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 iw, int ih, void *bitmap)
  30 {
  31         ddjvu_format_t *fmt;
  32         ddjvu_rect_t rect;
  33         rect.x = 0;
  34         rect.y = 0;
  35         rect.w = iw;
  36         rect.h = ih;
  37         fmt = ddjvu_format_create(DDJVU_FORMAT_RGB24, 0, 0);
  38         ddjvu_format_set_row_order(fmt, 1);
  39         memset(bitmap, 0, ih * iw * 3);
  40         ddjvu_page_render(page, DDJVU_RENDER_COLOR,
  41                                 &rect, &rect, fmt, iw * 3, bitmap);
  42         ddjvu_format_release(fmt);
  43 }
  44
  45 int doc_draw(struct doc *doc, int p, int zoom, int rotate,
  46                 fbval_t *bitmap, int *rows, int *cols)
  47 {
  48         ddjvu_page_t *page;
  49         ddjvu_pageinfo_t info;
  50         int iw, ih, dpi;
  51         unsigned char *bmp;
  52         int i, j;
  53         page = ddjvu_page_create_by_pageno(doc->doc, p - 1);
  54         if (!page)
  55                 return -1;
  56         while (!ddjvu_page_decoding_done(page))
  57                 if (djvu_handle(doc))
  58                         return -1;
  59         if (rotate)
  60                 ddjvu_page_set_rotation(page, (4 - (rotate / 90 % 4)) & 3);
  61         ddjvu_document_get_pageinfo(doc->doc, p - 1, &info);
  62         dpi = ddjvu_page_get_resolution(page);
  63         iw = ddjvu_page_get_width(page) * zoom * 10 / dpi;
  64         ih = ddjvu_page_get_height(page) * zoom * 10 / dpi;
  65         bmp = malloc(ih * iw * 3);
  66         djvu_render(page, iw, ih, bmp);
  67         ddjvu_page_release(page);
  68         for (i = 0; i < MIN(*rows, ih); i++) {
  69                 unsigned char *src = bmp + i * iw * 3;
  70                 fbval_t *dst = bitmap + i * *cols + (*cols - MIN(*cols, iw)) / 2;
  71                 for (j = 0; j < MIN(iw, *cols); j++)
  72                         dst[j] = FB_VAL(src[j * 3], src[j * 3 + 1], src[j * 3 + 2]);
  73         }
  74         free(bmp);
  75         *cols = MIN(*cols, iw);
  76         *rows = MIN(*rows, ih);
  77         return 0;
  78 }
  79
  80 int doc_pages(struct doc *doc)
  81 {
  82         return ddjvu_document_get_pagenum(doc->doc);
  83 }
  84
  85 struct doc *doc_open(char *path)
  86 {
  87         struct doc *doc = malloc(sizeof(*doc));
  88         doc->ctx = ddjvu_context_create("fbpdf");
  89         if (!doc->ctx)
  90                 goto fail;
  91         doc->doc = ddjvu_document_create_by_filename(doc->ctx, path, 1);
  92         if (!doc->doc)
  93                 goto fail;
  94         while (!ddjvu_document_decoding_done(doc->doc))
  95                 if (djvu_handle(doc))
  96                         goto fail;
  97         return doc;
  98 fail:
  99         doc_close(doc);
 100         return NULL;
 101 }
 102
 103 void doc_close(struct doc *doc)
 104 {
 105         if (doc->doc)
 106                 ddjvu_context_release(doc->ctx);
 107         if (doc->ctx)
 108                 ddjvu_document_release(doc->doc);
 109         free(doc);
 110 }