CnC_Remastered_Collection/REDALERT/RECT.CPP

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//
// Copyright 2020 Electronic Arts Inc.
//
// TiberianDawn.DLL and RedAlert.dll and corresponding source code is free
// software: you can redistribute it and/or modify it under the terms of
// the GNU General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
// TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed
// in the hope that it will be useful, but with permitted additional restrictions
// under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT
// distributed with this program. You should have received a copy of the
// GNU General Public License along with permitted additional restrictions
// with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection
/* $Header: /CounterStrike/RECT.CPP 1 3/03/97 10:25a Joe_bostic $ */
/***********************************************************************************************
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
***********************************************************************************************
* *
* Project Name : Command & Conquer *
* *
* File Name : RECT.CPP *
* *
* Programmer : Joe L. Bostic *
* *
* Start Date : 07/22/96 *
* *
* Last Update : July 22, 1996 [JLB] *
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* Rect::Rect -- Constructs a rectangle object. *
* Rect::Is_Valid -- Determines if the rectangle is valid. *
* Rect::Intersect -- Find the intersection between two rectangles. *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#include "rect.h"
/***********************************************************************************************
* Rect::Rect -- Constructs a rectangle object. *
* *
* This will construct a rectangle object according to the parameters specified. *
* *
* INPUT: x,y -- The X and Y values of the upper left corner of the rectangle. *
* *
* w,h -- The width and height values of the rectangle. *
* *
* OUTPUT: none *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 07/22/1996 JLB : Created. *
*=============================================================================================*/
Rect::Rect(int x, int y, int w, int h) :
X(x),
Y(y),
Width(w),
Height(h)
{
}
/***********************************************************************************************
* Rect::Is_Valid -- Determines if the rectangle is valid. *
* *
* An invalid rectangle has values that do not make any sense. This is a useful state since *
* this can be used to determine if a rectangle has been initialized correctly or for *
* detecting an error return condition for rectangle manipulation routines. *
* *
* INPUT: none *
* *
* OUTPUT: bool; Does this rectangle appear valid? *
* *
* WARNINGS: An invalid rectangle is one that has a width or height of less than one. *
* *
* HISTORY: *
* 07/22/1996 JLB : Created. *
*=============================================================================================*/
bool Rect::Is_Valid(void) const
{
return(Width > 0 && Height > 0);
}
/***********************************************************************************************
* Rect::Intersect -- Find the intersection between two rectangles. *
* *
* This routine will take the specified rectangle and use it like a "cookie cutter" on this *
* rectangle. The intersection of these two rectangles is returned. An optional X and *
* Y parameter is supplied so that an absolute coordinate can be maintained to the new *
* rectangle. *
* *
* INPUT: rectangle -- Reference to the rectangle to use as a cookie cutter. *
* *
* x,y -- Optional pointer to a coordinate that will be adjusted to stay *
* in an absolute position in coordinates even though it is a *
* relative offset. *
* *
* OUTPUT: Returns with the rectangle that is the intersection of the one specified and *
* this rectangle. *
* *
* WARNINGS: The rectangle returned may be invalid. This can occur if there is no legal *
* intersection between the rectangles. *
* *
* HISTORY: *
* 07/22/1996 JLB : Created. *
*=============================================================================================*/
Rect const Rect::Intersect(Rect const & rectangle, int * x, int * y) const
{
Rect rect(0, 0, 0, 0); // Dummy (illegal) rectangle.
Rect r = rectangle; // Working rectangle.
/*
** Both rectangles must be valid or else no intersection can occur. In such
** a case, return an illegal rectangle.
*/
if (!Is_Valid() || !rectangle.Is_Valid()) return(rect);
/*
** The rectangle spills past the left edge.
*/
if (r.X < X) {
r.Width -= X - r.X;
r.X = X;
}
if (r.Width < 1) return(rect);
/*
** The rectangle spills past top edge.
*/
if (r.Y < Y) {
r.Height -= Y - r.Y;
r.Y = Y;
}
if (r.Height < 1) return(rect);
/*
** The rectangle spills past the right edge.
*/
if (r.X + r.Width > X + Width) {
r.Width -= (r.X + r.Width) - (X + Width);
}
if (r.Width < 1) return(rect);
/*
** The rectangle spills past the bottom edge.
*/
if (r.Y + r.Height > Y + Height) {
r.Height -= (r.Y + r.Height) - (Y + Height);
}
if (r.Height < 1) return(rect);
/*
** Adjust Height relative draw position according to Height new rectangle
** union.
*/
if (x != NULL) {
*x -= (r.X-X);
}
if (y != NULL) {
*y -= (r.Y-Y);
}
return(r);
}
Rect const Union(Rect const & rect1, Rect const & rect2)
{
if (rect1.Is_Valid()) {
if (rect2.Is_Valid()) {
Rect result = rect1;
if (result.X > rect2.X) {
result.Width += result.X-rect2.X;
result.X = rect2.X;
}
if (result.Y > rect2.Y) {
result.Height += result.Y-rect2.Y;
result.Y = rect2.Y;
}
if (result.X+result.Width < rect2.X+rect2.Width) {
result.Width = ((rect2.X+rect2.Width)-result.X)+1;
}
if (result.Y+result.Height < rect2.Y+rect2.Height) {
result.Height = ((rect2.Y+rect2.Height)-result.Y)+1;
}
return(result);
}
return(rect1);
}
return(rect2);
}