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mirror of git://projects.qi-hardware.com/eda-tools.git synced 2024-11-25 20:12:48 +02:00

eeshow/gfx/pdftoc.c: edit Cairo-generated PDF to insert TOC

Based on schtoc.pl
This commit is contained in:
Werner Almesberger 2016-08-21 11:34:12 -03:00
parent 7652f3a88f
commit 71d03c7281
3 changed files with 374 additions and 1 deletions

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@ -21,7 +21,7 @@ OBJS = main.o version.o \
gui/help.o gui/icons.o \
file/file.o file/git-util.o file/git-file.o file/git-hist.o \
gfx/style.o gfx/fig.o gfx/record.o gfx/cro.o gfx/diff.o gfx/gfx.o \
gfx/text.o gfx/misc.o \
gfx/text.o gfx/misc.o gfx/pdftoc.o \
misc/diag.o
ICONS = delta diff

346
eeshow/gfx/pdftoc.c Normal file
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@ -0,0 +1,346 @@
/*
* gfx/pdftoc.c - PDF writer with TOC generation
*
* Written 2016 by Werner Almesberger
* Copyright 2016 by Werner Almesberger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/*
* Strongly influenced by https://neo900.org/git?p=misc;a=tree;f=schtoc
*
* PDF Reference:
* http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_reference_1-7.pdf
*/
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "misc/util.h"
#include "misc/diag.h"
#include "gfx/pdftoc.h"
struct title {
char *s;
struct title *next;
};
struct object {
int gen;
unsigned pos;
bool is_page;
};
struct pdftoc {
FILE *file;
enum state {
idle, /* between objects */
object, /* inside an object */
catalog,/* inside the catalog object */
xref, /* stopped at xref */
trailer,/* going through the trailer */
} state;
struct title *titles;
struct title **next_title;
unsigned n_titles;
char *buf;
unsigned left; /* bytes left in buffer */
unsigned offset; /* offset into buffer */
unsigned pos; /* position in file */
struct object *objs; /* object array */
struct object *curr_obj;
int top; /* highest object number; -1 if no objects */
int root; /* catalog dict */
int info; /* information dict, 0 if absent */
};
static bool begins(const char *s, const char *pfx)
{
return !strncmp(s, pfx, strlen(pfx));
}
struct pdftoc *pdftoc_begin(const char *file)
{
struct pdftoc *ctx;
ctx = alloc_type(struct pdftoc);
if (file) {
ctx->file = fopen(file, "w");
if (!ctx->file)
diag_pfatal(file);
} else {
ctx->file = stdout;
}
ctx->state = idle;
ctx->titles = NULL;
ctx->next_title = &ctx->titles;
ctx->n_titles = 0;
ctx->buf = NULL;
ctx->left = 0;
ctx->offset = 0;
ctx->pos = 0;
ctx->objs = NULL;
ctx->top = -1;
ctx->root = 0;
ctx->info = 0;
return ctx;
}
static void add_object(struct pdftoc *ctx, int id, int gen, unsigned pos)
{
struct object *obj;
if (id > ctx->top) {
ctx->objs = realloc(ctx->objs,
(id + 1) * sizeof(struct object));
memset(ctx->objs + ctx->top + 1 , 0,
(id - ctx->top) * sizeof(struct object));
ctx->top = id;
}
obj = ctx->objs + id;
ctx->curr_obj = obj;
obj->gen = gen;
obj->pos = pos;
obj->is_page = 0;
}
static bool parse_object(struct pdftoc *ctx, const char *s)
{
int id, gen;
int n = 0;
if (sscanf(s, "%d %d obj%n", &id, &gen, &n) != 2 || !n)
return 0;
add_object(ctx, id, gen, ctx->pos);
return 1;
}
static void line(struct pdftoc *ctx, const char *s)
{
switch (ctx->state) {
case idle:
if (parse_object(ctx, s)) {
ctx->state = object;
break;
}
if (begins(s, "xref")) {
ctx->state = xref;
break;
}
break;
case object:
if (begins(s, "endobj")) {
ctx->state = idle;
break;
}
if (begins(s, "<< /Type /Page")) {
ctx->curr_obj->is_page = 1;
break;
}
if (begins(s, "<< /Type /Catalog")) {
ctx->state = catalog;
break;
}
break;
case catalog:
if (begins(s, ">>")) {
ctx->state = object;
ctx->pos += fprintf(ctx->file,
" /Outlines %u 0 R\n",
ctx->top + 1);
break;
}
break;
case xref:
abort();
case trailer:
if (sscanf(s, " /Root %d 0 R", &ctx->root) == 1)
break;
if (sscanf(s, " /Info %d 0 R", &ctx->info) == 1)
break;
break;
default:
abort();
}
}
static void parse_buffer(struct pdftoc *ctx, bool do_write)
{
unsigned size, wrote;
char *nl;
while (ctx->state != xref) {
nl = memchr(ctx->buf + ctx->offset, '\n', ctx->left);
if (!nl)
break;
*nl = 0;
size = nl - (ctx->buf + ctx->offset);
line(ctx, ctx->buf + ctx->offset);
*nl = '\n';
if (ctx->state == xref)
break;
if (do_write) {
wrote = fwrite(ctx->buf + ctx->offset, 1, size + 1,
ctx->file);
if (wrote != size + 1)
diag_pfatal("fwrite");
ctx->pos += size + 1;
}
ctx->offset += size + 1;
ctx->left -= size + 1;
}
}
bool pdftoc_write(struct pdftoc *ctx, const void *data, unsigned length)
{
char *buf;
buf = alloc_size(ctx->left + length + 1);
memcpy(buf, ctx->buf + ctx->offset, ctx->left);
memcpy(buf + ctx->left, data, length);
ctx->offset = 0;
ctx->left += length;
free(ctx->buf);
ctx->buf = buf;
parse_buffer(ctx, 1);
return 1;
}
void pdftoc_title(struct pdftoc *ctx, const char *title)
{
struct title *t;
t = alloc_type(struct title);
t->s = stralloc(title);
*ctx->next_title = t;
t->next = NULL;
ctx->next_title = &t->next;
ctx->n_titles++;
}
static void write_trailer(struct pdftoc *ctx)
{
unsigned n = ctx->top + 1;
const struct object *obj = ctx->objs;
const struct object *end = ctx->objs + ctx->top + 1;
const struct title *t;
unsigned outline, tail;
/* Outline root */
outline = n;
add_object(ctx, n, 0, ctx->pos);
tail = fprintf(ctx->file,
"%u 0 obj\n<<\n"
" /Count %u\n"
" /First %u 0 R\n"
" /Last %u 0 R\n"
">>\nendobj\n",
n, ctx->n_titles, n + 1, n + ctx->n_titles);
/* Outline items */
n++;
for (t = ctx->titles; t; t = t->next) {
while (!obj->is_page) {
assert(obj != end);
obj++;
}
add_object(ctx, n, 0, ctx->pos + tail);
tail += fprintf(ctx->file,
"%u 0 obj\n<<\n"
" /Title (%s)\n"
" /Parent %u 0 R\n",
n, t->s, outline);
if (t != ctx->titles)
tail += fprintf(ctx->file,
" /Prev %u 0 R\n", n - 1);
if (t->next)
tail += fprintf(ctx->file,
" /Next %u 0 R\n", n + 1);
tail += fprintf(ctx->file,
" /Dest [%u %u R /Fit]\n"
">>\nendobj\n",
(unsigned) (obj - ctx->objs), obj->gen);
n++;
obj++;
}
/* xref table */
fprintf(ctx->file, "xref\n0 %u\n", n);
for (obj = ctx->objs; obj != ctx->objs + ctx->top + 1; obj++)
fprintf(ctx->file,
"%010u %05u %c \n",
obj->pos, obj->pos ? 0 : 65535, obj->pos ? 'n' : 'f');
fprintf(ctx->file,
"trailer\n"
"<< /Size %u\n"
" /Root %u 0 R\n",
n, ctx->root);
if (ctx->info)
fprintf(ctx->file, " /Info %u 0 R\n", ctx->info);
fprintf(ctx->file, ">>\nstartxref\n%u\n%%%%EOF\n", ctx->pos + tail);
}
void pdftoc_end(struct pdftoc *ctx)
{
struct title *next;
assert(ctx->state == xref);
ctx->state = trailer;
parse_buffer(ctx, 0);
if (ctx->left) {
fatal("%u bytes left in buffer at end\n", ctx->left);
exit(1);
}
write_trailer(ctx);
if (fclose(ctx->file) < 0)
diag_pfatal("fclose");
while (ctx->titles) {
next = ctx->titles->next;
free(ctx->titles->s);
free(ctx->titles);
ctx->titles = next;
}
free(ctx->buf);
free(ctx);
}

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eeshow/gfx/pdftoc.h Normal file
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/*
* gfx/pdftoc.h - PDF writer with TOC generation
*
* Written 2016 by Werner Almesberger
* Copyright 2016 by Werner Almesberger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef GFX_PDFTOC_H
#define GFX_PDFTOC_H
#include <stdbool.h>
struct pdftoc;
struct pdftoc *pdftoc_begin(const char *file);
bool pdftoc_write(struct pdftoc *ctx, const void *data, unsigned length);
void pdftoc_title(struct pdftoc *ctx, const char *title);
void pdftoc_end(struct pdftoc *ctx);
#endif /* !GFX_PDFTOC_H */