/*
Ensure we have an incremental xref section where we can store
updated versions of indirect objects
*/
static void ensure_incremental_xref(pdf_document *doc)
{
fz_context *ctx = doc->ctx;
if (!doc->xref_altered)
{
pdf_xref *xref = &doc->xref_sections[0];
pdf_xref *pxref;
pdf_xref_entry *new_table = fz_calloc(ctx, xref->len, sizeof(pdf_xref_entry));
pdf_obj *trailer = NULL;
fz_var(trailer);
fz_try(ctx)
{
trailer = pdf_copy_dict(xref->trailer);
doc->xref_sections = fz_resize_array(ctx, doc->xref_sections, doc->num_xref_sections + 1, sizeof(pdf_xref));
xref = &doc->xref_sections[0];
pxref = &doc->xref_sections[1];
memmove(pxref, xref, doc->num_xref_sections * sizeof(pdf_xref));
/* xref->len is already correct */
xref->table = new_table;
xref->trailer = trailer;
doc->num_xref_sections++;
doc->xref_altered = 1;
}
fz_catch(ctx)
{
fz_free(ctx, new_table);
pdf_drop_obj(trailer);
fz_rethrow(ctx);
}
}
static void decimatepages(fz_context *ctx, pdf_document *doc)
{
pdf_obj *oldroot, *root, *pages, *kids, *parent;
int num_pages = pdf_count_pages(ctx, doc);
int page, kidcount;
oldroot = pdf_dict_get(ctx, pdf_trailer(ctx, doc), PDF_NAME_Root);
pages = pdf_dict_get(ctx, oldroot, PDF_NAME_Pages);
root = pdf_new_dict(ctx, doc, 2);
pdf_dict_put(ctx, root, PDF_NAME_Type, pdf_dict_get(ctx, oldroot, PDF_NAME_Type));
pdf_dict_put(ctx, root, PDF_NAME_Pages, pdf_dict_get(ctx, oldroot, PDF_NAME_Pages));
pdf_update_object(ctx, doc, pdf_to_num(ctx, oldroot), root);
pdf_drop_obj(ctx, root);
/* Create a new kids array with our new pages in */
parent = pdf_new_indirect(ctx, doc, pdf_to_num(ctx, pages), pdf_to_gen(ctx, pages));
kids = pdf_new_array(ctx, doc, 1);
kidcount = 0;
for (page=0; page < num_pages; page++)
{
pdf_page *page_details = pdf_load_page(ctx, doc, page);
int xf = x_factor, yf = y_factor;
int x, y;
float w = page_details->mediabox.x1 - page_details->mediabox.x0;
float h = page_details->mediabox.y1 - page_details->mediabox.y0;
if (xf == 0 && yf == 0)
{
/* Nothing specified, so split along the long edge */
if (w > h)
xf = 2, yf = 1;
else
xf = 1, yf = 2;
}
else if (xf == 0)
xf = 1;
else if (yf == 0)
yf = 1;
for (y = yf-1; y >= 0; y--)
{
for (x = 0; x < xf; x++)
{
pdf_obj *newpageobj, *newpageref, *newmediabox;
fz_rect mb;
int num;
newpageobj = pdf_copy_dict(ctx, pdf_lookup_page_obj(ctx, doc, page));
num = pdf_create_object(ctx, doc);
pdf_update_object(ctx, doc, num, newpageobj);
newpageref = pdf_new_indirect(ctx, doc, num, 0);
newmediabox = pdf_new_array(ctx, doc, 4);
mb.x0 = page_details->mediabox.x0 + (w/xf)*x;
if (x == xf-1)
mb.x1 = page_details->mediabox.x1;
else
mb.x1 = page_details->mediabox.x0 + (w/xf)*(x+1);
mb.y0 = page_details->mediabox.y0 + (h/yf)*y;
if (y == yf-1)
mb.y1 = page_details->mediabox.y1;
else
mb.y1 = page_details->mediabox.y0 + (h/yf)*(y+1);
pdf_array_push(ctx, newmediabox, pdf_new_real(ctx, doc, mb.x0));
pdf_array_push(ctx, newmediabox, pdf_new_real(ctx, doc, mb.y0));
pdf_array_push(ctx, newmediabox, pdf_new_real(ctx, doc, mb.x1));
pdf_array_push(ctx, newmediabox, pdf_new_real(ctx, doc, mb.y1));
pdf_dict_put(ctx, newpageobj, PDF_NAME_Parent, parent);
pdf_dict_put(ctx, newpageobj, PDF_NAME_MediaBox, newmediabox);
/* Store page object in new kids array */
pdf_array_push(ctx, kids, newpageref);
kidcount++;
}
}
}
pdf_drop_obj(ctx, parent);
/* Update page count and kids array */
pdf_dict_put(ctx, pages, PDF_NAME_Count, pdf_new_int(ctx, doc, kidcount));
pdf_dict_put(ctx, pages, PDF_NAME_Kids, kids);
pdf_drop_obj(ctx, kids);
}
static void decimatepages(pdf_document *xref)
{
pdf_obj *oldroot, *root, *pages, *kids, *parent;
fz_context *ctx = xref->ctx;
int num_pages = pdf_count_pages(xref);
int page, kidcount;
/* Keep only pages/type and (reduced) dest entries to avoid
* references to unretained pages */
oldroot = pdf_dict_gets(pdf_trailer(xref), "Root");
pages = pdf_dict_gets(oldroot, "Pages");
root = pdf_new_dict(ctx, 2);
pdf_dict_puts(root, "Type", pdf_dict_gets(oldroot, "Type"));
pdf_dict_puts(root, "Pages", pdf_dict_gets(oldroot, "Pages"));
pdf_update_object(xref, pdf_to_num(oldroot), root);
pdf_drop_obj(root);
/* Create a new kids array with only the pages we want to keep */
parent = pdf_new_indirect(ctx, pdf_to_num(pages), pdf_to_gen(pages), xref);
kids = pdf_new_array(ctx, 1);
kidcount = 0;
for (page=0; page < num_pages; page++)
{
pdf_page *page_details = pdf_load_page(xref, page);
int xf = x_factor, yf = y_factor;
int x, y;
float w = page_details->mediabox.x1 - page_details->mediabox.x0;
float h = page_details->mediabox.y1 - page_details->mediabox.y0;
if (xf == 0 && yf == 0)
{
/* Nothing specified, so split along the long edge */
if (w > h)
xf = 2, yf = 1;
else
xf = 1, yf = 2;
}
else if (xf == 0)
xf = 1;
else if (yf == 0)
yf = 1;
for (y = yf-1; y >= 0; y--)
{
for (x = 0; x < xf; x++)
{
pdf_obj *newpageobj, *newpageref, *newmediabox;
fz_rect mb;
int num;
newpageobj = pdf_copy_dict(ctx, xref->page_objs[page]);
num = pdf_create_object(xref);
pdf_update_object(xref, num, newpageobj);
newpageref = pdf_new_indirect(ctx, num, 0, xref);
newmediabox = pdf_new_array(ctx, 4);
mb.x0 = page_details->mediabox.x0 + (w/xf)*x;
if (x == xf-1)
mb.x1 = page_details->mediabox.x1;
else
mb.x1 = page_details->mediabox.x0 + (w/xf)*(x+1);
mb.y0 = page_details->mediabox.y0 + (h/yf)*y;
if (y == yf-1)
mb.y1 = page_details->mediabox.y1;
else
mb.y1 = page_details->mediabox.y0 + (h/yf)*(y+1);
pdf_array_push(newmediabox, pdf_new_real(ctx, mb.x0));
pdf_array_push(newmediabox, pdf_new_real(ctx, mb.y0));
pdf_array_push(newmediabox, pdf_new_real(ctx, mb.x1));
pdf_array_push(newmediabox, pdf_new_real(ctx, mb.y1));
pdf_dict_puts(newpageobj, "Parent", parent);
pdf_dict_puts(newpageobj, "MediaBox", newmediabox);
/* Store page object in new kids array */
pdf_array_push(kids, newpageref);
kidcount++;
}
}
}
pdf_drop_obj(parent);
/* Update page count and kids array */
pdf_dict_puts(pages, "Count", pdf_new_int(ctx, kidcount));
pdf_dict_puts(pages, "Kids", kids);
pdf_drop_obj(kids);
}
