ref: 4d69aacea023546a7150d92e147e531c38de822f
dir: /sys/src/cmd/postscript/common/bbox.c/
/*
*
* Boundingbox code for PostScript translators. The boundingbox for each page
* is accumulated in bbox - the one for the whole document goes in docbbox. A
* call to writebbox() puts out an appropriate comment, updates docbbox, and
* resets bbox for the next page. The assumption made at the end of writebbox()
* is that we're really printing the current page only if output is now going
* to stdout - a valid assumption for all supplied translators. Needs the math
* library.
*
*/
#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <fcntl.h>
#include <math.h>
#include "comments.h" /* PostScript file structuring comments */
#include "gen.h" /* a few general purpose definitions */
#include "ext.h" /* external variable declarations */
typedef struct bbox {
int set;
double llx, lly;
double urx, ury;
} Bbox;
Bbox bbox = {FALSE, 0.0, 0.0, 0.0, 0.0};
Bbox docbbox = {FALSE, 0.0, 0.0, 0.0, 0.0};
double ctm[6] = {1.0, 0.0, 0.0, 1.0, 0.0, 0.0};
double matrix1[6], matrix2[6];
/*****************************************************************************/
cover(double x, double y)
{
/*
*
* Adds point (x, y) to bbox. Coordinates are in user space - the transformation
* to default coordinates happens in writebbox().
*
*/
if ( bbox.set == FALSE ) {
bbox.llx = bbox.urx = x;
bbox.lly = bbox.ury = y;
bbox.set = TRUE;
} else {
if ( x < bbox.llx )
bbox.llx = x;
if ( y < bbox.lly )
bbox.lly = y;
if ( x > bbox.urx )
bbox.urx = x;
if ( y > bbox.ury )
bbox.ury = y;
} /* End else */
} /* End of cover */
/*****************************************************************************/
writebbox(FILE *fp, char *keyword, int slop)
{
Bbox ubbox; /* user space bounding box */
double x, y;
/*
*
* Transforms the numbers in the bbox[] using ctm[], adjusts the corners a bit
* (depending on slop) and then writes comment. If *keyword is BoundingBox use
* whatever's been saved in docbbox, otherwise assume the comment is just for
* the current page.
*
*/
if ( strcmp(keyword, BOUNDINGBOX) == 0 )
bbox = docbbox;
if ( bbox.set == TRUE ) {
ubbox = bbox;
bbox.set = FALSE; /* so cover() works properly */
x = ctm[0] * ubbox.llx + ctm[2] * ubbox.lly + ctm[4];
y = ctm[1] * ubbox.llx + ctm[3] * ubbox.lly + ctm[5];
cover(x, y);
x = ctm[0] * ubbox.llx + ctm[2] * ubbox.ury + ctm[4];
y = ctm[1] * ubbox.llx + ctm[3] * ubbox.ury + ctm[5];
cover(x, y);
x = ctm[0] * ubbox.urx + ctm[2] * ubbox.ury + ctm[4];
y = ctm[1] * ubbox.urx + ctm[3] * ubbox.ury + ctm[5];
cover(x, y);
x = ctm[0] * ubbox.urx + ctm[2] * ubbox.lly + ctm[4];
y = ctm[1] * ubbox.urx + ctm[3] * ubbox.lly + ctm[5];
cover(x, y);
bbox.llx -= slop + 0.5;
bbox.lly -= slop + 0.5;
bbox.urx += slop + 0.5;
bbox.ury += slop + 0.5;
fprintf(fp, "%s %d %d %d %d\n", keyword, (int)bbox.llx, (int)bbox.lly,(int)bbox.urx, (int)bbox.ury);
bbox = ubbox;
} /* End if */
resetbbox((fp == stdout) ? TRUE : FALSE);
} /* End of writebbox */
/*****************************************************************************/
resetbbox(int output)
{
/*
*
* Adds bbox to docbbox and resets bbox for the next page. Only update docbbox
* if we really did output on the last page.
*
*/
if ( docbbox.set == TRUE ) {
cover(docbbox.llx, docbbox.lly);
cover(docbbox.urx, docbbox.ury);
} /* End if */
if ( output == TRUE ) {
docbbox = bbox;
docbbox.set = TRUE;
} /* End if */
bbox.set = FALSE;
} /* End of resetbbox */
/*****************************************************************************/
scale(double sx, double sy)
{
/*
*
* Scales the default matrix.
*
*/
matrix1[0] = sx;
matrix1[1] = 0;
matrix1[2] = 0;
matrix1[3] = sy;
matrix1[4] = 0;
matrix1[5] = 0;
concat(matrix1);
} /* End of scale */
/*****************************************************************************/
translate(double tx, double ty)
{
/*
*
* Translates the default matrix.
*
*/
matrix1[0] = 1.0;
matrix1[1] = 0.0;
matrix1[2] = 0.0;
matrix1[3] = 1.0;
matrix1[4] = tx;
matrix1[5] = ty;
concat(matrix1);
} /* End of translate */
/*****************************************************************************/
rotate(double angle)
{
/*
*
* Rotates by angle degrees.
*
*/
angle *= PI / 180;
matrix1[0] = matrix1[3] = cos(angle);
matrix1[1] = sin(angle);
matrix1[2] = -matrix1[1];
matrix1[4] = 0.0;
matrix1[5] = 0.0;
concat(matrix1);
} /* End of rotate */
/*****************************************************************************/
concat(double *m1)
{
double m2[6];
/*
*
* Replaces the ctm[] by the result of the matrix multiplication m1[] x ctm[].
*
*/
m2[0] = ctm[0];
m2[1] = ctm[1];
m2[2] = ctm[2];
m2[3] = ctm[3];
m2[4] = ctm[4];
m2[5] = ctm[5];
ctm[0] = m1[0] * m2[0] + m1[1] * m2[2];
ctm[1] = m1[0] * m2[1] + m1[1] * m2[3];
ctm[2] = m1[2] * m2[0] + m1[3] * m2[2];
ctm[3] = m1[2] * m2[1] + m1[3] * m2[3];
ctm[4] = m1[4] * m2[0] + m1[5] * m2[2] + m2[4];
ctm[5] = m1[4] * m2[1] + m1[5] * m2[3] + m2[5];
} /* End of concat */
/*****************************************************************************/