djvulibre.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include <unistd.h>
   4 #include <libdjvu/ddjvuapi.h>
   5 #include "draw.h"
   6 #include "doc.h"
   7
   8 #define MIN(a, b)       ((a) < (b) ? (a) : (b))
   9
  10 struct doc {
  11         ddjvu_context_t *ctx;
  12         ddjvu_document_t *doc;
  13 };
  14
  15 int djvu_handle(struct doc *doc)
  16 {
  17         ddjvu_message_t *msg;
  18         msg = ddjvu_message_wait(doc->ctx);
  19         while ((msg = ddjvu_message_peek(doc->ctx))) {
  20                 if (msg->m_any.tag == DDJVU_ERROR) {
  21                         fprintf(stderr,"ddjvu: %s\n", msg->m_error.message);
  22                         return 1;
  23                 }
  24                 ddjvu_message_pop(doc->ctx);
  25         }
  26         return 0;
  27 }
  28
  29 static void djvu_render(ddjvu_page_t *page, int mode, void *bitmap, int cols,
  30                 ddjvu_rect_t *prect, ddjvu_rect_t *rrect)
  31 {
  32         ddjvu_format_t *fmt;
  33         int i = 0;
  34         fmt = ddjvu_format_create(DDJVU_FORMAT_GREY8, 0, 0);
  35         ddjvu_format_set_row_order(fmt, 1);
  36
  37         while (i++ < 2 && !ddjvu_page_render(page, mode, prect,
  38                                                 rrect, fmt, cols, bitmap))
  39                 usleep(100000);
  40         ddjvu_format_release(fmt);
  41 }
  42
  43 #define SIZE            (1 << 13)
  44 static char img[SIZE * SIZE];
  45
  46 int doc_draw(struct doc *doc, int p, int zoom, int rotate,
  47                 fbval_t *bitmap, int *rows, int *cols)
  48 {
  49         ddjvu_page_t *page;
  50         ddjvu_rect_t rect;
  51         ddjvu_pageinfo_t info;
  52         int w, h;
  53         int i, j;
  54         page = ddjvu_page_create_by_pageno(doc->doc, p - 1);
  55         if (!page)
  56                 return -1;
  57         if (!ddjvu_page_decoding_done(page))
  58                 if (djvu_handle(doc))
  59                         return -1;
  60
  61         ddjvu_document_get_pageinfo(doc->doc, p - 1, &info);
  62         rect.x = 0;
  63         rect.y = 0;
  64         rect.w = ddjvu_page_get_width(page);
  65         rect.h = ddjvu_page_get_height(page);
  66
  67         /* mode: DDJVU_RENDER_(BLACK|COLOR|BACKGROUND|FOREGROUND) */
  68         djvu_render(page, DDJVU_RENDER_FOREGROUND, img, SIZE, &rect, &rect);
  69         ddjvu_page_release(page);
  70         zoom /= 4;
  71         w = MIN(*cols, rect.w * zoom / 10);
  72         h = MIN(*rows, rect.h * zoom / 10);
  73         for (i = 0; i < h; i++) {
  74                 int xs = i * *cols + (*cols - w) / 2;
  75                 for (j = 0; j < w; j++)
  76                         bitmap[xs + j] = img[i * 10 / zoom * SIZE + j * 10 / zoom];
  77         }
  78         *cols = w;
  79         *rows = h;
  80         return 0;
  81 }
  82
  83 int doc_pages(struct doc *doc)
  84 {
  85         return ddjvu_document_get_pagenum(doc->doc);
  86 }
  87
  88 struct doc *doc_open(char *path)
  89 {
  90         struct doc *doc = malloc(sizeof(*doc));
  91         doc->ctx = ddjvu_context_create("fbpdf");
  92         if (!doc->ctx)
  93                 goto fail;
  94         doc->doc = ddjvu_document_create_by_filename(doc->ctx, path, 1);
  95         if (!doc->doc)
  96                 goto fail;
  97         if (!ddjvu_document_decoding_done(doc->doc))
  98                 if (djvu_handle(doc))
  99                         goto fail;
 100         return doc;
 101 fail:
 102         doc_close(doc);
 103         return NULL;
 104 }
 105
 106 void doc_close(struct doc *doc)
 107 {
 108         if (doc->doc)
 109                 ddjvu_context_release(doc->ctx);
 110         if (doc->ctx)
 111                 ddjvu_document_release(doc->doc);
 112         free(doc);
 113 }