FACING.CPP (11316B)
1 // 2 // Copyright 2020 Electronic Arts Inc. 3 // 4 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is free 5 // software: you can redistribute it and/or modify it under the terms of 6 // the GNU General Public License as published by the Free Software Foundation, 7 // either version 3 of the License, or (at your option) any later version. 8 9 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed 10 // in the hope that it will be useful, but with permitted additional restrictions 11 // under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 12 // distributed with this program. You should have received a copy of the 13 // GNU General Public License along with permitted additional restrictions 14 // with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection 15 16 /* $Header: F:\projects\c&c\vcs\code\facing.cpv 1.9 16 Oct 1995 16:49:40 JOE_BOSTIC $ */ 17 /*********************************************************************************************** 18 *** 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 *** 19 *********************************************************************************************** 20 * * 21 * Project Name : Command & Conquer * 22 * * 23 * File Name : FACING.CPP * 24 * * 25 * Programmer : Joe L. Bostic * 26 * * 27 * Start Date : 03/21/95 * 28 * * 29 * Last Update : March 21, 1995 [JLB] * 30 * * 31 *---------------------------------------------------------------------------------------------* 32 * Functions: * 33 * FacingClass::Rotation_Adjust -- Perform a rotation adjustment to current facing. * 34 * FacingClass::Set_Current -- Sets the current rotation value. * 35 * FacingClass::Set_Desired -- Sets the desired facing value. * 36 * FacingClass::FacingClass -- Default constructor for the facing class. * 37 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 38 39 #include "function.h" 40 #include "facing.h" 41 42 43 /*********************************************************************************************** 44 * FacingClass::FacingClass -- Default constructor for the facing class. * 45 * * 46 * This default constructor merely sets the desired and current facing values to be the * 47 * same (North). * 48 * * 49 * INPUT: none * 50 * * 51 * OUTPUT: none * 52 * * 53 * WARNINGS: none * 54 * * 55 * HISTORY: * 56 * 03/21/1995 JLB : Created. * 57 *=============================================================================================*/ 58 FacingClass::FacingClass(void) 59 { 60 CurrentFacing = DIR_N; 61 DesiredFacing = DIR_N; 62 } 63 64 65 /*********************************************************************************************** 66 * FacingClass::Set_Desired -- Sets the desired facing value. * 67 * * 68 * This routine is used to set the desired facing value without altering the current * 69 * facing setting. Typicall use of this routine is when a vehicle needs to face a * 70 * direction, but currently isn't facing the correct direction. After this routine is * 71 * called, it is presumed that subsequent calls to Rotation_Adjust() will result in the * 72 * eventual alignment of the current facing. * 73 * * 74 * INPUT: facing -- The new facing to assign to the desired value. * 75 * * 76 * OUTPUT: bool; Did the desired facing value actually change by this routine call? * 77 * * 78 * WARNINGS: none * 79 * * 80 * HISTORY: * 81 * 03/21/1995 JLB : Created. * 82 *=============================================================================================*/ 83 int FacingClass::Set_Desired(DirType facing) 84 { 85 if (DesiredFacing != facing) { 86 DesiredFacing = facing; 87 return(true); 88 } 89 return(false); 90 } 91 92 93 /*********************************************************************************************** 94 * FacingClass::Set_Current -- Sets the current rotation value. * 95 * * 96 * This routine will set the current rotation value. It is used to override the facing * 97 * value without adjusting the desired setting. * 98 * * 99 * INPUT: facing -- The new facing to assign to the current facing value. * 100 * * 101 * OUTPUT: bool; Was the current setting changed by this routine. Failure means that the * 102 * current setting was already at the value specified. * 103 * * 104 * WARNINGS: none * 105 * * 106 * HISTORY: * 107 * 03/21/1995 JLB : Created. * 108 *=============================================================================================*/ 109 int FacingClass::Set_Current(DirType facing) 110 { 111 if (CurrentFacing != facing) { 112 CurrentFacing = facing; 113 return(true); 114 } 115 return(false); 116 } 117 118 119 /*********************************************************************************************** 120 * FacingClass::Rotation_Adjust -- Perform a rotation adjustment to current facing. * 121 * * 122 * This routine is used when the current and desired facings differ but the current * 123 * facing should be adjusted toward the desired facing. The amount of rotation to adjust * 124 * is provided as a rotation rate parameter. Typical use of this routine is for turrets * 125 * and other vehicle related rotating. * 126 * * 127 * INPUT: rate -- The rotation rate to use when adjusting the current facing toward the * 128 * desired facing. A value of 127 means instantaneous rotation. * 129 * * 130 * OUTPUT: bool; Did the rotation result in the current facing transitioning from one * 131 * 1/32 zone to another? If true, then the owning object most likely will * 132 * need to be redrawn to reflect the change. * 133 * * 134 * WARNINGS: none * 135 * * 136 * HISTORY: * 137 * 03/21/1995 JLB : Created. * 138 *=============================================================================================*/ 139 int FacingClass::Rotation_Adjust(int rate) 140 { 141 /* 142 ** Only perform the rotation adjustment if the desired facing is not the 143 ** same as the current facing. 144 */ 145 if (Is_Rotating()) { 146 rate = MIN(rate, 127); 147 148 DirType oldfacing = CurrentFacing; 149 int diff = Difference(); 150 151 /* 152 ** If the allowed facing change is greater than the difference between 153 ** the current facing and the desired facing, then just snap the 154 ** facing to the new value. 155 */ 156 if (ABS(diff) < rate) { 157 CurrentFacing = DesiredFacing; 158 } else { 159 160 /* 161 ** Adjust the current facing clockwise or counterclockwise depending 162 ** on the shortest distance to the desired facing from the current 163 ** facing. 164 */ 165 if (diff < 0) { 166 CurrentFacing = (DirType)(CurrentFacing - (DirType)rate); 167 } else { 168 CurrentFacing = (DirType)(CurrentFacing + (DirType)rate); 169 } 170 } 171 172 /* 173 ** If this facing adjustment caused the current facing to rotate into a 174 ** new 1/32 rotation zone (likely to cause a redraw), then return 175 ** this fact with a true value. 176 */ 177 return(Facing_To_32(CurrentFacing) != Facing_To_32(oldfacing)); 178 } 179 return(false); 180 }