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/*
* libtcod 1.6.3
* Copyright (c) 2008,2009,2010,2012,2013,2016,2017 Jice & Mingos & rmtew
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * The name of Jice or Mingos may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JICE, MINGOS AND RMTEW ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL JICE, MINGOS OR RMTEW BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <bresenham.h>
static TCOD_bresenham_data_t bresenham_data;
/* ********** bresenham line drawing ********** */
void TCOD_line_init_mt(int xFrom, int yFrom, int xTo, int yTo, TCOD_bresenham_data_t *data) {
data->origx=xFrom;
data->origy=yFrom;
data->destx=xTo;
data->desty=yTo;
data->deltax=xTo - xFrom;
data->deltay=yTo - yFrom;
if ( data->deltax > 0 ) {
data->stepx=1;
} else if ( data->deltax < 0 ){
data->stepx=-1;
} else data->stepx=0;
if ( data->deltay > 0 ) {
data->stepy=1;
} else if ( data->deltay < 0 ){
data->stepy=-1;
} else data->stepy = 0;
if ( data->stepx*data->deltax > data->stepy*data->deltay ) {
data->e = data->stepx*data->deltax;
data->deltax *= 2;
data->deltay *= 2;
} else {
data->e = data->stepy*data->deltay;
data->deltax *= 2;
data->deltay *= 2;
}
}
bool TCOD_line_step_mt(int *xCur, int *yCur, TCOD_bresenham_data_t *data) {
if ( data->stepx*data->deltax > data->stepy*data->deltay ) {
if ( data->origx == data->destx ) return true;
data->origx+=data->stepx;
data->e -= data->stepy*data->deltay;
if ( data->e < 0) {
data->origy+=data->stepy;
data->e+=data->stepx*data->deltax;
}
} else {
if ( data->origy == data->desty ) return true;
data->origy+=data->stepy;
data->e -= data->stepx*data->deltax;
if ( data->e < 0) {
data->origx+=data->stepx;
data->e+=data->stepy*data->deltay;
}
}
*xCur=data->origx;
*yCur=data->origy;
return false;
}
bool TCOD_line_mt(int xo, int yo, int xd, int yd, TCOD_line_listener_t listener, TCOD_bresenham_data_t *data) {
TCOD_line_init_mt(xo,yo,xd,yd,data);
do {
if (! listener(xo,yo)) return false;
} while (! TCOD_line_step_mt(&xo,&yo,data));
return true;
}
void TCOD_line_init(int xFrom, int yFrom, int xTo, int yTo) {
TCOD_line_init_mt(xFrom,yFrom,xTo,yTo,&bresenham_data);
}
bool TCOD_line_step(int *xCur, int *yCur) {
return TCOD_line_step_mt(xCur,yCur,&bresenham_data);
}
bool TCOD_line(int xo, int yo, int xd, int yd, TCOD_line_listener_t listener) {
return TCOD_line_mt(xo,yo,xd,yd,listener,&bresenham_data);
}