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/*
* Copyright 2018 Vincent Sanders <vince@netsurf-browser.org>
*
* This file is part of libnspdf.
*
* Licensed under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <nspdf/page.h>
#include "cos_object.h"
#include "pdf_doc.h"
/** page entry */
struct page_table_entry {
struct cos_object *resources;
struct cos_object *mediabox;
struct cos_object *contents;
};
/**
* recursively decodes a page tree
*/
nspdferror
nspdf__decode_page_tree(struct nspdf_doc *doc,
struct cos_object *page_tree_node,
unsigned int *page_index)
{
nspdferror res;
const char *type;
// Type = Pages
res = cos_get_dictionary_name(doc, page_tree_node, "Type", &type);
if (res != NSPDFERROR_OK) {
return res;
}
if (strcmp(type, "Pages") == 0) {
struct cos_object *kids;
unsigned int kids_size;
unsigned int kids_index;
if (doc->page_table == NULL) {
/* allocate top level page table */
int64_t count;
res = cos_get_dictionary_int(doc, page_tree_node, "Count", &count);
if (res != NSPDFERROR_OK) {
return res;
}
doc->page_table = calloc(count, sizeof(struct page_table_entry));
if (doc->page_table == NULL) {
return NSPDFERROR_NOMEM;
}
doc->page_table_size = count;
}
res = cos_get_dictionary_array(doc, page_tree_node, "Kids", &kids);
if (res != NSPDFERROR_OK) {
return res;
}
res = cos_get_array_size(doc, kids, &kids_size);
if (res != NSPDFERROR_OK) {
return res;
}
for (kids_index = 0; kids_index < kids_size; kids_index++) {
struct cos_object *kid;
res = cos_get_array_dictionary(doc, kids, kids_index, &kid);
if (res != NSPDFERROR_OK) {
return res;
}
res = nspdf__decode_page_tree(doc, kid, page_index);
if (res != NSPDFERROR_OK) {
return res;
}
}
} else if (strcmp(type, "Page") == 0) {
struct page_table_entry *page;
page = doc->page_table + (*page_index);
/* required heritable resources */
res = cos_heritable_dictionary_dictionary(doc,
page_tree_node,
"Resources",
&(page->resources));
if (res != NSPDFERROR_OK) {
return res;
}
/* required heritable mediabox */
res = cos_heritable_dictionary_array(doc,
page_tree_node,
"MediaBox",
&(page->mediabox));
if (res != NSPDFERROR_OK) {
return res;
}
/* optional page contents */
res = cos_get_dictionary_value(doc,
page_tree_node,
"Contents",
&(page->contents));
if ((res != NSPDFERROR_OK) &&
(res != NSPDFERROR_NOTFOUND)) {
return res;
}
/*
printf("page index:%d page:%p resources:%p mediabox:%p contents:%p contents type:%d\n",
*page_index,
page,
page->resources,
page->mediabox,
page->contents,
page->contents->type);
*/
(*page_index)++;
res = NSPDFERROR_OK;
} else {
res = NSPDFERROR_FORMAT;
}
return res;
}
/* exported interface documented in nspdf/page.h */
nspdferror
nspdf_page_count(struct nspdf_doc *doc, unsigned int *pages_out)
{
*pages_out = doc->page_table_size;
return NSPDFERROR_OK;
}
static nspdferror
nspdf__render_content_stream(struct nspdf_doc *doc,
struct cos_stream *content_stream)
{
printf("%.*s", (int)content_stream->length, content_stream->data);
return NSPDFERROR_OK;
}
/* exported interface documented in nspdf/page.h */
nspdferror
nspdf_page_render(struct nspdf_doc *doc, unsigned int page_number)
{
struct page_table_entry *page_entry;
struct cos_object *content_array;
struct cos_stream *content_stream;
nspdferror res;
page_entry = doc->page_table + page_number;
/* contents may be an array of stream objects or just a single one */
res = cos_get_array(doc, page_entry->contents, &content_array);
if (res == NSPDFERROR_OK) {
unsigned int content_stream_count;
unsigned int content_stream_index;
res = cos_get_array_size(doc, content_array, &content_stream_count);
if (res != NSPDFERROR_OK) {
return res;
}
for (content_stream_index = 0;
content_stream_index < content_stream_count;
content_stream_index++) {
struct cos_object *content_entry;
res = cos_get_array_value(doc,
content_array,
content_stream_index,
&content_entry);
if (res != NSPDFERROR_OK) {
return res;
}
res = cos_get_stream(doc, content_entry, &content_stream);
if (res != NSPDFERROR_OK) {
return res;
}
res = nspdf__render_content_stream(doc, content_stream);
if (res != NSPDFERROR_OK) {
return res;
}
}
} else if (res == NSPDFERROR_TYPE) {
res = cos_get_stream(doc, page_entry->contents, &content_stream);
if (res != NSPDFERROR_OK) {
return res;
}
res = nspdf__render_content_stream(doc, content_stream);
if (res != NSPDFERROR_OK) {
return res;
}
} else {
return res;
}
return res;
}
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