pangocairo-win32font.c

GTK+-2.0源码之pango-1.15.6.tar.gz

/* Pango
 * pangocairowin32-font.c: Cairo font handling, Win32 backend
 *
 * Copyright (C) 2000-2005 Red Hat Software
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <config.h>

#include <math.h>
#include <stdlib.h>
#include <string.h>

#include "pango-fontmap.h"
#include "pango-impl-utils.h"
#include "pangocairo-private.h"
#include "pangocairo-win32.h"

#include <cairo-win32.h>

#define PANGO_TYPE_CAIRO_WIN32_FONT           (pango_cairo_win32_font_get_type ())
#define PANGO_CAIRO_WIN32_FONT(object)        (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_TYPE_CAIRO_WIN32_FONT, PangoCairoWin32Font))
#define PANGO_CAIRO_WIN32_FONT_CLASS(klass)   (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_CAIRO_WIN32_FONT, PangoCairoWin32FontClass))
#define PANGO_CAIRO_IS_FONT_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_CAIRO_WIN32_FONT))
#define PANGO_CAIRO_WIN32_FONT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_CAIRO_WIN32_FONT, PangoCairoWin32FontClass))

typedef struct _PangoCairoWin32Font      PangoCairoWin32Font;
typedef struct _PangoCairoWin32FontClass PangoCairoWin32FontClass;
typedef struct _PangoCairoWin32GlyphInfo PangoCairoWin32GlyphInfo;

struct _PangoCairoWin32Font
{
  PangoWin32Font font;

  int size;

  cairo_font_face_t *font_face;
  cairo_scaled_font_t *scaled_font;

  cairo_matrix_t font_matrix;
  cairo_matrix_t ctm;
  cairo_font_options_t *options;

  GSList *metrics_by_lang;
  GHashTable *glyph_info;
};

struct _PangoCairoWin32FontClass
{
  PangoWin32FontClass  parent_class;
};

struct _PangoCairoWin32GlyphInfo
{
  PangoRectangle logical_rect;
  PangoRectangle ink_rect;
};

GType pango_cairo_win32_font_get_type (void);

/*******************************
 *       Utility functions     *
 *******************************/

static cairo_font_face_t *
pango_cairo_win32_font_get_font_face (PangoCairoFont *font)
{
  PangoCairoWin32Font *cwfont = PANGO_CAIRO_WIN32_FONT (font);
  PangoWin32Font *win32font = PANGO_WIN32_FONT (cwfont);

  if (cwfont->font_face == NULL)
    {
      LOGFONTW logfontw;

      /* Count here on the fact that all the struct fields are the
       * same for LOGFONTW and LOGFONTA except lfFaceName which is the
       * last field
       */
      memcpy (&logfontw, &win32font->logfont, sizeof (LOGFONTA));

      if (!MultiByteToWideChar (CP_ACP, MB_ERR_INVALID_CHARS,
				win32font->logfont.lfFaceName, -1,
				logfontw.lfFaceName, G_N_ELEMENTS (logfontw.lfFaceName)))
	logfontw.lfFaceName[0] = 0; /* Hopefully this will select some font */

      cwfont->font_face = cairo_win32_font_face_create_for_logfontw (&logfontw);

      /* Failure of the above should only occur for out of memory,
       * we can't proceed at that point
       */
      if (!cwfont->font_face)
	g_error ("Unable to create Win32 cairo font face.\nThis means out of memory or a cairo/fontconfig/FreeType bug");
    }

  return cwfont->font_face;
}

static cairo_scaled_font_t *
pango_cairo_win32_font_get_scaled_font (PangoCairoFont *font)
{
  PangoCairoWin32Font *cwfont = PANGO_CAIRO_WIN32_FONT (font);

  if (!cwfont->scaled_font)
    {
      cairo_font_face_t *font_face;

      font_face = pango_cairo_win32_font_get_font_face (font);
      cwfont->scaled_font = cairo_scaled_font_create (font_face,
						      &cwfont->font_matrix,
						      &cwfont->ctm,
						      cwfont->options);

      /* Failure of the above should only occur for out of memory,
       * we can't proceed at that point
       */
      if (!cwfont->scaled_font)
	g_error ("Unable to create Win32 cairo scaled font.\nThis means out of memory or a cairo/fontconfig/FreeType bug");
    }

  return cwfont->scaled_font;
}

/********************************
 *    Method implementations    *
 ********************************/

static gboolean
pango_cairo_win32_font_install (PangoCairoFont *font,
				cairo_t        *cr)
{
  PangoCairoWin32Font *cwfont = PANGO_CAIRO_WIN32_FONT (font);

  cairo_set_font_face (cr,
		       pango_cairo_win32_font_get_font_face (font));
  cairo_set_font_matrix (cr, &cwfont->font_matrix);
  cairo_set_font_options (cr, cwfont->options);

  return TRUE;
}

static void
cairo_font_iface_init (PangoCairoFontIface *iface)
{
  iface->install = pango_cairo_win32_font_install;
  iface->get_font_face = pango_cairo_win32_font_get_font_face;
  iface->get_scaled_font = pango_cairo_win32_font_get_scaled_font;
}

G_DEFINE_TYPE_WITH_CODE (PangoCairoWin32Font, pango_cairo_win32_font, PANGO_TYPE_WIN32_FONT,
    { G_IMPLEMENT_INTERFACE (PANGO_TYPE_CAIRO_FONT, cairo_font_iface_init) });

static void
free_metrics_info (PangoWin32MetricsInfo *info)
{
  pango_font_metrics_unref (info->metrics);
  g_slice_free (PangoWin32MetricsInfo, info);
}

static void
pango_cairo_win32_font_finalize (GObject *object)
{
  PangoCairoWin32Font *cwfont = PANGO_CAIRO_WIN32_FONT (object);

  g_hash_table_destroy (cwfont->glyph_info);

  g_slist_foreach (cwfont->metrics_by_lang, (GFunc)free_metrics_info, NULL);
  g_slist_free (cwfont->metrics_by_lang);

  if (cwfont->scaled_font)
    cairo_scaled_font_destroy (cwfont->scaled_font);

  if (cwfont->options)
    cairo_font_options_destroy (cwfont->options);

  G_OBJECT_CLASS (pango_cairo_win32_font_parent_class)->finalize (object);
}

static void
compute_glyph_extents (PangoFont        *font,
		       PangoGlyph        glyph,
		       PangoRectangle   *ink_rect,
		       PangoRectangle   *logical_rect)
{
  PangoCairoFont *cfont = (PangoCairoFont *)font;
  cairo_scaled_font_t *scaled_font = pango_cairo_win32_font_get_scaled_font (PANGO_CAIRO_FONT (cfont));

  /* It may well be worth caching the font_extents here, since getting them
   * is pretty expensive.
   */
  cairo_font_extents_t font_extents;
  cairo_text_extents_t extents;
  cairo_glyph_t cairo_glyph;

  cairo_scaled_font_extents (scaled_font, &font_extents);

  logical_rect->x = 0;
  logical_rect->y = - font_extents.ascent * PANGO_SCALE;
  logical_rect->width = 0;
  logical_rect->height = (font_extents.ascent + font_extents.descent) * PANGO_SCALE;

  if (glyph == PANGO_GLYPH_EMPTY)
    {
      /* already initialized above */
    }
  else if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
    {
      /* space for the hex box */
      _pango_cairo_get_glyph_extents_missing(cfont, glyph, ink_rect, logical_rect);
    }
  else
    {
      cairo_glyph.index = glyph;
      cairo_glyph.x = 0;
      cairo_glyph.y = 0;

      cairo_scaled_font_glyph_extents (scaled_font,
				       &cairo_glyph, 1, &extents);

      ink_rect->x = extents.x_bearing * PANGO_SCALE;
      ink_rect->y = extents.y_bearing * PANGO_SCALE;
      ink_rect->width = extents.width * PANGO_SCALE;
      ink_rect->height = extents.height * PANGO_SCALE;

      logical_rect->width = extents.x_advance * PANGO_SCALE;
    }
}

static PangoCairoWin32GlyphInfo *
pango_cairo_win32_font_get_glyph_info (PangoFont   *font,
				       PangoGlyph   glyph)
{
  PangoCairoWin32Font *cwfont = (PangoCairoWin32Font *)font;
  PangoCairoWin32GlyphInfo *info;

  info = g_hash_table_lookup (cwfont->glyph_info, GUINT_TO_POINTER (glyph));
  if (!info)
    {
      info = g_new0 (PangoCairoWin32GlyphInfo, 1);

      compute_glyph_extents (font, glyph,
			     &info->ink_rect,
			     &info->logical_rect);

      g_hash_table_insert (cwfont->glyph_info, GUINT_TO_POINTER (glyph), info);
    }

  return info;
}

static void
pango_cairo_win32_font_get_glyph_extents (PangoFont        *font,
					  PangoGlyph        glyph,
					  PangoRectangle   *ink_rect,
					  PangoRectangle   *logical_rect)
{
  PangoCairoWin32GlyphInfo *info;

  info = pango_cairo_win32_font_get_glyph_info (font, glyph);

  if (ink_rect)
    *ink_rect = info->ink_rect;
  if (logical_rect)
    *logical_rect = info->logical_rect;
}