djvulibre.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include <libdjvu/ddjvuapi.h>
   4 #include "draw.h"
   5 #include "doc.h"
   6
   7 #define MIN(a, b)       ((a) < (b) ? (a) : (b))
   8
   9 struct doc {
  10         ddjvu_context_t *ctx;
  11         ddjvu_document_t *doc;
  12 };
  13
  14 int djvu_handle(struct doc *doc)
  15 {
  16         ddjvu_message_t *msg;
  17         msg = ddjvu_message_wait(doc->ctx);
  18         while ((msg = ddjvu_message_peek(doc->ctx))) {
  19                 if (msg->m_any.tag == DDJVU_ERROR) {
  20                         fprintf(stderr,"ddjvu: %s\n", msg->m_error.message);
  21                         return 1;
  22                 }
  23                 ddjvu_message_pop(doc->ctx);
  24         }
  25         return 0;
  26 }
  27
  28 static void djvu_render(ddjvu_page_t *page, int mode, void *bitmap, int cols,
  29                 ddjvu_rect_t *prect, ddjvu_rect_t *rrect)
  30 {
  31         ddjvu_format_t *fmt;
  32         fmt = ddjvu_format_create(DDJVU_FORMAT_GREY8, 0, 0);
  33         ddjvu_format_set_row_order(fmt, 1);
  34
  35         ddjvu_page_render(page, mode, prect, rrect, fmt, cols, bitmap);
  36         ddjvu_format_release(fmt);
  37 }
  38
  39 #define SIZE            (1 << 13)
  40 static char img[SIZE * SIZE];
  41
  42 int doc_draw(struct doc *doc, fbval_t *bitmap, int p, int rows, int cols,
  43                 int zoom, int rotate)
  44 {
  45         ddjvu_page_t *page;
  46         ddjvu_rect_t rect;
  47         ddjvu_pageinfo_t info;
  48         int w, h;
  49         int i, j;
  50         page = ddjvu_page_create_by_pageno(doc->doc, p - 1);
  51         if (!page)
  52                 return -1;
  53         if (!ddjvu_page_decoding_done(page))
  54                 if (djvu_handle(doc))
  55                         return -1;
  56
  57         ddjvu_document_get_pageinfo(doc->doc, p - 1, &info);
  58         rect.x = 0;
  59         rect.y = 0;
  60         rect.w = ddjvu_page_get_width(page);
  61         rect.h = ddjvu_page_get_height(page);
  62
  63         /* mode: DDJVU_RENDER_(BLACK|COLOR|BACKGROUND|FOREGROUND) */
  64         djvu_render(page, DDJVU_RENDER_FOREGROUND, img, SIZE, &rect, &rect);
  65         ddjvu_page_release(page);
  66         zoom /= 4;
  67         w = MIN(cols, rect.w * zoom / 10);
  68         h = MIN(cols, rect.h * zoom / 10);
  69         for (i = 0; i < h; i++) {
  70                 int xs = i * cols + (cols - w) / 2;
  71                 for (j = 0; j < w; j++)
  72                         bitmap[xs + j] = img[i * 10 / zoom * SIZE + j * 10 / zoom];
  73         }
  74         return 0;
  75 }
  76
  77 int doc_pages(struct doc *doc)
  78 {
  79         return ddjvu_document_get_pagenum(doc->doc);
  80 }
  81
  82 struct doc *doc_open(char *path)
  83 {
  84         struct doc *doc = malloc(sizeof(*doc));
  85         doc->ctx = ddjvu_context_create("fbpdf");
  86         if (!doc->ctx)
  87                 goto fail;
  88         doc->doc = ddjvu_document_create_by_filename(doc->ctx, path, 1);
  89         if (!doc->doc)
  90                 goto fail;
  91         if (!ddjvu_document_decoding_done(doc->doc))
  92                 if (djvu_handle(doc))
  93                         goto fail;
  94         return doc;
  95 fail:
  96         doc_close(doc);
  97         return NULL;
  98 }
  99
 100 void doc_close(struct doc *doc)
 101 {
 102         if (doc->doc)
 103                 ddjvu_context_release(doc->ctx);
 104         if (doc->ctx)
 105                 ddjvu_document_release(doc->doc);
 106         free(doc);
 107 }