src/corelib/object.c

@@ -0,0 +1,16 @@
+#include "object.h"
+
+object_t object_default() {
+  return (object_t){
+    .active = 1,
+	  .enabled = 1,
+	  .collider = collider_default(),
+	  .evt_draw = &object_draw_sprite,
+	  .evt_update = NULL,
+    .sprite = sprite_default(),
+  };
+}
+
+void object_draw_sprite(object_t* object) {
+	draw_sprite(&object->sprite);
+}

src/corelib/object.h

@@ -0,0 +1,29 @@
+#ifndef _object_h
+#define _object_h
+
+#include "render.h"
+#include "physics.h"
+
+typedef struct object_t object_t;
+typedef struct collider_t collider_t;
+
+typedef void(*tick_fn)(struct object_t*);
+typedef void(*draw_fn)(struct object_t*);
+
+struct object_t {
+	sprite_t sprite;
+	int active; // 1 if this object is in use and should not be overriden.
+	int enabled; // 1 if this object's events should be triggered.
+	collider_t collider; // the collider to use for this object's physics interaction.
+
+	uintptr_t timer; // free to use for whatever
+
+	tick_fn evt_update;
+	draw_fn evt_draw;
+};
+
+object_t object_default();
+
+void object_draw_sprite(object_t* object);
+
+#endif /* _object_h */

src/corelib/physics.c

@@ -0,0 +1,269 @@
+#include "physics.h"
+#include "object.h"
+#include "world.h"
+#include "math/vec.h"
+
+static inline
+float fclampf(float x, float min_, float max_) {
+	return fminf(max_, fmaxf(min_, x));
+}
+
+
+collider_t collider_default() {
+	return (collider_t) {
+		.type=COLLIDERTYPE_NONE
+	};
+}
+
+void object_broadcast_collision(object_t* this, object_t* other) {
+	if(this->collider.evt_collision != NULL) {
+		this->collider.evt_collision(this, other);
+	}
+}
+short can_collide(const object_t* this) {
+	return this->active && this->enabled;
+}
+
+static inline
+int _rect_overlap(float aminx, float aminy, float amaxx, float amaxy, float bminx, float bminy, float bmaxx, float bmaxy) {
+	return
+	(
+		(aminx < bmaxx && aminx > bmaxx) 
+		||
+		(amaxx > bminx && amaxx < bmaxx)
+	) && (
+		(aminy < bmaxy && aminy > bmaxy)
+		||
+		(amaxy > bminy && amaxy < bmaxy)
+	);
+}
+
+static inline
+short _collision_aabb_aabb(const object_t* a, const object_t* b) {
+	const float aminx = a->collider.aabb.x + a->sprite.x, aminy = a->collider.aabb.y + a->sprite.x;
+	const float amaxx = aminx + a->collider.aabb.w, amaxy = aminy + a->collider.aabb.h;
+	const float bminx = b->collider.aabb.x, bminy = b->collider.aabb.y;
+	const float bmaxx = b->collider.aabb.x + b->collider.aabb.w, bmaxy = b->collider.aabb.y + b->collider.aabb.h;
+
+	return _rect_overlap(aminx, aminy, amaxx, amaxy, bminx, bminy, bmaxx, bmaxy);
+}
+
+static inline
+short _collision_circle_circle(const object_t* a, const object_t* b) {
+	const float ax = a->sprite.x + a->collider.circle.x, ay = a->sprite.y + a->collider.circle.y,
+		  		bx = b->sprite.x + b->collider.circle.x, by = b->sprite.y + b->collider.circle.y;
+	const float dx = fabsf(ax-bx), dy = fabsf(ay-by);
+	const float sqrdist = dx*dx+dy*dy;
+	const float mindist = a->collider.circle.radius + b->collider.circle.radius;
+	const float mindistsqr = mindist*mindist;
+	return sqrdist < mindistsqr;
+}
+
+static inline
+short _collision_circle_aabb(const object_t* circle, const object_t* aabb) {
+	// generate a point on the edge of the rectangle that is closest to the circle
+	const float bbminx = aabb->collider.aabb.x + aabb->sprite.x, bbmaxx = bbminx + aabb->collider.aabb.w,
+				bbminy = aabb->collider.aabb.y + aabb->sprite.y, bbmaxy = bbminy + aabb->collider.aabb.h;
+	const float cx = circle->sprite.x + circle->collider.circle.x,
+				cy = circle->sprite.y + circle->collider.circle.y;
+	const float x = fclampf(cx, bbminx, bbmaxx),
+				y = fclampf(cy, bbminy, bbmaxy);
+	const float dx = fabsf(cx - x), dy = fabsf(cy - y);
+
+	// calculate the square distance from the centre of the circle to the edge of the aabb
+	const float distsqr = dx*dx+dy*dy;
+	const float rsqr = circle->collider.circle.radius*circle->collider.circle.radius;
+
+	// return if the square distance is larger than the square of the radius
+	return distsqr < rsqr;
+}
+
+static inline
+short _collision_check(const object_t* a, const object_t* b) {
+	if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_AABB) {
+		return _collision_aabb_aabb(a, b);
+	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_CIRCLE) {
+		return _collision_circle_circle(a, b);
+	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_AABB) {
+		return _collision_circle_aabb(a, b);
+	} else if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_CIRCLE) {
+		return _collision_circle_aabb(b, a);
+	}
+	return 0;
+}
+
+static inline
+float _solve_circle_aabb(const object_t* circle, const object_t* aabb, float* out_px, float* out_py) {
+	// generate a point on the edge of the rectangle that is closest to the circle
+	const float bbminx = aabb->collider.aabb.x + aabb->sprite.x, bbmaxx = bbminx + aabb->collider.aabb.w,
+	            bbminy = aabb->collider.aabb.y + aabb->sprite.y, bbmaxy = bbminy + aabb->collider.aabb.h;
+	// the centre of the circle in world space
+	const float cx = circle->sprite.x + circle->collider.circle.x,
+	            cy = circle->sprite.y + circle->collider.circle.y;
+	// the point on the rectangle closest to the centre of the circle
+	const float x = fclampf(cx, bbminx, bbmaxx),
+	            y = fclampf(cy, bbminy, bbmaxy);
+	// the relative position of the point on the rectangle 
+	const float dif_x = cx - x,
+	            dif_y = cy - y;
+	// absolute difference for use in calculating euclidean distance 
+	const float dist_x = fabsf(dif_x),
+	            dist_y = fabsf(dif_y);
+	// euclidean distance
+	const float dist = sqrt(dist_x*dist_x + dist_y*dist_y);
+	const float solve_distance = circle->collider.circle.radius - dist;
+	// distance to solve collision
+	float solve_x, solve_y;
+	normalize(dif_x, dif_y, &solve_x, &solve_y);
+	*out_px = solve_x * solve_distance;
+	*out_py = solve_y * solve_distance;
+	return solve_distance;
+}
+
+static inline
+float _solve_circle_circle(const object_t* a, const object_t* b, float* out_px, float* out_py) {
+	const float x1 = a->collider.circle.x + a->sprite.x, y1 = a->collider.circle.y + a->sprite.y;
+	const float x2 = b->collider.circle.x + b->sprite.x, y2 = b->collider.circle.y + b->sprite.y;
+	const float dif_x = x1 - x2, dif_y = y1 - y2;
+	const float difference = sqrtf(fabsf(dif_x*dif_x) + fabsf(dif_y*dif_y));
+	const float target_difference = a->collider.circle.radius + b->collider.circle.radius;
+	float dir_x, dir_y;
+	normalize(dif_x, dif_y, &dir_x, &dir_y);
+	*out_px = dir_x * target_difference;
+	*out_py = dir_y * target_difference;
+	return target_difference;
+}
+
+static inline
+float _solve_aabb_aabb(const object_t* a, const object_t* b, float* out_px, float* out_py) {
+	float right = (a->collider.aabb.x + a->collider.aabb.w + a->sprite.x) - (b->collider.aabb.x + b->sprite.x);
+	float left = (a->collider.aabb.x + a->sprite.x) - (b->collider.aabb.x + b->collider.aabb.w + b->sprite.x);
+	float top = (a->collider.aabb.y + a->sprite.y) - (b->collider.aabb.y + b->collider.aabb.w + b->sprite.y);
+	float bottom = (a->collider.aabb.y + a->collider.aabb.h) - (b->collider.aabb.y + b->sprite.y);
+
+	float ret = right;
+	*out_px = right;
+	*out_py = 0.f;
+	if(fabsf(left) < fabsf(ret)) {
+		*out_px = left;
+		*out_py = 0.f;
+		ret = left;
+	}
+	if(fabsf(top) < fabsf(ret)) {
+		*out_px = 0.f;
+		*out_py = top;
+		ret = top;
+	}
+
+	if(fabsf(bottom) < fabsf(ret)) {
+		*out_px = 0.f;
+		*out_py = bottom;
+		return bottom;
+	}
+
+	return ret;
+}
+
+float get_solve_force(const object_t* a, const object_t* b, float* out_px, float* out_py) {
+	if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_AABB) {
+		return _solve_aabb_aabb(a, b, out_px, out_py);
+	} else if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_CIRCLE) {
+		float penetration_distance = _solve_circle_aabb(b, a, out_px, out_py);
+		*out_px = -(*out_px);
+		*out_py = -(*out_py);
+	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_AABB) {
+		return _solve_circle_aabb(a, b, out_px, out_py);
+	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_CIRCLE) {
+		return _solve_circle_circle(a, b, out_px, out_py);
+	}
+}
+
+static inline
+void _solve_collision_slide(object_t* this, object_t* other, float old_x, float old_y, float new_x, float new_y) {
+	float dx, dy;
+	const float d = get_solve_force(this, other, &dx, &dy);
+	this->sprite.x += dx;
+	this->sprite.y += dy;
+	
+	return;
+	this->sprite.x = old_x;
+	this->sprite.y = new_y;
+	if(!_collision_check(other, this)) {
+		return;
+	}
+
+	this->sprite.x = new_x;
+	this->sprite.y = old_y;
+	if(!_collision_check(other, this)) {
+		return;
+	}
+
+	this->sprite.x = old_x;
+	this->sprite.y = old_y;
+	if(!_collision_check(other, this)) {
+		return;
+	}
+}
+
+void interpolate_move(object_t* object, const float target_x, const float target_y, const float max_step_size, const int slide) {
+	// calculate step delta
+	float dx = target_x - object->sprite.x, dy = target_y - object->sprite.y;
+	if(dx == 0 && dy == 0)
+		return;
+	// calculate direction x,y
+	float m = sqrtf(dx*dx + dy*dy);
+	if(dx != 0)
+		dx /= m;
+	if(dy != 0)
+		dy /= m;
+	dx *= max_step_size; dy *= max_step_size;
+	int step_count = max_step_size / m;
+
+	// ensure this object would ever collide
+	// if it wouldn't collide anyway, just set position
+	if(!can_collide(object)) {
+		object->sprite.x = target_x;
+		object->sprite.y = target_y;
+		return;
+	}
+
+	/*
+	 * 1. move towards target
+	 * 2. check collision with every other object
+	 */
+	for(int steps = 0; steps < step_count && (object->sprite.x != target_x || object->sprite.y != target_y); ++steps) {
+		// move towards target, snap to target if distance is too low
+		const float old_x = object->sprite.x, old_y = object->sprite.y;
+		float new_x, new_y;
+
+		const float distx = fabsf(object->sprite.x - target_x), disty = fabsf(object->sprite.y - target_y);
+		const float sqdist = distx*distx + disty*disty;
+		if(sqdist > max_step_size) {
+			object->sprite.x += dx;
+			object->sprite.y += dy;
+			new_x = object->sprite.x;
+			new_y = object->sprite.y;
+		} else {
+			new_x = object->sprite.x = target_x;
+			new_y = object->sprite.y = target_y;
+		}
+
+		// loop over all objects and check collision if applicable
+		for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
+			// get pointer to other object
+			object_t* other = g_objects + i;
+			// check collision, return if found
+			if(can_collide(other) && object != other && _collision_check(other, object)) {
+				object_broadcast_collision(other, object);
+				object_broadcast_collision(object, other);
+				if(slide) {
+					_solve_collision_slide(object, other, old_x, old_y, new_x, new_y);
+				} else {
+					object->sprite.x = old_x;
+					object->sprite.y = old_y;
+					return;
+				}
+			}
+		}
+	}
+}

src/corelib/physics.h

@@ -0,0 +1,41 @@
+#ifndef _physics_h
+#define _physics_h
+
+#include "SDL2/SDL_rect.h"
+
+typedef struct object_t object_t;
+
+typedef void(*collided_fn)(object_t*, struct object_t*);
+
+typedef enum collider_type_t {
+	COLLIDERTYPE_MIN,
+	COLLIDERTYPE_NONE,
+	COLLIDERTYPE_CIRCLE,
+	COLLIDERTYPE_AABB,
+	COLLIDERTYPE_MAX,
+} collider_type_t;
+
+typedef struct collider_t {
+	collider_type_t type;
+	collided_fn evt_collision;
+	union {
+		struct {
+			float x, y;
+			float radius;
+		} circle;
+		SDL_FRect aabb;
+	};
+} collider_t;
+
+collider_t collider_default();
+
+void object_broadcast_evt_collision(object_t* this, object_t* other);
+
+void physics_update();
+
+void interpolate_move(object_t* object, float target_x, float target_y, float max_step_size, int slide);
+
+extern short can_collide(const object_t* this);
+extern float get_solve_force(const object_t* this, const object_t* other, float* solve_x, float* solve_y);
+
+#endif /* _physics_h */

src/corelib/render.c

@@ -253,6 +253,19 @@ void _exec_text_cmd(const drawcmd_t* cmd) {
 	free(cmd->text.text);
 }
 
+sprite_t sprite_default() {
+	return (sprite_t){
+		.texture = NULL,
+		.x = 0.f, .y = 0.f,
+		.origin = (SDL_FPoint){0.f, 0.f},
+		.sx = 1.f, .sy = 1.f,
+		.rot = 0.f,
+		.depth = RLAYER_SPRITES,
+		.uv = (SDL_Rect){0.f, 0.f, 0.f, 0.f},
+		.flip = SDL_FLIP_NONE,
+	};
+}
+
 sprite_t render_text(const char* str, SDL_FRect area, text_style_t style) {
 	SDL_FRect r = area;
 	int fh = TTF_FontHeight(style.font);

src/corelib/render.h

@@ -91,6 +91,8 @@ extern void screen_to_view(float* x, float* y);
 extern void clear_buffer();
 extern void swap_buffer();
 
+extern sprite_t sprite_default();
+
 extern sprite_t render_text(const char* str, SDL_FRect area, text_style_t style);
 extern void draw_sprite(const sprite_t* sprite);
 extern void draw_rect(const rectshape_t* rect);

src/corelib/world.c

@@ -10,10 +10,6 @@ void world_clear() {
 	}
 }
 
-void object_draw_sprite(object_t* object) {
-	draw_sprite(&object->sprite);
-}
-
 object_t* _find_free_object() {
 	for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
 		if(g_objects[i].active == 0) {
@@ -25,12 +21,7 @@ object_t* _find_free_object() {
 
 object_t* make_object() {
 	object_t* o = _find_free_object();
-	o->active = 1;
-	o->enabled = 1;
-	o->collider = collider_default();
-	o->evt_draw = &object_draw_sprite;
-	o->evt_update = NULL;
-	memset(&o->sprite, 0, sizeof(sprite_t));
+	*o = object_default();
 	return o;
 }
 
@@ -41,13 +32,7 @@ object_t* instantiate_object(const object_t *original) {
 	return obj;
 }
 
-collider_t collider_default() {
-	return (collider_t) {
-		.type=COLLIDERTYPE_NONE
-	};
-}
-
-void update_objects() {
+void world_update() {
 	for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
 		if(g_objects[i].active == 1
 		&& g_objects[i].enabled == 1
@@ -57,7 +42,7 @@ void update_objects() {
 	}
 }
 
-void draw_objects() {
+void world_draw() {
 	for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
 		if(g_objects[i].active == 1
 		&& g_objects[i].enabled == 1
@@ -66,280 +51,3 @@ void draw_objects() {
 		}
 	}
 }
-
-static inline
-int _rect_overlap(float aminx, float aminy, float amaxx, float amaxy, float bminx, float bminy, float bmaxx, float bmaxy) {
-	return
-	(
-		(aminx < bmaxx && aminx > bmaxx) 
-		||
-		(amaxx > bminx && amaxx < bmaxx)
-	) && (
-		(aminy < bmaxy && aminy > bmaxy)
-		||
-		(amaxy > bminy && amaxy < bmaxy)
-	);
-}
-
-static inline
-short _collision_aabb_aabb(const object_t* a, const object_t* b) {
-	const float aminx = a->collider.aabb.x + a->sprite.x, aminy = a->collider.aabb.y + a->sprite.x;
-	const float amaxx = aminx + a->collider.aabb.w, amaxy = aminy + a->collider.aabb.h;
-	const float bminx = b->collider.aabb.x, bminy = b->collider.aabb.y;
-	const float bmaxx = b->collider.aabb.x + b->collider.aabb.w, bmaxy = b->collider.aabb.y + b->collider.aabb.h;
-
-	return _rect_overlap(aminx, aminy, amaxx, amaxy, bminx, bminy, bmaxx, bmaxy);
-}
-
-static inline
-short _collision_circle_circle(const object_t* a, const object_t* b) {
-	const float ax = a->sprite.x + a->collider.circle.x, ay = a->sprite.y + a->collider.circle.y,
-		  		bx = b->sprite.x + b->collider.circle.x, by = b->sprite.y + b->collider.circle.y;
-	const float dx = fabsf(ax-bx), dy = fabsf(ay-by);
-	const float sqrdist = dx*dx+dy*dy;
-	const float mindist = a->collider.circle.radius + b->collider.circle.radius;
-	const float mindistsqr = mindist*mindist;
-	return sqrdist < mindistsqr;
-}
-
-static inline
-float fclampf(float x, float min_, float max_) {
-	return fminf(max_, fmaxf(min_, x));
-}
-
-static inline
-float _circle_aabb_overlap(const object_t* circle, const object_t* aabb, float* out_px, float* out_py) {
-	// generate a point on the edge of the rectangle that is closest to the circle
-	const float bbminx = aabb->collider.aabb.x + aabb->sprite.x, bbmaxx = bbminx + aabb->collider.aabb.w,
-	            bbminy = aabb->collider.aabb.y + aabb->sprite.y, bbmaxy = bbminy + aabb->collider.aabb.h;
-	// the centre of the circle in world space
-	const float cx = circle->sprite.x + circle->collider.circle.x,
-	            cy = circle->sprite.y + circle->collider.circle.y;
-	// the point on the rectangle closest to the centre of the circle
-	const float x = fclampf(cx, bbminx, bbmaxx),
-	            y = fclampf(cy, bbminy, bbmaxy);
-	// the relative position of the point on the rectangle 
-	const float dif_x = cx - x,
-	            dif_y = cy - y;
-	// absolute difference for use in calculating euclidean distance 
-	const float dist_x = fabsf(dif_x),
-	            dist_y = fabsf(dif_y);
-	// euclidean distance
-	const float dist = sqrt(dist_x*dist_x + dist_y*dist_y);
-	const float solve_distance = circle->collider.circle.radius - dist;
-	// distance to solve collision
-	float solve_x, solve_y;
-	normalize(dif_x, dif_y, &solve_x, &solve_y);
-	*out_px = solve_x * solve_distance;
-	*out_py = solve_y * solve_distance;
-	return solve_distance;
-}
-
-static inline
-float _circle_circle_overlap(const object_t* a, const object_t* b, float* out_px, float* out_py) {
-	const float x1 = a->collider.circle.x + a->sprite.x, y1 = a->collider.circle.y + a->sprite.y;
-	const float x2 = b->collider.circle.x + b->sprite.x, y2 = b->collider.circle.y + b->sprite.y;
-	const float dif_x = x1 - x2, dif_y = y1 - y2;
-	const float difference = sqrtf(fabsf(dif_x*dif_x) + fabsf(dif_y*dif_y));
-	const float target_difference = a->collider.circle.radius + b->collider.circle.radius;
-	float dir_x, dir_y;
-	normalize(dif_x, dif_y, &dir_x, &dir_y);
-	*out_px = dir_x * target_difference;
-	*out_py = dir_y * target_difference;
-	return target_difference;
-}
-
-static inline
-float _aabb_aabb_overlap(const object_t* a, const object_t* b, float* out_px, float* out_py) {
-	float right = (a->collider.aabb.x + a->collider.aabb.w + a->sprite.x) - (b->collider.aabb.x + b->sprite.x);
-	float left = (a->collider.aabb.x + a->sprite.x) - (b->collider.aabb.x + b->collider.aabb.w + b->sprite.x);
-	float top = (a->collider.aabb.y + a->sprite.y) - (b->collider.aabb.y + b->collider.aabb.w + b->sprite.y);
-	float bottom = (a->collider.aabb.y + a->collider.aabb.h) - (b->collider.aabb.y + b->sprite.y);
-
-	float ret = right;
-	*out_px = right;
-	*out_py = 0.f;
-	if(fabsf(left) < fabsf(ret)) {
-		*out_px = left;
-		*out_py = 0.f;
-		ret = left;
-	}
-	if(fabsf(top) < fabsf(ret)) {
-		*out_px = 0.f;
-		*out_py = top;
-		ret = top;
-	}
-
-	if(fabsf(bottom) < fabsf(ret)) {
-		*out_px = 0.f;
-		*out_py = bottom;
-		return bottom;
-	}
-
-	return ret;
-}
-
-static inline
-float _get_overlap(const object_t* a, const object_t* b, float* out_px, float* out_py) {
-	if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_AABB) {
-		return _aabb_aabb_overlap(a, b, out_px, out_py);
-	} else if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_CIRCLE) {
-		float penetration_distance = _circle_aabb_overlap(b, a, out_px, out_py);
-		*out_px = -(*out_px);
-		*out_py = -(*out_py);
-	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_AABB) {
-		return _circle_aabb_overlap(a, b, out_px, out_py);
-	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_CIRCLE) {
-		return _circle_circle_overlap(a, b, out_px, out_py);
-	}
-}
-
-static inline
-short _collision_circle_aabb(const object_t* circle, const object_t* aabb) {
-	// generate a point on the edge of the rectangle that is closest to the circle
-	const float bbminx = aabb->collider.aabb.x + aabb->sprite.x, bbmaxx = bbminx + aabb->collider.aabb.w,
-				bbminy = aabb->collider.aabb.y + aabb->sprite.y, bbmaxy = bbminy + aabb->collider.aabb.h;
-	const float cx = circle->sprite.x + circle->collider.circle.x,
-				cy = circle->sprite.y + circle->collider.circle.y;
-	const float x = fclampf(cx, bbminx, bbmaxx),
-				y = fclampf(cy, bbminy, bbmaxy);
-	const float dx = fabsf(cx - x), dy = fabsf(cy - y);
-
-	// calculate the square distance from the centre of the circle to the edge of the aabb
-	const float distsqr = dx*dx+dy*dy;
-	const float rsqr = circle->collider.circle.radius*circle->collider.circle.radius;
-
-	// return if the square distance is larger than the square of the radius
-	return distsqr < rsqr;
-}
-
-static inline
-short _collision_check(const object_t* a, const object_t* b) {
-	if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_AABB) {
-		return _collision_aabb_aabb(a, b);
-	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_CIRCLE) {
-		return _collision_circle_circle(a, b);
-	} else if(a->collider.type == COLLIDERTYPE_CIRCLE && b->collider.type == COLLIDERTYPE_AABB) {
-		return _collision_circle_aabb(a, b);
-	} else if(a->collider.type == COLLIDERTYPE_AABB && b->collider.type == COLLIDERTYPE_CIRCLE) {
-		return _collision_circle_aabb(b, a);
-	}
-	return 0;
-}
-
-static inline
-short _can_collide(const object_t* object) {
-	return object->active && object->enabled;
-}
-
-void object_broadcast_collision(object_t* this, object_t* other) {
-	if(this->collider.evt_collision != NULL) {
-		this->collider.evt_collision(this, other);
-	}
-}
-
-void update_collision() {
-	for(int outer = 0; outer < WORLD_NUM_OBJECTS; ++outer) {
-		object_t* oobject = g_objects + outer;
-		if(!_can_collide(oobject)) continue;
-		for(int inner = 0; inner < WORLD_NUM_OBJECTS; ++inner) {
-			object_t* iobject = g_objects + inner;
-			if(!_can_collide(oobject)) continue;
-
-			if(outer != inner && _collision_check(iobject, oobject)) {
-				object_broadcast_collision(oobject, iobject);
-				object_broadcast_collision(iobject, oobject);
-			}
-		}
-	}
-}
-
-static inline
-void _slide_collision(object_t* this, object_t* other, float old_x, float old_y, float new_x, float new_y) {
-	float dx, dy;
-	const float d = _get_overlap(this, other, &dx, &dy);
-	this->sprite.x += dx;
-	this->sprite.y += dy;
-	
-	return;
-	this->sprite.x = old_x;
-	this->sprite.y = new_y;
-	if(!_collision_check(other, this)) {
-		return;
-	}
-
-	this->sprite.x = new_x;
-	this->sprite.y = old_y;
-	if(!_collision_check(other, this)) {
-		return;
-	}
-
-	this->sprite.x = old_x;
-	this->sprite.y = old_y;
-	if(!_collision_check(other, this)) {
-		return;
-	}
-}
-
-void interpolate_move(object_t* object, const float target_x, const float target_y, const float max_step_size, const int slide) {
-	// calculate step delta
-	float dx = target_x - object->sprite.x, dy = target_y - object->sprite.y;
-	if(dx == 0 && dy == 0)
-		return;
-	// calculate direction x,y
-	float m = sqrtf(dx*dx + dy*dy);
-	if(dx != 0)
-		dx /= m;
-	if(dy != 0)
-		dy /= m;
-	dx *= max_step_size; dy *= max_step_size;
-	int step_count = max_step_size / m;
-
-	// ensure this object would ever collide
-	// if it wouldn't collide anyway, just set position
-	if(!_can_collide(object)) {
-		object->sprite.x = target_x;
-		object->sprite.y = target_y;
-		return;
-	}
-
-	/*
-	 * 1. move towards target
-	 * 2. check collision with every other object
-	 */
-	for(int steps = 0; steps < step_count && (object->sprite.x != target_x || object->sprite.y != target_y); ++steps) {
-		// move towards target, snap to target if distance is too low
-		const float old_x = object->sprite.x, old_y = object->sprite.y;
-		float new_x, new_y;
-
-		const float distx = fabsf(object->sprite.x - target_x), disty = fabsf(object->sprite.y - target_y);
-		const float sqdist = distx*distx + disty*disty;
-		if(sqdist > max_step_size) {
-			object->sprite.x += dx;
-			object->sprite.y += dy;
-			new_x = object->sprite.x;
-			new_y = object->sprite.y;
-		} else {
-			new_x = object->sprite.x = target_x;
-			new_y = object->sprite.y = target_y;
-		}
-
-		// loop over all objects and check collision if applicable
-		for(int i = 0; i < WORLD_NUM_OBJECTS; ++i) {
-			// get pointer to other object
-			object_t* other = g_objects + i;
-			// check collision, return if found
-			if(_can_collide(other) && object != other && _collision_check(other, object)) {
-				object_broadcast_collision(other, object);
-				object_broadcast_collision(object, other);
-				if(slide) {
-					_slide_collision(object, other, old_x, old_y, new_x, new_y);
-				} else {
-					object->sprite.x = old_x;
-					object->sprite.y = old_y;
-					return;
-				}
-			}
-		}
-	}
-}

src/corelib/world.h

@@ -1,67 +1,20 @@
 #ifndef _world_h
 #define _world_h
 
-#include "render.h"
-#include <stdint.h>
+#include "object.h"
 
 #define WORLD_NUM_OBJECTS 255
 
 typedef struct object_t object_t;
 
-typedef void(*tick_fn)(struct object_t*);
-typedef void(*draw_fn)(struct object_t*);
-typedef void(*collided_fn)(struct object_t*, struct object_t*);
-
-typedef enum collider_type_t {
-	COLLIDERTYPE_MIN,
-	COLLIDERTYPE_NONE,
-	COLLIDERTYPE_CIRCLE,
-	COLLIDERTYPE_AABB,
-	COLLIDERTYPE_MAX,
-} collider_type_t;
-
-typedef struct collider_t {
-	collider_type_t type;
-	collided_fn evt_collision;
-	union {
-		struct {
-			float x, y;
-			float radius;
-		} circle;
-		SDL_FRect aabb;
-	};
-} collider_t;
-
-struct object_t {
-	sprite_t sprite;
-	int active; // 1 if this object is in use and should not be overriden.
-	int enabled; // 1 if this object's events should be triggered.
-	collider_t collider; // the collider to use for this object's physics interaction.
-
-	uintptr_t timer; // free to use for whatever
-
-	tick_fn evt_update;
-	draw_fn evt_draw;
-};
-
 extern object_t g_objects[WORLD_NUM_OBJECTS];
 
-void world_clear();
-
-
 object_t* make_object();
 object_t* instantiate_object(const object_t* original);
 
-collider_t collider_default();
+void world_clear();
 
-void object_draw_sprite(object_t* object);
-void object_broadcast_evt_collision(object_t* this, object_t* other);
-
-void update_objects();
-void draw_objects();
-
-void update_collision();
-
-void interpolate_move(object_t* object, float target_x, float target_y, float max_step_size, int slide);
+void world_update();
+void world_draw();
 
 #endif /* _world_h */

src/engine.c

@@ -82,8 +82,8 @@ int _engine_run() {
 		update_ui();
 		_render_mode = 0;
 		update_game();
-		update_objects();	// update world objects
-		draw_objects();		// draw world objects
+		world_update();	// update world objects
+		world_draw();		// draw world objects
 		swap_buffer();
 		do {
 			timespec_get(&next_time, TIME_UTC);