semantics.c

/*
 * tumble: build a PDF file from image files
 *
 * Semantic routines for spec file parser
 * Copyright 2001, 2002, 2003, 2017 Eric Smith <spacewar@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.  Note that permission is
 * not granted to redistribute this program under the terms of any
 * other version of the General Public License.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
 *
 *  2009-03-13 [JDB] Add support for blank pages, overlay images, color
 *                   mapping, color-key masking, and push/pop of input
 *                   contexts.
 */


#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "semantics.h"

#ifdef CTL_LANG
#include "parser.tab.h"
#endif

#include "tumble.h"


typedef struct
{
  bool has_page_size;
  page_size_t page_size;

  bool has_rotation;
  int rotation;

  bool has_crop;
  crop_t crop;

  bool has_transparency;
  rgb_range_t transparency;
} input_modifiers_t;


typedef struct input_context_t
{
  struct input_context_t *parent;
  struct input_context_t *next;

  int image_count;  /* how many pages reference this context,
		      including those from subcontexts */

  char *input_file;
  bool is_blank;

  input_modifiers_t modifiers;
} input_context_t;


typedef struct input_image_t
{
  struct input_image_t *next;
  input_context_t *input_context;
  range_t range;
} input_image_t;


typedef struct output_context_t
{
  struct output_context_t *parent;
  struct output_context_t *next;

  int page_count;  /* how many pages reference this context,
		      including those from subcontexts */

  char *output_file;
  pdf_file_attributes_t file_attributes;

  bookmark_t *first_bookmark;
  bookmark_t *last_bookmark;

  bool has_page_label;
  page_label_t page_label;

  bool has_colormap;
  colormap_t colormap;
} output_context_t;


typedef struct output_page_t
{
  struct output_page_t *next;
  output_context_t *output_context;
  range_t range;
  bookmark_t *bookmark_list;
  bool has_overlay;
  overlay_t overlay;
} output_page_t;


#ifdef SEMANTIC_DEBUG
#define SDBG(x) printf x
#else
#define SDBG(x)
#endif


extern FILE *yyin;  // forward declaration, will be defined by bison
int line;  /* line number in spec file */

int bookmark_level;

input_context_t *first_input_context;
input_context_t *last_input_context;

input_image_t *first_input_image;
input_image_t *last_input_image;

output_context_t *first_output_context;
output_context_t *last_output_context;

output_page_t *first_output_page;
output_page_t *last_output_page;


void input_push_context (void)
{
  input_context_t *new_input_context;

  new_input_context = malloc (sizeof (input_context_t));
  if (! new_input_context)
    {
      fprintf (stderr, "failed to malloc an input context\n");
      return;
    }

  if (last_input_context)
    {
      memcpy (new_input_context, last_input_context, sizeof (input_context_t));
      new_input_context->image_count = 0;
    }
  else
    {
      memset (new_input_context, 0, sizeof (input_context_t));
      first_input_context = new_input_context;
    }

  new_input_context->parent = last_input_context;
  last_input_context = new_input_context;
};

void input_pop_context (void)
{
  if (! last_input_context)
    {
      fprintf (stderr, "failed to pop an input context\n");
      return;
    }

  last_input_context = last_input_context->parent;
};

static void input_clone (void)
{
  input_context_t *new_input_context;

  if (! last_input_context->image_count)
    return;

  new_input_context = malloc (sizeof (input_context_t));
  if (! new_input_context)
    {
      fprintf (stderr, "failed to malloc an input context\n");
      return;
    }

  memcpy (new_input_context, last_input_context, sizeof (input_context_t));
  new_input_context->image_count = 0;
  last_input_context->next = new_input_context;
  last_input_context = new_input_context;
}

void input_set_file (char *name)
{
  input_clone ();
  last_input_context->input_file = name;
  last_input_context->is_blank = (name == NULL);
};

void input_set_rotation (int rotation)
{
  last_input_context->modifiers.has_rotation = 1;
  last_input_context->modifiers.rotation = rotation;
  SDBG(("rotation %d\n", rotation));
}

void input_set_page_size (page_size_t size)
{
  last_input_context->modifiers.has_page_size = 1;
  last_input_context->modifiers.page_size = size;
  SDBG(("page size %f, %f\n", size.width, size.height));
}

void input_set_transparency (rgb_range_t rgb_range)
{
  last_input_context->modifiers.has_transparency = 1;
  last_input_context->modifiers.transparency = rgb_range;
}

static void increment_input_image_count (int count)
{
  input_context_t *context;

  for (context = last_input_context; context; context = context->parent)
    context->image_count += count;
}

void input_images (range_t range)
{
  input_image_t *new_image;
  int count = ((range.last - range.first) + 1);

#ifdef SEMANTIC_DEBUG
  if (range.first == range.last)
    SDBG(("image %d\n", range.first));
  else
    SDBG(("images %d..%d\n", range.first, range.last));
#endif /* SEMANTIC_DEBUG */

  new_image = calloc (1, sizeof (input_image_t));
  if (! new_image)
    {
      fprintf (stderr, "failed to malloc an input image struct\n");
      return;
    }
  if (first_input_image)
    {
      last_input_image->next = new_image;
      last_input_image = new_image;
    }
  else
    {
      first_input_image = last_input_image = new_image;
    }
  new_image->range = range;
  new_image->input_context = last_input_context;
  increment_input_image_count (count);
}


void output_push_context (void)
{
  output_context_t *new_output_context;

  new_output_context = malloc (sizeof (output_context_t));
  if (! new_output_context)
    {
      fprintf (stderr, "failed to malloc an output context\n");
      return;
    }

  if (last_output_context)
    {
      memcpy (new_output_context, last_output_context, sizeof (output_context_t));
      new_output_context->page_count = 0;
      new_output_context->first_bookmark = NULL;
      new_output_context->last_bookmark = NULL;
    }
  else
    {
      memset (new_output_context, 0, sizeof (output_context_t));
      first_output_context = new_output_context;
    }

  new_output_context->parent = last_output_context;
  last_output_context = new_output_context;
};

void output_pop_context (void)
{
  if (! last_output_context)
    {
      fprintf (stderr, "failed to pop an output context\n");
      return;
    }

  last_output_context = last_output_context->parent;
};

static void output_clone (void)
{
  output_context_t *new_output_context;

  if (! last_output_context->page_count)
    return;

  new_output_context = malloc (sizeof (output_context_t));
  if (! new_output_context)
    {
      fprintf (stderr, "failed to malloc an output context\n");
      return;
    }

  memcpy (new_output_context, last_output_context, sizeof (output_context_t));
  new_output_context->page_count = 0;
  last_output_context->next = new_output_context;
  last_output_context = new_output_context;
}

void output_set_file (char *name)
{
  output_clone ();
  last_output_context->output_file = name;
  last_output_context->file_attributes.author = NULL;
  last_output_context->file_attributes.creator = NULL;
  last_output_context->file_attributes.title = NULL;
  last_output_context->file_attributes.subject = NULL;
  last_output_context->file_attributes.keywords = NULL;
};

void output_set_author (char *author)
{
  last_output_context->file_attributes.author = author;
}

void output_set_creator (char *creator)
{
  last_output_context->file_attributes.creator = creator;
}

void output_set_title (char *title)
{
  last_output_context->file_attributes.title = title;
}

void output_set_subject (char *subject)
{
  last_output_context->file_attributes.subject = subject;
}

void output_set_keywords (char *keywords)
{
  last_output_context->file_attributes.keywords = keywords;
}

void output_set_bookmark (char *name)
{
  bookmark_t *new_bookmark;

  /* As the language is defined (parser.y), a bookmark can only appear
     at the beginning of a context! */
  if (last_output_context->page_count)
    {
      fprintf (stderr, "internal error, bookmark not at beginning of context\n");
      exit (2);
    }

  new_bookmark = calloc (1, sizeof (bookmark_t));
  if (! new_bookmark)
    {
      fprintf (stderr, "failed to calloc a bookmark\n");
      return;
    }

  new_bookmark->level = bookmark_level;
  new_bookmark->name = name;
  if (last_output_context->first_bookmark)
    last_output_context->last_bookmark->next = new_bookmark;
  else
    last_output_context->first_bookmark = new_bookmark;
  last_output_context->last_bookmark = new_bookmark;
}

void output_set_page_label (page_label_t label)
{
  output_clone ();
  last_output_context->has_page_label = 1;
  last_output_context->page_label = label;
}

static void increment_output_page_count (int count)
{
  output_context_t *context;

  for (context = last_output_context; context; context = context->parent)
    context->page_count += count;
}


void output_pages (range_t range)
{
  output_page_t *new_page;
  output_context_t *context;
  int count = ((range.last - range.first) + 1);

#ifdef SEMANTIC_DEBUG
  if (range.first == range.last)
    SDBG(("page %d\n", range.first));
  else
    SDBG(("pages %d..%d\n", range.first, range.last));
#endif /* SEMANTIC_DEBUG */

  new_page = calloc (1, sizeof (output_page_t));
  if (! new_page)
    {
      fprintf (stderr, "failed to malloc an output page struct\n");
      return;
    }
  if (first_output_page)
    {
      last_output_page->next = new_page;
      last_output_page = new_page;
    }
  else
    {
      first_output_page = last_output_page = new_page;
    }
  new_page->range = range;
  new_page->output_context = last_output_context;

  /* transfer bookmarks from context(s) to page */
  for (context = last_output_context; context; context = context->parent)
    if (context->first_bookmark)
      {
	context->last_bookmark->next = new_page->bookmark_list;
	new_page->bookmark_list = context->first_bookmark;
	context->first_bookmark = NULL;
	context->last_bookmark = NULL;
      }

  increment_output_page_count (count);
}


void output_overlay (overlay_t overlay)
{
  output_pages (last_output_page->range);
  last_output_page->has_overlay = true;
  last_output_page->overlay = overlay;
}

void output_set_colormap (rgb_t black_color, rgb_t white_color)
{
  output_clone ();
  last_output_context->has_colormap = 1;
  last_output_context->colormap.black_map = black_color;
  last_output_context->colormap.white_map = white_color;
}

void output_imagemask (rgb_t foreground_color)
{
  output_pages (last_output_page->range);
  last_output_page->has_overlay = true;
  last_output_page->overlay.imagemask = true;
  last_output_page->overlay.foreground = foreground_color;
}

void yyerror (const char *s)
{
  fprintf (stderr, "%d: %s\n", line, s);
}

static char *get_input_filename (input_context_t *context)
{
  for (; context; context = context->parent)
    if ((context->input_file) || (context->is_blank))
      return context->input_file;
  fprintf (stderr, "no input file name found\n");
  exit (2);
}

static bool get_input_rotation (input_context_t *context,
				int *rotation)
{
  for (; context; context = context->parent)
    {
      if (context->modifiers.has_rotation)
	{
	  * rotation = context->modifiers.rotation;
	  return true;
	}
    }
  return false;  /* default */
}

static rgb_range_t *get_input_transparency (input_context_t *context)
{
  for (; context; context = context->parent)
    {
      if (context->modifiers.has_transparency)
	{
	  return & (context->modifiers.transparency);
	}
    }
  return NULL;  /* default */
}

static bool get_input_page_size (input_context_t *context,
				 page_size_t *page_size)
{
  for (; context; context = context->parent)
    {
      if (context->modifiers.has_page_size)
	{
	  * page_size = context->modifiers.page_size;
	  return true;
	}
    }
  return false;  /* default */
}

static char *get_output_filename (output_context_t *context)
{
  for (; context; context = context->parent)
    if (context->output_file)
      return context->output_file;
  fprintf (stderr, "no output file found\n");
  exit (2);
}

static pdf_file_attributes_t *get_output_file_attributes (output_context_t *context)
{
  for (; context; context = context->parent)
    if (context->output_file)
      return & context->file_attributes;
  fprintf (stderr, "no output file found\n");
  exit (2);
}

static page_label_t *get_output_page_label (output_context_t *context)
{
  for (; context; context = context->parent)
    if (context->has_page_label)
      return & context->page_label;
  return NULL;  /* default */
}

static colormap_t *get_output_colormap (output_context_t *context)
{
  for (; context; context = context->parent)
    if (context->has_colormap)
      return & context->colormap;
  return NULL;  /* default */
}


#ifdef SEMANTIC_DEBUG
void dump_input_tree (void)
{
  input_image_t *image;
  int i;
  char *fn;

  printf ("input images:\n");
  for (image = first_input_image; image; image = image->next)
    for (i = image->range.first; i <= image->range.last; i++)
      {
	bool has_rotation, has_page_size;
	int rotation;
	page_size_t page_size;
	rgb_range_t *transparency;

	has_rotation = get_input_rotation (image->input_context,
					   & rotation);
	has_page_size = get_input_page_size (image->input_context,
					     & page_size);
	transparency = get_input_transparency (image->input_context);
	fn = get_input_filename (image->input_context);
	if (fn)
	  printf ("file '%s' image %d", fn, i);
	else
	  printf ("blank image %d", i);
	if (has_rotation)
	  printf (" rotation %d", rotation);
	if (transparency)
	  printf (" transparency %d..%d, %d..%d, %d..%d",
		  transparency->red.first,   transparency->red.last,  
		  transparency->green.first, transparency->green.last,
		  transparency->blue.first,  transparency->blue.last);
	if (has_page_size)
	  printf (" size %f, %f", page_size.width, page_size.height);
	printf ("\n");
	printf ("input context: %p\n", image->input_context);
      }
}

void dump_output_tree (void)
{
  int i;
  output_page_t *page;
  bookmark_t *bookmark;

  printf ("output pages:\n");
  for (page = first_output_page; page; page = page->next)
    {
      if (page->bookmark_list)
	{
	  for (bookmark = page->bookmark_list; bookmark; bookmark = bookmark->next)
	    printf ("bookmark %d \"%s\"\n", bookmark->level, bookmark->name);
	}
      for (i = page->range.first; i <= page->range.last; i++)
	{
	  page_label_t *label = get_output_page_label (page->output_context);
	  colormap_t *colormap = get_output_colormap (page->output_context);
	  printf ("file \"%s\" ", get_output_filename (page->output_context));
	  if (label)
	    {
	      printf ("label ");
	      if (label->prefix)
		printf ("\"%s\" ", label->prefix);
	      if (label->style)
		printf ("'%c' ", label->style);
	    }
	  if (colormap)
	    printf ("colormap (%d %d %d) (%d %d %d) ",
		    colormap->black_map.red, colormap->black_map.green, colormap->black_map.blue,
		    colormap->white_map.red, colormap->white_map.green, colormap->white_map.blue);
	  printf ("page %d\n", i);
	  printf ("output context %p\n", page->output_context);
	}
    }
}
#endif /* SEMANTIC_DEBUG */


static inline int range_count (range_t range)
{
  return (range.last - range.first) + 1;
}


#ifdef CTL_LANG
bool parse_control_file (char *fn)
{
  bool result = 0;

  yyin = fopen (fn, "r");
  if (! yyin)
    {
      fprintf (stderr, "can't open spec file '%s'\n", fn);
      goto fail;
    }

  line = 1;

  input_push_context ();  /* create root input context */
  input_push_context ();  /* create inital input context */

  output_push_context ();  /* create root output context */
  output_push_context ();  /* create initial output context */

  yyparse ();

  if (first_input_context->image_count != first_output_context->page_count)
    {
      fprintf (stderr, "input image count %d != output page count %d\n",
	       first_input_context->image_count,
	       first_output_context->page_count);
      goto fail;
    }

  fprintf (stderr, "%d images specified\n", first_input_context->image_count);

  result = 1;

#ifdef SEMANTIC_DEBUG
  dump_input_tree ();
  dump_output_tree ();
#endif /* SEMANTIC_DEBUG */

 fail:
  if (yyin)
    fclose (yyin);

  return result;
}

bool omit_label (page_label_t *page_label)
{
  static page_label_t *last_page_label;
  bool unneeded;

  unneeded = ( (last_page_label != NULL) &&
	       page_label->prefix &&
	       last_page_label->prefix &&
	       (strcmp (page_label->prefix, last_page_label->prefix) == 0) &&
	       (page_label->style == last_page_label->style) &&
	       (page_label->base == last_page_label->base + 1) );

  last_page_label = page_label;

  return unneeded;
}

bool process_controls (void)
{
  input_image_t *image = NULL;
  output_page_t *page = NULL;
  int i = 0;
  int p = 0;
  int page_index = 0;
  input_attributes_t input_attributes;
  page_label_t *page_label;
  output_attributes_t output_attributes;

  for (;;)
    {
      if ((! image) || (i >= range_count (image->range)))
	{
	  char *input_fn;
	  if (image)
	    image = image->next;
	  else
	    image = first_input_image;
	  if (! image)
	    return true;  /* done */
	  i = 0;
	  input_fn = get_input_filename (image->input_context);
	  if (verbose)
	    {
	      if (input_fn)
		fprintf (stderr, "opening input file '%s'\n", input_fn);
	      else
		fprintf (stderr, "generating blank image\n");
	    }
	  if (! open_input_file (input_fn))
	    {
	      fprintf (stderr, "error opening input file '%s'\n", input_fn);
	      return false;
	    }
	}

      if ((! page) || (p >= range_count (page->range)))
	{
	  char *output_fn;
	  if (page)
	    page = page->next;
	  else
	    page = first_output_page;
	  p = 0;
	  output_fn = get_output_filename (page->output_context);
	  if (verbose)
	    fprintf (stderr, "opening PDF file '%s'\n", output_fn);
	  if (! open_pdf_output_file (output_fn,
				      get_output_file_attributes (page->output_context)))
	    {
	      fprintf (stderr, "error opening PDF file '%s'\n", output_fn);
	      return false;
	    }
	}

      memset (& input_attributes, 0, sizeof (input_attributes));

      input_attributes.rotation = 0;
      input_attributes.has_rotation = get_input_rotation (image->input_context,
							  & input_attributes.rotation);

      input_attributes.has_page_size = get_input_page_size (image->input_context,
							    & input_attributes.page_size);

      input_attributes.transparency = get_input_transparency (image->input_context);

      memset (& output_attributes, 0, sizeof (output_attributes));
      output_attributes.colormap = get_output_colormap (page->output_context);

      if (page->has_overlay)
	output_attributes.overlay = & page->overlay;

      if (verbose)
	{
	  fprintf(stderr, "processing image %d", image->range.first + i);
	  if (page->has_overlay)
	    fprintf(stderr, " overlay");
	  fprintf(stderr, "\n");
	}

      if (p || page->has_overlay)
	page_label = NULL;
      else
	{
	  page_label = get_output_page_label (page->output_context);
	  if (page_label)
	    {
	      page_label->page_index = page_index;
	      page_label->base = page->range.first;
	      page_label->count = range_count (page->range);

	      if (omit_label (page_label))
		page_label = NULL;
	    }
	}

      if (! process_page (image->range.first + i,
			  input_attributes,
			  p ? NULL : page->bookmark_list,
			  page_label,
			  output_attributes))
	{
	  fprintf (stderr, "error processing image %d\n", image->range.first + i);
	  return false;
	}
      i++;
      p++;

      if (! page->has_overlay)
	page_index++;
    }
}
#endif /* CTL_LANG */