pango-renderer.c

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

  *total = *global;
  pango_matrix_concat (total, &local);

  total->x0 = (global->xx * x + global->xy * y) / PANGO_SCALE + global->x0;
  total->y0 = (global->yx * x + global->yy * y) / PANGO_SCALE + global->y0;
}

static void
pango_renderer_default_draw_error_underline (PangoRenderer *renderer,
					     int            x,
					     int            y,
					     int            width,
					     int            height)
{
  int square = height / HEIGHT_SQUARES;
  int unit_width = (HEIGHT_SQUARES - 1) * square;
  int width_units = (width + unit_width / 2) / unit_width;
  static const PangoMatrix identity = PANGO_MATRIX_INIT;
  const PangoMatrix *matrix;

  x += (width - width_units * unit_width) / 2;
  width = width_units * unit_width;

  if (renderer->matrix)
    matrix = renderer->matrix;
  else
    matrix = &identity;

  while (TRUE)
    {
      PangoMatrix total;
      get_total_matrix (&total, matrix, x, y, square);

      draw_rectangle (renderer, &total, PANGO_RENDER_PART_UNDERLINE, /* A */
		      0,                      0,
		      HEIGHT_SQUARES * 2 - 1, 1);

      if (width_units > 2)
	{
	  draw_rectangle (renderer, &total, PANGO_RENDER_PART_UNDERLINE, /* B */
			  HEIGHT_SQUARES * 2 - 2, - (HEIGHT_SQUARES * 2 - 3),
			  1,                      HEIGHT_SQUARES * 2 - 3);
	  width_units -= 2;
	  x += unit_width * 2;
	}
      else if (width_units == 2)
	{
	  draw_rectangle (renderer, &total, PANGO_RENDER_PART_UNDERLINE, /* C */
			  HEIGHT_SQUARES * 2 - 2, - (HEIGHT_SQUARES * 2 - 2),
			  1,                      HEIGHT_SQUARES * 2 - 2);
	  break;
	}
      else
	break;
    }
}

/**
 * pango_renderer_draw_trapezoid:
 * @renderer: a #PangoRenderer
 * @part: type of object this trapezoid is part of
 * @y1_: Y coordinate of top of trapezoid
 * @x11: X coordinate of left end of top of trapezoid
 * @x21: X coordinate of right end of top of trapezoid
 * @y2: Y coordinate of bottom of trapezoid
 * @x12: X coordinate of left end of bottom of trapezoid
 * @x22: X coordinate of right end of bottom of trapezoid
 *
 * Draws a trapezoid with the parallel sides aligned with the X axis
 * using the given #PangoRenderer; coordinates are in device space.
 *
 * Since: 1.8
 **/
void
pango_renderer_draw_trapezoid (PangoRenderer  *renderer,
			       PangoRenderPart part,
			       double          y1_,
			       double          x11,
			       double          x21,
			       double          y2,
			       double          x12,
			       double          x22)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
  g_return_if_fail (renderer->active_count > 0);

  if (PANGO_RENDERER_GET_CLASS (renderer)->draw_trapezoid)
    PANGO_RENDERER_GET_CLASS (renderer)->draw_trapezoid (renderer, part,
							 y1_, x11, x21,
							 y2, x12, x22);
}

/**
 * pango_renderer_draw_glyph:
 * @renderer: a #PangoRenderer
 * @font: a #PangoFont
 * @glyph: the glyph index of a single glyph
 * @x: X coordinate of left edge of baseline of glyph
 * @y: Y coordinate of left edge of baseline of glyph
 *
 * Draws a single glyph with coordinates in device space.
 *
 * Since: 1.8
 **/
void
pango_renderer_draw_glyph (PangoRenderer *renderer,
			   PangoFont     *font,
			   PangoGlyph     glyph,
			   double         x,
			   double         y)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
  g_return_if_fail (renderer->active_count > 0);

  if (glyph == PANGO_GLYPH_EMPTY) /* glyph PANGO_GLYPH_EMPTY never renders */
    return;

  if (PANGO_RENDERER_GET_CLASS (renderer)->draw_glyph)
    PANGO_RENDERER_GET_CLASS (renderer)->draw_glyph (renderer, font, glyph, x, y);
}

/**
 * pango_renderer_activate:
 * @renderer: a #PangoRenderer
 *
 * Does initial setup before rendering operations on @renderer.
 * pango_renderer_deactivate() should be called when done drawing.
 * Calls such as pango_renderer_draw_layout() automatically
 * activate the layout before drawing on it. Calls to
 * pango_renderer_activate() and pango_renderer_deactivate() can
 * be nested and the renderer will only be initialized and
 * deinitialized once.
 *
 * Since: 1.8
 **/
void
pango_renderer_activate (PangoRenderer *renderer)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));

  renderer->active_count++;
  if (renderer->active_count == 1)
    {
      if (PANGO_RENDERER_GET_CLASS (renderer)->begin)
	PANGO_RENDERER_GET_CLASS (renderer)->begin (renderer);
    }
}

/**
 * pango_renderer_deactivate:
 * @renderer: a #PangoRenderer
 *
 * Cleans up after rendering operations on @renderer. See
 * docs for pango_renderer_activate().
 *
 * Since: 1.8
 **/
void
pango_renderer_deactivate (PangoRenderer *renderer)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
  g_return_if_fail (renderer->active_count > 0);

  if (renderer->active_count == 1)
    {
      if (PANGO_RENDERER_GET_CLASS (renderer)->end)
	PANGO_RENDERER_GET_CLASS (renderer)->end (renderer);
    }
  renderer->active_count--;
}

/**
 * pango_renderer_set_color:
 * @renderer: a #PangoRenderer
 * @part: the part to change the color of
 * @color: the new color or %NULL to unset the current color
 *
 * Sets the color for part of the rendering.
 *
 * Since: 1.8
 **/
void
pango_renderer_set_color (PangoRenderer    *renderer,
			  PangoRenderPart   part,
			  const PangoColor *color)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
  g_return_if_fail (IS_VALID_PART (part));

  if ((!color && !renderer->priv->color_set[part]) ||
      (color && renderer->priv->color_set[part] &&
       renderer->priv->color[part].red == color->red &&
       renderer->priv->color[part].green == color->green &&
       renderer->priv->color[part].blue == color->blue))
    return;

  pango_renderer_part_changed (renderer, part);

  if (color)
    {
      renderer->priv->color_set[part] = TRUE;
      renderer->priv->color[part] = *color;
    }
  else
    {
      renderer->priv->color_set[part] = FALSE;
    }
}

/**
 * pango_renderer_get_color:
 * @renderer: a #PangoRenderer
 * @part: the part to get the color for
 *
 * Gets the current rendering color for the specified part.
 *
 * Return value: the color for the specified part, or %NULL
 *  if it hasn't been set and should be inherited from the
 *  environment.
 *
 * Since: 1.8
 **/
PangoColor *
pango_renderer_get_color (PangoRenderer   *renderer,
			  PangoRenderPart  part)
{
  g_return_val_if_fail (PANGO_IS_RENDERER_FAST (renderer), NULL);
  g_return_val_if_fail (IS_VALID_PART (part), NULL);

  if (renderer->priv->color_set[part])
    return &renderer->priv->color[part];
  else
    return NULL;
}

/**
 * pango_renderer_part_changed:
 * @renderer: a #PangoRenderer
 * @part: the part for which rendering has changed.
 *
 * Informs Pango that the way that the rendering is done
 * for @part has changed in a way that would prevent multiple
 * pieces being joined together into one drawing call. For
 * instance, if a subclass of #PangoRenderer was to add a stipple
 * option for drawing underlines, it needs to call
 *
 * <informalexample><programlisting>
 * pango_renderer_part_changed (render, PANGO_RENDER_PART_UNDERLINE);
 * </programlisting></informalexample>
 *
 * When the stipple changes or underlines with different stipples
 * might be joined together. Pango automatically calls this for
 * changes to colors. (See pango_renderer_set_color())
 *
 * Since: 1.8
 **/
void
pango_renderer_part_changed (PangoRenderer    *renderer,
			     PangoRenderPart   part)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
  g_return_if_fail (IS_VALID_PART (part));
  g_return_if_fail (renderer->active_count > 0);

  handle_line_state_change (renderer, part);

  if (PANGO_RENDERER_GET_CLASS (renderer)->part_changed)
    PANGO_RENDERER_GET_CLASS (renderer)->part_changed (renderer, part);
}

/**
 * pango_renderer_prepare_run:
 * @renderer: a #PangoRenderer
 * @run: a #PangoLayoutRun
 *
 * Set up the state of the #PangoRenderer for rendering @run.
 *
 * Since: 1.8
 **/
static void
pango_renderer_prepare_run (PangoRenderer  *renderer,
			    PangoLayoutRun *run)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));

  PANGO_RENDERER_GET_CLASS (renderer)->prepare_run (renderer, run);
}

static void
pango_renderer_default_prepare_run (PangoRenderer  *renderer,
				    PangoLayoutRun *run)
{
  PangoColor *fg_color = NULL;
  PangoColor *bg_color = NULL;
  PangoColor *underline_color = NULL;
  PangoColor *strikethrough_color = NULL;
  GSList *l;

  renderer->underline = PANGO_UNDERLINE_NONE;
  renderer->strikethrough = FALSE;

  for (l = run->item->analysis.extra_attrs; l; l = l->next)
    {
      PangoAttribute *attr = l->data;

      switch (attr->klass->type)
	{
	case PANGO_ATTR_UNDERLINE:
	  renderer->underline = ((PangoAttrInt *)attr)->value;
	  break;

	case PANGO_ATTR_STRIKETHROUGH:
	  renderer->strikethrough = ((PangoAttrInt *)attr)->value;
	  break;

	case PANGO_ATTR_FOREGROUND:
	  fg_color = &((PangoAttrColor *)attr)->color;
	  break;

	case PANGO_ATTR_BACKGROUND:
	  bg_color = &((PangoAttrColor *)attr)->color;
	  break;

	case PANGO_ATTR_UNDERLINE_COLOR:
	  underline_color = &((PangoAttrColor *)attr)->color;
	  break;

	case PANGO_ATTR_STRIKETHROUGH_COLOR:
	  strikethrough_color = &((PangoAttrColor *)attr)->color;
	  break;

	default:
	  break;
	}
    }

  if (!underline_color)
    underline_color = fg_color;

  if (!strikethrough_color)
    strikethrough_color = fg_color;

  pango_renderer_set_color (renderer, PANGO_RENDER_PART_FOREGROUND, fg_color);
  pango_renderer_set_color (renderer, PANGO_RENDER_PART_BACKGROUND, bg_color);
  pango_renderer_set_color (renderer, PANGO_RENDER_PART_UNDERLINE, underline_color);
  pango_renderer_set_color (renderer, PANGO_RENDER_PART_STRIKETHROUGH, strikethrough_color);
}

/**
 * pango_renderer_set_matrix:
 * @renderer: a #PangoRenderer
 * @matrix: a #PangoMatrix, or %NULL to unset any existing matrix.
 *  (No matrix set is the same as setting the identity matrix.)
 *
 * Sets the transformation matrix that will be applied when rendering.
 *
 * Since: 1.8
 **/
void
pango_renderer_set_matrix (PangoRenderer     *renderer,
			   const PangoMatrix *matrix)
{
  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));

  if (renderer->matrix)
    pango_matrix_free (renderer->matrix);
  if (matrix)
    renderer->matrix = pango_matrix_copy (matrix);
  else
    renderer->matrix = NULL;

}

/**
 * pango_renderer_get_matrix:
 * @renderer: a #PangoRenderer
 *
 * Gets the transformation matrix that will be applied when
 * rendering. See pango_renderer_set_matrix().
 *
 * Return value: the matrix, or %NULL if no matrix has been set
 *  (which is the same as the identity matrix). The returned
 *  matrix is owned by Pango and must not be modified or
 *  freed.
 *
 * Since: 1.8
 **/
G_CONST_RETURN PangoMatrix *
pango_renderer_get_matrix (PangoRenderer *renderer)
{
  g_return_val_if_fail (PANGO_IS_RENDERER (renderer), NULL);

  return renderer->matrix;
}

/**
 * pango_renderer_get_layout:
 * @renderer: a #PangoRenderer
 *
 * Gets the layout currently being rendered using @renderer.
 * Calling this function only makes sense from inside a subclass's
 * methods, like in its draw_shape<!---->() for example.
 *
 * The returned layout should not be modified while still being
 * rendered.
 *
 * Return value: the layout, or %NULL if no layout is being
 *  rendered using @renderer at this time.
 *
 * Since: 1.20
 **/
PangoLayout *
pango_renderer_get_layout      (PangoRenderer     *renderer)
{
  if (G_UNLIKELY (renderer->priv->line == NULL))
    return NULL;

  return renderer->priv->line->layout;
}

/**
 * pango_renderer_get_layout_line:
 * @renderer: a #PangoRenderer
 *
 * Gets the layout line currently being rendered using @renderer.
 * Calling this function only makes sense from inside a subclass's
 * methods, like in its draw_shape<!---->() for example.
 *
 * The returned layout line should not be modified while still being
 * rendered.
 *
 * Return value: the layout line, or %NULL if no layout line is being
 *  rendered using @renderer at this time.
 *
 * Since: 1.20
 **/
PangoLayoutLine *
pango_renderer_get_layout_line (PangoRenderer     *renderer)
{
  return renderer->priv->line;
}