Added physics engine-module and example

- Added new physics engine-module with four new data types: Physics,
Transform, Rigidbody and Collider. This library contains functions to
apply physics calculations to a position vector calculating collisions
automatically.

- Fixed some writing mistakes of lighting module.

1 files changed, 99 insertions, 0 deletions

diff --git a/src/physics.h b/src/physics.h
new file mode 100644
index 00000000..211f31a2
--- /dev/null
+++ b/src/physics.h
@@ -0,0 +1,99 @@
+/**********************************************************************************************
+*
+*   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.
+*
+**********************************************************************************************/
+
+#ifndef PHYSICS_H
+#define PHYSICS_H
+
+//----------------------------------------------------------------------------------
+// Defines and Macros
+//----------------------------------------------------------------------------------
+// ...
+
+//----------------------------------------------------------------------------------
+// Types and Structures Definition
+//----------------------------------------------------------------------------------
+typedef enum { RectangleCollider, CircleCollider } ColliderType;
+
+// Physics struct
+typedef struct Physics {
+    bool enabled;
+    bool debug;     // Should be used by programmer for testing purposes
+    Vector2 gravity;
+} Physics;
+
+// Transform struct
+typedef struct Transform {
+    Vector2 position;
+    float rotation;
+    Vector2 scale;
+} Transform;
+
+// Rigidbody struct
+typedef struct Rigidbody {
+    bool enabled;
+    float mass;
+    Vector2 acceleration;
+    Vector2 velocity;
+    bool isGrounded;
+    bool isContact;     // Avoid freeze player when touching floor
+    bool applyGravity;
+    float friction;     // 0.0f to 1.0f
+    float bounciness;   // 0.0f to 1.0f
+} Rigidbody;
+
+// Collider struct
+typedef struct Collider {
+    bool enabled;
+    ColliderType type;
+    Rectangle bounds;   // Just used for RectangleCollider type
+    int radius;     // Just used for CircleCollider type
+} Collider;
+
+#ifdef __cplusplus
+extern "C" {            // Prevents name mangling of functions
+#endif
+
+//----------------------------------------------------------------------------------
+// Module Functions Declaration
+//----------------------------------------------------------------------------------
+void InitPhysics();                                                     // Initialize all internal physics values
+void SetPhysics(Physics settings);                                      // Set physics settings values using Physics data type to overwrite internal physics settings
+
+void AddRigidbody(int index, Rigidbody rigidbody);                      // Initialize a new rigidbody with parameters to internal index slot
+void AddCollider(int index, Collider collider);                         // Initialize a new Collider with parameters to internal index slot
+
+void ApplyPhysics(int index, Vector2 *position);                        // Apply physics to internal rigidbody, physics calculations are applied to position pointer parameter
+void SetRigidbodyEnabled(int index, bool state);                        // Set enabled state to a defined rigidbody
+void SetRigidbodyVelocity(int index, Vector2 velocity);                 // Set velocity of rigidbody (without considering of mass value)
+void AddRigidbodyForce(int index, Vector2 force);                       // Set rigidbody force (considering mass value)
+
+void SetColliderEnabled(int index, bool state);                         // Set enabled state to a defined collider
+
+Rigidbody GetRigidbody(int index);                                      // Returns the internal rigidbody data defined by index parameter
+Collider GetCollider(int index);                                        // Returns the internal collider data defined by index parameter
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // PHYSICS_H
\ No newline at end of file