; ; Command & Conquer Red Alert(tm) ; Copyright 2025 Electronic Arts Inc. ; ; This program 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. ; ; This program is distributed in the hope that it will be useful, ; but WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ; GNU General Public License for more details. ; ; You should have received a copy of the GNU General Public License ; along with this program. If not, see <http://www.gnu.org/licenses/>. ; ;*************************************************************************** ;** 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 : Draw Shape Routines for library. * ;* * ;* File Name : DS_DN.ASM * ;* * ;* Programmer : Scott K. Bowen * ;* * ;* Start Date : August 24, 1993 * ;* * ;* Last Update : September 6, 1994 [IML] * ;* * ;*-------------------------------------------------------------------------* ;* Functions: * ;* Draw_Normal -- Draws a normal row of pixels to the viewport * ;* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * IDEAL P386 MODEL USE32 FLAT ;******************************** Includes ********************************* INCLUDE "shape.inc" ;********************************* Code ************************************ CODESEG ;*************************************************************************** ;* Draw_Normal -- Draws a normal row of pixels to the viewport * ;* * ;* INPUT: * ;* ECX = number of pixels (not bytes) to draw * ;* EDX = XTotal initializer value * ;* ESI = shape (source) buffer address * ;* EDI = viewport (destination) address * ;* [WidthCount] = remaining bytes on the line * ;* * ;* OUTPUT: * ;* ESI - updated to current location in the shape data * ;* EDI - incr/decr by # pixels (not bytes) drawn/skipped * ;* [WidthCount] - bytes remaining on the line * ;* * ;* WARNINGS: none * ;* * ;* HISTORY: * ;* 04/14/1992 PWG : Created. * ;* 08/19/1993 SKB : Split drawshp.asm into several modules. * ;* 06/02/1994 BR : Converted to 32-bit. * ;* 08/09/1994 IML : Optimized for 32-bit. * ;* 09/06/1994 IML : Integrated p_* and ds_* routines. * ;*=========================================================================* PROC Draw_Normal NOLANGUAGE NEAR mov [StashEDX],edx ; save edx mov edx,[Flags] mov eax,0 ; init to zero sub [WidthCount],ecx ; decrement bytes remaining by pixels ; to draw ;-------------------------------------------------------------------- ; Drawing Loop: ; - Get a data byte ; - If it's a 0, handle the run: ; - get repetition value ; - add it to EDI ; - subtract it from [WidthCount] ; - subtract it from ECX ; - if ECX>0, draw again, else exit ; - Otherwise: ; - draw the pixel ; - increment EDI to next pixel location ; - decrement [WidthCount] ; - loop until ECX is 0 ;-------------------------------------------------------------------- test edx,SHAPE_EFFECTS ; are any effects flags set? jnz short ??general_draw_continue ; if so use the general purpose loop ;-------------------------------------------------------------------- ; Extra fast draw loop for shapes with no flags set. ;-------------------------------------------------------------------- ??fast_draw_loop: mov al,[esi] ; get a byte of the source inc esi or eax,eax ; is the byte a transparent run? jz short ??fast_is_run ; if yes then handle the run mov [edi],al ; store color value to viewport inc edi ; point to next viewport pixel dec ecx ; any source pixels left? jnz short ??fast_draw_loop ; if not then go home jmp ??out ??fast_is_run: mov al,[esi] inc esi add edi,eax ; move the viewport pointer sub ecx,eax ; chop down the width to do jg short ??fast_draw_loop ; while more to do, loop back up jmp ??out ;-------------------------------------------------------------------- ; General purpose draw loop for shapes with one or more flags set. ;-------------------------------------------------------------------- ??general_draw_loop: test edx,SHAPE_FADING ; if fading is enabled test for jz short ??no_fading_draw_loop ; transparency or eax,eax jz short ??is_transparent ??no_fading_draw_loop: mov [edi],al ; store color value to viewport ??is_transparent: inc edi ; point to next viewport pixel dec ecx ; any source pixels left? jz ??out ; if not then go home ??general_draw_continue: mov al,[esi] ; get a byte of the source inc esi or eax,eax ; is the byte a transparent run? jz ??general_is_run ; if yes then handle the run ??test_priority: test edx,SHAPE_PRIORITY jnz short ??priority ??test_predator: test edx,SHAPE_PREDATOR jnz short ??predator ??test_compact: test edx,SHAPE_COMPACT jnz ??compact ??test_shadow: test edx,SHAPE_SHADOW jnz ??shadow ??test_translucency: test edx,SHAPE_GHOST jz short ??test_fading mov ebx,[IsTranslucent] ; is it a translucent color? mov bh,[BYTE PTR ebx + eax] or bh,bh js short ??test_fading and ebx,0FF00h ; clear all of ebx except bh ; we have the index to the translation table ; ((trans_colour * 256) + dest colour) mov al,[edi] ; mov pixel at destination to al add ebx,[Translucent] ; get the ptr to it! ; Add the (trans_color * 256) of the translation equ. mov al,[BYTE PTR ebx + eax] ; get new pixel in al jmp short ??test_fading ??test_fading: test edx,SHAPE_FADING jnz ??fading jmp short ??general_draw_loop ??priority: mov ebx,[MaskAdjust] ; get mask page offset mov bl,[BYTE PTR ebx + edi] ; get mask value and bl,CLEAR_UNUSED_BITS ; clear unused bits cmp [PriLevel],bl ; are we in front of jge short ??test_predator ; background? mov ebx,[BackAdjust] ; get background page offset mov al,[BYTE PTR ebx + edi] ; get background pixel jmp ??general_draw_loop ??predator: mov ebx,[PartialCount] add ebx,[PartialPred] or bh,bh jnz short ??draw_pred ; is this a predator pixel? mov [PartialCount],ebx jmp short ??test_compact ??draw_pred: xor bh,bh mov [PartialCount],ebx mov ebx,[PredValue] ; pick up a color offset a pseudo- ; random amount from the current mov al,[edi + ebx] ; viewport address jmp ??general_draw_loop ??compact: mov ebx,[ColorTable] ; get the address of the color table mov al,[BYTE PTR ebx + eax] ; convert it into the proper byte jmp ??test_shadow ??shadow: cmp al,SHADOW_COL jne ??test_translucency ; is the table value a magic number? mov al,[edi] ; get the destination color and mov ebx,[ShadowingTable] ; index into the shadow table mov al,[BYTE PTR ebx + eax] jmp ??general_draw_loop ??fading: mov [StashECX],ecx ; preserve ecx for later mov ebx,[FadingTable] ; run color through fading table mov ecx,[FadingNum] ??fade_loop: mov al, [BYTE PTR ebx + eax] dec ecx jnz short ??fade_loop mov ecx,[StashECX] ; restore ecx for main draw loop jmp ??general_draw_loop ??general_is_run: mov al,[esi] inc esi add edi,eax ; move the viewport pointer sub ecx,eax ; chop down the width to do jg ??general_draw_continue ; while more to do, loop back up ??out: add [WidthCount],ecx ; adjust for source ending in a run mov edx,[StashEDX] ret ENDP Draw_Normal END ;**************************** End of ds_dn.asm *****************************