Initial writing support.

This commit is contained in:
Michael R Sweet 2021-05-16 11:39:05 -04:00
parent 4bb81417a8
commit 548ff7d119
No known key found for this signature in database
GPG Key ID: 999559A027815955
8 changed files with 652 additions and 41 deletions

View File

@ -573,7 +573,7 @@ _pdfioArrayWrite(pdfio_array_t *a) // I - Array
// Write each value...
for (i = a->num_values, v = a->values; i > 0; i --, v ++)
{
if (!_pdfioValueWrite(pdf, v))
if (!_pdfioValueWrite(pdf, v, NULL))
return (false);
}

View File

@ -805,7 +805,7 @@ _pdfioDictWrite(pdfio_dict_t *dict, // I - Dictionary
if (!_pdfioFilePuts(pdf, " 9999999999"))
return (false);
}
else if (!_pdfioValueWrite(pdf, &pair->value))
else if (!_pdfioValueWrite(pdf, &pair->value, NULL))
return (false);
}

View File

@ -27,6 +27,8 @@ static int compare_objs(pdfio_obj_t **a, pdfio_obj_t **b);
static bool load_obj_stream(pdfio_obj_t *obj);
static bool load_pages(pdfio_file_t *pdf, pdfio_obj_t *obj);
static bool load_xref(pdfio_file_t *pdf, off_t xref_offset);
static bool write_catalog(pdfio_file_t *pdf);
static bool write_pages(pdfio_file_t *pdf);
static bool write_trailer(pdfio_file_t *pdf);
@ -89,7 +91,14 @@ pdfioFileClose(pdfio_file_t *pdf) // I - PDF file
// Close the file itself...
if (pdf->mode == _PDFIO_MODE_WRITE)
ret = write_trailer(pdf);
{
ret = false;
if (write_pages(pdf))
if (write_catalog(pdf))
if (write_trailer(pdf))
ret = _pdfioFileFlush(pdf);
}
if (close(pdf->fd) < 0)
ret = false;
@ -132,10 +141,13 @@ pdfio_file_t * // O - PDF file or `NULL` on error
pdfioFileCreate(
const char *filename, // I - Filename
const char *version, // I - PDF version number or `NULL` for default (2.0)
pdfio_rect_t *media_box, // I - Default MediaBox for pages
pdfio_rect_t *crop_box, // I - Default CropBox for pages
pdfio_error_cb_t error_cb, // I - Error callback or `NULL` for default
void *error_data) // I - Error callback data, if any
{
pdfio_file_t *pdf; // PDF file
pdfio_dict_t *dict; // Dictionary for pages object
// Range check input...
@ -169,6 +181,30 @@ pdfioFileCreate(
pdf->error_cb = error_cb;
pdf->error_data = error_data;
if (media_box)
{
pdf->media_box = *media_box;
}
else
{
// Default to "universal" size (intersection of A4 and US Letter)
pdf->media_box.x2 = 210.0f * 72.0f / 25.4f;
pdf->media_box.y2 = 11.0f * 72.0f;
}
if (crop_box)
{
pdf->crop_box = *crop_box;
}
else
{
// Default to "universal" size (intersection of A4 and US Letter) with 1/4" margins
pdf->crop_box.x1 = 18.0f;
pdf->crop_box.y1 = 18.0f;
pdf->crop_box.x2 = 210.0f * 72.0f / 25.4f - 18.0f;
pdf->crop_box.y2 = 11.0f * 72.0f - 18.0f;
}
// Create the file...
if ((pdf->fd = open(filename, O_WRONLY | O_BINARY | O_CREAT | O_TRUNC, 0666)) < 0)
{
@ -187,6 +223,23 @@ pdfioFileCreate(
return (NULL);
}
// Create the pages object...
if ((dict = pdfioDictCreate(pdf)) == NULL)
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
pdfioDictSetName(dict, "Type", "Pages");
if ((pdf->pages_root = pdfioFileCreateObject(pdf, dict)) == NULL)
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
return (pdf);
}
@ -246,7 +299,6 @@ pdfioFileCreateObject(
// Initialize the object...
obj->pdf = pdf;
obj->number = pdf->num_objs;
obj->offset = _pdfioFileTell(pdf);
obj->value.type = PDFIO_VALTYPE_DICT;
obj->value.value.dict = dict;
@ -259,14 +311,73 @@ pdfioFileCreateObject(
// 'pdfioFileCreatePage()' - Create a page in a PDF file.
//
pdfio_obj_t * // O - New object
pdfio_stream_t * // O - Contents stream
pdfioFileCreatePage(pdfio_file_t *pdf, // I - PDF file
pdfio_dict_t *dict) // I - Page dictionary
{
// TODO: Implement pdfioFileCreatePage
(void)pdf;
(void)dict;
pdfio_obj_t *page, // Page object
*contents; // Contents object
pdfio_dict_t *contents_dict; // Dictionary for Contents object
// Range check input...
if (!pdf)
return (NULL);
// Copy the page dictionary...
if (dict)
dict = pdfioDictCopy(pdf, dict);
else
dict = pdfioDictCreate(pdf);
// Make sure the page dictionary has all of the required keys...
if (!_pdfioDictGetValue(dict, "CropBox"))
pdfioDictSetRect(dict, "CropBox", &pdf->crop_box);
if (!_pdfioDictGetValue(dict, "MediaBox"))
pdfioDictSetRect(dict, "MediaBox", &pdf->media_box);
pdfioDictSetObject(dict, "Parent", pdf->pages_root);
if (!_pdfioDictGetValue(dict, "Resources"))
pdfioDictSetDict(dict, "Resources", pdfioDictCreate(pdf));
if (!_pdfioDictGetValue(dict, "Type"))
pdfioDictSetName(dict, "Type", "Page");
// Create the page object...
page = pdfioFileCreateObject(pdf, dict);
// Create a contents object to hold the contents of the page...
contents_dict = pdfioDictCreate(pdf);
pdfioDictSetName(contents_dict, "Filter", "FlateDecode");
contents = pdfioFileCreateObject(pdf, contents_dict);
// Add the contents stream to the pages object and write it...
pdfioDictSetObject(dict, "Contents", contents);
if (!pdfioObjClose(page))
return (NULL);
// Add the page to the array of pages...
if (pdf->num_pages >= pdf->alloc_pages)
{
pdfio_obj_t **temp = (pdfio_obj_t **)realloc(pdf->pages, (pdf->alloc_pages + 16) * sizeof(pdfio_obj_t *));
if (!temp)
{
_pdfioFileError(pdf, "Unable to allocate memory for pages.");
return (NULL);
}
pdf->alloc_pages += 16;
pdf->pages = temp;
}
pdf->pages[pdf->num_pages ++] = page;
// Create the contents stream...
return (pdfioObjCreateStream(contents, PDFIO_FILTER_FLATE));
}
@ -1114,6 +1225,56 @@ load_xref(pdfio_file_t *pdf, // I - PDF file
}
//
// 'write_catalog()' - Write the PDF root object/catalog.
//
static bool // O - `true` on success, `false` on failure
write_catalog(pdfio_file_t *pdf) // I - PDF file
{
pdfio_dict_t *dict; // Dictionary for catalog...
if ((dict = pdfioDictCreate(pdf)) == NULL)
return (false);
pdfioDictSetName(dict, "Type", "Catalog");
pdfioDictSetObject(dict, "Pages", pdf->pages_root);
// TODO: Add support for all of the root object dictionary keys
if ((pdf->root = pdfioFileCreateObject(pdf, dict)) == NULL)
return (false);
else
return (pdfioObjClose(pdf->root));
}
//
// 'write_pages()' - Write the PDF pages objects.
//
static bool // O - `true` on success, `false` on failure
write_pages(pdfio_file_t *pdf) // I - PDF file
{
pdfio_array_t *kids; // Pages array
size_t i; // Looping var
// Build the "Kids" array pointing to each page...
if ((kids = pdfioArrayCreate(pdf)) == NULL)
return (false);
for (i = 0; i < pdf->num_pages; i ++)
pdfioArrayAppendObject(kids, pdf->pages[i]);
pdfioDictSetNumber(pdf->pages_root->value.value.dict, "Count", pdf->num_pages);
pdfioDictSetArray(pdf->pages_root->value.value.dict, "Kids", kids);
// Write the Pages object...
return (pdfioObjClose(pdf->pages_root));
}
//
// 'write_trailer()' - Write the PDF catalog object, xref table, and trailer.
//
@ -1121,8 +1282,80 @@ load_xref(pdfio_file_t *pdf, // I - PDF file
static bool // O - `true` on success, `false` on failure
write_trailer(pdfio_file_t *pdf) // I - PDF file
{
// TODO: Write trailer
(void)pdf;
bool ret = true; // Return value
off_t xref_offset; // Offset to xref table
size_t i; // Looping var
int fd; // File for /dev/urandom
unsigned char id_values[2][16]; // ID array values
return (false);
// Write the xref table...
// TODO: Look at adding support for xref streams...
xref_offset = _pdfioFileTell(pdf);
if (!_pdfioFilePrintf(pdf, "xref\n0 %lu \n0000000000 65535 f \n", (unsigned long)pdf->num_objs))
{
_pdfioFileError(pdf, "Unable to write cross-reference table.");
ret = false;
goto done;
}
for (i = 0; i < pdf->num_objs; i ++)
{
pdfio_obj_t *obj = pdf->objs[i]; // Current object
if (!_pdfioFilePrintf(pdf, "%010lu %05u n \n", (unsigned long)obj->offset, obj->generation))
{
_pdfioFileError(pdf, "Unable to write cross-reference table.");
ret = false;
goto done;
}
}
// Write the trailer...
if (!_pdfioFilePuts(pdf, "trailer\n"))
{
_pdfioFileError(pdf, "Unable to write trailer.");
ret = false;
goto done;
}
if ((fd = open("/dev/urandom", O_RDONLY)) >= 0)
{
// Load ID array with random values from /dev/urandom...
memset(id_values, 0, sizeof(id_values));
read(fd, id_values[0], sizeof(id_values[0]));
read(fd, id_values[1], sizeof(id_values[1]));
close(fd);
pdf->id_array = pdfioArrayCreate(pdf);
pdfioArrayAppendBinary(pdf->id_array, id_values[0], sizeof(id_values[0]));
pdfioArrayAppendBinary(pdf->id_array, id_values[1], sizeof(id_values[1]));
}
pdf->trailer = pdfioDictCreate(pdf);
if (pdf->encrypt)
pdfioDictSetObject(pdf->trailer, "Encrypt", pdf->encrypt);
if (pdf->id_array)
pdfioDictSetArray(pdf->trailer, "ID", pdf->id_array);
pdfioDictSetObject(pdf->trailer, "Info", pdf->info);
pdfioDictSetObject(pdf->trailer, "Root", pdf->root);
pdfioDictSetNumber(pdf->trailer, "Size", pdf->num_objs + 1);
if (!_pdfioDictWrite(pdf->trailer, NULL))
{
_pdfioFileError(pdf, "Unable to write trailer.");
ret = false;
goto done;
}
if (!_pdfioFilePrintf(pdf, "\nstartxref\n%lu\n%%EOF\n", (unsigned long)xref_offset))
{
_pdfioFileError(pdf, "Unable to write xref offset.");
ret = false;
}
done:
return (ret);
}

View File

@ -14,6 +14,13 @@
#include "pdfio-private.h"
//
// Local functions...
//
static bool write_obj_header(pdfio_obj_t *obj);
//
// 'pdfioObjClose()' - Close an object, writing any data as needed to the PDF
// file.
@ -22,10 +29,20 @@
bool // O - `true` on success, `false` on failure
pdfioObjClose(pdfio_obj_t *obj) // I - Object
{
// TODO: Implement pdfioObjClose
(void)obj;
// Range check input
if (!obj)
return (false);
if (obj->pdf->mode != _PDFIO_MODE_WRITE)
return (true); // Nothing to do when reading
// Write what remains for the object...
if (!obj->offset)
return (write_obj_header(obj)); // Just write the object value
else if (obj->stream)
return (pdfioStreamClose(obj->stream));
else
return (true); // Already closed
}
@ -54,11 +71,40 @@ pdfioObjCreateStream(
pdfio_obj_t *obj, // I - Object
pdfio_filter_t filter) // I - Type of compression to apply
{
// TODO: Implement pdfioObjCreateStream
(void)obj;
(void)filter;
// Range check input
if (!obj || obj->pdf->mode != _PDFIO_MODE_WRITE || obj->value.type != PDFIO_VALTYPE_DICT)
return (NULL);
if (obj->offset)
{
_pdfioFileError(obj->pdf, "Object has already been written.");
return (NULL);
}
if (filter != PDFIO_FILTER_NONE && filter != PDFIO_FILTER_FLATE)
{
_pdfioFileError(obj->pdf, "Unsupported filter value for pdfioObjCreateStream.");
return (NULL);
}
// Write the header...
if (!_pdfioDictGetValue(obj->value.value.dict, "Length"))
{
// Need a Length key for the stream, add a placeholder that we can fill in
// later...
pdfioDictSetNumber(obj->value.value.dict, "Length", 0.0f);
}
if (!write_obj_header(obj))
return (NULL);
if (!_pdfioFilePuts(obj->pdf, "stream\n"))
return (NULL);
obj->stream_offset = _pdfioFileTell(obj->pdf);
// Return the new stream...
return (_pdfioStreamCreate(obj, filter));
}
@ -295,3 +341,22 @@ pdfioObjOpenStream(pdfio_obj_t *obj, // I - Object
// Open the stream...
return (_pdfioStreamOpen(obj, decode));
}
//
// 'write_obj_header()' - Write the object header...
//
static bool // O - `true` on success, `false` on failure
write_obj_header(pdfio_obj_t *obj) // I - Object
{
obj->offset = _pdfioFileTell(obj->pdf);
if (!_pdfioFilePrintf(obj->pdf, "%lu %u obj\n", (unsigned long)obj->number, obj->generation))
return (false);
if (!_pdfioValueWrite(obj->pdf, &obj->value, &obj->length_offset))
return (false);
return (_pdfioFilePuts(obj->pdf, "\n"));
}

View File

@ -77,7 +77,8 @@ typedef enum _pdfio_predictor_e // PNG predictor constants
_PDFIO_PREDICTOR_PNG_SUB = 11, // PNG Sub predictor
_PDFIO_PREDICTOR_PNG_UP = 12, // PNG Up predictor
_PDFIO_PREDICTOR_PNG_AVERAGE = 13, // PNG Average predictor
_PDFIO_PREDICTOR_PNG_PAETH = 14 // PNG Paeth predictor
_PDFIO_PREDICTOR_PNG_PAETH = 14, // PNG Paeth predictor
_PDFIO_PREDICTOR_PNG_AUTO = 15 // PNG "auto" predictor (currently mapped to Paeth)
} _pdfio_predictor_t;
typedef ssize_t (*_pdfio_tconsume_cb_t)(void *data, size_t bytes);
@ -154,6 +155,8 @@ struct _pdfio_file_s // PDF file structure
{
char *filename; // Filename
char *version; // Version number
pdfio_rect_t media_box, // Default MediaBox value
crop_box; // Default CropBox value
_pdfio_mode_t mode; // Read/write mode
pdfio_error_cb_t error_cb; // Error callback
void *error_data; // Data for error callback
@ -167,6 +170,7 @@ struct _pdfio_file_s // PDF file structure
pdfio_dict_t *trailer; // Trailer dictionary
pdfio_obj_t *root; // Root object/dictionary
pdfio_obj_t *info; // Information object/dictionary
pdfio_obj_t *pages_root; // Root pages object
pdfio_obj_t *encrypt; // Encryption object/dictionary
pdfio_array_t *id_array; // ID array
@ -275,6 +279,6 @@ extern _pdfio_value_t *_pdfioValueCopy(pdfio_file_t *pdfdst, _pdfio_value_t *vds
extern void _pdfioValueDebug(_pdfio_value_t *v, FILE *fp) PDFIO_INTERNAL;
extern void _pdfioValueDelete(_pdfio_value_t *v) PDFIO_INTERNAL;
extern _pdfio_value_t *_pdfioValueRead(pdfio_file_t *pdf, _pdfio_token_t *ts, _pdfio_value_t *v) PDFIO_INTERNAL;
extern bool _pdfioValueWrite(pdfio_file_t *pdf, _pdfio_value_t *v) PDFIO_INTERNAL;
extern bool _pdfioValueWrite(pdfio_file_t *pdf, _pdfio_value_t *v, off_t *length) PDFIO_INTERNAL;
#endif // !PDFIO_PRIVATE_H

View File

@ -20,6 +20,7 @@
static unsigned char stream_paeth(unsigned char a, unsigned char b, unsigned char c);
static ssize_t stream_read(pdfio_stream_t *st, char *buffer, size_t bytes);
static bool stream_write(pdfio_stream_t *st, const void *buffer, size_t bytes);
//
@ -29,6 +30,9 @@ static ssize_t stream_read(pdfio_stream_t *st, char *buffer, size_t bytes);
bool // O - `true` on success, `false` on failure
pdfioStreamClose(pdfio_stream_t *st) // I - Stream
{
bool ret = true; // Return value
// Range check input...
if (!st)
return (false);
@ -41,15 +45,85 @@ pdfioStreamClose(pdfio_stream_t *st) // I - Stream
}
else
{
// TODO: Implement close for writing
return (false);
// Close stream for writing...
if (st->filter == PDFIO_FILTER_FLATE)
{
// Finalize flate compression stream...
int status; // Deflate status
while ((status = deflate(&st->flate, Z_FINISH)) != Z_STREAM_END)
{
if (status < Z_OK && status != Z_BUF_ERROR)
{
_pdfioFileError(st->pdf, "Flate compression failed (%d)", status);
ret = false;
goto done;
}
if (!_pdfioFileWrite(st->pdf, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out))
{
ret = false;
goto done;
}
st->flate.next_out = (Bytef *)st->cbuffer;
st->flate.avail_out = (uInt)sizeof(st->cbuffer);
}
if (st->flate.avail_out < (uInt)sizeof(st->cbuffer))
{
// Write any residuals...
if (!_pdfioFileWrite(st->pdf, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out))
{
ret = false;
goto done;
}
}
}
// Save the length of this stream...
st->obj->stream_length = (size_t)(_pdfioFileTell(st->pdf) - st->obj->stream_offset);
// End of stream marker...
if (!_pdfioFilePuts(st->pdf, "\nendstream\n"))
{
ret = false;
goto done;
}
// Update the length as needed...
if (st->obj->length_offset)
{
// Seek back to the "/Length 9999999999" we wrote...
if (_pdfioFileSeek(st->pdf, st->obj->length_offset, SEEK_SET) < 0)
{
ret = false;
goto done;
}
// Write the updated length value...
if (!_pdfioFilePrintf(st->pdf, "%-10lu", (unsigned long)st->obj->stream_length))
{
ret = false;
goto done;
}
// Seek to the end of the PDF file...
if (_pdfioFileSeek(st->pdf, 0, SEEK_END) < 0)
{
ret = false;
goto done;
}
}
}
done:
free(st->pbuffers[0]);
free(st->pbuffers[1]);
free(st);
return (true);
return (ret);
}
@ -64,13 +138,112 @@ _pdfioStreamCreate(
pdfio_obj_t *obj, // I - Object
pdfio_filter_t compression) // I - Compression to apply
{
// TODO: Implement _pdfioStreamCreate
(void)obj;
(void)compression;
pdfio_stream_t *st; // Stream
// Allocate a new stream object...
if ((st = (pdfio_stream_t *)calloc(1, sizeof(pdfio_stream_t))) == NULL)
{
_pdfioFileError(obj->pdf, "Unable to allocate memory for a stream.");
return (NULL);
}
st->pdf = obj->pdf;
st->obj = obj;
st->filter = compression;
if (compression == PDFIO_FILTER_FLATE)
{
// Flate compression
pdfio_dict_t *params = pdfioDictGetDict(obj->value.value.dict, "DecodeParms");
// Decoding parameters
int bpc = (int)pdfioDictGetNumber(params, "BitsPerComponent");
// Bits per component
int colors = (int)pdfioDictGetNumber(params, "Colors");
// Number of colors
int columns = (int)pdfioDictGetNumber(params, "Columns");
// Number of columns
int predictor = (int)pdfioDictGetNumber(params, "Predictor");
// Predictory value, if any
PDFIO_DEBUG("_pdfioStreamCreate: FlateDecode - BitsPerComponent=%d, Colors=%d, Columns=%d, Predictor=%d\n", bpc, colors, columns, predictor);
if (bpc == 0)
{
bpc = 8;
}
else if (bpc < 1 || bpc == 3 || (bpc > 4 && bpc < 8) || (bpc > 8 && bpc < 16) || bpc > 16)
{
_pdfioFileError(st->pdf, "Unsupported BitsPerColor value %d.", bpc);
free(st);
return (NULL);
}
if (colors == 0)
{
colors = 1;
}
else if (colors < 0 || colors > 4)
{
_pdfioFileError(st->pdf, "Unsupported Colors value %d.", colors);
free(st);
return (NULL);
}
if (columns == 0)
{
columns = 1;
}
else if (columns < 0)
{
_pdfioFileError(st->pdf, "Unsupported Columns value %d.", columns);
free(st);
return (NULL);
}
if ((predictor > 1 && predictor < 10) || predictor > 15)
{
_pdfioFileError(st->pdf, "Unsupported Predictor function %d.", predictor);
free(st);
return (NULL);
}
else if (predictor)
{
// Using a PNG predictor function
st->predictor = (_pdfio_predictor_t)predictor;
st->pbpixel = (size_t)(bpc * colors + 7) / 8;
st->pbsize = (size_t)(bpc * colors * columns + 7) / 8;
if (predictor >= 10)
st->pbsize ++; // Add PNG predictor byte
if ((st->pbuffers[0] = calloc(1, st->pbsize)) == NULL || (st->pbuffers[1] = calloc(1, st->pbsize)) == NULL)
{
_pdfioFileError(st->pdf, "Unable to allocate %lu bytes for Predictor buffers.", (unsigned long)st->pbsize);
free(st->pbuffers[0]);
free(st->pbuffers[1]);
free(st);
return (NULL);
}
}
else
st->predictor = _PDFIO_PREDICTOR_NONE;
st->flate.next_out = (Bytef *)st->cbuffer;
st->flate.avail_out = (uInt)sizeof(st->cbuffer);
if (deflateInit(&(st->flate), 9) != Z_OK)
{
_pdfioFileError(st->pdf, "Unable to start Flate filter.");
free(st->pbuffers[0]);
free(st->pbuffers[1]);
free(st);
return (NULL);
}
}
return (st);
}
//
// 'pdfioStreamConsume()' - Consume bytes from the stream.
@ -268,13 +441,8 @@ _pdfioStreamOpen(pdfio_obj_t *obj, // I - Object
else
st->predictor = _PDFIO_PREDICTOR_NONE;
st->flate.zalloc = (alloc_func)0;
st->flate.zfree = (free_func)0;
st->flate.opaque = (voidpf)0;
st->flate.next_in = (Bytef *)st->cbuffer;
st->flate.next_out = NULL;
st->flate.avail_in = (uInt)_pdfioFileRead(st->pdf, st->cbuffer, sizeof(st->cbuffer));
st->flate.avail_out = 0;
if (inflateInit(&(st->flate)) != Z_OK)
{
@ -474,14 +642,112 @@ pdfioStreamWrite(
const void *buffer, // I - Data to write
size_t bytes) // I - Number of bytes to write
{
size_t pbpixel = st->pbpixel,
// Size of pixel in bytes
pbline = st->pbsize - 1,
// Bytes per line
remaining, // Remaining bytes on this line
firstcol = pbline - pbpixel;
// First column bytes remaining
const unsigned char *bufptr = (const unsigned char *)buffer;
// Pointer into buffer
unsigned char *thisptr, // Current raw buffer
*prevptr; // Previous raw buffer
// Range check input...
if (!st || st->pdf->mode != _PDFIO_MODE_WRITE || !buffer || !bytes)
return (false);
// TODO: Implement pdfioStreamWrite
// Write it...
if (st->filter == PDFIO_FILTER_NONE)
{
// No filtering so just write it...
return (_pdfioFileWrite(st->pdf, buffer, bytes));
}
if (st->predictor == _PDFIO_PREDICTOR_NONE)
{
// No predictor, just write it out straight...
return (stream_write(st, buffer, bytes));
}
else if ((bytes % pbline) != 0)
{
_pdfioFileError(st->pdf, "Write buffer size must be a multiple of a complete row.");
return (false);
}
while (bytes > 0)
{
// Store the PNG predictor in the first byte of the buffer...
if (st->predictor == _PDFIO_PREDICTOR_PNG_AUTO)
st->pbuffers[st->pbcurrent][0] = 4;
else
st->pbuffers[st->pbcurrent][0] = (unsigned char)(st->predictor - 10);
// Then process the current line using the specified PNG predictor...
thisptr = st->pbuffers[st->pbcurrent] + 1;
prevptr = st->pbuffers[!st->pbcurrent] + 1;
switch (st->predictor)
{
default :
// Anti-compiler-warning code (NONE is handled above, TIFF is not supported for writing)
return (false);
case _PDFIO_PREDICTOR_PNG_SUB :
// Encode the difference from the previous column
for (remaining = pbline; remaining > 0; remaining --, bufptr ++, thisptr ++)
{
if (remaining < firstcol)
*thisptr = *bufptr - thisptr[-pbpixel];
else
*thisptr = *bufptr;
}
break;
case _PDFIO_PREDICTOR_PNG_UP :
// Encode the difference from the previous line
for (remaining = pbline; remaining > 0; remaining --, bufptr ++, thisptr ++, prevptr ++)
{
*thisptr = *bufptr - *prevptr;
}
break;
case _PDFIO_PREDICTOR_PNG_AVERAGE :
// Encode the difference with the average of the previous column and line
for (remaining = pbline; remaining > 0; remaining --, bufptr ++, thisptr ++, prevptr ++)
{
if (remaining < firstcol)
*thisptr = *bufptr - (thisptr[-pbpixel] + *prevptr) / 2;
else
*thisptr = *bufptr - *prevptr / 2;
}
break;
case _PDFIO_PREDICTOR_PNG_PAETH :
case _PDFIO_PREDICTOR_PNG_AUTO :
// Encode the difference with a linear transform function
for (remaining = pbline; remaining > 0; remaining --, bufptr ++, thisptr ++, prevptr ++)
{
if (remaining < firstcol)
*thisptr = *bufptr - stream_paeth(thisptr[-pbpixel], *prevptr, prevptr[-pbpixel]);
else
*thisptr = *bufptr - stream_paeth(0, *prevptr, 0);
}
break;
}
// Write the encoded line...
if (!stream_write(st, st->pbuffers[st->pbcurrent], st->pbsize))
return (false);
st->pbcurrent = !st->pbcurrent;
}
return (true);
}
//
// 'stream_paeth()' - PaethPredictor function for PNG decompression filter.
@ -674,3 +940,44 @@ stream_read(pdfio_stream_t *st, // I - Stream
return (-1);
}
//
// 'stream_write()' - Write flate-compressed data...
//
static bool // O - `true` on success, `false` on failure
stream_write(pdfio_stream_t *st, // I - Stream
const void *buffer, // I - Buffer to write
size_t bytes) // I - Number of bytes to write
{
int status; // Compression status
// Flate-compress the buffer...
st->flate.avail_in = (uInt)bytes;
st->flate.next_in = (Bytef *)buffer;
while (st->flate.avail_in > 0)
{
if (st->flate.avail_out < (sizeof(st->cbuffer) / 8))
{
// Flush the compression buffer...
if (!_pdfioFileWrite(st->pdf, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out))
return (false);
st->flate.next_out = (Bytef *)st->cbuffer;
st->flate.avail_out = sizeof(st->cbuffer);
}
// Deflate what we can this time...
status = deflate(&st->flate, Z_NO_FLUSH);
if (status < Z_OK && status != Z_BUF_ERROR)
{
_pdfioFileError(st->pdf, "Flate compression failed (%d)", status);
return (false);
}
}
return (true);
}

View File

@ -349,7 +349,8 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
bool // O - `true` on success, `false` on failure
_pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
_pdfio_value_t *v) // I - Value
_pdfio_value_t *v, // I - Value
off_t *length)// O - Offset to /Length value, if any
{
switch (v->type)
{
@ -394,7 +395,7 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
}
case PDFIO_VALTYPE_DICT :
return (_pdfioDictWrite(v->value.dict, NULL));
return (_pdfioDictWrite(v->value.dict, length));
case PDFIO_VALTYPE_INDIRECT :
return (_pdfioFilePrintf(pdf, " %lu %u R", (unsigned long)v->value.indirect.number, v->value.indirect.generation));

View File

@ -147,9 +147,10 @@ extern bool pdfioDictSetString(pdfio_dict_t *dict, const char *key, const char
extern bool pdfioDictSetStringf(pdfio_dict_t *dict, const char *key, const char *format, ...) PDFIO_PUBLIC PDFIO_FORMAT(3,4);
extern bool pdfioFileClose(pdfio_file_t *pdf) PDFIO_PUBLIC;
extern pdfio_file_t *pdfioFileCreate(const char *filename, const char *version, pdfio_error_cb_t error_cb, void *error_data) PDFIO_PUBLIC;
extern pdfio_file_t *pdfioFileCreate(const char *filename, const char *version, pdfio_rect_t *media_box, pdfio_rect_t *crop_box, pdfio_error_cb_t error_cb, void *error_data) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileCreateObject(pdfio_file_t *pdf, pdfio_dict_t *dict) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileCreatePage(pdfio_file_t *pdf, pdfio_dict_t *dict) PDFIO_PUBLIC;
// TODO: Add number, array, string, etc. versions of pdfioFileCreateObject?
extern pdfio_stream_t *pdfioFileCreatePage(pdfio_file_t *pdf, pdfio_dict_t *dict) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileFindObject(pdfio_file_t *pdf, size_t number) PDFIO_PUBLIC;
extern pdfio_array_t *pdfioFileGetID(pdfio_file_t *pdf) PDFIO_PUBLIC;
extern const char *pdfioFileGetName(pdfio_file_t *pdf) PDFIO_PUBLIC;