371 lines
8.4 KiB
C
371 lines
8.4 KiB
C
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#include "fitz.h"
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#include "mupdf.h"
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struct info
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{
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fz_obj *resources;
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fz_obj *mediabox;
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fz_obj *cropbox;
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fz_obj *rotate;
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};
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int
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pdf_count_pages(pdf_xref *xref)
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{
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return xref->page_len;
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}
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int
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pdf_find_page_number(pdf_xref *xref, fz_obj *page)
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{
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int i, num = fz_to_num(page);
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for (i = 0; i < xref->page_len; i++)
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if (num == fz_to_num(xref->page_refs[i]))
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return i;
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return -1;
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}
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static void
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pdf_load_page_tree_node(pdf_xref *xref, fz_obj *node, struct info info)
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{
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fz_obj *dict, *kids, *count;
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fz_obj *obj, *tmp;
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int i, n;
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/* prevent infinite recursion */
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if (fz_dict_gets(node, ".seen"))
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return;
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kids = fz_dict_gets(node, "Kids");
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count = fz_dict_gets(node, "Count");
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if (fz_is_array(kids) && fz_is_int(count))
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{
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obj = fz_dict_gets(node, "Resources");
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if (obj)
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info.resources = obj;
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obj = fz_dict_gets(node, "MediaBox");
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if (obj)
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info.mediabox = obj;
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obj = fz_dict_gets(node, "CropBox");
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if (obj)
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info.cropbox = obj;
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obj = fz_dict_gets(node, "Rotate");
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if (obj)
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info.rotate = obj;
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tmp = fz_new_null();
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fz_dict_puts(node, ".seen", tmp);
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fz_drop_obj(tmp);
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n = fz_array_len(kids);
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for (i = 0; i < n; i++)
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{
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obj = fz_array_get(kids, i);
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pdf_load_page_tree_node(xref, obj, info);
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}
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fz_dict_dels(node, ".seen");
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}
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else
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{
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dict = fz_resolve_indirect(node);
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if (info.resources && !fz_dict_gets(dict, "Resources"))
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fz_dict_puts(dict, "Resources", info.resources);
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if (info.mediabox && !fz_dict_gets(dict, "MediaBox"))
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fz_dict_puts(dict, "MediaBox", info.mediabox);
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if (info.cropbox && !fz_dict_gets(dict, "CropBox"))
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fz_dict_puts(dict, "CropBox", info.cropbox);
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if (info.rotate && !fz_dict_gets(dict, "Rotate"))
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fz_dict_puts(dict, "Rotate", info.rotate);
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if (xref->page_len == xref->page_cap)
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{
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fz_warn("found more pages than expected");
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xref->page_cap ++;
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xref->page_refs = fz_realloc(xref->page_refs, xref->page_cap, sizeof(fz_obj*));
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xref->page_objs = fz_realloc(xref->page_objs, xref->page_cap, sizeof(fz_obj*));
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}
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xref->page_refs[xref->page_len] = fz_keep_obj(node);
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xref->page_objs[xref->page_len] = fz_keep_obj(dict);
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xref->page_len ++;
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}
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}
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fz_error
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pdf_load_page_tree(pdf_xref *xref)
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{
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struct info info;
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fz_obj *catalog = fz_dict_gets(xref->trailer, "Root");
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fz_obj *pages = fz_dict_gets(catalog, "Pages");
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fz_obj *count = fz_dict_gets(pages, "Count");
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if (!fz_is_dict(pages))
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return fz_throw("missing page tree");
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if (!fz_is_int(count))
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return fz_throw("missing page count");
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xref->page_cap = fz_to_int(count);
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xref->page_len = 0;
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xref->page_refs = fz_calloc(xref->page_cap, sizeof(fz_obj*));
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xref->page_objs = fz_calloc(xref->page_cap, sizeof(fz_obj*));
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info.resources = NULL;
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info.mediabox = NULL;
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info.cropbox = NULL;
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info.rotate = NULL;
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pdf_load_page_tree_node(xref, pages, info);
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return fz_okay;
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}
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/* We need to know whether to install a page-level transparency group */
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static int pdf_resources_use_blending(fz_obj *rdb);
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static int
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pdf_extgstate_uses_blending(fz_obj *dict)
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{
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fz_obj *obj = fz_dict_gets(dict, "BM");
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if (fz_is_name(obj) && strcmp(fz_to_name(obj), "Normal"))
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return 1;
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return 0;
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}
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static int
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pdf_pattern_uses_blending(fz_obj *dict)
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{
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fz_obj *obj;
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obj = fz_dict_gets(dict, "Resources");
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if (pdf_resources_use_blending(obj))
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return 1;
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obj = fz_dict_gets(dict, "ExtGState");
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if (pdf_extgstate_uses_blending(obj))
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return 1;
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return 0;
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}
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static int
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pdf_xobject_uses_blending(fz_obj *dict)
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{
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fz_obj *obj = fz_dict_gets(dict, "Resources");
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if (pdf_resources_use_blending(obj))
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return 1;
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return 0;
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}
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static int
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pdf_resources_use_blending(fz_obj *rdb)
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{
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fz_obj *dict;
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fz_obj *tmp;
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int i;
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if (!rdb)
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return 0;
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/* stop on cyclic resource dependencies */
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if (fz_dict_gets(rdb, ".useBM"))
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return fz_to_bool(fz_dict_gets(rdb, ".useBM"));
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tmp = fz_new_bool(0);
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fz_dict_puts(rdb, ".useBM", tmp);
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fz_drop_obj(tmp);
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dict = fz_dict_gets(rdb, "ExtGState");
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for (i = 0; i < fz_dict_len(dict); i++)
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if (pdf_extgstate_uses_blending(fz_dict_get_val(dict, i)))
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goto found;
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dict = fz_dict_gets(rdb, "Pattern");
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for (i = 0; i < fz_dict_len(dict); i++)
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if (pdf_pattern_uses_blending(fz_dict_get_val(dict, i)))
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goto found;
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dict = fz_dict_gets(rdb, "XObject");
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for (i = 0; i < fz_dict_len(dict); i++)
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if (pdf_xobject_uses_blending(fz_dict_get_val(dict, i)))
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goto found;
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return 0;
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found:
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tmp = fz_new_bool(1);
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fz_dict_puts(rdb, ".useBM", tmp);
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fz_drop_obj(tmp);
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return 1;
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}
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/* we need to combine all sub-streams into one for the content stream interpreter */
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static fz_error
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pdf_load_page_contents_array(fz_buffer **bigbufp, pdf_xref *xref, fz_obj *list)
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{
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fz_error error;
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fz_buffer *big;
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fz_buffer *one;
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int i, n;
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big = fz_new_buffer(32 * 1024);
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n = fz_array_len(list);
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for (i = 0; i < n; i++)
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{
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fz_obj *stm = fz_array_get(list, i);
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error = pdf_load_stream(&one, xref, fz_to_num(stm), fz_to_gen(stm));
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if (error)
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{
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fz_catch(error, "cannot load content stream part %d/%d", i + 1, n);
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continue;
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}
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if (big->len + one->len + 1 > big->cap)
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fz_resize_buffer(big, big->len + one->len + 1);
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memcpy(big->data + big->len, one->data, one->len);
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big->data[big->len + one->len] = ' ';
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big->len += one->len + 1;
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fz_drop_buffer(one);
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}
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if (n > 0 && big->len == 0)
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{
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fz_drop_buffer(big);
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return fz_throw("cannot load content stream");
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}
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*bigbufp = big;
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return fz_okay;
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}
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static fz_error
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pdf_load_page_contents(fz_buffer **bufp, pdf_xref *xref, fz_obj *obj)
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{
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fz_error error;
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if (fz_is_array(obj))
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{
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error = pdf_load_page_contents_array(bufp, xref, obj);
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if (error)
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return fz_rethrow(error, "cannot load content stream array");
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}
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else if (pdf_is_stream(xref, fz_to_num(obj), fz_to_gen(obj)))
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{
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error = pdf_load_stream(bufp, xref, fz_to_num(obj), fz_to_gen(obj));
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if (error)
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return fz_rethrow(error, "cannot load content stream (%d 0 R)", fz_to_num(obj));
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}
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else
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{
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fz_warn("page contents missing, leaving page blank");
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*bufp = fz_new_buffer(0);
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}
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return fz_okay;
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}
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fz_error
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pdf_load_page(pdf_page **pagep, pdf_xref *xref, int number)
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{
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fz_error error;
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pdf_page *page;
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pdf_annot *annot;
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fz_obj *pageobj, *pageref;
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fz_obj *obj;
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fz_bbox bbox;
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if (number < 0 || number >= xref->page_len)
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return fz_throw("cannot find page %d", number + 1);
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/* Ensure that we have a store for resource objects */
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if (!xref->store)
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xref->store = pdf_new_store();
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pageobj = xref->page_objs[number];
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pageref = xref->page_refs[number];
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page = fz_malloc(sizeof(pdf_page));
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page->resources = NULL;
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page->contents = NULL;
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page->transparency = 0;
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page->links = NULL;
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page->annots = NULL;
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obj = fz_dict_gets(pageobj, "MediaBox");
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bbox = fz_round_rect(pdf_to_rect(obj));
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if (fz_is_empty_rect(pdf_to_rect(obj)))
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{
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fz_warn("cannot find page size for page %d", number + 1);
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bbox.x0 = 0;
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bbox.y0 = 0;
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bbox.x1 = 612;
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bbox.y1 = 792;
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}
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obj = fz_dict_gets(pageobj, "CropBox");
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if (fz_is_array(obj))
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{
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fz_bbox cropbox = fz_round_rect(pdf_to_rect(obj));
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bbox = fz_intersect_bbox(bbox, cropbox);
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}
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page->mediabox.x0 = MIN(bbox.x0, bbox.x1);
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page->mediabox.y0 = MIN(bbox.y0, bbox.y1);
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page->mediabox.x1 = MAX(bbox.x0, bbox.x1);
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page->mediabox.y1 = MAX(bbox.y0, bbox.y1);
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if (page->mediabox.x1 - page->mediabox.x0 < 1 || page->mediabox.y1 - page->mediabox.y0 < 1)
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{
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fz_warn("invalid page size in page %d", number + 1);
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page->mediabox = fz_unit_rect;
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}
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page->rotate = fz_to_int(fz_dict_gets(pageobj, "Rotate"));
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obj = fz_dict_gets(pageobj, "Annots");
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if (obj)
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{
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pdf_load_links(&page->links, xref, obj);
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pdf_load_annots(&page->annots, xref, obj);
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}
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page->resources = fz_dict_gets(pageobj, "Resources");
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if (page->resources)
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fz_keep_obj(page->resources);
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obj = fz_dict_gets(pageobj, "Contents");
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error = pdf_load_page_contents(&page->contents, xref, obj);
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if (error)
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{
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pdf_free_page(page);
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return fz_rethrow(error, "cannot load page %d contents (%d 0 R)", number + 1, fz_to_num(pageref));
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}
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if (pdf_resources_use_blending(page->resources))
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page->transparency = 1;
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for (annot = page->annots; annot && !page->transparency; annot = annot->next)
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if (pdf_resources_use_blending(annot->ap->resources))
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page->transparency = 1;
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*pagep = page;
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return fz_okay;
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}
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void
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pdf_free_page(pdf_page *page)
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{
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if (page->resources)
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fz_drop_obj(page->resources);
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if (page->contents)
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fz_drop_buffer(page->contents);
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if (page->links)
|
||
|
|
pdf_free_link(page->links);
|
||
|
|
if (page->annots)
|
||
|
|
pdf_free_annot(page->annots);
|
||
|
|
fz_free(page);
|
||
|
|
}
|