util/view-cairo.hh - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2011  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
  *
  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  *
  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * Google Author(s): Behdad Esfahbod
  */

 #ifndef VIEW_CAIRO_HH
 #define VIEW_CAIRO_HH

 #include "view-options.hh"
 #include "output-options.hh"
 #include "helper-cairo.hh"

 struct view_cairo_t : view_options_t, output_options_t<>
 {
   ~view_cairo_t ()
   {
     cairo_debug_reset_static_data ();
   }

   void add_options (option_parser_t *parser)
   {
     parser->set_summary ("View text with given font.");
     parser->set_description ("Shows image of rendering text with a given font in various formats.");

     view_options_t::add_options (parser);
     output_options_t::add_options (parser, helper_cairo_supported_formats);
   }

   void init (hb_buffer_t *buffer, const font_options_t *font_opts)
   {
     lines = g_array_new (false, false, sizeof (helper_cairo_line_t));
     subpixel_bits = font_opts->subpixel_bits;
   }
   void new_line () {}
   void consume_text (hb_buffer_t  *buffer,
 		     const char   *text,
 		     unsigned int  text_len,
 		     hb_bool_t     utf8_clusters) {}
   void error (const char *message)
   { g_printerr ("%s: %s\n", g_get_prgname (), message); }
   void consume_glyphs (hb_buffer_t  *buffer,
 		       const char   *text,
 		       unsigned int  text_len,
 		       hb_bool_t     utf8_clusters)
   {
     direction = hb_buffer_get_direction (buffer);
     helper_cairo_line_t l (text, text_len, buffer, utf8_clusters, subpixel_bits);
     g_array_append_val (lines, l);
   }
   void finish (hb_buffer_t *buffer, const font_options_t *font_opts)
   {
     render (font_opts);

     for (unsigned int i = 0; i < lines->len; i++) {
       helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
       line.finish ();
     }
     g_array_unref (lines);
   }

   protected:

   void render (const font_options_t *font_opts);
   void draw_lines (cairo_t *cr, hb_font_t *font, double leading, int vert, int horiz);

   hb_direction_t direction = HB_DIRECTION_INVALID; // Remove this, make segment_properties accessible
   GArray *lines = nullptr;
   unsigned subpixel_bits = 0;
 };

 inline void
 view_cairo_t::draw_lines (cairo_t *cr, hb_font_t *font, double leading, int vert, int horiz)
 {
   const bool use_foreground_palette =
     foreground_use_palette && foreground_palette && foreground_palette->len;
   const bool use_stroke = stroke_enabled && stroke_width > 0;
   unsigned palette_glyph_index = 0;

   cairo_translate (cr, +vert * leading, -horiz * leading);
   for (unsigned int i = 0; i < lines->len; i++)
   {
     helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i);

     cairo_translate (cr, -vert * leading, +horiz * leading);

     if (show_extents)
     {
       cairo_save (cr);

       cairo_set_source_rgba (cr, 1., 0., 0., .5);
       cairo_set_line_width (cr, 10);
       cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
       for (unsigned i = 0; i < l.num_glyphs; i++) {
 	cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y);
 	cairo_rel_line_to (cr, 0, 0);
       }
       cairo_stroke (cr);

       cairo_restore (cr);
       cairo_save (cr);

       cairo_set_source_rgba (cr, 1., 0., 1., .5);
       cairo_set_line_width (cr, 3);
       for (unsigned i = 0; i < l.num_glyphs; i++)
       {
 	hb_glyph_extents_t hb_extents;
 	if (hb_font_get_glyph_extents (font, l.glyphs[i].index, &hb_extents))
 	{
 	  double x1 = scalbn ((double) hb_extents.x_bearing, - (int) subpixel_bits);
 	  double y1 = -scalbn ((double) hb_extents.y_bearing, - (int) subpixel_bits);
 	  double width = scalbn ((double) hb_extents.width, - (int) subpixel_bits);
 	  double height = -scalbn ((double) hb_extents.height, - (int) subpixel_bits);

 	  cairo_rectangle (cr, l.glyphs[i].x + x1, l.glyphs[i].y + y1, width, height);
 	}
       }
       cairo_stroke (cr);

       cairo_restore (cr);
     }

     if (use_foreground_palette)
     {
       for (unsigned j = 0; j < l.num_glyphs; j++)
       {
 	auto &color = g_array_index (foreground_palette, rgba_color_t,
 				      palette_glyph_index++ % foreground_palette->len);
 	cairo_set_source_rgba (cr,
 			       color.r / 255.,
 			       color.g / 255.,
 			       color.b / 255.,
 			       color.a / 255.);
 	cairo_show_glyphs (cr, l.glyphs + j, 1);
       }
     }
     else
     {
       // https://github.com/harfbuzz/harfbuzz/issues/4378
 #if CAIRO_VERSION >= 11705
       if (l.num_clusters)
 	cairo_show_text_glyphs (cr,
 				l.utf8, l.utf8_len,
 				l.glyphs, l.num_glyphs,
 				l.clusters, l.num_clusters,
 				l.cluster_flags);
       else
 #endif
 	cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
     }

     if (use_stroke && l.num_glyphs)
     {
       cairo_save (cr);
       cairo_set_source_rgba (cr,
 			     stroke_color.r / 255.,
 			     stroke_color.g / 255.,
 			     stroke_color.b / 255.,
 			     stroke_color.a / 255.);
       cairo_set_line_width (cr, stroke_width);
       cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
       cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
       cairo_new_path (cr);
       cairo_glyph_path (cr, l.glyphs, l.num_glyphs);
       cairo_stroke (cr);
       cairo_restore (cr);
     }
   }
 }

 inline void
 view_cairo_t::render (const font_options_t *font_opts)
 {
   bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
   int vert  = vertical ? 1 : 0;
   int horiz = vertical ? 0 : 1;

   int x_sign = font_opts->font_size_x < 0 ? -1 : +1;
   int y_sign = font_opts->font_size_y < 0 ? -1 : +1;

   hb_font_t *font = font_opts->font;

   if (!have_font_extents)
   {
     hb_font_extents_t hb_extents;
     hb_font_get_extents_for_direction (font, direction, &hb_extents);
     font_extents.ascent = scalbn ((double) hb_extents.ascender, - (int) subpixel_bits);
     font_extents.descent = -scalbn ((double) hb_extents.descender, - (int) subpixel_bits);
     font_extents.line_gap = scalbn ((double) hb_extents.line_gap, - (int) subpixel_bits);
     have_font_extents = true;
   }

   double ascent = y_sign * font_extents.ascent;
   double descent = y_sign * font_extents.descent;
   double line_gap = y_sign * font_extents.line_gap + line_space;
   double leading = ascent + descent + line_gap;

   /* Calculate logical surface size. */
   double logical_w = 0, logical_h = 0;
   (vertical ? logical_w : logical_h) = (int) lines->len * leading - (font_extents.line_gap + line_space);
   (vertical ? logical_h : logical_w) = 0;
   for (unsigned int i = 0; i < lines->len; i++) {
     helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
     double x_advance, y_advance;
     line.get_advance (&x_advance, &y_advance);
     if (vertical)
       logical_h =  MAX (logical_h, y_sign * y_advance);
     else
       logical_w =  MAX (logical_w, x_sign * x_advance);
   }

   cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts,
 								      this);

   /* See if font needs color. */
   cairo_content_t content = CAIRO_CONTENT_ALPHA;
   if (helper_cairo_scaled_font_has_color (scaled_font))
     content = CAIRO_CONTENT_COLOR;

   double surface_w = logical_w, surface_h = logical_h;
   double surface_shift_x = 0, surface_shift_y = 0;
   bool include_logical = include_logical_extents ();
   bool include_ink = include_ink_extents ();
   if (include_ink)
   {
     cairo_surface_t *ink_surface = cairo_recording_surface_create (content, nullptr);
     cairo_t *ink_cr = cairo_create (ink_surface);
     cairo_set_scaled_font (ink_cr, scaled_font);

     if (vertical)
       cairo_translate (ink_cr,
 		       logical_w - ascent, /* We currently always stack lines right to left */
 		       y_sign < 0 ? logical_h : 0);
     else
      {
       cairo_translate (ink_cr,
 		       x_sign < 0 ? logical_w : 0,
 		       y_sign < 0 ? descent : ascent);
      }

     draw_lines (ink_cr, font, leading, vert, horiz);

     double ink_x, ink_y, ink_w, ink_h;
     cairo_recording_surface_ink_extents (ink_surface, &ink_x, &ink_y, &ink_w, &ink_h);
     if (ink_w > 0 && ink_h > 0)
     {
       if (include_logical)
       {
 	double x1 = MIN (0., ink_x);
 	double y1 = MIN (0., ink_y);
 	double x2 = MAX (logical_w, ink_x + ink_w);
 	double y2 = MAX (logical_h, ink_y + ink_h);
 	surface_w = x2 - x1;
 	surface_h = y2 - y1;
 	surface_shift_x = -x1;
 	surface_shift_y = -y1;
       }
       else
       {
 	surface_w = ink_w;
 	surface_h = ink_h;
 	surface_shift_x = -ink_x;
 	surface_shift_y = -ink_y;
       }
     }

     cairo_destroy (ink_cr);
     cairo_surface_destroy (ink_surface);
   }

   /* Create surface. */
   cairo_t *cr = helper_cairo_create_context (surface_w + margin.l + margin.r,
 					     surface_h + margin.t + margin.b,
 					     this,
 					     this,
 					     content);
   cairo_set_scaled_font (cr, scaled_font);

   /* Setup coordinate system. */
   cairo_translate (cr, margin.l + surface_shift_x, margin.t + surface_shift_y);
   if (vertical)
     cairo_translate (cr,
 		     logical_w - ascent, /* We currently always stack lines right to left */
 		     y_sign < 0 ? logical_h : 0);
   else
    {
     cairo_translate (cr,
 		     x_sign < 0 ? logical_w : 0,
 		     y_sign < 0 ? descent : ascent);
    }

   /* Draw. */
   draw_lines (cr, font, leading, vert, horiz);

   /* Clean up. */
   helper_cairo_destroy_context (cr);
   cairo_scaled_font_destroy (scaled_font);
 }

 #endif
	/*
	* Copyright © 2011 Google, Inc.
	*
	* This is part of HarfBuzz, a text shaping library.
	*
	* Permission is hereby granted, without written agreement and without
	* license or royalty fees, to use, copy, modify, and distribute this
	* software and its documentation for any purpose, provided that the
	* above copyright notice and the following two paragraphs appear in
	* all copies of this software.
	*
	* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
	* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
	* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
	* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
	* DAMAGE.
	*
	* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
	* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
	* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
	* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
	* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
	*
	* Google Author(s): Behdad Esfahbod
	*/

	#ifndef VIEW_CAIRO_HH
	#define VIEW_CAIRO_HH

	#include "view-options.hh"
	#include "output-options.hh"
	#include "helper-cairo.hh"

	struct view_cairo_t : view_options_t, output_options_t<>
	{
	~view_cairo_t ()
	{
	cairo_debug_reset_static_data ();
	}

	void add_options (option_parser_t *parser)
	{
	parser->set_summary ("View text with given font.");
	parser->set_description ("Shows image of rendering text with a given font in various formats.");

	view_options_t::add_options (parser);
	output_options_t::add_options (parser, helper_cairo_supported_formats);
	}

	void init (hb_buffer_t buffer, const font_options_t font_opts)
	{
	lines = g_array_new (false, false, sizeof (helper_cairo_line_t));
	subpixel_bits = font_opts->subpixel_bits;
	}
	void new_line () {}
	void consume_text (hb_buffer_t *buffer,
	const char *text,
	unsigned int text_len,
	hb_bool_t utf8_clusters) {}
	void error (const char *message)
	{ g_printerr ("%s: %s\n", g_get_prgname (), message); }
	void consume_glyphs (hb_buffer_t *buffer,
	const char *text,
	unsigned int text_len,
	hb_bool_t utf8_clusters)
	{
	direction = hb_buffer_get_direction (buffer);
	helper_cairo_line_t l (text, text_len, buffer, utf8_clusters, subpixel_bits);
	g_array_append_val (lines, l);
	}
	void finish (hb_buffer_t buffer, const font_options_t font_opts)
	{
	render (font_opts);

	for (unsigned int i = 0; i < lines->len; i++) {
	helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
	line.finish ();
	}
	g_array_unref (lines);
	}

	protected:

	void render (const font_options_t *font_opts);
	void draw_lines (cairo_t cr, hb_font_t font, double leading, int vert, int horiz);

	hb_direction_t direction = HB_DIRECTION_INVALID; // Remove this, make segment_properties accessible
	GArray *lines = nullptr;
	unsigned subpixel_bits = 0;
	};

	inline void
	view_cairo_t::draw_lines (cairo_t cr, hb_font_t font, double leading, int vert, int horiz)
	{
	const bool use_foreground_palette =
	foreground_use_palette && foreground_palette && foreground_palette->len;
	const bool use_stroke = stroke_enabled && stroke_width > 0;
	unsigned palette_glyph_index = 0;

	cairo_translate (cr, +vert * leading, -horiz * leading);
	for (unsigned int i = 0; i < lines->len; i++)
	{
	helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i);

	cairo_translate (cr, -vert * leading, +horiz * leading);

	if (show_extents)
	{
	cairo_save (cr);

	cairo_set_source_rgba (cr, 1., 0., 0., .5);
	cairo_set_line_width (cr, 10);
	cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
	for (unsigned i = 0; i < l.num_glyphs; i++) {
	cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y);
	cairo_rel_line_to (cr, 0, 0);
	}
	cairo_stroke (cr);

	cairo_restore (cr);
	cairo_save (cr);

	cairo_set_source_rgba (cr, 1., 0., 1., .5);
	cairo_set_line_width (cr, 3);
	for (unsigned i = 0; i < l.num_glyphs; i++)
	{
	hb_glyph_extents_t hb_extents;
	if (hb_font_get_glyph_extents (font, l.glyphs[i].index, &hb_extents))
	{
	double x1 = scalbn ((double) hb_extents.x_bearing, - (int) subpixel_bits);
	double y1 = -scalbn ((double) hb_extents.y_bearing, - (int) subpixel_bits);
	double width = scalbn ((double) hb_extents.width, - (int) subpixel_bits);
	double height = -scalbn ((double) hb_extents.height, - (int) subpixel_bits);

	cairo_rectangle (cr, l.glyphs[i].x + x1, l.glyphs[i].y + y1, width, height);
	}
	}
	cairo_stroke (cr);

	cairo_restore (cr);
	}

	if (use_foreground_palette)
	{
	for (unsigned j = 0; j < l.num_glyphs; j++)
	{
	auto &color = g_array_index (foreground_palette, rgba_color_t,
	palette_glyph_index++ % foreground_palette->len);
	cairo_set_source_rgba (cr,
	color.r / 255.,
	color.g / 255.,
	color.b / 255.,
	color.a / 255.);
	cairo_show_glyphs (cr, l.glyphs + j, 1);
	}
	}
	else
	{
	// https://github.com/harfbuzz/harfbuzz/issues/4378
	#if CAIRO_VERSION >= 11705
	if (l.num_clusters)
	cairo_show_text_glyphs (cr,
	l.utf8, l.utf8_len,
	l.glyphs, l.num_glyphs,
	l.clusters, l.num_clusters,
	l.cluster_flags);
	else
	#endif
	cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
	}

	if (use_stroke && l.num_glyphs)
	{
	cairo_save (cr);
	cairo_set_source_rgba (cr,
	stroke_color.r / 255.,
	stroke_color.g / 255.,
	stroke_color.b / 255.,
	stroke_color.a / 255.);
	cairo_set_line_width (cr, stroke_width);
	cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
	cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
	cairo_new_path (cr);
	cairo_glyph_path (cr, l.glyphs, l.num_glyphs);
	cairo_stroke (cr);
	cairo_restore (cr);
	}
	}
	}

	inline void
	view_cairo_t::render (const font_options_t *font_opts)
	{
	bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
	int vert = vertical ? 1 : 0;
	int horiz = vertical ? 0 : 1;

	int x_sign = font_opts->font_size_x < 0 ? -1 : +1;
	int y_sign = font_opts->font_size_y < 0 ? -1 : +1;

	hb_font_t *font = font_opts->font;

	if (!have_font_extents)
	{
	hb_font_extents_t hb_extents;
	hb_font_get_extents_for_direction (font, direction, &hb_extents);
	font_extents.ascent = scalbn ((double) hb_extents.ascender, - (int) subpixel_bits);
	font_extents.descent = -scalbn ((double) hb_extents.descender, - (int) subpixel_bits);
	font_extents.line_gap = scalbn ((double) hb_extents.line_gap, - (int) subpixel_bits);
	have_font_extents = true;
	}

	double ascent = y_sign * font_extents.ascent;
	double descent = y_sign * font_extents.descent;
	double line_gap = y_sign * font_extents.line_gap + line_space;
	double leading = ascent + descent + line_gap;

	/* Calculate logical surface size. */
	double logical_w = 0, logical_h = 0;
	(vertical ? logical_w : logical_h) = (int) lines->len * leading - (font_extents.line_gap + line_space);
	(vertical ? logical_h : logical_w) = 0;
	for (unsigned int i = 0; i < lines->len; i++) {
	helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
	double x_advance, y_advance;
	line.get_advance (&x_advance, &y_advance);
	if (vertical)
	logical_h = MAX (logical_h, y_sign * y_advance);
	else
	logical_w = MAX (logical_w, x_sign * x_advance);
	}

	cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts,
	this);

	/* See if font needs color. */
	cairo_content_t content = CAIRO_CONTENT_ALPHA;
	if (helper_cairo_scaled_font_has_color (scaled_font))
	content = CAIRO_CONTENT_COLOR;

	double surface_w = logical_w, surface_h = logical_h;
	double surface_shift_x = 0, surface_shift_y = 0;
	bool include_logical = include_logical_extents ();
	bool include_ink = include_ink_extents ();
	if (include_ink)
	{
	cairo_surface_t *ink_surface = cairo_recording_surface_create (content, nullptr);
	cairo_t *ink_cr = cairo_create (ink_surface);
	cairo_set_scaled_font (ink_cr, scaled_font);

	if (vertical)
	cairo_translate (ink_cr,
	logical_w - ascent, /* We currently always stack lines right to left */
	y_sign < 0 ? logical_h : 0);
	else
	{
	cairo_translate (ink_cr,
	x_sign < 0 ? logical_w : 0,
	y_sign < 0 ? descent : ascent);
	}

	draw_lines (ink_cr, font, leading, vert, horiz);

	double ink_x, ink_y, ink_w, ink_h;
	cairo_recording_surface_ink_extents (ink_surface, &ink_x, &ink_y, &ink_w, &ink_h);
	if (ink_w > 0 && ink_h > 0)
	{
	if (include_logical)
	{
	double x1 = MIN (0., ink_x);
	double y1 = MIN (0., ink_y);
	double x2 = MAX (logical_w, ink_x + ink_w);
	double y2 = MAX (logical_h, ink_y + ink_h);
	surface_w = x2 - x1;
	surface_h = y2 - y1;
	surface_shift_x = -x1;
	surface_shift_y = -y1;
	}
	else
	{
	surface_w = ink_w;
	surface_h = ink_h;
	surface_shift_x = -ink_x;
	surface_shift_y = -ink_y;
	}
	}

	cairo_destroy (ink_cr);
	cairo_surface_destroy (ink_surface);
	}

	/* Create surface. */
	cairo_t *cr = helper_cairo_create_context (surface_w + margin.l + margin.r,
	surface_h + margin.t + margin.b,
	this,
	this,
	content);
	cairo_set_scaled_font (cr, scaled_font);

	/* Setup coordinate system. */
	cairo_translate (cr, margin.l + surface_shift_x, margin.t + surface_shift_y);
	if (vertical)
	cairo_translate (cr,
	logical_w - ascent, /* We currently always stack lines right to left */
	y_sign < 0 ? logical_h : 0);
	else
	{
	cairo_translate (cr,
	x_sign < 0 ? logical_w : 0,
	y_sign < 0 ? descent : ascent);
	}

	/* Draw. */
	draw_lines (cr, font, leading, vert, horiz);

	/* Clean up. */
	helper_cairo_destroy_context (cr);
	cairo_scaled_font_destroy (scaled_font);
	}

	#endif