i don't even know

1 files changed, 95 insertions, 0 deletions

diff --git a/phys.h b/phys.h
new file mode 100644
index 0000000..d7b3a76
--- /dev/null
+++ b/phys.h
@@ -0,0 +1,95 @@
+i32 add_entity(entity_t entity, elist_t *list)
+{
+	assert(list);
+	i32 i;
+	for (i = 0; i < MAX_ENTITIES; ++i)
+		if (!list->nodes[i].id)
+			break;
+	if (i == MAX_ENTITIES) {
+		printf("error: failed to add entity\n");
+		return 0;
+	}
+	++list->count;
+	enode_t *node = list->nodes+i;
+	node->id = list->count;
+	node->entity = entity;
+	dllpushback(list->first, list->last, node);
+	return node->id;
+}
+
+void delete_entity(i32 id, elist_t *list)
+{
+	assert(list);
+	for (enode_t *node = list->first; node; node = node->next) {
+		if (node->id == id) {
+			dllremove(list->first, list->last, node);
+			memzero_struct(node);
+			list->count--;
+			printf("info: entity %d deleted\n", id);
+			return;
+		}
+	}
+	printf("error: entity %d failed to delete\n", id);
+}
+
+entity_t *get_entity(elist_t list, i32 id)
+{
+	for (enode_t *node = list.first; node; node = node->next)
+		if (node->id == id)
+			return &node->entity;
+	return 0;
+}
+
+i32 aabb3d(bbox_t a, bbox_t b)
+{
+	i32 result = ((b.start.x <= a.end.x) && (b.end.x >= a.start.x)) &&
+		((b.start.y <= a.end.y) && (b.end.y >= a.start.y)) &&
+		((b.start.z <= a.end.z) && (b.end.z >= a.start.z));
+	return result;
+}
+
+i32 check_collision(entity_t *a, entity_t *b)
+{
+	if (!(a->flags & ENTITY_COLLIDE) || !(b->flags & ENTITY_COLLIDE))
+		return 0;
+
+	bbox_t bboxa = {
+		v3_add(a->bbox.start, a->position),
+		v3_add(a->bbox.end, a->position)
+	};
+
+	bbox_t bboxb = {
+		v3_add(b->bbox.start, b->position),
+		v3_add(b->bbox.end, b->position)
+	};
+
+	i32 result = aabb3d(bboxa, bboxb);
+
+	return result;
+}
+
+entity_t move_entity(entity_t old, v3 acceleration, float dt)
+{
+	entity_t new = old;
+	new.position = v3_add(old.position, v3_scalef(old.velocity, dt));
+	new.velocity = v3_add(old.velocity, v3_scalef(acceleration, dt*dt));
+	new.velocity = v3_sub(new.velocity, v3_scalef(V3_UP, dt));
+	return new;
+}
+
+/*
+void update_entities(elist_t list)
+{
+	for (enode_t *node = list.first; node; node = node->next) {
+		if (node->entity.flags & ENTITY_MOVE)
+			move_entity(node->entity, );
+		if (node->entity.flags & ENTITY_COLLIDE) {
+			for (enode_t *test = list.first; test; test = test->next) {
+				if (check_collision(node->entity, test->entity)) {
+
+				}
+			}
+		}
+	}
+}
+*/