cpml/cpml-extents.c

   1 /* CPML - Cairo Path Manipulation Library
   2  * Copyright (C) 2008, 2009  Nicola Fontana <ntd at entidi.it>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301, USA.
  18  */
  19
  20
  21 /**
  22  * SECTION:extents
  23  * @Section_Id:CpmlExtents
  24  * @title: CpmlExtents
  25  * @short_description: A rectangular area representing a bounding box
  26  *
  27  * The #CpmlExtents struct groups two pairs representing the area of a
  28  * bounding box. The <fieldname>org</fieldname> field holds the lowest
  29  * (x, y) coordinates while <fieldname>size</fieldname> holds the x and
  30  * y extents of the area. The additional <fieldname>is_defined</fieldname>
  31  * boolean flag can be checked to know if #CpmlExtents has been computed
  32  * (when equal to %1) or not (when <fieldname>is_defined</fieldname> is %0).
  33  **/
  34
  35 /**
  36  * CpmlExtents:
  37  * @is_defined: %1 if these extents should be considered, %0 otherwise
  38  * @org: the lowest x,y coordinates
  39  * @size: the width (x) and height (y) of the extents
  40  *
  41  * A structure defining a bounding box area.
  42  **/
  43
  44
  45 #include "cpml-extents.h"
  46
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <math.h>
  50
  51
  52 /**
  53  * cpml_extents_copy:
  54  * @extents: the destination #CpmlExtents
  55  * @src: the source #CpmlExtents
  56  *
  57  * Copies @src in @extents.
  58  *
  59  * Return value: @extents
  60  **/
  61 CpmlExtents *
  62 cpml_extents_copy(CpmlExtents *extents, const CpmlExtents *src)
  63 {
  64     return memcpy(extents, src, sizeof(CpmlExtents));
  65 }
  66
  67 /**
  68  * cpml_extents_from_cairo_text:
  69  * @extents: the destination #CpmlExtents
  70  * @cairo_extents: the source cairo_text_extents_t struct
  71  *
  72  * Converts @cairo_extents in a #CpmlExtents format and stores the
  73  * result in @extents.
  74  *
  75  * Returns: @extents
  76  **/
  77 CpmlExtents *
  78 cpml_extents_from_cairo_text(CpmlExtents *extents,
  79                              const cairo_text_extents_t *cairo_extents)
  80 {
  81     extents->is_defined = 1;
  82     extents->org.x = cairo_extents->x_bearing;
  83     extents->org.y = cairo_extents->y_bearing;
  84     extents->size.x = cairo_extents->width;
  85     extents->size.y = cairo_extents->height;
  86
  87     return extents;
  88 }
  89
  90 /**
  91  * cpml_extents_add:
  92  * @extents: the destination #CpmlExtents
  93  * @src: the extents to add
  94  *
  95  * Merges @extents and @src and store the result in @extents.
  96  **/
  97 void
  98 cpml_extents_add(CpmlExtents *extents, const CpmlExtents *src)
  99 {
 100     if (src->is_defined == 0)
 101         return;
 102
 103     if (extents->is_defined == 0) {
 104         cpml_extents_copy(extents, src);
 105         return;
 106     }
 107
 108     extents->is_defined = 1;
 109
 110     if (src->org.x < extents->org.x) {
 111         extents->size.x += extents->org.x - src->org.x;
 112         extents->org.x = src->org.x;
 113     }
 114
 115     if (src->org.y < extents->org.y) {
 116         extents->size.y += extents->org.y - src->org.y;
 117         extents->org.y = src->org.y;
 118     }
 119
 120     if (src->org.x + src->size.x > extents->org.x + extents->size.x)
 121         extents->size.x = src->org.x + src->size.x - extents->org.x;
 122
 123     if (src->org.y + src->size.y > extents->org.y + extents->size.y)
 124         extents->size.y = src->org.y + src->size.y - extents->org.y;
 125 }