pdfrects.h

/*
 * pdfrects.h
 *
 * functions on poppler rectangles:
 *
 * - functions on individual rectangles (containment, join, etc.)
 * - functions for rectangle lists representing the union of their areas
 * - functions for blocks of text in a page
 * - functions for short, recurring blocks of text
 */

#ifdef _PDFRECTS_H
#else
#define _PDFRECTS_H

/*
 * functions on individual rectangles
 */

/* print a rectangle */
void rectangle_print(FILE *, PopplerRectangle *);
void rectangle_printyaml(FILE *, char *first, char *indent, PopplerRectangle *);

/* parse a rectangle */
PopplerRectangle *rectangle_parse(char *s);

/* normalize a rectangle: x1 <= x2 and y1 <= y2 */
void rectangle_normalize(PopplerRectangle *);

/* width, height and area of a rectangle */
double rectangle_width(PopplerRectangle *);
double rectangle_height(PopplerRectangle *);
double rectangle_area(PopplerRectangle *r);

/* check if two rectangles are the same */
gboolean rectangle_hequal(PopplerRectangle *a, PopplerRectangle *b);
gboolean rectangle_vequal(PopplerRectangle *a, PopplerRectangle *b);
gboolean rectangle_equal(PopplerRectangle *a, PopplerRectangle *b);

/* check whether the first rectangle contains the second */
gboolean rectangle_hcontain(PopplerRectangle *, PopplerRectangle *);
gboolean rectangle_vcontain(PopplerRectangle *, PopplerRectangle *);
gboolean rectangle_contain(PopplerRectangle *, PopplerRectangle *);

/* check if rectangles overlap */
gboolean rectangle_hoverlap(PopplerRectangle *, PopplerRectangle *);
gboolean rectangle_voverlap(PopplerRectangle *, PopplerRectangle *);
gboolean rectangle_overlap(PopplerRectangle *, PopplerRectangle *);

/* check if rectangles touch (meet or overlap) */
gboolean rectangle_htouch(PopplerRectangle *a, PopplerRectangle *b);
gboolean rectangle_vtouch(PopplerRectangle *a, PopplerRectangle *b);
gboolean rectangle_touch(PopplerRectangle *, PopplerRectangle *);

/* horizontal and vertical distance between rectangles */
gdouble rectangle_hdistance(PopplerRectangle *a, PopplerRectangle *b);
gdouble rectangle_vdistance(PopplerRectangle *a, PopplerRectangle *b);

/* copy and swap rectangles */
void rectangle_copy(PopplerRectangle *dest, PopplerRectangle *orig);
void rectangle_swap(PopplerRectangle *a, PopplerRectangle *b);

/* shift and expand a rectangle */
void rectangle_shift(PopplerRectangle *, gdouble x, gdouble y);
void rectangle_expand(PopplerRectangle *, gdouble dx, gdouble dy);

/* make the first rectangle the intersection of the other two */
void rectangle_intersect(PopplerRectangle *r,
		PopplerRectangle *a, PopplerRectangle *b);

/* join rectangles: the first becomes the smallest rectangle containing both */
void rectangle_join(PopplerRectangle *, PopplerRectangle *);

/* compare the position of two rectangles */
int rectangle_hcompare(PopplerRectangle *a, PopplerRectangle *b);
int rectangle_vcompare(PopplerRectangle *a, PopplerRectangle *b);
int rectangle_compare(PopplerRectangle *, PopplerRectangle *);

/* compare the area of two rectangles */
int rectangle_areacompare(PopplerRectangle *a, PopplerRectangle *b);

/* a rectangle as large as the page */
void rectangle_page(PopplerPage *page, PopplerRectangle *rect);

/*
 * functions on lists of rectangles
 */

#define MAXRECT 4096
typedef struct {
	/* public */
	PopplerRectangle *rect;
	gint num;

	/* private */
	gint max;
} RectangleList;

/*
 * minimal size for both dimensions of a rectangle and for each
 */
typedef struct {
	gdouble both;
	gdouble each;
} RectangleBound;

/* allocate a list with maximum number of elements, currently none */
RectangleList *rectanglelist_new(int);

/* make a copy of a rectangle list */
RectangleList *rectanglelist_copy(RectangleList *src);

/* thighten a rectangle list by deallocating the unused entries */
void rectanglelist_tighten(RectangleList *);

/* free a rectangle list */
void rectanglelist_free(RectangleList *);

/* print a rectangle list */
void rectanglelist_print(FILE *, RectangleList *);
void rectanglelist_printyaml(FILE *, char *first, char *indent,
	RectangleList *);

/* remove a rectangle from a list */
void rectanglelist_delete(RectangleList *, gint);

/* append a rectangle to a list */
void rectanglelist_append(RectangleList *rl, PopplerRectangle *rect);

/* add a rectangle to a list, if not redundant */
gboolean rectanglelist_add(RectangleList *, PopplerRectangle *);

/* smallest rectangle enclosing all in a rectangle list */
PopplerRectangle *rectanglelist_joinall(RectangleList *);

/* horizontal or vertical extents of a rectangle list */
RectangleList *rectanglelist_hextents(RectangleList *);
RectangleList *rectanglelist_vextents(RectangleList *);

/* total width and height of a rectangle list */
double rectanglelist_sumwidth(RectangleList *rl);
double rectanglelist_sumheight(RectangleList *rl);

/* average width and height of a rectangle list */
double rectanglelist_averagewidth(RectangleList *rl);
double rectanglelist_averageheight(RectangleList *rl);

/* index of first rectangle in list in a relation to another rectangle */
gint rectanglelist_contain(RectangleList *, PopplerRectangle *);
gint rectanglelist_touch(RectangleList *, PopplerRectangle *);
gint rectanglelist_overlap(RectangleList *, PopplerRectangle *);

/* sort a rectangle list by position */
void rectanglelist_quicksort(RectangleList *, PopplerPage *);
void rectanglelist_twosort(RectangleList *, PopplerPage *);
void rectanglelist_charsort(RectangleList *, PopplerPage *);

/* find the largest rectangle in a list or sort by area */
PopplerRectangle *rectanglelist_largest(RectangleList *);
void rectanglelist_areasort(RectangleList *);

/* position a rectangle in a page partially filled by others */
gboolean rectanglelist_place(PopplerRectangle *page,
		RectangleList *rl, PopplerRectangle *r,
		PopplerRectangle *moved);

/* subtract a rectangle list from another: orig -= sub */
gboolean rectanglelist_subtract(RectangleList **orig, RectangleList *sub,
		PopplerRectangle *cont, RectangleBound *b);

/* subtract a rectangle list from a single rectangle: res = r - rl */
RectangleList *rectanglelist_subtract1(PopplerRectangle *r, RectangleList *rl,
		PopplerRectangle *cont, RectangleBound *b);

/*
 * functions on text-enclosing rectangles
 * rectangles of white spaces ' ' are made 0-width
 */

/* debug */
extern int debugtextrectangles;

/* the rectangles of the single characters in the page */
RectangleList *rectanglelist_characters(PopplerPage *);

/* area of text in a page */
RectangleList *rectanglelist_textarea(PopplerPage *);

/* area of text in a page, with minimal distance considered a white space */
RectangleList *rectanglelist_textarea_distance(PopplerPage *, gdouble);

/* bounding box of the page or document (NULL if no text) */
PopplerRectangle *rectanglelist_boundingbox(PopplerPage *);
PopplerRectangle *rectanglelist_boundingbox_document(PopplerDocument *doc);

/* largest box in a page or document (NULL if no text) */
PopplerRectangle *rectanglelist_pagelargest(PopplerPage *page);
PopplerRectangle *rectanglelist_largest_document(PopplerDocument *doc);

/* list of squares of a grid that are painted in a page */
RectangleList *rectanglelist_painted(PopplerPage *page, int distance);

/* area of painted squares in a page, with minimal distance of white space */
RectangleList *rectanglelist_paintedarea_distance(PopplerPage *, gdouble);

/* bounding box of a page, based on painted squares */
PopplerRectangle *rectanglelist_boundingbox_painted(PopplerPage *page, int d);

/* list of rows in a page */
RectangleList *rectanglelist_rows(PopplerPage *page, gdouble distance);

/*
 * functions for recurring blocks of text (page numbers, headers and footers)
 */

typedef struct {
	int num;
	int size;
	struct {
		int rank;
		PopplerRectangle rect;
	} rect[];
} RectangleVector;

/* debug areas often taken by short blocks of text */
extern int debugfrequent;

/* create an empty rectangle vector of a given size */
RectangleVector *rectanglevector_create(int size);

/* print a rectangle vector */
void rectanglevector_print(FILE *fd, RectangleVector *v);
void rectanglevector_printyaml(FILE *fd, char *first, char *indent,
		RectangleVector *v);

/* make a rectangle list out of a rectangle vector */
RectangleList *rectanglevector_list(RectangleVector *c);

/* insert a rectangle in a vector */
void rectanglevector_insert(RectangleVector *v, int rank, PopplerRectangle *r);

/* add a rectangle to a frequency vector, allowing horizontal containment */
void rectanglevector_add(RectangleVector *v, PopplerRectangle *r);

/* rectangles often taken by short blocks of text */
RectangleList *rectanglevector_frequent(PopplerDocument *doc,
		gdouble height, gdouble distance);

/* a rectangle as large as the page minus headers and footers */
PopplerRectangle *rectanglevector_main(PopplerDocument *doc,
		RectangleList *recur, gdouble height, gdouble distance);

/*
 * drawing-related functions
 */

/* use rectangle in cairo */
void rectangle_cairo(cairo_t *cr, PopplerRectangle *rect, gdouble enlarge);

/* draw a rectangle, possibly filled or enclosing */
void rectangle_draw(cairo_t *, PopplerRectangle *,
	gboolean randomcolor, gboolean fill, gboolean enclosing);

/* draw a rectangle list, possibly numbering each */
void rectanglelist_draw(cairo_t *, RectangleList *,
	gboolean fill, gboolean enclosing, gboolean num, gboolean inside);

/* apply the current transformation to a rectangle */
void rectangle_transform(cairo_t *cr, PopplerRectangle *r);

/* map a poppler rectangle into a cairo surface */
void rectangle_map_to_cairo(cairo_t *cr,
		PopplerRectangle *dst, PopplerRectangle *src,
		gboolean horizontal, gboolean vertical,
		gboolean ratio, gboolean topalign, gboolean leftalign);

/* clip out all textarea rectangles containing any in the remove list */
void rectanglelist_clip_containing(cairo_t *cr, PopplerPage *page,
		RectangleList *textarea, RectangleList *rm);

/*
 * helper functions
 */

/* from name to paper size (pointer to statically allocated structure) */
PopplerRectangle *get_papersize(char *name);

/* default paper size, from /etc/papersize */
char *defaultpapersize();

/* from file name to uri */
char *filenametouri(char *);

/* turn file.pdf into file-suffix.pdf */
char *pdfaddsuffix(char *infile, char *suffix);

#endif