Subversion Repositories planix.SVN

/*

 * 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.

 */

#define _RESEARCH_SOURCE

#include <stdio.h>

#include <stdlib.h>

#include <string.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];

void	concat(double []);

void	resetbbox(int);

void	rotate(double);

void	scale(double, double);

void	translate(double, double);

void	writebbox(FILE *, char *, int);

void

cover(x, y)

    double	x, 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;

    }

}

void

writebbox(fp, keyword, slop)

    FILE	*fp;			/* the comment is written here */

    char	*keyword;		/* the boundingbox comment string */

    int		slop;			/* expand (or contract?) the box a bit */

{

    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;

    }

    resetbbox(fp == stdout);

}

void

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);

    }

    if ( output == TRUE ) {

	docbbox = bbox;

	docbbox.set = TRUE;

    }

    bbox.set = FALSE;

}

void

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);

}

void

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);

}

void

rotate(double angle)

{

/*

 * Rotates by angle degrees.

 */

    angle *= M_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);

}

void

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];

}