initial commit

1 files changed, 41 insertions, 0 deletions

diff --git a/src/Physics.h b/src/Physics.h
new file mode 100644
index 0000000..c39cdaf
--- /dev/null
+++ b/src/Physics.h
@@ -0,0 +1,41 @@
+#ifndef CC_PHYSICS_H
+#define CC_PHYSICS_H
+#include "Vectors.h"
+/* 
+Provides various physics related structs and methods such as:
+   - An axis aligned bounding box, and various methods related to them.
+   - Various methods for intersecting geometry.
+   - Calculates all possible blocks that a moving entity can intersect with
+Copyright 2014-2023 ClassiCube | Licensed under BSD-3
+*/
+struct Entity;
+
+/* Descibes an axis aligned bounding box. */
+struct AABB { Vec3 Min, Max; };
+
+/* Makes an AABB centred at the base of the given position, that is: */
+/* Min = [pos.x - size.x/2, pos.y         , pos.z - size.z/2] */
+/* Max = [pos.x + size.x/2, pos.y + size.y, pos.z + size.z/2] */
+CC_API void AABB_Make(struct AABB* result, const Vec3* pos, const Vec3* size);
+/* Adds amount to Min and Max corners of the given AABB. */
+void AABB_Offset(struct AABB* result, const struct AABB* bb, const Vec3* amount);
+/* Whether the given AABB touches another AABB on any axis. */
+cc_bool AABB_Intersects(const struct AABB* bb, const struct AABB* other);
+/* Whether the given ABBB contains another AABB. */
+cc_bool AABB_Contains(const struct AABB* parent, const struct AABB* child);
+/* Whether the given point lies insides bounds of the given AABB. */
+cc_bool AABB_ContainsPoint(const struct AABB* parent, const Vec3* P);
+
+/* Calculates the intersection point of a ray and a rotated bounding box. */
+cc_bool Intersection_RayIntersectsRotatedBox(Vec3 origin, Vec3 dir, struct Entity* target, float* tMin, float* tMax);
+/* Calculates the intersection point of a ray and a bounding box.
+Source: http://www.cs.utah.edu/~awilliam/box/box.pdf */
+/* NOTE: invDir is inverse of ray's direction (i.e. 1.0f / dir) */
+cc_bool Intersection_RayIntersectsBox(Vec3 origin, Vec3 invDir, Vec3 min, Vec3 max, float* t0, float* t1);
+
+struct SearcherState { int x, y, z; float tSquared; };
+extern struct SearcherState* Searcher_States;
+int Searcher_FindReachableBlocks(struct Entity* entity, struct AABB* entityBB, struct AABB* entityExtentBB);
+void Searcher_CalcTime(Vec3* vel, struct AABB *entityBB, struct AABB* blockBB, float* tx, float* ty, float* tz);
+void Searcher_Free(void);
+#endif