util/helper-image-output.hh - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2026  Behdad Esfahbod
  *
  *  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.
  *
  * Author(s): Behdad Esfahbod
  */

 #ifndef HELPER_IMAGE_OUTPUT_HH
 #define HELPER_IMAGE_OUTPUT_HH

 #include "hb.hh"

 #ifdef HAVE_CAIRO
 #include <cairo.h>
 #endif

 #ifdef HAVE_CAIRO
 using helper_image_status_t = cairo_status_t;
 using helper_image_write_func_t = cairo_write_func_t;
 #define HELPER_IMAGE_STATUS_SUCCESS CAIRO_STATUS_SUCCESS
 #else
 using helper_image_status_t = int;
 using helper_image_write_func_t = helper_image_status_t (*) (void                *closure,
 							     const unsigned char *data,
 							     unsigned int         size);
 #define HELPER_IMAGE_STATUS_SUCCESS 0
 #endif

 #include "ansi-print.hh"

 enum class helper_image_protocol_t {
   NONE = 0,
   ITERM2,
   KITTY,
 };

 static inline helper_image_status_t
 helper_image_stdio_write_func (void                *closure,
 			       const unsigned char *data,
 			       unsigned int         size)
 {
   FILE *fp = (FILE *) closure;

   while (size)
   {
     size_t ret = fwrite (data, 1, size, fp);
     size -= ret;
     data += ret;
     if (size && ferror (fp))
       fail (false, "Failed to write output: %s", strerror (errno));
   }

   return HELPER_IMAGE_STATUS_SUCCESS;
 }

 static inline const char *
 helper_image_get_implicit_output_format (FILE                    *fp,
 					 const char              *default_format,
 					 helper_image_protocol_t *protocol)
 {
   *protocol = helper_image_protocol_t::NONE;

 #if HAVE_ISATTY
   if (isatty (fileno (fp)))
   {
 #ifdef HAVE_PNG
     const char *name;
     /* https://gitlab.com/gnachman/iterm2/-/issues/7154 */
     if ((name = getenv ("LC_TERMINAL")) != nullptr &&
 	0 == g_ascii_strcasecmp (name, "iTerm2"))
     {
       *protocol = helper_image_protocol_t::ITERM2;
       return "png";
     }
     if ((name = getenv ("TERM_PROGRAM")) != nullptr &&
 	0 == g_ascii_strcasecmp (name, "WezTerm"))
     {
       *protocol = helper_image_protocol_t::ITERM2;
       return "png";
     }
     if ((name = getenv ("TERM")) != nullptr &&
 	0 == g_ascii_strcasecmp (name, "xterm-kitty"))
     {
       *protocol = helper_image_protocol_t::KITTY;
       return "png";
     }
 #endif
     return "ansi";
   }
 #endif

   return default_format;
 }

 static inline void
 helper_image_write_png_data (const unsigned char   *data,
 			     unsigned int           length,
 			     helper_image_write_func_t write_func,
 			     void                  *closure,
 			     helper_image_protocol_t protocol)
 {
   if (protocol == helper_image_protocol_t::NONE)
   {
     write_func (closure, data, length);
     return;
   }

   gchar *base64 = g_base64_encode (data, length);
   size_t base64_len = strlen (base64);
   GString *string = g_string_new (nullptr);

   if (protocol == helper_image_protocol_t::ITERM2)
   {
     /* https://iterm2.com/documentation-images.html */
     g_string_printf (string, "\033]1337;File=inline=1;size=%zu:%s\a\n",
 		     base64_len, base64);
   }
   else if (protocol == helper_image_protocol_t::KITTY)
   {
 #define CHUNK_SIZE 4096
     /* https://sw.kovidgoyal.net/kitty/graphics-protocol.html */
     for (size_t pos = 0; pos < base64_len; pos += CHUNK_SIZE)
     {
       size_t len = base64_len - pos;

       if (pos == 0)
 	g_string_append (string, "\033_Ga=T,f=100,m=");
       else
 	g_string_append (string, "\033_Gm=");

       if (len > CHUNK_SIZE)
       {
 	g_string_append (string, "1;");
 	g_string_append_len (string, base64 + pos, CHUNK_SIZE);
       }
       else
       {
 	g_string_append (string, "0;");
 	g_string_append_len (string, base64 + pos, len);
       }

       g_string_append (string, "\033\\");
     }
     g_string_append (string, "\n");
 #undef CHUNK_SIZE
   }

   write_func (closure, (const unsigned char *) string->str, string->len);

   g_free (base64);
   g_string_free (string, TRUE);
 }

 #ifdef HAVE_CHAFA
 # include <chafa.h>

 /* Similar to ansi-print.cc */
 # define CELL_W 8
 # define CELL_H (2 * CELL_W)

 static void
 chafa_print_image_rgb24 (const void *data, int width, int height, int stride, int level,
 			 helper_image_write_func_t write_func,
 			 void		     *closure)
 {
   ChafaTermInfo *term_info;
   ChafaSymbolMap *symbol_map;
   ChafaCanvasConfig *config;
   ChafaCanvas *canvas;
   GString *gs;
   unsigned int cols = (width +  CELL_W - 1) / CELL_W;
   unsigned int rows = (height + CELL_H - 1) / CELL_H;
   gchar **environ;
   ChafaCanvasMode mode;
   ChafaPixelMode pixel_mode;

   /* Adapt to terminal; use sixels if available, and fall back to symbols
    * with as many colors as are supported */

   chafa_set_n_threads (1); // https://github.com/hpjansson/chafa/issues/125#issuecomment-1397475217

   environ = g_get_environ ();
   term_info = chafa_term_db_detect (chafa_term_db_get_default (),
                                     environ);

   pixel_mode = CHAFA_PIXEL_MODE_SYMBOLS;

   if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_BEGIN_SIXELS))
   {
     pixel_mode = CHAFA_PIXEL_MODE_SIXELS;
     mode = CHAFA_CANVAS_MODE_TRUECOLOR;
   }
   else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_SET_COLOR_FGBG_DIRECT))
     mode = CHAFA_CANVAS_MODE_TRUECOLOR;
   else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_SET_COLOR_FGBG_256))
     mode = CHAFA_CANVAS_MODE_INDEXED_240;
   else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_SET_COLOR_FGBG_16))
     mode = CHAFA_CANVAS_MODE_INDEXED_16;
   else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_INVERT_COLORS))
     mode = CHAFA_CANVAS_MODE_FGBG_BGFG;
   else
     mode = CHAFA_CANVAS_MODE_FGBG;

   symbol_map = chafa_symbol_map_new ();
   chafa_symbol_map_add_by_tags (symbol_map,
                                 (ChafaSymbolTags) (CHAFA_SYMBOL_TAG_BLOCK
                                                    | CHAFA_SYMBOL_TAG_SPACE
 						   | (level >= 2 ? CHAFA_SYMBOL_TAG_WEDGE : 0)
 						   | (level >= 3 ? CHAFA_SYMBOL_TAG_ALL : 0)
 				));

   config = chafa_canvas_config_new ();
   chafa_canvas_config_set_canvas_mode (config, mode);
   chafa_canvas_config_set_pixel_mode (config, pixel_mode);
   chafa_canvas_config_set_cell_geometry (config, CELL_W, CELL_H);
   chafa_canvas_config_set_geometry (config, cols, rows);
   chafa_canvas_config_set_symbol_map (config, symbol_map);
   chafa_canvas_config_set_color_extractor (config, CHAFA_COLOR_EXTRACTOR_MEDIAN);
   chafa_canvas_config_set_work_factor (config, 1.0f);

   canvas = chafa_canvas_new (config);
   chafa_canvas_draw_all_pixels (canvas,
                                 G_BYTE_ORDER == G_LITTLE_ENDIAN
                                   ? CHAFA_PIXEL_BGRA8_PREMULTIPLIED
                                   : CHAFA_PIXEL_ARGB8_PREMULTIPLIED,
                                 (const guint8 *) data,
                                 width,
                                 height,
                                 stride);
   gs = chafa_canvas_print (canvas, term_info);

   write_func (closure, (const unsigned char *) gs->str, gs->len);

   if (pixel_mode != CHAFA_PIXEL_MODE_SIXELS)
     write_func (closure, (const unsigned char *) "\n", 1);

   g_string_free (gs, TRUE);
   chafa_canvas_unref (canvas);
   chafa_canvas_config_unref (config);
   chafa_symbol_map_unref (symbol_map);
   chafa_term_info_unref (term_info);
   g_strfreev (environ);
 }

 #endif /* HAVE_CHAFA */

 static inline helper_image_status_t
 helper_image_write_to_ansi_stream_rgb24 (const uint32_t        *data,
 					 unsigned int           width,
 					 unsigned int           height,
 					 unsigned int           stride,
 					 helper_image_write_func_t write_func,
 					 void                  *closure)
 {
   /* We don't have rows to spare on the terminal window...
    * Find the tight image top/bottom and only print in between. */

   uint32_t bg_color = data ? * (uint32_t *) data : 0;

   auto orig_data = data;
   while (height)
   {
     unsigned int i;
     for (i = 0; i < width; i++)
       if (data[i] != bg_color)
 	break;
     if (i < width)
       break;
     data += stride / 4;
     height--;
   }
   if (orig_data < data)
   {
     data -= stride / 4;
     height++;
   }

   auto orig_height = height;
   while (height)
   {
     const uint32_t *row = data + (height - 1) * stride / 4;
     unsigned int i;
     for (i = 0; i < width; i++)
       if (row[i] != bg_color)
 	break;
     if (i < width)
       break;
     height--;
   }
   if (height < orig_height)
     height++;

   if (width && height)
   {
 #ifdef HAVE_CHAFA
     const char *env = getenv ("HB_CHAFA");
     int chafa_level = 1;
     if (env)
       chafa_level = atoi (env);
     if (chafa_level)
       chafa_print_image_rgb24 (data, width, height, stride, chafa_level,
 			       write_func, closure);
     else
 #endif
       ansi_print_image_rgb24 (data, width, height, stride / 4,
 			      write_func, closure);
   }

   return HELPER_IMAGE_STATUS_SUCCESS;
 }

 #endif
	/*
	* Copyright © 2026 Behdad Esfahbod
	*
	* 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.
	*
	* Author(s): Behdad Esfahbod
	*/

	#ifndef HELPER_IMAGE_OUTPUT_HH
	#define HELPER_IMAGE_OUTPUT_HH

	#include "hb.hh"

	#ifdef HAVE_CAIRO
	#include <cairo.h>
	#endif

	#ifdef HAVE_CAIRO
	using helper_image_status_t = cairo_status_t;
	using helper_image_write_func_t = cairo_write_func_t;
	#define HELPER_IMAGE_STATUS_SUCCESS CAIRO_STATUS_SUCCESS
	#else
	using helper_image_status_t = int;
	using helper_image_write_func_t = helper_image_status_t () (void closure,
	const unsigned char *data,
	unsigned int size);
	#define HELPER_IMAGE_STATUS_SUCCESS 0
	#endif

	#include "ansi-print.hh"

	enum class helper_image_protocol_t {
	NONE = 0,
	ITERM2,
	KITTY,
	};

	static inline helper_image_status_t
	helper_image_stdio_write_func (void *closure,
	const unsigned char *data,
	unsigned int size)
	{
	FILE fp = (FILE ) closure;

	while (size)
	{
	size_t ret = fwrite (data, 1, size, fp);
	size -= ret;
	data += ret;
	if (size && ferror (fp))
	fail (false, "Failed to write output: %s", strerror (errno));
	}

	return HELPER_IMAGE_STATUS_SUCCESS;
	}

	static inline const char *
	helper_image_get_implicit_output_format (FILE *fp,
	const char *default_format,
	helper_image_protocol_t *protocol)
	{
	*protocol = helper_image_protocol_t::NONE;

	#if HAVE_ISATTY
	if (isatty (fileno (fp)))
	{
	#ifdef HAVE_PNG
	const char *name;
	/* https://gitlab.com/gnachman/iterm2/-/issues/7154 */
	if ((name = getenv ("LC_TERMINAL")) != nullptr &&
	0 == g_ascii_strcasecmp (name, "iTerm2"))
	{
	*protocol = helper_image_protocol_t::ITERM2;
	return "png";
	}
	if ((name = getenv ("TERM_PROGRAM")) != nullptr &&
	0 == g_ascii_strcasecmp (name, "WezTerm"))
	{
	*protocol = helper_image_protocol_t::ITERM2;
	return "png";
	}
	if ((name = getenv ("TERM")) != nullptr &&
	0 == g_ascii_strcasecmp (name, "xterm-kitty"))
	{
	*protocol = helper_image_protocol_t::KITTY;
	return "png";
	}
	#endif
	return "ansi";
	}
	#endif

	return default_format;
	}

	static inline void
	helper_image_write_png_data (const unsigned char *data,
	unsigned int length,
	helper_image_write_func_t write_func,
	void *closure,
	helper_image_protocol_t protocol)
	{
	if (protocol == helper_image_protocol_t::NONE)
	{
	write_func (closure, data, length);
	return;
	}

	gchar *base64 = g_base64_encode (data, length);
	size_t base64_len = strlen (base64);
	GString *string = g_string_new (nullptr);

	if (protocol == helper_image_protocol_t::ITERM2)
	{
	/* https://iterm2.com/documentation-images.html */
	g_string_printf (string, "\033]1337;File=inline=1;size=%zu:%s\a\n",
	base64_len, base64);
	}
	else if (protocol == helper_image_protocol_t::KITTY)
	{
	#define CHUNK_SIZE 4096
	/* https://sw.kovidgoyal.net/kitty/graphics-protocol.html */
	for (size_t pos = 0; pos < base64_len; pos += CHUNK_SIZE)
	{
	size_t len = base64_len - pos;

	if (pos == 0)
	g_string_append (string, "\033_Ga=T,f=100,m=");
	else
	g_string_append (string, "\033_Gm=");

	if (len > CHUNK_SIZE)
	{
	g_string_append (string, "1;");
	g_string_append_len (string, base64 + pos, CHUNK_SIZE);
	}
	else
	{
	g_string_append (string, "0;");
	g_string_append_len (string, base64 + pos, len);
	}

	g_string_append (string, "\033\\");
	}
	g_string_append (string, "\n");
	#undef CHUNK_SIZE
	}

	write_func (closure, (const unsigned char *) string->str, string->len);

	g_free (base64);
	g_string_free (string, TRUE);
	}

	#ifdef HAVE_CHAFA
	# include <chafa.h>

	/* Similar to ansi-print.cc */
	# define CELL_W 8
	# define CELL_H (2 * CELL_W)

	static void
	chafa_print_image_rgb24 (const void *data, int width, int height, int stride, int level,
	helper_image_write_func_t write_func,
	void *closure)
	{
	ChafaTermInfo *term_info;
	ChafaSymbolMap *symbol_map;
	ChafaCanvasConfig *config;
	ChafaCanvas *canvas;
	GString *gs;
	unsigned int cols = (width + CELL_W - 1) / CELL_W;
	unsigned int rows = (height + CELL_H - 1) / CELL_H;
	gchar **environ;
	ChafaCanvasMode mode;
	ChafaPixelMode pixel_mode;

	/* Adapt to terminal; use sixels if available, and fall back to symbols
	* with as many colors as are supported */

	chafa_set_n_threads (1); // https://github.com/hpjansson/chafa/issues/125#issuecomment-1397475217

	environ = g_get_environ ();
	term_info = chafa_term_db_detect (chafa_term_db_get_default (),
	environ);

	pixel_mode = CHAFA_PIXEL_MODE_SYMBOLS;

	if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_BEGIN_SIXELS))
	{
	pixel_mode = CHAFA_PIXEL_MODE_SIXELS;
	mode = CHAFA_CANVAS_MODE_TRUECOLOR;
	}
	else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_SET_COLOR_FGBG_DIRECT))
	mode = CHAFA_CANVAS_MODE_TRUECOLOR;
	else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_SET_COLOR_FGBG_256))
	mode = CHAFA_CANVAS_MODE_INDEXED_240;
	else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_SET_COLOR_FGBG_16))
	mode = CHAFA_CANVAS_MODE_INDEXED_16;
	else if (chafa_term_info_have_seq (term_info, CHAFA_TERM_SEQ_INVERT_COLORS))
	mode = CHAFA_CANVAS_MODE_FGBG_BGFG;
	else
	mode = CHAFA_CANVAS_MODE_FGBG;

	symbol_map = chafa_symbol_map_new ();
	chafa_symbol_map_add_by_tags (symbol_map,
	(ChafaSymbolTags) (CHAFA_SYMBOL_TAG_BLOCK
	\| CHAFA_SYMBOL_TAG_SPACE
	\| (level >= 2 ? CHAFA_SYMBOL_TAG_WEDGE : 0)
	\| (level >= 3 ? CHAFA_SYMBOL_TAG_ALL : 0)
	));

	config = chafa_canvas_config_new ();
	chafa_canvas_config_set_canvas_mode (config, mode);
	chafa_canvas_config_set_pixel_mode (config, pixel_mode);
	chafa_canvas_config_set_cell_geometry (config, CELL_W, CELL_H);
	chafa_canvas_config_set_geometry (config, cols, rows);
	chafa_canvas_config_set_symbol_map (config, symbol_map);
	chafa_canvas_config_set_color_extractor (config, CHAFA_COLOR_EXTRACTOR_MEDIAN);
	chafa_canvas_config_set_work_factor (config, 1.0f);

	canvas = chafa_canvas_new (config);
	chafa_canvas_draw_all_pixels (canvas,
	G_BYTE_ORDER == G_LITTLE_ENDIAN
	? CHAFA_PIXEL_BGRA8_PREMULTIPLIED
	: CHAFA_PIXEL_ARGB8_PREMULTIPLIED,
	(const guint8 *) data,
	width,
	height,
	stride);
	gs = chafa_canvas_print (canvas, term_info);

	write_func (closure, (const unsigned char *) gs->str, gs->len);

	if (pixel_mode != CHAFA_PIXEL_MODE_SIXELS)
	write_func (closure, (const unsigned char *) "\n", 1);

	g_string_free (gs, TRUE);
	chafa_canvas_unref (canvas);
	chafa_canvas_config_unref (config);
	chafa_symbol_map_unref (symbol_map);
	chafa_term_info_unref (term_info);
	g_strfreev (environ);
	}

	#endif /* HAVE_CHAFA */

	static inline helper_image_status_t
	helper_image_write_to_ansi_stream_rgb24 (const uint32_t *data,
	unsigned int width,
	unsigned int height,
	unsigned int stride,
	helper_image_write_func_t write_func,
	void *closure)
	{
	/* We don't have rows to spare on the terminal window...
	* Find the tight image top/bottom and only print in between. */

	uint32_t bg_color = data ? * (uint32_t *) data : 0;

	auto orig_data = data;
	while (height)
	{
	unsigned int i;
	for (i = 0; i < width; i++)
	if (data[i] != bg_color)
	break;
	if (i < width)
	break;
	data += stride / 4;
	height--;
	}
	if (orig_data < data)
	{
	data -= stride / 4;
	height++;
	}

	auto orig_height = height;
	while (height)
	{
	const uint32_t row = data + (height - 1) stride / 4;
	unsigned int i;
	for (i = 0; i < width; i++)
	if (row[i] != bg_color)
	break;
	if (i < width)
	break;
	height--;
	}
	if (height < orig_height)
	height++;

	if (width && height)
	{
	#ifdef HAVE_CHAFA
	const char *env = getenv ("HB_CHAFA");
	int chafa_level = 1;
	if (env)
	chafa_level = atoi (env);
	if (chafa_level)
	chafa_print_image_rgb24 (data, width, height, stride, chafa_level,
	write_func, closure);
	else
	#endif
	ansi_print_image_rgb24 (data, width, height, stride / 4,
	write_func, closure);
	}

	return HELPER_IMAGE_STATUS_SUCCESS;
	}

	#endif