Function RotateAndScaleObjects

roomedit/source/objects.cpp:1656–1761

*/

void RotateAndScaleObjects (int objtype, SelPtr obj, double angle, double scale)
{
	SHORT  n, m;
	SHORT  dx, dy;
	SHORT  centerx, centery;
	LONG   accx, accy, num;
	SelPtr cur, vertices;

	if (obj == NULL)
		return;

	switch (objtype)
	{
	case OBJ_THINGS:
		accx = 0L;
		accy = 0L;
		num = 0L;
		for (cur = obj; cur; cur = cur->next)
		{
			assert_tnum(cur->objnum);
			Thing *pThing = &Things[cur->objnum];

			accx += (LONG) pThing->xpos;
			accy += (LONG) pThing->ypos;
			num++;
		}
		centerx = (SHORT) ((accx + num / 2L) / num);
		centery = (SHORT) ((accy + num / 2L) / num);

		for (cur = obj; cur; cur = cur->next)
		{
			assert_tnum(cur->objnum);
			Thing *pThing = &Things[cur->objnum];

			dx = pThing->xpos - centerx;
			dy = pThing->ypos - centery;
			RotateAndScaleCoords (&dx, &dy, angle, scale);
			pThing->xpos = centerx + dx;
			pThing->ypos = centery + dy;
		}
		MadeChanges = TRUE;
		break;

	  case OBJ_VERTEXES:
		accx = 0L;
		accy = 0L;
		num = 0L;
		for (cur = obj; cur; cur = cur->next)
		{
			accx += (LONG) Vertexes[ cur->objnum].x;
			accy += (LONG) Vertexes[ cur->objnum].y;
			num++;
		}
		centerx = (SHORT) ((accx + num / 2L) / num);
		centery = (SHORT) ((accy + num / 2L) / num);

		for (cur = obj; cur; cur = cur->next)
		{