| /* @#) line drawer. adapted to draw for graphics system |
| * @(#) Modified to be compatible with the vasari library |
| * @(#) In order to use this function, the input file should have been set by |
| * @(#) im_mmapinrw() |
| * |
| * Copyright: N. Dessipris |
| * Written: 02/01/1990 |
| * Modified : |
| * 22/7/93 JC |
| * - im_incheck() added |
| * - externs removed |
| * 16/8/94 JC |
| * - im_incheck() changed to im_makerw() |
| * 5/12/06 |
| * - im_invalidate() after paint |
| */ |
| |
| /* |
| |
| This file is part of VIPS. |
| |
| VIPS 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 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 Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| */ |
| |
| /* |
| |
| These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk |
| |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif /*HAVE_CONFIG_H*/ |
| #include <vips/intl.h> |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <math.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| int im_line(image, x1, y1, x2, y2, pelval) |
| IMAGE *image; |
| int x1, x2, y1, y2, pelval; |
| { |
| |
| double x, y, dx, dy, m; |
| long offset; |
| double signx, signy; |
| |
| if( im_rwcheck( image ) ) |
| return( -1 ); |
| /* check coordinates */ |
| if ( (x1 > image->Xsize)||(x1<0)||(y1 > image->Ysize)||(y1<0) |
| ||(x2 > image->Xsize)||(x2<0)||(y2 > image->Ysize)||(y2<0) ) { |
| im_error( "im_line", "%s", _( "invalid line cooordinates") ); |
| return(-1); } |
| if ((pelval > 255)||(pelval < 0)) { |
| im_error( "im_line", "%s", _( "line intensity between 0 and 255") ); |
| return(-1); } |
| |
| if (image->Bands != 1) { |
| im_error( "im_line", "%s", _( "image should have one band only") ); |
| return(-1); } |
| |
| dx = (double)(x2 - x1); |
| dy = (double)(y2 - y1); |
| |
| if (dx < 0.0) |
| signx = -1.0; |
| else |
| signx = 1.0; |
| |
| if (dy < 0.0) |
| signy = -1.0; |
| else |
| signy = 1.0; |
| |
| if (dx == 0.0) |
| { |
| x = x1; y = y1; |
| while (y != y2) |
| { |
| offset = (int)(x+.5) + ((int)(y +.5)) * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| y += signy; |
| } |
| /* Draw point (x2, y2) */ |
| offset = x2 + y2 * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| return(0); |
| } |
| |
| if (dy == 0.0) |
| { |
| y = y1; x = x1; |
| while (x != x2) |
| { |
| offset = (int)(x+.5) + ((int)(y +.5)) * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| x += signx; |
| } |
| /* Draw point (x2, y2) */ |
| offset = x2 + y2 * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| return(0); |
| } |
| |
| if (fabs(dy) < fabs(dx)) |
| { |
| m = fabs(dy/dx)*signy; |
| y = y1; |
| x = x1; |
| while (x != x2) |
| { |
| offset = (int)(x+.5) + ((int)(y +.5)) * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| x += signx; |
| y += m; |
| } |
| } |
| else |
| { |
| m = fabs(dx/dy)*signx; |
| x = x1; y = y1; |
| while (y != y2) |
| { |
| offset = (int)(x+.5) + ((int)(y +.5)) * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| x += m; |
| y += signy; |
| } |
| } |
| /* Draw point (x2, y2) */ |
| offset = x2 + y2 * image->Xsize; |
| *(image->data + offset) = (PEL)pelval; |
| im_invalidate( image ); |
| return(0); |
| } |