pangox.c

GTK+-2.0源码之pango-1.15.6.tar.gz

	  if (font)
	    metrics = pango_font_get_metrics (font, NULL);
	  else
	    metrics = NULL;

	  if (metrics)
	    {
	      y1 = glyph_y - PANGO_PIXELS (metrics->ascent);
	      y2 = y1 + PANGO_PIXELS (metrics->ascent + metrics->descent);
	    }
	  else
	    {
	      y2 = glyph_y;
	      y1 = y2 - PANGO_UNKNOWN_GLYPH_HEIGHT;
	    }

	  x1 = glyph_x;
	  x2 = x1 + PANGO_PIXELS (glyphs->glyphs[i].geometry.width);

	  baseline = glyph_y;
	  stroke_thick = MAX ((int) (0.5 + 0.075 * (y2 - y1)), 1);

	  if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
	    wc = glyph & (~PANGO_GLYPH_UNKNOWN_FLAG);
	  else
	    wc = 0;

	  switch (wc)
	    {
	    case '\n':
	    case '\r':
	    case 0x2028: /* Line separator */
	    case 0x2029: /* Paragraph separator */
	      {
		/* Draw a carriage-return thingy */
		PangoRectangle up_stroke;
		PangoRectangle across_stroke;

		int hborder = (x2 - x1) * 0.1;
		int arrow_height = 0.25 * (y2 - y1);
		int top_border = (y2 - y1) * 0.25;

		int arrow_x, arrow_width, tmp_height;

		/* Draw the arrow-head */

		tmp_height = (stroke_thick % 2 == 0) ? 2 : 1; /* Starting height */
		arrow_height = 2 * ((1 + arrow_height - tmp_height) / 2) + tmp_height; /* Force symmetry */
		arrow_width = 2 + arrow_height - tmp_height;

		for (arrow_x = x1 + hborder; arrow_x < x1 + hborder + arrow_width; arrow_x++)
		  {
		    XDrawLine (display, d, gc,
			       arrow_x,
			       baseline - stroke_thick + (stroke_thick - tmp_height) / 2,
			       arrow_x,
			       baseline - stroke_thick + (stroke_thick - tmp_height) / 2 + tmp_height - 1);

		    if ((arrow_x - x1 - hborder) % 2 == 1)
		      tmp_height += 2;
		  }

		across_stroke.x = arrow_x;
		across_stroke.width = x2 - hborder - arrow_x - stroke_thick;
		across_stroke.y = baseline - stroke_thick;
		across_stroke.height = stroke_thick;

		XFillRectangle (display, d, gc,
				across_stroke.x, across_stroke.y,
				across_stroke.width, across_stroke.height);

		up_stroke.x = across_stroke.x + across_stroke.width;
		up_stroke.width = stroke_thick;
		up_stroke.y = y1 + top_border;
		up_stroke.height = baseline - up_stroke.y;

		XFillRectangle (display, d, gc,
				up_stroke.x, up_stroke.y,
				up_stroke.width, up_stroke.height);
	      }
	      break;

	    default:
	      {
		/* Perhaps we should draw the box-with-numbers as in the
		 * Xft backend, though we have no guarantee of having
		 * an appropriate size of font. Right now, we just
		 * draw an empty box. (To draw the box-with-numbers.
		 * the backends would have to be changed to use
		 * pango_x_font_get_unknown_glyph() rather than
		 * pango_x_get_unknown_glyph().
		 */

		int xspace = MAX ((int) (0.5 + 0.1 * (x2 - x1)), 1);
		int yspace = MAX ((int) (0.5 + 0.1 * (y2 - y1)), 1);

		x1 += xspace;
		x2 -= xspace;
		y1 += yspace;
		y2 -= yspace;

		XFillRectangle (display, d, gc,
				x1, y1,
				x2 - x1, stroke_thick);
		XFillRectangle (display, d, gc,
				x1, y1 + stroke_thick,
				stroke_thick, y2 - y1 - 2 * stroke_thick);
		XFillRectangle (display, d, gc,
				x2 - stroke_thick, y1 + stroke_thick,
				stroke_thick, y2 - y1 - 2 * stroke_thick);
		XFillRectangle (display, d, gc,
				x1, y2 - stroke_thick,
				x2 - x1, stroke_thick);

		break;
	      }
	    }

	  pango_font_metrics_unref (metrics);
	}

    next_glyph:
      x_off += glyphs->glyphs[i].geometry.width;
    }
  FLUSH;
}

#undef FLUSH

static void
pango_x_font_get_glyph_extents  (PangoFont      *font,
				 PangoGlyph      glyph,
				 PangoRectangle *ink_rect,
				 PangoRectangle *logical_rect)
{
  XCharStruct *cs;
  PangoXSubfontInfo *subfont;

  if (glyph == PANGO_GLYPH_EMPTY)
    {
      if (ink_rect)
	ink_rect->x = ink_rect->width = ink_rect->y = ink_rect->height = 0;
      if (logical_rect)
	logical_rect->x = logical_rect->width = logical_rect->y = logical_rect->height = 0;
      return;
    }
  if ((glyph & PANGO_GLYPH_UNKNOWN_FLAG) == 0 && pango_x_find_glyph (font, glyph, &subfont, &cs))
    {
      if (ink_rect)
	{
	  ink_rect->x = PANGO_SCALE * cs->lbearing;
	  ink_rect->width = PANGO_SCALE * (cs->rbearing - cs->lbearing);
	  ink_rect->y = PANGO_SCALE * -cs->ascent;
	  ink_rect->height = PANGO_SCALE * (cs->ascent + cs->descent);
	}
      if (logical_rect)
	{
	  logical_rect->x = 0;
	  logical_rect->width = PANGO_SCALE * cs->width;
	  logical_rect->y = - PANGO_SCALE * subfont->font_struct->ascent;
	  logical_rect->height = PANGO_SCALE * (subfont->font_struct->ascent + subfont->font_struct->descent);
	}
    }
  else
    {
      PangoFontMetrics *metrics;
      gunichar wc;
      gdouble width_factor;
      int w;

      if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
	wc = glyph & (~PANGO_GLYPH_UNKNOWN_FLAG);
      else
	wc = 0;

      switch (wc)
	{
	case '\n':
	case '\r':
	case 0x2028: /* Line separator */
	case 0x2029: /* Paragraph separator */
	  {
#define MAGIC_FACTOR 1.2

	    /* carriage-return thingy */
	    width_factor = MAGIC_FACTOR;
	    break;
	  }
	default:
	  {
	    /* Unknown glyph square */
	    width_factor = 1.0;
	  }
	}

      metrics = pango_font_get_metrics (font, NULL);

      if (metrics)
	{
	  w = metrics->approximate_char_width * width_factor;
	  w = PANGO_SCALE * PANGO_PIXELS (w);

	  if (ink_rect)
	    {
	      ink_rect->x = PANGO_SCALE;
	      ink_rect->width = w - 2 * PANGO_SCALE;
	      ink_rect->y = - (metrics->ascent - PANGO_SCALE);
	      ink_rect->height = metrics->ascent + metrics->descent - 2 * PANGO_SCALE;
	    }
	  if (logical_rect)
	    {
	      logical_rect->x = 0;
	      logical_rect->width = w;
	      logical_rect->y = - metrics->ascent;
	      logical_rect->height = metrics->ascent + metrics->descent;
	    }

	  pango_font_metrics_unref (metrics);
	}
      else
	{
	  if (ink_rect)
	    ink_rect->x = ink_rect->y = ink_rect->height = ink_rect->width = 0;
	  if (logical_rect)
	    logical_rect->x = logical_rect->y = logical_rect->height = logical_rect->width = 0;
	}
    }
}

static gboolean
get_int_prop (Atom         atom,
	      XFontStruct *fs,
	      int         *val)
{
  int i;

  *val = 0;

  i = 0;
  while (i < fs->n_properties)
    {
      if (fs->properties[i].name == atom)
	{
	  *val = fs->properties[i].card32;
	  return TRUE;
	}

      ++i;
    }

  return FALSE;
}

/* Call @func with each glyph resulting from shaping @string with each
 * glyph. This duplicates quite a bit of code from pango_itemize. This
 * function should die and we should simply add the ability to specify
 * particular fonts when itemizing.
 */
static void
itemize_string_foreach (PangoFont     *font,
			PangoLanguage *language,
			const char    *str,
			void         (*func) (PangoFont      *font,
					      PangoGlyphInfo *glyph_info,
					      gpointer        data),
			gpointer       data)
{
  const char *start, *p;
  PangoGlyphString *glyph_str = pango_glyph_string_new ();
  PangoEngineShape *shaper, *last_shaper;
  int last_level;
  int i;
  guint8 *embedding_levels;
  PangoDirection base_dir = PANGO_DIRECTION_LTR;
  gboolean finished = FALSE;

  embedding_levels = pango_log2vis_get_embedding_levels (str, -1, &base_dir);

  last_shaper = NULL;
  last_level = 0;

  i = 0;
  p = start = str;
  while (*p || !finished)
    {
      gunichar wc;

      if (*p)
	{
	  wc = g_utf8_get_char (p);
	  shaper = pango_font_find_shaper (font, language, wc);
	}
      else
	{
	  finished = TRUE;
	  shaper = NULL;
	}

      if (p > start &&
	  (finished ||
	   (shaper != last_shaper || last_level != embedding_levels[i])))
	{
	  PangoAnalysis analysis;
	  int j;

	  analysis.shape_engine = last_shaper;
	  analysis.lang_engine = NULL;
	  analysis.font = font;
	  analysis.language = language;
	  analysis.level = last_level;
	  analysis.extra_attrs = NULL;

	  pango_shape (start, p - start, &analysis, glyph_str);

	  for (j = 0; j < glyph_str->num_glyphs; j++)
	    (*func) (font, &glyph_str->glyphs[j], data);

	  start = p;
	}

      if (!finished)
	{
	  p = g_utf8_next_char (p);

	  last_shaper = shaper;
	  last_level = embedding_levels[i];
	  i++;
	}
    }

  pango_glyph_string_free (glyph_str);
  g_free (embedding_levels);
}

/* Get composite font metrics for all subfonts in list
 */
static void
get_font_metrics_from_subfonts (PangoFont        *font,
				GSList           *subfonts,
				PangoFontMetrics *metrics)
{
  PangoXFont *xfont = (PangoXFont *)font;
  GSList *tmp_list = subfonts;
  gboolean first = TRUE;
  int total_avg_widths = 0;
  int n_avg_widths = 0;
  Atom avg_width_atom;

  avg_width_atom = pango_x_fontmap_atom_from_name (xfont->fontmap,
						   "AVERAGE_WIDTH");

  metrics->ascent = 0;
  metrics->descent = 0;

  while (tmp_list)
    {
      PangoXSubfontInfo *subfont = pango_x_find_subfont (font, GPOINTER_TO_UINT (tmp_list->data));

      if (subfont)
	{
	  XFontStruct *fs = pango_x_get_font_struct (font, subfont);
	  gint avg_width = 0;

	  if (fs)
	    {
	      if (first)
		{
		  metrics->ascent = fs->ascent * PANGO_SCALE;
		  metrics->descent = fs->descent * PANGO_SCALE;
		  first = FALSE;
		}
	      else
		{
		  metrics->ascent = MAX (fs->ascent * PANGO_SCALE, metrics->ascent);
		  metrics->descent = MAX (fs->descent * PANGO_SCALE, metrics->descent);
		}

	      if (get_int_prop (avg_width_atom, fs, &avg_width))
		{
		  /* convert decipoints --> Pango units.
		   * Resolution is in (points * PANGO_SCALE) / pixel,
		   * avg_width in decipoints.
		   * We want pixels * PANGO_SCALE
		   */

		  /* Convert to points * PANGO_SCALE */
		  avg_width *= PANGO_SCALE / (double) 10.0;
		  /* Convert to pixels * PANGO_SCALE */
		  avg_width *= (PANGO_SCALE / PANGO_X_FONT_MAP (PANGO_X_FONT (font)->fontmap)->resolution);
		}
	      else
		{
		  avg_width = PANGO_SCALE * ((fs->min_bounds.width + fs->max_bounds.width) / 2);
		}
	    }

	  if (avg_width)
	    {
	      total_avg_widths += avg_width;
	      n_avg_widths += 1;
	    }
	}
      else
	g_warning ("Invalid subfont %d in get_font_metrics_from_subfonts", GPOINTER_TO_UINT (tmp_list->data));

      tmp_list = tmp_list->next;
    }

  /* This is pretty darn bogus. */
  if (n_avg_widths)
    metrics->approximate_char_width = total_avg_widths / n_avg_widths;
  else
    metrics->approximate_char_width = PANGO_UNKNOWN_GLYPH_WIDTH * PANGO_SCALE;
  if (metrics->ascent + metrics->descent == 0)
    {
      metrics->ascent = PANGO_UNKNOWN_GLYPH_HEIGHT * PANGO_SCALE;
      metrics->descent = 0;
    }
}

static void
get_subfonts_foreach (PangoFont      *font,
		      PangoGlyphInfo *glyph_info,
		      gpointer        data)
{
  GSList **subfonts = data;
  PangoGlyph glyph = glyph_info->glyph;
  PangoXSubfont subfont;

  if (glyph == PANGO_GLYPH_EMPTY)
    return;

  /* Use an arbitrary subfont for unknown glyphs...*/
  if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
    {
    if (((PangoXFont *)font)->n_subfonts > 0)
      glyph = PANGO_X_MAKE_GLYPH (1, 0);
    else
      return;
    }

  subfont = PANGO_X_GLYPH_SUBFONT (glyph);
  if (!g_slist_find (*subfonts, GUINT_TO_POINTER ((guint)subfont)))
    *subfonts = g_slist_prepend (*subfonts, GUINT_TO_POINTER ((guint)subfont));
}

/* Get composite font metrics for all subfonts resulting from shaping
 * string str with the given font
 */
static void
get_font_metrics_from_string (PangoFont        *font,
			      PangoLanguage    *language,