#include "rect.h"

int rects_overlap(const Rect* a, const Rect* b) {
	return
		a->x + a->w > b->x &&
		a->y + a->h > b->y &&
		a->x < b->x + b->w &&
		a->y < b->y + b->h;
}

int point_rect_overlap(const Rect* r, int px, int py) {
	return
		px >= r->x &&
		py >= r->y &&
		px <= r->x + r->w &&
		py <= r->y + r->h;
}

Rect* rect_clip(Rect* r, const Rect* c) {
	int n;
	if ((n = c->x - r->x) > 0) {
		r->w -= n;
		r->x += n;
	}
	if ((n = c->y - r->y) > 0) {
		r->h -= n;
		r->y += n;
	}
	if ((n = r->x + r->w - (c->x + c->w)) > 0)
		r->w -= n;
	if ((n = r->y + r->h - (c->y + c->h)) > 0)
		r->h -= n;
	return r;
}

Rect* rect_clipr(Rect* r, const int* c) {
	int n;
	if ((n = c[0] - r->x) > 0) {
		r->w -= n;
		r->x += n;
	}
	if ((n = c[1] - r->y) > 0) {
		r->h -= n;
		r->y += n;
	}
	if ((n = r->x + r->w - c[2]) > 0)
		r->w -= n;
	if ((n = r->y + r->h - c[3]) > 0)
		r->h -= n;
	return r;
}

Rect* rect_clips(Rect* r, Rect* s, const Rect* c) {
	int n;
	if ((n = c->x - r->x) > 0) {
		r->w -= n;
		r->x += n;
		s->w -= n;
		s->x += n;
	}
	if ((n = c->y - r->y) > 0) {
		r->h -= n;
		r->y += n;
		s->h -= n;
		s->y += n;
	}
	if ((n = r->x + r->w - (c->x + c->w)) > 0) {
		r->w -= n;
		s->w -= n;
	}
	if ((n = r->y + r->h - (c->y + c->h)) > 0) {
		r->h -= n;
		s->h -= n;
	}
	return r;
}

Rect* rect_clipsr(Rect* r, Rect* s, const int* c) {
	int n;
	if ((n = c[0] - r->x) > 0) {
		r->w -= n;
		r->x += n;
		s->w -= n;
		s->x += n;
	}
	if ((n = c[1] - r->y) > 0) {
		r->h -= n;
		r->y += n;
		s->h -= n;
		s->y += n;
	}
	if ((n = r->x + r->w - c[2]) > 0) {
		r->w -= n;
		s->w -= n;
	}
	if ((n = r->y + r->h - c[3]) > 0) {
		r->h -= n;
		s->h -= n;
	}
	return r;
}