GRASS GIS 8 Programmer's Manual  8.2.2dev(2023)-3d2c704037
pngdriver/box.c
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1 /*!
2  \file lib/pngdriver/box.c
3 
4  \brief GRASS png display driver - draw box
5 
6  (C) 2003-2014 by Per Henrik Johansen and the GRASS Development Team
7 
8  This program is free software under the GNU General Public License
9  (>=v2). Read the file COPYING that comes with GRASS for details.
10 
11  \author Per Henrik Johansen (original contributor)
12  \author Glynn Clements
13 */
14 
15 #include <math.h>
16 #include "pngdriver.h"
17 
18 /*!
19  \brief Draw a (filled) rectangle
20 
21  \param fx1,fy1,fx2,fy2 rectangle coordinates
22 */
23 
24 void PNG_Box(double fx1, double fy1, double fx2, double fy2)
25 {
26  int x1 = (int) floor(fx1 + 0.5);
27  int y1 = (int) floor(fy1 + 0.5);
28  int x2 = (int) floor(fx2 + 0.5);
29  int y2 = (int) floor(fy2 + 0.5);
30  int tmp;
31  int x, y;
32 
33  if (x1 > x2)
34  tmp = x1, x1 = x2, x2 = tmp;
35 
36  if (y1 > y2)
37  tmp = y1, y1 = y2, y2 = tmp;
38 
39  if (x2 < 0 || x1 > png.width)
40  return;
41 
42  if (y2 < 0 || y1 > png.height)
43  return;
44 
45  if (x1 < png.clip_left)
46  x1 = png.clip_left;
47 
48  if (x2 > png.clip_rite)
49  x2 = png.clip_rite;
50 
51  if (y1 < png.clip_top)
52  y1 = png.clip_top;
53 
54  if (y2 > png.clip_bot)
55  y2 = png.clip_bot;
56 
57  for (y = y1; y < y2; y++) {
58  unsigned int *p = &png.grid[y * png.width + x1];
59 
60  for (x = x1; x < x2; x++)
61  *p++ = png.current_color;
62  }
63 
64  png.modified = 1;
65 }
int width
Definition: pngdriver.h:43
double clip_left
Definition: pngdriver.h:42
int current_color
Definition: pngdriver.h:34
GRASS png display driver - header file.
int height
Definition: pngdriver.h:43
double clip_top
Definition: pngdriver.h:42
double clip_rite
Definition: pngdriver.h:42
double clip_bot
Definition: pngdriver.h:42
#define x
struct png_state png
void PNG_Box(double fx1, double fy1, double fx2, double fy2)
Draw a (filled) rectangle.
Definition: pngdriver/box.c:24
int modified
Definition: pngdriver.h:47
unsigned int * grid
Definition: pngdriver.h:44