1 /*
2  *
3  * Boundingbox code for PostScript translators. The boundingbox for each page
4  * is accumulated in bbox - the one for the whole document goes in docbbox. A
5  * call to writebbox() puts out an appropriate comment, updates docbbox, and
6  * resets bbox for the next page. The assumption made at the end of writebbox()
7  * is that we're really printing the current page only if output is now going
8  * to stdout - a valid assumption for all supplied translators. Needs the math
9  * library.
10  *
11  */
12 
13 #include <stdio.h>
14 #include <string.h>
15 #include <ctype.h>
16 #include <sys/types.h>
17 #include <fcntl.h>
18 #include <math.h>
19 
20 #include "comments.h"			/* PostScript file structuring comments */
21 #include "gen.h"			/* a few general purpose definitions */
22 #include "ext.h"			/* external variable declarations */
23 
24 typedef struct bbox {
25 	int	set;
26 	double	llx, lly;
27 	double	urx, ury;
28 } Bbox;
29 
30 Bbox	bbox = {FALSE, 0.0, 0.0, 0.0, 0.0};
31 Bbox	docbbox = {FALSE, 0.0, 0.0, 0.0, 0.0};
32 
33 double	ctm[6] = {1.0, 0.0, 0.0, 1.0, 0.0, 0.0};
34 double	matrix1[6], matrix2[6];
35 
36 /*****************************************************************************/
37 
38 void
39 cover(x, y)
40 
41     double	x, y;
42 
43 {
44 
45 /*
46  *
47  * Adds point (x, y) to bbox. Coordinates are in user space - the transformation
48  * to default coordinates happens in writebbox().
49  *
50  */
51 
52     if ( bbox.set == FALSE ) {
53 	bbox.llx = bbox.urx = x;
54 	bbox.lly = bbox.ury = y;
55 	bbox.set = TRUE;
56     } else {
57 	if ( x < bbox.llx )
58 	    bbox.llx = x;
59 	if ( y < bbox.lly )
60 	    bbox.lly = y;
61 	if ( x > bbox.urx )
62 	    bbox.urx = x;
63 	if ( y > bbox.ury )
64 	    bbox.ury = y;
65     }	/* End else */
66 
67 }   /* End of cover */
68 
69 /*****************************************************************************/
70 void	resetbbox();
71 
72 void
73 writebbox(fp, keyword, slop)
74 
75     FILE	*fp;			/* the comment is written here */
76     char	*keyword;		/* the boundingbox comment string */
77     int		slop;			/* expand (or contract?) the box a bit */
78 
79 {
80 
81     Bbox	ubbox;			/* user space bounding box */
82     double	x, y;
83 
84 /*
85  *
86  * Transforms the numbers in the bbox[] using ctm[], adjusts the corners a bit
87  * (depending on slop) and then writes comment. If *keyword is BoundingBox use
88  * whatever's been saved in docbbox, otherwise assume the comment is just for
89  * the current page.
90  *
91  */
92 
93     if ( strcmp(keyword, BOUNDINGBOX) == 0 )
94 	bbox = docbbox;
95 
96     if ( bbox.set == TRUE ) {
97 	ubbox = bbox;
98 	bbox.set = FALSE;		/* so cover() works properly */
99 	x = ctm[0] * ubbox.llx + ctm[2] * ubbox.lly + ctm[4];
100 	y = ctm[1] * ubbox.llx + ctm[3] * ubbox.lly + ctm[5];
101 	cover(x, y);
102 	x = ctm[0] * ubbox.llx + ctm[2] * ubbox.ury + ctm[4];
103 	y = ctm[1] * ubbox.llx + ctm[3] * ubbox.ury + ctm[5];
104 	cover(x, y);
105 	x = ctm[0] * ubbox.urx + ctm[2] * ubbox.ury + ctm[4];
106 	y = ctm[1] * ubbox.urx + ctm[3] * ubbox.ury + ctm[5];
107 	cover(x, y);
108 	x = ctm[0] * ubbox.urx + ctm[2] * ubbox.lly + ctm[4];
109 	y = ctm[1] * ubbox.urx + ctm[3] * ubbox.lly + ctm[5];
110 	cover(x, y);
111 	bbox.llx -= slop + 0.5;
112 	bbox.lly -= slop + 0.5;
113 	bbox.urx += slop + 0.5;
114 	bbox.ury += slop + 0.5;
115 	fprintf(fp, "%s %d %d %d %d\n", keyword, (int)bbox.llx, (int)bbox.lly,(int)bbox.urx, (int)bbox.ury);
116 	bbox = ubbox;
117     }	/* End if */
118 
119     resetbbox((fp == stdout) ? TRUE : FALSE);
120 
121 }   /* End of writebbox */
122 
123 /*****************************************************************************/
124 void
125 resetbbox(output)
126 
127     int		output;
128 
129 {
130 
131 /*
132  *
133  * Adds bbox to docbbox and resets bbox for the next page. Only update docbbox
134  * if we really did output on the last page.
135  *
136  */
137 
138     if ( docbbox.set == TRUE ) {
139 	cover(docbbox.llx, docbbox.lly);
140 	cover(docbbox.urx, docbbox.ury);
141     }	/* End if */
142 
143     if ( output == TRUE ) {
144 	docbbox = bbox;
145 	docbbox.set = TRUE;
146     }	/* End if */
147 
148     bbox.set = FALSE;
149 
150 }   /* End of resetbbox */
151 
152 /*****************************************************************************/
153 void
154 scale(sx, sy)
155 
156     double	sx, sy;
157 
158 {
159 
160 /*
161  *
162  * Scales the default matrix.
163  *
164  */
165 
166     matrix1[0] = sx;
167     matrix1[1] = 0;
168     matrix1[2] = 0;
169     matrix1[3] = sy;
170     matrix1[4] = 0;
171     matrix1[5] = 0;
172 
173     concat(matrix1);
174 
175 }   /* End of scale */
176 
177 /*****************************************************************************/
178 void
179 translate(tx, ty)
180 
181     double	tx, ty;
182 
183 {
184 
185 /*
186  *
187  * Translates the default matrix.
188  *
189  */
190 
191     matrix1[0] = 1.0;
192     matrix1[1] = 0.0;
193     matrix1[2] = 0.0;
194     matrix1[3] = 1.0;
195     matrix1[4] = tx;
196     matrix1[5] = ty;
197 
198     concat(matrix1);
199 
200 }   /* End of translate */
201 
202 /*****************************************************************************/
203 void
204 rotate(angle)
205 
206     double	angle;
207 
208 {
209 
210 /*
211  *
212  * Rotates by angle degrees.
213  *
214  */
215 
216     angle *= 3.1416 / 180;
217 
218     matrix1[0] = matrix1[3] = cos(angle);
219     matrix1[1] = sin(angle);
220     matrix1[2] = -matrix1[1];
221     matrix1[4] = 0.0;
222     matrix1[5] = 0.0;
223 
224     concat(matrix1);
225 
226 }   /* End of rotate */
227 
228 /*****************************************************************************/
229 
230 void
231 concat(m1)
232 
233     double	m1[];
234 
235 {
236 
237     double	m2[6];
238 
239 /*
240  *
241  * Replaces the ctm[] by the result of the matrix multiplication m1[] x ctm[].
242  *
243  */
244 
245     m2[0] = ctm[0];
246     m2[1] = ctm[1];
247     m2[2] = ctm[2];
248     m2[3] = ctm[3];
249     m2[4] = ctm[4];
250     m2[5] = ctm[5];
251 
252     ctm[0] = m1[0] * m2[0] + m1[1] * m2[2];
253     ctm[1] = m1[0] * m2[1] + m1[1] * m2[3];
254     ctm[2] = m1[2] * m2[0] + m1[3] * m2[2];
255     ctm[3] = m1[2] * m2[1] + m1[3] * m2[3];
256     ctm[4] = m1[4] * m2[0] + m1[5] * m2[2] + m2[4];
257     ctm[5] = m1[4] * m2[1] + m1[5] * m2[3] + m2[5];
258 
259 }   /* End of concat */
260 
261 /*****************************************************************************/
262