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/*
* 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 );
}
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