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Diffstat (limited to 'src/physics.c')
| -rw-r--r-- | src/physics.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/src/physics.c b/src/physics.c new file mode 100644 index 00000000..90a8b2e9 --- /dev/null +++ b/src/physics.c @@ -0,0 +1,272 @@ +/********************************************************************************************** +* +* raylib physics engine module - Basic functions to apply physics to 2D objects +* +* Copyright (c) 2015 Victor Fisac and Ramon Santamaria +* +* 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. +* +* Permission is granted to anyone to use this software for any purpose, including commercial +* applications, and to alter it and redistribute it freely, subject to the following restrictions: +* +* 1. The origin of this software must not be misrepresented; you must not claim that you +* wrote the original software. If you use this software in a product, an acknowledgment +* in the product documentation would be appreciated but is not required. +* +* 2. Altered source versions must be plainly marked as such, and must not be misrepresented +* as being the original software. +* +* 3. This notice may not be removed or altered from any source distribution. +* +**********************************************************************************************/ + +//#define PHYSICS_STANDALONE // NOTE: To use the physics module as standalone lib, just uncomment this line + +#if defined(PHYSICS_STANDALONE) + #include "physics.h" +#else + #include "raylib.h" +#endif + +#include <math.h> +#include <stdio.h> + +//---------------------------------------------------------------------------------- +// Defines and Macros +//---------------------------------------------------------------------------------- +#define MAX_ELEMENTS 1024 // Stored rigidbodies and colliders array length +#define DECIMAL_FIX 0.01f // Decimal margin for collision checks (avoid rigidbodies shake) + +//---------------------------------------------------------------------------------- +// Types and Structures Definition +//---------------------------------------------------------------------------------- +// ... + +//---------------------------------------------------------------------------------- +// Global Variables Definition +//---------------------------------------------------------------------------------- +static Physics physics; +static Collider colliders[MAX_ELEMENTS]; +static Rigidbody rigidbodies[MAX_ELEMENTS]; +static bool collisionChecker = false; + +//---------------------------------------------------------------------------------- +// Module Functions Definition +//---------------------------------------------------------------------------------- +void InitPhysics() +{ + for (int i = 0; i < MAX_ELEMENTS; i++) + { + rigidbodies[i].enabled = false; + rigidbodies[i].mass = 0.0f; + rigidbodies[i].velocity = (Vector2){0, 0}; + rigidbodies[i].acceleration = (Vector2){0, 0}; + rigidbodies[i].isGrounded = false; + rigidbodies[i].isContact = false; + rigidbodies[i].friction = 0.0f; + + colliders[i].enabled = false; + colliders[i].bounds = (Rectangle){0, 0, 0, 0}; + colliders[i].radius = 0; + } +} + +void SetPhysics(Physics settings) +{ + physics = settings; + + // To get good results, gravity needs to be 1:10 from original parameter + physics.gravity = (Vector2){physics.gravity.x / 10, physics.gravity.y / 10}; +} + +void AddCollider(int index, Collider collider) +{ + colliders[index] = collider; +} + +void AddRigidbody(int index, Rigidbody rigidbody) +{ + rigidbodies[index] = rigidbody; +} + +void ApplyPhysics(int index, Vector2 *position) +{ + if (rigidbodies[index].enabled) + { + // Apply gravity + rigidbodies[index].velocity.y += rigidbodies[index].acceleration.y; + rigidbodies[index].velocity.x += rigidbodies[index].acceleration.x; + + rigidbodies[index].velocity.y += physics.gravity.y; + rigidbodies[index].velocity.x += physics.gravity.x; + + // Apply friction to velocity + if (rigidbodies[index].isGrounded) + { + if (rigidbodies[index].velocity.x > DECIMAL_FIX) + { + rigidbodies[index].velocity.x -= rigidbodies[index].friction; + } + else if (rigidbodies[index].velocity.x < -DECIMAL_FIX) + { + rigidbodies[index].velocity.x += rigidbodies[index].friction; + } + else + { + rigidbodies[index].velocity.x = 0; + } + } + + if (rigidbodies[index].velocity.y > DECIMAL_FIX) + { + rigidbodies[index].velocity.y -= rigidbodies[index].friction; + } + else if (rigidbodies[index].velocity.y < -DECIMAL_FIX) + { + rigidbodies[index].velocity.y += rigidbodies[index].friction; + } + else + { + rigidbodies[index].velocity.y = 0; + } + + // Apply friction to acceleration + if (rigidbodies[index].isGrounded) + { + if (rigidbodies[index].acceleration.x > DECIMAL_FIX) + { + rigidbodies[index].acceleration.x -= rigidbodies[index].friction; + } + else if (rigidbodies[index].acceleration.x < -DECIMAL_FIX) + { + rigidbodies[index].acceleration.x += rigidbodies[index].friction; + } + else + { + rigidbodies[index].acceleration.x = 0; + } + } + + if (rigidbodies[index].acceleration.y > DECIMAL_FIX) + { + rigidbodies[index].acceleration.y -= rigidbodies[index].friction; + } + else if (rigidbodies[index].acceleration.y < -DECIMAL_FIX) + { + rigidbodies[index].acceleration.y += rigidbodies[index].friction; + } + else + { + rigidbodies[index].acceleration.y = 0; + } + + // Update position vector + position->x += rigidbodies[index].velocity.x; + position->y -= rigidbodies[index].velocity.y; + + // Update collider bounds + colliders[index].bounds.x = position->x; + colliders[index].bounds.y = position->y; + + // Check collision with other colliders + collisionChecker = false; + rigidbodies[index].isContact = false; + for (int j = 0; j < MAX_ELEMENTS; j++) + { + if (index != j) + { + if (colliders[index].enabled && colliders[j].enabled) + { + if (colliders[index].type == RectangleCollider) + { + if (colliders[j].type == RectangleCollider) + { + if (CheckCollisionRecs(colliders[index].bounds, colliders[j].bounds)) + { + collisionChecker = true; + + if ((colliders[index].bounds.y + colliders[index].bounds.height <= colliders[j].bounds.y) == false) + { + rigidbodies[index].isContact = true; + } + } + } + else + { + if (CheckCollisionCircleRec((Vector2){colliders[j].bounds.x, colliders[j].bounds.y}, colliders[j].radius, colliders[index].bounds)) + { + collisionChecker = true; + } + } + } + else + { + if (colliders[j].type == RectangleCollider) + { + if (CheckCollisionCircleRec((Vector2){colliders[index].bounds.x, colliders[index].bounds.y}, colliders[index].radius, colliders[j].bounds)) + { + collisionChecker = true; + } + } + else + { + if (CheckCollisionCircles((Vector2){colliders[j].bounds.x, colliders[j].bounds.y}, colliders[j].radius, (Vector2){colliders[index].bounds.x, colliders[index].bounds.y}, colliders[index].radius)) + { + collisionChecker = true; + } + } + } + } + } + } + + // Update grounded rigidbody state + rigidbodies[index].isGrounded = collisionChecker; + + // Set grounded state if needed (fix overlap and set y velocity) + if (collisionChecker && rigidbodies[index].velocity.y != 0) + { + position->y += rigidbodies[index].velocity.y; + rigidbodies[index].velocity.y = -rigidbodies[index].velocity.y * rigidbodies[index].bounciness; + } + + if (rigidbodies[index].isContact) + { + position->x -= rigidbodies[index].velocity.x; + rigidbodies[index].velocity.x = rigidbodies[index].velocity.x; + } + } +} + +void SetRigidbodyEnabled(int index, bool state) +{ + rigidbodies[index].enabled = state; +} + +void SetRigidbodyVelocity(int index, Vector2 velocity) +{ + rigidbodies[index].velocity.x = velocity.x; + rigidbodies[index].velocity.y = velocity.y; +} + +void AddRigidbodyForce(int index, Vector2 force) +{ + rigidbodies[index].acceleration.x = force.x * rigidbodies[index].mass; + rigidbodies[index].acceleration.y = force.y * rigidbodies[index].mass; +} + +void SetColliderEnabled(int index, bool state) +{ + colliders[index].enabled = state; +} + +Collider GetCollider(int index) +{ + return colliders[index]; +} + +Rigidbody GetRigidbody(int index) +{ + return rigidbodies[index]; +}
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