CnC_Remastered_Collection/TIBERIANDAWN/FACING.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: F:\projects\c&c\vcs\code\facing.cpv 1.9 16 Oct 1995 16:49:40 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 : FACING.CPP *
* *
* Programmer : Joe L. Bostic *
* *
* Start Date : 03/21/95 *
* *
* Last Update : March 21, 1995 [JLB] *
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* FacingClass::Rotation_Adjust -- Perform a rotation adjustment to current facing. *
* FacingClass::Set_Current -- Sets the current rotation value. *
* FacingClass::Set_Desired -- Sets the desired facing value. *
* FacingClass::FacingClass -- Default constructor for the facing class. *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#include "function.h"
#include "facing.h"
/***********************************************************************************************
* FacingClass::FacingClass -- Default constructor for the facing class. *
* *
* This default constructor merely sets the desired and current facing values to be the *
* same (North). *
* *
* INPUT: none *
* *
* OUTPUT: none *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 03/21/1995 JLB : Created. *
*=============================================================================================*/
FacingClass::FacingClass(void)
{
CurrentFacing = DIR_N;
DesiredFacing = DIR_N;
}
/***********************************************************************************************
* FacingClass::Set_Desired -- Sets the desired facing value. *
* *
* This routine is used to set the desired facing value without altering the current *
* facing setting. Typicall use of this routine is when a vehicle needs to face a *
* direction, but currently isn't facing the correct direction. After this routine is *
* called, it is presumed that subsequent calls to Rotation_Adjust() will result in the *
* eventual alignment of the current facing. *
* *
* INPUT: facing -- The new facing to assign to the desired value. *
* *
* OUTPUT: bool; Did the desired facing value actually change by this routine call? *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 03/21/1995 JLB : Created. *
*=============================================================================================*/
int FacingClass::Set_Desired(DirType facing)
{
if (DesiredFacing != facing) {
DesiredFacing = facing;
return(true);
}
return(false);
}
/***********************************************************************************************
* FacingClass::Set_Current -- Sets the current rotation value. *
* *
* This routine will set the current rotation value. It is used to override the facing *
* value without adjusting the desired setting. *
* *
* INPUT: facing -- The new facing to assign to the current facing value. *
* *
* OUTPUT: bool; Was the current setting changed by this routine. Failure means that the *
* current setting was already at the value specified. *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 03/21/1995 JLB : Created. *
*=============================================================================================*/
int FacingClass::Set_Current(DirType facing)
{
if (CurrentFacing != facing) {
CurrentFacing = facing;
return(true);
}
return(false);
}
/***********************************************************************************************
* FacingClass::Rotation_Adjust -- Perform a rotation adjustment to current facing. *
* *
* This routine is used when the current and desired facings differ but the current *
* facing should be adjusted toward the desired facing. The amount of rotation to adjust *
* is provided as a rotation rate parameter. Typical use of this routine is for turrets *
* and other vehicle related rotating. *
* *
* INPUT: rate -- The rotation rate to use when adjusting the current facing toward the *
* desired facing. A value of 127 means instantaneous rotation. *
* *
* OUTPUT: bool; Did the rotation result in the current facing transitioning from one *
* 1/32 zone to another? If true, then the owning object most likely will *
* need to be redrawn to reflect the change. *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 03/21/1995 JLB : Created. *
*=============================================================================================*/
int FacingClass::Rotation_Adjust(int rate)
{
/*
** Only perform the rotation adjustment if the desired facing is not the
** same as the current facing.
*/
if (Is_Rotating()) {
rate = MIN(rate, 127);
DirType oldfacing = CurrentFacing;
int diff = Difference();
/*
** If the allowed facing change is greater than the difference between
** the current facing and the desired facing, then just snap the
** facing to the new value.
*/
if (ABS(diff) < rate) {
CurrentFacing = DesiredFacing;
} else {
/*
** Adjust the current facing clockwise or counterclockwise depending
** on the shortest distance to the desired facing from the current
** facing.
*/
if (diff < 0) {
CurrentFacing = (DirType)(CurrentFacing - (DirType)rate);
} else {
CurrentFacing = (DirType)(CurrentFacing + (DirType)rate);
}
}
/*
** If this facing adjustment caused the current facing to rotate into a
** new 1/32 rotation zone (likely to cause a redraw), then return
** this fact with a true value.
*/
return(Facing_To_32(CurrentFacing) != Facing_To_32(oldfacing));
}
return(false);
}