/*
 * coords.h
 *
 * Miscellaneous handling of window-related geometries
 *
 * © 1994-1998 Straylight
 */

/*----- Licensing note ----------------------------------------------------*
 *
 * This file is part of Straylight's Steel library.
 *
 * Steel is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * Steel is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Steel.  If not, write to the Free Software Foundation,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef __coords_h
#define __coords_h

#ifndef __wimp
  #include "wimp.h"
#endif

/* --- Passing window information to coords --- */

typedef struct
{
  wimp_box box;
  int scx;
  int scy;
}
coords_cvtstr;

/* --- Passing individual points --- *
 *
 * This is actually slightly silly, but we do it this way for compatibility
 * with RISC_OSLib
 */

typedef struct
{
  int x;
  int y;
}
coords_pointstr;

/*
 * int coords_x_toscreen(int x,coords_cvtstr *c)
 * int coords_y_toscreen(int y,coords_cvtstr *c)
 * int coords_x_toworkarea(int x,coords_cvtstr *c)
 * int coords_y_toworkarea(int y,coords_cvtstr *c)
 *
 * Use
 *  Convert x- or y-coordinates from window to screen coordinates or vice-
 *  versa.
 *
 * Parameters
 *  int x or int y == the coordinate to convert
 *  coords_cvtstr *c == pointer to window information (e.g. cast from a
 *    wimp_wstate or a wimp_redrawstr)
 *
 * Returns
 *  The appropriate screen- or window-relative coordinate
 */

int coords_x_toscreen(int x,coords_cvtstr *c);
int coords_y_toscreen(int y,coords_cvtstr *c);
int coords_x_toworkarea(int x,coords_cvtstr *c);
int coords_y_toworkarea(int y,coords_cvtstr *c);

/*
 * void coords_box_toscreen(wimp_box *b,coords_cvtstr *c)
 * void coords_box_toworkarea(wimp_box *b,coords_cvtstr *c)
 *
 * Use
 *  Converts a whole rectangle from window to screen coordinates or vice-
 *  versa.
 *
 * Parameters
 *  wimp_box *b == pointer to the rectangle to convert
 *  coords_cvtstr *c == pointer to the window information to use
 */

void coords_box_toscreen(wimp_box *b,coords_cvtstr *c);
void coords_box_toworkarea(wimp_box *b,coords_cvtstr *c);

/*
 * void coords_point_toscreen(coords_pointstr *p,coords_cvtstr *c)
 * void coords_point_toworkarea(coords_pointstr *p,coords_cvtstr *c)
 *
 * Use
 *  Converts a single point from window to screen coordinates or vice-versa.
 *
 * Parameters
 *  coords_pointstr *p == pointer to the rectangle to convert
 *  coords_cvtstr *c == pointer to the window information to use
 */

void coords_point_toscreen(coords_pointstr *p,coords_cvtstr *c);
void coords_point_toworkarea(wimp_box *b,coords_cvtstr *c);

/*
 * BOOL coords_withinbox(coords_pointstr *p,wimp_box *b)
 *
 * Use
 *  Returns whether the given point lies within (or on the edge of) the
 *  specified box
 *
 * Parameters
 *  coords_pointstr *p == pointer to the point
 *  wimp_box *b == pointer to the box
 *
 * Returns
 *  TRUE if the point is indeed within the box, and FALSE otherwise
 */

BOOL coords_withinbox(coords_pointstr *p,wimp_box *b);

/*
 * void coords_offsetbox(wimp_box *source,int ox,int oy,wimp_box *dest)
 *
 * Use
 *  Nudges the given rectangle by adding the given offsets to the x and y
 *  coordinates.
 *
 * Parameters
 *  wimp_box *source == pointer to the rectangle to nudge
 *  int ox == amount to nudge the x-coordinates of the box
 *  int oy == amount to nudge the y-coordinates of the box
 *  wimp_box *dest == pointer to where to put the nudged rectangle (may be
 *    the same as source)
 */

void coords_offsetbox(wimp_box *source,int ox,int oy,wimp_box *dest);

/*
 * BOOL coords_intersects(wimp_box *line,wimp_box *box,int width)
 *
 * Use
 *  Returns FALSE only if the line specified does not intersect the specified
 *  box.  The line is considered to have a thickness of width.  The method
 *  used is very approximate, and false positives may occur.
 *
 * Parameters
 *  wimp_box *line == pointer to the coordinates of the line
 *  wimp_box *box == pointer to the coordinates of the box
 *
 * Returns
 *  FALSE if the line does not intersect the box
 */

BOOL coords_intersects(wimp_box *line,wimp_box *box,int width);

/*
 * BOOL coords_boxesoverlap(wimp_box *a,wimp_box *b)
 *
 * Use
 *  Determines whether two boxes overlap at all (useful for checking whether
 *  to redraw something).
 *
 * Parameters
 *  wimp_box *a == pointer to one of the rectangles to test
 *  wimp_box *b == pointer to the other rectangle
 *
 * Returns
 *  TRUE if the boxes overlap, or FALSE if they don't
 */

BOOL coords_boxesoverlap(wimp_box *a,wimp_box *b);

#endif