodies[i]->rigidbody.enabled)
{
// Calculate inverted mass ration
ratio = physicBodies[i]->rigidbody.mass/massSum;
// Apply impulse direction to velocity
physicBodies[i]->rigidbody.velocity.x -= impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
physicBodies[i]->rigidbody.velocity.y -= impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
}
if (physicBodies[k]->rigidbody.enabled)
{
// Calculate inverted mass ration
ratio = physicBodies[k]->rigidbody.mass/massSum;
// Apply impulse direction to velocity
physicBodies[k]->rigidbody.velocity.x += impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
physicBodies[k]->rigidbody.velocity.y += impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness);
}
// 3. Correct colliders overlaping (transform position)
// ---------------------------------------------------------------------------------------------------------------------------------
// Calculate transform position penetration correction
Vector2 posCorrection;
posCorrection.x = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.x;
posCorrection.y = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.y;
// Fix transform positions
if (physicBodies[i]->rigidbody.enabled)
{
// Fix physic objects transform position
physicBodies[i]->transform.position.x -= 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.x;
physicBodies[i]->transform.position.y += 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.y;
// Update collider bounds
physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform);
if (physicBodies[k]->rigidbody.enabled)
{
// Fix physic objects transform position
physicBodies[k]->transform.position.x += 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.x;
physicBodies[k]->transform.position.y -= 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.y;
// Update collider bounds
physicBodies[k]->collider.bounds = TransformToRectangle(physicBodies[k]->transform);
}
}
}
}
}
}
}
}
}
#endif // PHYSAC_IMPLEMENTATION

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