// // 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 /*;*************************************************************************** ;** C O N F I D E N T I A L --- W E S T W O O D A S S O C I A T E S ** ;*************************************************************************** ;* * ;* Project Name : Support Library * ;* * ;* File Name : FACINGFF.ASM * ;* * ;* Programmer : Joe L. Bostic * ;* * ;* Start Date : May 8, 1991 * ;* * ;* Last Update : February 6, 1995 [BWG] * ;* * ;*-------------------------------------------------------------------------* ;* Functions: * ;* Desired_Facing256 -- Determines facing to reach a position. * ;* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * */ #ifndef FACINGFF_H #define FACINGFF_H //IDEAL //P386 //MODEL USE32 FLAT //GLOBAL C Desired_Facing256 :NEAR //; INCLUDE "wwlib.i" //INCLUDE "..\include\gbuffer.inc" // CODESEG /* ;*************************************************************************** ;* Desired_Facing256 -- Desired facing algorithm 0..255 resolution. * ;* * ;* This is a desired facing algorithm that has a resolution of 0 * ;* through 255. * ;* * ;* INPUT: srcx,srcy -- Source coordinate. * ;* * ;* dstx,dsty -- Destination coordinate. * ;* * ;* OUTPUT: Returns with the desired facing to face the destination * ;* coordinate from the position of the source coordinate. North * ;* is 0, East is 64, etc. * ;* * ;* WARNINGS: This routine is slower than the other forms of desired * ;* facing calculation. Use this routine when accuracy is * ;* required. * ;* * ;* HISTORY: * ;* 12/24/1991 JLB : Adapted. * ;*=========================================================================*/ int __cdecl Desired_Facing256(LONG srcx, LONG srcy, LONG dstx, LONG dsty); #if (0) PROC Desired_Facing256 C near USES ebx, ecx, edx ARG srcx:DWORD ARG srcy:DWORD ARG dstx:DWORD ARG dsty:DWORD xor ebx,ebx ; Facing number. ; Determine absolute X delta and left/right direction. mov ecx,[dstx] sub ecx,[srcx] jge short ??xnotneg neg ecx mov ebx,11000000b ; Set bit 7 and 6 for leftward. ??xnotneg: ; Determine absolute Y delta and top/bottom direction. mov eax,[srcy] sub eax,[dsty] jge short ??ynotneg xor ebx,01000000b ; Complement bit 6 for downward. neg eax ??ynotneg: ; Set DX=64 for quadrants 0 and 2. mov edx,ebx and edx,01000000b xor edx,01000000b ; Determine if the direction is closer to the Y axis and make sure that ; CX holds the larger of the two deltas. This is in preparation for the ; divide. cmp eax,ecx jb short ??gotaxis xchg eax,ecx xor edx,01000000b ; Closer to Y axis so make DX=64 for quad 0 and 2. ??gotaxis: ; If closer to the X axis then add 64 for quadrants 0 and 2. If ; closer to the Y axis then add 64 for quadrants 1 and 3. Determined ; add value is in DX and save on stack. push edx ; Make sure that the division won't overflow. Reduce precision until ; the larger number is less than 256 if it appears that an overflow ; will occur. If the high byte of the divisor is not zero, then this ; guarantees no overflow, so just abort shift operation. test eax,0FFFFFF00h jnz short ??nooverflow ??again: test ecx,0FFFFFF00h jz short ??nooverflow shr ecx,1 shr eax,1 jmp short ??again ??nooverflow: ; Make sure that the division won't underflow (divide by zero). If ; this would occur, then set the quotient to $FF and skip divide. or ecx,ecx jnz short ??nounderflow mov eax,0FFFFFFFFh jmp short ??divcomplete ; Derive a pseudo angle number for the octant. The angle is based ; on $00 = angle matches long axis, $00 = angle matches $FF degrees. ??nounderflow: xor edx,edx shld edx,eax,8 ; shift high byte of eax into dl shl eax,8 div ecx ??divcomplete: ; Integrate the 5 most significant bits into the angle index. If DX ; is not zero, then it is 64. This means that the dividend must be negated ; before it is added into the final angle value. shr eax,3 pop edx or edx,edx je short ??noneg dec edx neg eax ??noneg: add eax,edx add eax,ebx and eax,0FFH ret ENDP Desired_Facing256 END #endif /* ;*************************************************************************** ;** C O N F I D E N T I A L --- W E S T W O O D A S S O C I A T E S ** ;*************************************************************************** ;* * ;* Project Name : Support Library * ;* * ;* File Name : FACING8.ASM * ;* * ;* Programmer : Joe L. Bostic * ;* * ;* Start Date : May 8, 1991 * ;* * ;* Last Update : February 6, 1995 [BWG] * ;* * ;*-------------------------------------------------------------------------* ;* Functions: * ;* Desired_Facing8 -- Determines facing to reach a position. * ;* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * IDEAL P386 MODEL USE32 FLAT GLOBAL C Desired_Facing8 :NEAR ; INCLUDE "wwlib.i" DATASEG ; 8 direction desired facing lookup table. Build the index according ; to the following bits: ; ; bit 3 = Is y2 < y1? ; bit 2 = Is x2 < x1? ; bit 1 = Is the ABS(x2-x1) < ABS(y2-y1)? ; bit 0 = Is the facing closer to a major axis? //NewFacing8 DB 1,2,1,0,7,6,7,0,3,2,3,4,5,6,5,4 // CODESEG */ /* ;*************************************************************************** ;* DESIRED_FACING8 -- Determines facing to reach a position. * ;* * ;* This routine will return with the most desirable facing to reach * ;* one position from another. It is accurate to a resolution of 0 to * ;* 7. * ;* * ;* INPUT: x1,y1 -- Position of origin point. * ;* * ;* x2,y2 -- Position of target. * ;* * ;* OUTPUT: Returns desired facing as a number from 0..255 with an * ;* accuracy of 32 degree increments. * ;* * ;* WARNINGS: If the two coordinates are the same, then -1 will be * ;* returned. It is up to you to handle this case. * ;* * ;* HISTORY: * ;* 07/15/1991 JLB : Documented. * ;* 08/08/1991 JLB : Same position check. * ;* 08/14/1991 JLB : New algorithm * ;* 02/06/1995 BWG : Convert to 32-bit * ;*=========================================================================* */ int __cdecl Desired_Facing8(long x1, long y1, long x2, long y2); #if (0) PROC Desired_Facing8 C near USES ebx, ecx, edx ARG x1:DWORD ARG y1:DWORD ARG x2:DWORD ARG y2:DWORD xor ebx,ebx ; Index byte (built). ; Determine Y axis difference. mov edx,[y1] mov ecx,[y2] sub edx,ecx ; DX = Y axis (signed). jns short ??absy inc ebx ; Set the signed bit. neg edx ; ABS(y) ??absy: ; Determine X axis difference. shl ebx,1 mov eax,[x1] mov ecx,[x2] sub ecx,eax ; CX = X axis (signed). jns short ??absx inc ebx ; Set the signed bit. neg ecx ; ABS(x) ??absx: ; Determine the greater axis. cmp ecx,edx jb short ??dxisbig xchg ecx,edx ??dxisbig: rcl ebx,1 ; Y > X flag bit. ; Determine the closeness or farness of lesser axis. mov eax,edx inc eax ; Round up. shr eax,1 cmp ecx,eax rcl ebx,1 ; Close to major axis bit. xor eax,eax mov al,[NewFacing8+ebx] ; Normalize to 0..FF range. shl eax,5 ret ENDP Desired_Facing8 END #endif /* ; $Header: //depot/Projects/Mobius/QA/Project/Run/SOURCECODE/TIBERIANDAWN/WIN32LIB/FACINGFF.h#131 $ ;*************************************************************************** ;** C O N F I D E N T I A L --- W E S T W O O D A S S O C I A T E S ** ;*************************************************************************** ;* * ;* Project Name : Support Library * ;* * ;* File Name : FACING16.ASM * ;* * ;* Programmer : Joe L. Bostic * ;* * ;* Start Date : May 8, 1991 * ;* * ;* Last Update : February 6, 1995 [BWG] * ;* * ;*-------------------------------------------------------------------------* ;* Functions: * ;* Desired_Facing16 -- Converts coordinates into a facing number. * ;* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * IDEAL P386 MODEL USE32 FLAT GLOBAL C Desired_Facing16 :NEAR ; INCLUDE "wwlib.i" DATASEG ; 16 direction desired facing lookup table. Build the index according ; to the following bits: ; ; bit 4 = Is y2 < y1? ; bit 3 = Is x2 < x1? ; bit 2 = Is the ABS(x2-x1) < ABS(y2-y1)? ; bit 1 = Is the lesser absolute difference very close to zero? ; bit 0 = Is the lesser absolute difference very close to the greater dist? NewFacing16 DB 3, 2, 4,-1, 1, 2,0,-1 DB 13,14,12,-1,15,14,0,-1 DB 5, 6, 4,-1, 7, 6,8,-1 DB 11,10,12,-1, 9,10,8,-1 CODESEG ;*************************************************************************** ;* DESIRED_FACING16 -- Converts coordinates into a facing number. * ;* * ;* This converts coordinates into a desired facing number that ranges * ;* from 0 to 15 (0 equals North and going clockwise). * ;* * ;* INPUT: x1,y1 -- Position of origin point. * ;* * ;* x2,y2 -- Position of target. * ;* * ;* OUTPUT: Returns desired facing as a number from 0 to 255 but * ;* accurate to 22.5 degree increments. * ;* * ;* WARNINGS: If the two coordinates are the same, then -1 will be * ;* returned. It is up to you to handle this case. * ;* * ;* HISTORY: * ;* 08/14/1991 JLB : Created. * ;*=========================================================================* */ long __cdecl Desired_Facing16(long x1, long y1, long x2, long y2); #if (0) PROC Desired_Facing16 C near USES ebx, ecx, edx ARG x1:DWORD ARG y1:DWORD ARG x2:DWORD ARG y2:DWORD xor ebx,ebx ; Index byte (built). ; Determine Y axis difference. mov edx,[y1] mov ecx,[y2] sub edx,ecx ; DX = Y axis (signed). jns short ??absy inc ebx ; Set the signed bit. neg edx ; ABS(y) ??absy: ; Determine X axis difference. shl ebx,1 mov eax,[x1] mov ecx,[x2] sub ecx,eax ; CX = X axis (signed). jns short ??absx inc ebx ; Set the signed bit. neg ecx ; ABS(x) ??absx: ; Determine the greater axis. cmp ecx,edx jb short ??dxisbig xchg ecx,edx ??dxisbig: rcl ebx,1 ; Y > X flag bit. ; Determine the closeness or farness of lesser axis. mov eax,edx inc eax ; Round up. shr eax,1 inc eax ; Round up. shr eax,1 ; 1/4 of greater axis. cmp ecx,eax rcl ebx,1 ; Very close to major axis bit. sub edx,eax cmp edx,ecx rcl ebx,1 ; Very far from major axis bit. xor eax,eax mov al,[NewFacing16+ebx] ; Normalize to 0..FF range. shl eax,4 ret ENDP Desired_Facing16 END #endif #endif FACINGFF_H