pangox.c

GTK+-2.0源码之pango-1.15.6.tar.gz

/* pangox.c: Routines for handling X fonts
 *
 * Copyright (C) 1999 Red Hat Software
 * Copyright (C) 2000 SuSE Linux Ltd
 *
 * 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 <string.h>
#include <stdlib.h>
#include <math.h>

#include <X11/Xlib.h>
#include "pango-impl-utils.h"
#include "modules.h"

#undef PANGO_DISABLE_DEPRECATED

#include "pangox.h"
#include "pangox-private.h"

#define PANGO_TYPE_X_FONT              (pango_x_font_get_type ())
#define PANGO_X_FONT(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_TYPE_X_FONT, PangoXFont))
#define PANGO_X_FONT_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_X_FONT, PangoXFontClass))
#define PANGO_X_IS_FONT(object)        (G_TYPE_CHECK_INSTANCE_TYPE ((object), PANGO_TYPE_X_FONT))
#define PANGO_X_IS_FONT_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_X_FONT))
#define PANGO_X_FONT_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_X_FONT, PangoXFontClass))

typedef struct _PangoXFontClass   PangoXFontClass;
typedef struct _PangoXMetricsInfo PangoXMetricsInfo;
typedef struct _PangoXContextInfo PangoXContextInfo;

struct _PangoXSubfontInfo
{
  char *xlfd;
  XFontStruct *font_struct;
  gboolean     is_1byte;
  int          range_byte1;
  int          range_byte2;
};

struct _PangoXMetricsInfo
{
  const char *sample_str;
  PangoFontMetrics *metrics;
};

struct _PangoXContextInfo
{
  PangoGetGCFunc  get_gc_func;
  PangoFreeGCFunc free_gc_func;
};

struct _PangoXFontClass
{
  PangoFontClass parent_class;
};

static PangoFontClass *parent_class;	/* Parent class structure for PangoXFont */

static void pango_x_font_class_init (PangoXFontClass *class);
static void pango_x_font_init       (PangoXFont      *xfont);
static void pango_x_font_dispose    (GObject         *object);
static void pango_x_font_finalize   (GObject         *object);

static PangoFontDescription *pango_x_font_describe          (PangoFont        *font);
static PangoCoverage *       pango_x_font_get_coverage      (PangoFont        *font,
							     PangoLanguage    *language);
static PangoEngineShape *    pango_x_font_find_shaper       (PangoFont        *font,
							     PangoLanguage    *language,
							     guint32           ch);
static void                  pango_x_font_get_glyph_extents (PangoFont        *font,
							     PangoGlyph        glyph,
							     PangoRectangle   *ink_rect,
							     PangoRectangle   *logical_rect);
static PangoFontMetrics *    pango_x_font_get_metrics       (PangoFont        *font,
							     PangoLanguage    *language);
static PangoFontMap *        pango_x_font_get_font_map      (PangoFont        *font);

static PangoXSubfontInfo * pango_x_find_subfont    (PangoFont          *font,
						    PangoXSubfont       subfont_index);
static XCharStruct *       pango_x_get_per_char    (PangoFont          *font,
						    PangoXSubfontInfo  *subfont,
						    guint16             char_index);
static gboolean            pango_x_find_glyph      (PangoFont          *font,
						    PangoGlyph          glyph,
						    PangoXSubfontInfo **subfont_return,
						    XCharStruct       **charstruct_return);
static XFontStruct *       pango_x_get_font_struct (PangoFont          *font,
						    PangoXSubfontInfo  *info);

static void     pango_x_get_item_properties (PangoItem      *item,
					     PangoUnderline *uline,
					     PangoAttrColor *fg_color,
					     gboolean       *fg_set,
					     PangoAttrColor *bg_color,
					     gboolean       *bg_set);

static inline PangoXSubfontInfo *
pango_x_find_subfont (PangoFont  *font,
		      PangoXSubfont subfont_index)
{
  PangoXFont *xfont = (PangoXFont *)font;

  if (subfont_index < 1 || subfont_index > xfont->n_subfonts)
    {
      g_warning ("Invalid subfont %d", subfont_index);
      return NULL;
    }

  return xfont->subfonts[subfont_index-1];
}

static void
pango_x_make_font_struct (PangoFont *font, PangoXSubfontInfo *info)
{
  PangoXFont *xfont = (PangoXFont *)font;
  PangoXFontCache *cache;

  cache = pango_x_font_map_get_font_cache (xfont->fontmap);

  info->font_struct = pango_x_font_cache_load (cache, info->xlfd);
  if (!info->font_struct)
    {
      g_warning ("Cannot load font for XLFD '%s\n", info->xlfd);

      /* Prevent a segfault, but probably not much more */
      info->font_struct = pango_x_font_cache_load (cache, "fixed");
    }

  info->is_1byte = (info->font_struct->min_byte1 == 0 && info->font_struct->max_byte1 == 0);
  info->range_byte1 = info->font_struct->max_byte1 - info->font_struct->min_byte1 + 1;
  info->range_byte2 = info->font_struct->max_char_or_byte2 - info->font_struct->min_char_or_byte2 + 1;
}

static inline XFontStruct *
pango_x_get_font_struct (PangoFont *font, PangoXSubfontInfo *info)
{
  if (!info->font_struct)
    pango_x_make_font_struct (font, info);

  return info->font_struct;
}

/**
 * pango_x_get_context:
 * @display: an X display (As returned by XOpenDisplay().)
 *
 * Retrieves a #PangoContext appropriate for rendering with X fonts on the
 * given display.
 *
 * Return value: the new #PangoContext.
 **/
PangoContext *
pango_x_get_context (Display *display)
{
  PangoContext *result;
  PangoXContextInfo *info;
  int i;
  static gboolean registered_modules = FALSE;

  g_return_val_if_fail (display != NULL, NULL);

  if (!registered_modules)
    {
      registered_modules = TRUE;

      for (i = 0; _pango_included_x_modules[i].list; i++)
	pango_module_register (&_pango_included_x_modules[i]);
    }

  result = pango_context_new ();

  info = g_new (PangoXContextInfo, 1);
  info->get_gc_func = NULL;
  info->free_gc_func = NULL;
  g_object_set_qdata_full (G_OBJECT (result),
			   g_quark_from_static_string ("pango-x-info"),
			   info, (GDestroyNotify)g_free);

  pango_context_set_font_map (result, pango_x_font_map_for_display (display));

  return result;
}

/**
 * pango_x_context_set_funcs:
 * @context: a #PangoContext.
 * @get_gc_func: function called to create a new GC for a given color.
 * @free_gc_func: function called to free a GC created with @get_gc_func.
 *
 * Sets the functions that will be used to get GC's in various colors when
 * rendering layouts with this context.
 **/
void
pango_x_context_set_funcs  (PangoContext     *context,
			    PangoGetGCFunc    get_gc_func,
			    PangoFreeGCFunc   free_gc_func)
{
  PangoXContextInfo *info;

  g_return_if_fail (context != NULL);

  info = g_object_get_qdata (G_OBJECT (context),
			     g_quark_from_static_string ("pango-x-info"));

  info->get_gc_func = get_gc_func;
  info->free_gc_func = free_gc_func;
}

static GType
pango_x_font_get_type (void)
{
  static GType object_type = 0;

  if (!object_type)
    {
      const GTypeInfo object_info =
      {
	sizeof (PangoXFontClass),
	(GBaseInitFunc) NULL,
	(GBaseFinalizeFunc) NULL,
	(GClassInitFunc) pango_x_font_class_init,
	NULL,           /* class_finalize */
	NULL,           /* class_data */
	sizeof (PangoXFont),
	0,              /* n_preallocs */
	(GInstanceInitFunc) pango_x_font_init,
	NULL            /* value_table */
      };

      object_type = g_type_register_static (PANGO_TYPE_FONT,
					    I_("PangoXFont"),
					    &object_info, 0);
    }

  return object_type;
}

static void
pango_x_font_init (PangoXFont *xfont)
{
  xfont->subfonts_by_charset = g_hash_table_new (g_str_hash, g_str_equal);
  xfont->subfonts = g_new (PangoXSubfontInfo *, 1);

  xfont->n_subfonts = 0;
  xfont->max_subfonts = 1;

  xfont->metrics_by_lang = NULL;

  xfont->size = -1;
  xfont->xface = NULL;
}

static void
pango_x_font_class_init (PangoXFontClass *class)
{
  GObjectClass *object_class = G_OBJECT_CLASS (class);
  PangoFontClass *font_class = PANGO_FONT_CLASS (class);

  parent_class = g_type_class_peek_parent (class);

  object_class->finalize = pango_x_font_finalize;
  object_class->dispose = pango_x_font_dispose;

  font_class->describe = pango_x_font_describe;
  font_class->get_coverage = pango_x_font_get_coverage;
  font_class->find_shaper = pango_x_font_find_shaper;
  font_class->get_glyph_extents = pango_x_font_get_glyph_extents;
  font_class->get_metrics = pango_x_font_get_metrics;
  font_class->get_font_map = pango_x_font_get_font_map;
}

PangoXFont *
pango_x_font_new (PangoFontMap *fontmap, const char *spec, int size)
{
  PangoXFont *result;

  g_return_val_if_fail (fontmap != NULL, NULL);
  g_return_val_if_fail (spec != NULL, NULL);

  result = g_object_new (PANGO_TYPE_X_FONT, NULL);

  result->fontmap = fontmap;
  g_object_ref (fontmap);
  result->display = pango_x_fontmap_get_display (fontmap);

  result->fonts = g_strsplit(spec, ",", -1);
  for (result->n_fonts = 0; result->fonts[result->n_fonts]; result->n_fonts++)
    ; /* Nothing */

  result->size = size;

  return result;
}

/**
 * pango_x_load_font:
 * @display: the X display.
 * @spec:    a comma-separated list of XLFD's.
 *
 * Loads up a logical font based on a "fontset" style text
 * specification. This is not remotely useful (Pango API's generally
 * work in terms of #PangoFontDescription) and the result may not
 * work correctly in all circumstances. Use of this function should
 * be avoided.
 *
 * Returns a new #PangoFont.
 */
PangoFont *
pango_x_load_font (Display    *display,
		   const char *spec)
{
  PangoXFont *result;

  g_return_val_if_fail (display != NULL, NULL);
  g_return_val_if_fail (spec != NULL, NULL);

  result = pango_x_font_new (pango_x_font_map_for_display (display), spec, -1);

  return (PangoFont *)result;
}


#define FLUSH						\
  G_STMT_START {					\
    if (charcount)					\
      {							\
	XDrawString16 (display, d, gc,			\
		       glyph_x0, glyph_y0,		\
		       xcharbuffer, charcount);		\
	charcount = 0;					\
      }							\
  } G_STMT_END


/**
 * pango_x_render:
 * @display: the X display.
 * @d:       the drawable on which to draw string.
 * @gc:      the graphics context.
 * @font:    the font in which to draw the string.
 * @glyphs:  the glyph string to draw.
 * @x:       the x position of start of string (in pixels).
 * @y:       the y position of baseline (in pixels).
 *
 * Renders a #PangoGlyphString onto an X drawable.
 */
void
pango_x_render  (Display           *display,
		 Drawable           d,
		 GC                 gc,
		 PangoFont         *font,
		 PangoGlyphString  *glyphs,
		 int                x,
		 int                y)
{
  Font old_fid = None;
  XFontStruct *fs;
  int i;
  int x_off = 0;

  /*
   * We collect the characters in this buffer as long as the font does not
   * change.  At that time, or when the buffer runs full, or at the end,
   * then we empty the buffer.
   */
  XChar2b xcharbuffer[1000];
  int glyph_x0 = 0, expected_x = 0; /* x/y initializations are to quiet GCC */
  int glyph_y0 = 0;
  int charcount = 0;

  g_return_if_fail (display != NULL);
  g_return_if_fail (glyphs != NULL);

  for (i=0; i<glyphs->num_glyphs; i++)
    {
      PangoGlyph glyph = glyphs->glyphs[i].glyph;
      int glyph_x = x + PANGO_PIXELS (x_off + glyphs->glyphs[i].geometry.x_offset);
      int glyph_y = y + PANGO_PIXELS (glyphs->glyphs[i].geometry.y_offset);

      /* Clip glyphs into the X coordinate range; we really
       * want to clip glyphs with an ink rect outside the
       * [0,32767] x [0,32767] rectangle but looking up
       * the ink rect here would be a noticeable speed hit.
       * This is close enough.
       */
      if (!(glyph != PANGO_GLYPH_EMPTY &&
	    glyph_x >= -16384 && glyph_x <= 32767 &&
	    glyph_y >= -16384 && glyph_y <= 32767))
	goto next_glyph;

      if ((glyph & PANGO_GLYPH_UNKNOWN_FLAG) == 0)
	{
	  guint16 index = PANGO_X_GLYPH_INDEX (glyph);
	  guint16 subfont_index = PANGO_X_GLYPH_SUBFONT (glyph);
	  PangoXSubfontInfo *subfont;

	  subfont = pango_x_find_subfont (font, subfont_index);
	  if (subfont)
	    {
	      fs = pango_x_get_font_struct (font, subfont);
	      if (!fs)
		continue;

	      if (fs->fid != old_fid)
		{
		  FLUSH;
		  XSetFont (display, gc, fs->fid);
		  old_fid = fs->fid;
		}

	      if (charcount == G_N_ELEMENTS (xcharbuffer) ||
		  (charcount > 0 && (glyph_y != glyph_y0 ||
				     glyph_x != expected_x)))
		FLUSH;

	      if (charcount == 0)
		{
		  glyph_x0 = glyph_x;
		  glyph_y0 = glyph_y;
		}
	      xcharbuffer[charcount].byte1 = index / 256;
	      xcharbuffer[charcount].byte2 = index % 256;

	      expected_x = glyph_x + XTextWidth16 (fs, &xcharbuffer[charcount], 1);

	      charcount++;
	    } else
	      goto unknown_glyph;
	} else {
	  PangoFontMetrics *metrics;
	  int x1, y1, x2, y2; /* rectangle the character should go inside. */
	  int baseline;
	  int stroke_thick;
	  gunichar wc;

	unknown_glyph:
	  FLUSH;