| /* |
| * LineDDA |
| * |
| * Copyright 1993 Bob Amstadt |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library 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 |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include <stdlib.h> |
| #include "windef.h" |
| #include "wingdi.h" |
| #include "wine/wingdi16.h" |
| |
| /* ### start build ### */ |
| extern WORD CALLBACK DDA_CallTo16_word_wwl(LINEDDAPROC16,WORD,WORD,LONG); |
| /* ### stop build ### */ |
| |
| struct linedda16_info |
| { |
| LINEDDAPROC16 proc; |
| LPARAM param; |
| }; |
| |
| |
| static void CALLBACK DDA_callback( INT x, INT y, LPARAM param ) |
| { |
| const struct linedda16_info *info = (struct linedda16_info *)param; |
| DDA_CallTo16_word_wwl( info->proc, x, y, info->param ); |
| } |
| |
| /********************************************************************** |
| * LineDDA (GDI32.@) |
| */ |
| BOOL WINAPI LineDDA(INT nXStart, INT nYStart, INT nXEnd, INT nYEnd, |
| LINEDDAPROC callback, LPARAM lParam ) |
| { |
| INT xadd = 1, yadd = 1; |
| INT err,erradd; |
| INT cnt; |
| INT dx = nXEnd - nXStart; |
| INT dy = nYEnd - nYStart; |
| |
| if (dx < 0) { |
| dx = -dx; xadd = -1; |
| } |
| if (dy < 0) { |
| dy = -dy; yadd = -1; |
| } |
| if (dx > dy) { /* line is "more horizontal" */ |
| err = 2*dy - dx; erradd = 2*dy - 2*dx; |
| for(cnt = 0;cnt <= dx; cnt++) { |
| callback(nXStart,nYStart,lParam); |
| if (err > 0) { |
| nYStart += yadd; |
| err += erradd; |
| } else { |
| err += 2*dy; |
| } |
| nXStart += xadd; |
| } |
| } else { /* line is "more vertical" */ |
| err = 2*dx - dy; erradd = 2*dx - 2*dy; |
| for(cnt = 0;cnt <= dy; cnt++) { |
| callback(nXStart,nYStart,lParam); |
| if (err > 0) { |
| nXStart += xadd; |
| err += erradd; |
| } else { |
| err += 2*dx; |
| } |
| nYStart += yadd; |
| } |
| } |
| return TRUE; |
| } |
| |
| |
| /********************************************************************** |
| * LineDDA (GDI.100) |
| */ |
| void WINAPI LineDDA16( INT16 nXStart, INT16 nYStart, INT16 nXEnd, |
| INT16 nYEnd, LINEDDAPROC16 proc, LPARAM lParam ) |
| { |
| struct linedda16_info info; |
| info.proc = proc; |
| info.param = lParam; |
| LineDDA( nXStart, nYStart, nXEnd, nYEnd, DDA_callback, (LPARAM)&info ); |
| } |