diff options
Diffstat (limited to 'contrib/libpng/pngwutil.c')
| -rw-r--r-- | contrib/libpng/pngwutil.c | 2948 |
1 files changed, 0 insertions, 2948 deletions
diff --git a/contrib/libpng/pngwutil.c b/contrib/libpng/pngwutil.c deleted file mode 100644 index 2c35785..0000000 --- a/contrib/libpng/pngwutil.c +++ /dev/null @@ -1,2948 +0,0 @@ - -/* pngwutil.c - utilities to write a PNG file - * - * Last changed in libpng 1.5.0 [January 6, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" - -#ifdef PNG_WRITE_SUPPORTED - -#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED -/* Place a 32-bit number into a buffer in PNG byte order. We work - * with unsigned numbers for convenience, although one supported - * ancillary chunk uses signed (two's complement) numbers. - */ -void PNGAPI -png_save_uint_32(png_bytep buf, png_uint_32 i) -{ - buf[0] = (png_byte)((i >> 24) & 0xff); - buf[1] = (png_byte)((i >> 16) & 0xff); - buf[2] = (png_byte)((i >> 8) & 0xff); - buf[3] = (png_byte)(i & 0xff); -} - -#ifdef PNG_SAVE_INT_32_SUPPORTED -/* The png_save_int_32 function assumes integers are stored in two's - * complement format. If this isn't the case, then this routine needs to - * be modified to write data in two's complement format. Note that, - * the following works correctly even if png_int_32 has more than 32 bits - * (compare the more complex code required on read for sign extention.) - */ -void PNGAPI -png_save_int_32(png_bytep buf, png_int_32 i) -{ - buf[0] = (png_byte)((i >> 24) & 0xff); - buf[1] = (png_byte)((i >> 16) & 0xff); - buf[2] = (png_byte)((i >> 8) & 0xff); - buf[3] = (png_byte)(i & 0xff); -} -#endif - -/* Place a 16-bit number into a buffer in PNG byte order. - * The parameter is declared unsigned int, not png_uint_16, - * just to avoid potential problems on pre-ANSI C compilers. - */ -void PNGAPI -png_save_uint_16(png_bytep buf, unsigned int i) -{ - buf[0] = (png_byte)((i >> 8) & 0xff); - buf[1] = (png_byte)(i & 0xff); -} -#endif - -/* Simple function to write the signature. If we have already written - * the magic bytes of the signature, or more likely, the PNG stream is - * being embedded into another stream and doesn't need its own signature, - * we should call png_set_sig_bytes() to tell libpng how many of the - * bytes have already been written. - */ -void PNGAPI -png_write_sig(png_structp png_ptr) -{ - png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the signature is being written */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; -#endif - - /* Write the rest of the 8 byte signature */ - png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], - (png_size_t)(8 - png_ptr->sig_bytes)); - - if (png_ptr->sig_bytes < 3) - png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; -} - -/* Write a PNG chunk all at once. The type is an array of ASCII characters - * representing the chunk name. The array must be at least 4 bytes in - * length, and does not need to be null terminated. To be safe, pass the - * pre-defined chunk names here, and if you need a new one, define it - * where the others are defined. The length is the length of the data. - * All the data must be present. If that is not possible, use the - * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() - * functions instead. - */ -void PNGAPI -png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name, - png_const_bytep data, png_size_t length) -{ - if (png_ptr == NULL) - return; - - png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); - png_write_chunk_data(png_ptr, data, (png_size_t)length); - png_write_chunk_end(png_ptr); -} - -/* Write the start of a PNG chunk. The type is the chunk type. - * The total_length is the sum of the lengths of all the data you will be - * passing in png_write_chunk_data(). - */ -void PNGAPI -png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, - png_uint_32 length) -{ - png_byte buf[8]; - - png_debug2(0, "Writing %s chunk, length = %lu", chunk_name, - (unsigned long)length); - - if (png_ptr == NULL) - return; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the chunk header is being written. - * PNG_IO_CHUNK_HDR requires a single I/O call. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; -#endif - - /* Write the length and the chunk name */ - png_save_uint_32(buf, length); - png_memcpy(buf + 4, chunk_name, 4); - png_write_data(png_ptr, buf, (png_size_t)8); - - /* Put the chunk name into png_ptr->chunk_name */ - png_memcpy(png_ptr->chunk_name, chunk_name, 4); - - /* Reset the crc and run it over the chunk name */ - png_reset_crc(png_ptr); - - png_calculate_crc(png_ptr, chunk_name, 4); - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that chunk data will (possibly) be written. - * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; -#endif -} - -/* Write the data of a PNG chunk started with png_write_chunk_start(). - * Note that multiple calls to this function are allowed, and that the - * sum of the lengths from these calls *must* add up to the total_length - * given to png_write_chunk_start(). - */ -void PNGAPI -png_write_chunk_data(png_structp png_ptr, png_const_bytep data, - png_size_t length) -{ - /* Write the data, and run the CRC over it */ - if (png_ptr == NULL) - return; - - if (data != NULL && length > 0) - { - png_write_data(png_ptr, data, length); - - /* Update the CRC after writing the data, - * in case that the user I/O routine alters it. - */ - png_calculate_crc(png_ptr, data, length); - } -} - -/* Finish a chunk started with png_write_chunk_start(). */ -void PNGAPI -png_write_chunk_end(png_structp png_ptr) -{ - png_byte buf[4]; - - if (png_ptr == NULL) return; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the chunk CRC is being written. - * PNG_IO_CHUNK_CRC requires a single I/O function call. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; -#endif - - /* Write the crc in a single operation */ - png_save_uint_32(buf, png_ptr->crc); - - png_write_data(png_ptr, buf, (png_size_t)4); -} - -#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED) -/* This pair of functions encapsulates the operation of (a) compressing a - * text string, and (b) issuing it later as a series of chunk data writes. - * The compression_state structure is shared context for these functions - * set up by the caller in order to make the whole mess thread-safe. - */ - -typedef struct -{ - png_const_bytep input; /* The uncompressed input data */ - png_size_t input_len; /* Its length */ - int num_output_ptr; /* Number of output pointers used */ - int max_output_ptr; /* Size of output_ptr */ - png_bytep *output_ptr; /* Array of pointers to output */ -} compression_state; - -/* Compress given text into storage in the png_ptr structure */ -static int /* PRIVATE */ -png_text_compress(png_structp png_ptr, - png_const_charp text, png_size_t text_len, int compression, - compression_state *comp) -{ - int ret; - - comp->num_output_ptr = 0; - comp->max_output_ptr = 0; - comp->output_ptr = NULL; - comp->input = NULL; - comp->input_len = 0; - - /* We may just want to pass the text right through */ - if (compression == PNG_TEXT_COMPRESSION_NONE) - { - comp->input = (png_const_bytep)text; - comp->input_len = text_len; - return((int)text_len); - } - - if (compression >= PNG_TEXT_COMPRESSION_LAST) - { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[50]; - png_snprintf(msg, 50, "Unknown compression type %d", compression); - png_warning(png_ptr, msg); -#else - png_warning(png_ptr, "Unknown compression type"); -#endif - } - - /* We can't write the chunk until we find out how much data we have, - * which means we need to run the compressor first and save the - * output. This shouldn't be a problem, as the vast majority of - * comments should be reasonable, but we will set up an array of - * malloc'd pointers to be sure. - * - * If we knew the application was well behaved, we could simplify this - * greatly by assuming we can always malloc an output buffer large - * enough to hold the compressed text ((1001 * text_len / 1000) + 12) - * and malloc this directly. The only time this would be a bad idea is - * if we can't malloc more than 64K and we have 64K of random input - * data, or if the input string is incredibly large (although this - * wouldn't cause a failure, just a slowdown due to swapping). - */ - - /* Set up the compression buffers */ - /* TODO: the following cast hides a potential overflow problem. */ - png_ptr->zstream.avail_in = (uInt)text_len; - /* NOTE: assume zlib doesn't overwrite the input */ - png_ptr->zstream.next_in = (Bytef *)text; - png_ptr->zstream.avail_out = png_ptr->zbuf_size; - png_ptr->zstream.next_out = png_ptr->zbuf; - - /* This is the same compression loop as in png_write_row() */ - do - { - /* Compress the data */ - ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); - - if (ret != Z_OK) - { - /* Error */ - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); - - else - png_error(png_ptr, "zlib error"); - } - - /* Check to see if we need more room */ - if (!(png_ptr->zstream.avail_out)) - { - /* Make sure the output array has room */ - if (comp->num_output_ptr >= comp->max_output_ptr) - { - int old_max; - - old_max = comp->max_output_ptr; - comp->max_output_ptr = comp->num_output_ptr + 4; - if (comp->output_ptr != NULL) - { - png_bytepp old_ptr; - - old_ptr = comp->output_ptr; - - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (png_alloc_size_t) - (comp->max_output_ptr * png_sizeof(png_charpp))); - - png_memcpy(comp->output_ptr, old_ptr, old_max - * png_sizeof(png_charp)); - - png_free(png_ptr, old_ptr); - } - else - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (png_alloc_size_t) - (comp->max_output_ptr * png_sizeof(png_charp))); - } - - /* Save the data */ - comp->output_ptr[comp->num_output_ptr] = - (png_bytep)png_malloc(png_ptr, - (png_alloc_size_t)png_ptr->zbuf_size); - - png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, - png_ptr->zbuf_size); - - comp->num_output_ptr++; - - /* and reset the buffer */ - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->zstream.next_out = png_ptr->zbuf; - } - /* Continue until we don't have any more to compress */ - } while (png_ptr->zstream.avail_in); - - /* Finish the compression */ - do - { - /* Tell zlib we are finished */ - ret = deflate(&png_ptr->zstream, Z_FINISH); - - if (ret == Z_OK) - { - /* Check to see if we need more room */ - if (!(png_ptr->zstream.avail_out)) - { - /* Check to make sure our output array has room */ - if (comp->num_output_ptr >= comp->max_output_ptr) - { - int old_max; - - old_max = comp->max_output_ptr; - comp->max_output_ptr = comp->num_output_ptr + 4; - if (comp->output_ptr != NULL) - { - png_bytepp old_ptr; - - old_ptr = comp->output_ptr; - - /* This could be optimized to realloc() */ - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (png_alloc_size_t)(comp->max_output_ptr * - png_sizeof(png_charp))); - - png_memcpy(comp->output_ptr, old_ptr, - old_max * png_sizeof(png_charp)); - - png_free(png_ptr, old_ptr); - } - - else - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (png_alloc_size_t)(comp->max_output_ptr * - png_sizeof(png_charp))); - } - - /* Save the data */ - comp->output_ptr[comp->num_output_ptr] = - (png_bytep)png_malloc(png_ptr, - (png_alloc_size_t)png_ptr->zbuf_size); - - png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, - png_ptr->zbuf_size); - - comp->num_output_ptr++; - - /* and reset the buffer pointers */ - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->zstream.next_out = png_ptr->zbuf; - } - } - else if (ret != Z_STREAM_END) - { - /* We got an error */ - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); - - else - png_error(png_ptr, "zlib error"); - } - } while (ret != Z_STREAM_END); - - /* Text length is number of buffers plus last buffer */ - text_len = png_ptr->zbuf_size * comp->num_output_ptr; - - if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) - text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; - - return((int)text_len); -} - -/* Ship the compressed text out via chunk writes */ -static void /* PRIVATE */ -png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) -{ - int i; - - /* Handle the no-compression case */ - if (comp->input) - { - png_write_chunk_data(png_ptr, comp->input, comp->input_len); - - return; - } - - /* Write saved output buffers, if any */ - for (i = 0; i < comp->num_output_ptr; i++) - { - png_write_chunk_data(png_ptr, comp->output_ptr[i], - (png_size_t)png_ptr->zbuf_size); - - png_free(png_ptr, comp->output_ptr[i]); - } - - if (comp->max_output_ptr != 0) - png_free(png_ptr, comp->output_ptr); - - /* Write anything left in zbuf */ - if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) - png_write_chunk_data(png_ptr, png_ptr->zbuf, - (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); - - /* Reset zlib for another zTXt/iTXt or image data */ - deflateReset(&png_ptr->zstream); - png_ptr->zstream.data_type = Z_BINARY; -} -#endif - -/* Write the IHDR chunk, and update the png_struct with the necessary - * information. Note that the rest of this code depends upon this - * information being correct. - */ -void /* PRIVATE */ -png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, - int bit_depth, int color_type, int compression_type, int filter_type, - int interlace_type) -{ - PNG_IHDR; - int ret; - - png_byte buf[13]; /* Buffer to store the IHDR info */ - - png_debug(1, "in png_write_IHDR"); - - /* Check that we have valid input data from the application info */ - switch (color_type) - { - case PNG_COLOR_TYPE_GRAY: - switch (bit_depth) - { - case 1: - case 2: - case 4: - case 8: -#ifdef PNG_WRITE_16BIT_SUPPORTED - case 16: -#endif - png_ptr->channels = 1; break; - - default: - png_error(png_ptr, - "Invalid bit depth for grayscale image"); - } - break; - - case PNG_COLOR_TYPE_RGB: -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (bit_depth != 8 && bit_depth != 16) -#else - if (bit_depth != 8) -#endif - png_error(png_ptr, "Invalid bit depth for RGB image"); - - png_ptr->channels = 3; - break; - - case PNG_COLOR_TYPE_PALETTE: - switch (bit_depth) - { - case 1: - case 2: - case 4: - case 8: - png_ptr->channels = 1; - break; - - default: - png_error(png_ptr, "Invalid bit depth for paletted image"); - } - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - if (bit_depth != 8 && bit_depth != 16) - png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); - - png_ptr->channels = 2; - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (bit_depth != 8 && bit_depth != 16) -#else - if (bit_depth != 8) -#endif - png_error(png_ptr, "Invalid bit depth for RGBA image"); - - png_ptr->channels = 4; - break; - - default: - png_error(png_ptr, "Invalid image color type specified"); - } - - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - { - png_warning(png_ptr, "Invalid compression type specified"); - compression_type = PNG_COMPRESSION_TYPE_BASE; - } - - /* Write filter_method 64 (intrapixel differencing) only if - * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and - * 2. Libpng did not write a PNG signature (this filter_method is only - * used in PNG datastreams that are embedded in MNG datastreams) and - * 3. The application called png_permit_mng_features with a mask that - * included PNG_FLAG_MNG_FILTER_64 and - * 4. The filter_method is 64 and - * 5. The color_type is RGB or RGBA - */ - if ( -#ifdef PNG_MNG_FEATURES_SUPPORTED - !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && - ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && - (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_RGB_ALPHA) && - (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && -#endif - filter_type != PNG_FILTER_TYPE_BASE) - { - png_warning(png_ptr, "Invalid filter type specified"); - filter_type = PNG_FILTER_TYPE_BASE; - } - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - if (interlace_type != PNG_INTERLACE_NONE && - interlace_type != PNG_INTERLACE_ADAM7) - { - png_warning(png_ptr, "Invalid interlace type specified"); - interlace_type = PNG_INTERLACE_ADAM7; - } -#else - interlace_type=PNG_INTERLACE_NONE; -#endif - - /* Save the relevent information */ - png_ptr->bit_depth = (png_byte)bit_depth; - png_ptr->color_type = (png_byte)color_type; - png_ptr->interlaced = (png_byte)interlace_type; -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_ptr->filter_type = (png_byte)filter_type; -#endif - png_ptr->compression_type = (png_byte)compression_type; - png_ptr->width = width; - png_ptr->height = height; - - png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); - png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); - /* Set the usr info, so any transformations can modify it */ - png_ptr->usr_width = png_ptr->width; - png_ptr->usr_bit_depth = png_ptr->bit_depth; - png_ptr->usr_channels = png_ptr->channels; - - /* Pack the header information into the buffer */ - png_save_uint_32(buf, width); - png_save_uint_32(buf + 4, height); - buf[8] = (png_byte)bit_depth; - buf[9] = (png_byte)color_type; - buf[10] = (png_byte)compression_type; - buf[11] = (png_byte)filter_type; - buf[12] = (png_byte)interlace_type; - - /* Write the chunk */ - png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); - - /* Initialize zlib with PNG info */ - png_ptr->zstream.zalloc = png_zalloc; - png_ptr->zstream.zfree = png_zfree; - png_ptr->zstream.opaque = (voidpf)png_ptr; - - if (!(png_ptr->do_filter)) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || - png_ptr->bit_depth < 8) - png_ptr->do_filter = PNG_FILTER_NONE; - - else - png_ptr->do_filter = PNG_ALL_FILTERS; - } - - if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) - { - if (png_ptr->do_filter != PNG_FILTER_NONE) - png_ptr->zlib_strategy = Z_FILTERED; - - else - png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; - } - - if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) - png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; - - if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) - png_ptr->zlib_mem_level = 8; - - if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) - png_ptr->zlib_window_bits = 15; - - if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) - png_ptr->zlib_method = 8; - - ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, - png_ptr->zlib_method, png_ptr->zlib_window_bits, - png_ptr->zlib_mem_level, png_ptr->zlib_strategy); - - if (ret != Z_OK) - { - if (ret == Z_VERSION_ERROR) - png_error(png_ptr, - "zlib failed to initialize compressor -- version error"); - - if (ret == Z_STREAM_ERROR) - png_error(png_ptr, - "zlib failed to initialize compressor -- stream error"); - - if (ret == Z_MEM_ERROR) - png_error(png_ptr, - "zlib failed to initialize compressor -- mem error"); - - png_error(png_ptr, "zlib failed to initialize compressor"); - } - - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - /* libpng is not interested in zstream.data_type, so set it - * to a predefined value, to avoid its evaluation inside zlib - */ - png_ptr->zstream.data_type = Z_BINARY; - - png_ptr->mode = PNG_HAVE_IHDR; -} - -/* Write the palette. We are careful not to trust png_color to be in the - * correct order for PNG, so people can redefine it to any convenient - * structure. - */ -void /* PRIVATE */ -png_write_PLTE(png_structp png_ptr, png_const_colorp palette, - png_uint_32 num_pal) -{ - PNG_PLTE; - png_uint_32 i; - png_const_colorp pal_ptr; - png_byte buf[3]; - - png_debug(1, "in png_write_PLTE"); - - if (( -#ifdef PNG_MNG_FEATURES_SUPPORTED - !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && -#endif - num_pal == 0) || num_pal > 256) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - png_error(png_ptr, "Invalid number of colors in palette"); - } - - else - { - png_warning(png_ptr, "Invalid number of colors in palette"); - return; - } - } - - if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) - { - png_warning(png_ptr, - "Ignoring request to write a PLTE chunk in grayscale PNG"); - - return; - } - - png_ptr->num_palette = (png_uint_16)num_pal; - png_debug1(3, "num_palette = %d", png_ptr->num_palette); - - png_write_chunk_start(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); -#ifdef PNG_POINTER_INDEXING_SUPPORTED - - for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) - { - buf[0] = pal_ptr->red; - buf[1] = pal_ptr->green; - buf[2] = pal_ptr->blue; - png_write_chunk_data(png_ptr, buf, (png_size_t)3); - } - -#else - /* This is a little slower but some buggy compilers need to do this - * instead - */ - pal_ptr=palette; - - for (i = 0; i < num_pal; i++) - { - buf[0] = pal_ptr[i].red; - buf[1] = pal_ptr[i].green; - buf[2] = pal_ptr[i].blue; - png_write_chunk_data(png_ptr, buf, (png_size_t)3); - } - -#endif - png_write_chunk_end(png_ptr); - png_ptr->mode |= PNG_HAVE_PLTE; -} - -/* Write an IDAT chunk */ -void /* PRIVATE */ -png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) -{ - PNG_IDAT; - - png_debug(1, "in png_write_IDAT"); - - /* Optimize the CMF field in the zlib stream. */ - /* This hack of the zlib stream is compliant to the stream specification. */ - if (!(png_ptr->mode & PNG_HAVE_IDAT) && - png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) - { - unsigned int z_cmf = data[0]; /* zlib compression method and flags */ - if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) - { - /* Avoid memory underflows and multiplication overflows. - * - * The conditions below are practically always satisfied; - * however, they still must be checked. - */ - if (length >= 2 && - png_ptr->height < 16384 && png_ptr->width < 16384) - { - png_uint_32 uncompressed_idat_size = png_ptr->height * - ((png_ptr->width * - png_ptr->channels * png_ptr->bit_depth + 15) >> 3); - unsigned int z_cinfo = z_cmf >> 4; - unsigned int half_z_window_size = 1 << (z_cinfo + 7); - while (uncompressed_idat_size <= half_z_window_size && - half_z_window_size >= 256) - { - z_cinfo--; - half_z_window_size >>= 1; - } - - z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); - - if (data[0] != z_cmf) - { - int tmp; - data[0] = (png_byte)z_cmf; - tmp = data[1] & 0xe0; - tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; - data[1] = (png_byte)tmp; - } - } - } - - else - png_error(png_ptr, - "Invalid zlib compression method or flags in IDAT"); - } - - png_write_chunk(png_ptr, png_IDAT, data, length); - png_ptr->mode |= PNG_HAVE_IDAT; -} - -/* Write an IEND chunk */ -void /* PRIVATE */ -png_write_IEND(png_structp png_ptr) -{ - PNG_IEND; - - png_debug(1, "in png_write_IEND"); - - png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); - png_ptr->mode |= PNG_HAVE_IEND; -} - -#ifdef PNG_WRITE_gAMA_SUPPORTED -/* Write a gAMA chunk */ -void /* PRIVATE */ -png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) -{ - PNG_gAMA; - png_byte buf[4]; - - png_debug(1, "in png_write_gAMA"); - - /* file_gamma is saved in 1/100,000ths */ - png_save_uint_32(buf, (png_uint_32)file_gamma); - png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); -} -#endif - -#ifdef PNG_WRITE_sRGB_SUPPORTED -/* Write a sRGB chunk */ -void /* PRIVATE */ -png_write_sRGB(png_structp png_ptr, int srgb_intent) -{ - PNG_sRGB; - png_byte buf[1]; - - png_debug(1, "in png_write_sRGB"); - - if (srgb_intent >= PNG_sRGB_INTENT_LAST) - png_warning(png_ptr, - "Invalid sRGB rendering intent specified"); - - buf[0]=(png_byte)srgb_intent; - png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); -} -#endif - -#ifdef PNG_WRITE_iCCP_SUPPORTED -/* Write an iCCP chunk */ -void /* PRIVATE */ -png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, - png_const_charp profile, int profile_len) -{ - PNG_iCCP; - png_size_t name_len; - png_charp new_name; - compression_state comp; - int embedded_profile_len = 0; - - png_debug(1, "in png_write_iCCP"); - - comp.num_output_ptr = 0; - comp.max_output_ptr = 0; - comp.output_ptr = NULL; - comp.input = NULL; - comp.input_len = 0; - - if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0) - return; - - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - png_warning(png_ptr, "Unknown compression type in iCCP chunk"); - - if (profile == NULL) - profile_len = 0; - - if (profile_len > 3) - embedded_profile_len = - ((*( (png_const_bytep)profile ))<<24) | - ((*( (png_const_bytep)profile + 1))<<16) | - ((*( (png_const_bytep)profile + 2))<< 8) | - ((*( (png_const_bytep)profile + 3)) ); - - if (embedded_profile_len < 0) - { - png_warning(png_ptr, - "Embedded profile length in iCCP chunk is negative"); - - png_free(png_ptr, new_name); - return; - } - - if (profile_len < embedded_profile_len) - { - png_warning(png_ptr, - "Embedded profile length too large in iCCP chunk"); - - png_free(png_ptr, new_name); - return; - } - - if (profile_len > embedded_profile_len) - { - png_warning(png_ptr, - "Truncating profile to actual length in iCCP chunk"); - - profile_len = embedded_profile_len; - } - - if (profile_len) - profile_len = png_text_compress(png_ptr, profile, - (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); - - /* Make sure we include the NULL after the name and the compression type */ - png_write_chunk_start(png_ptr, png_iCCP, - (png_uint_32)(name_len + profile_len + 2)); - - new_name[name_len + 1] = 0x00; - - png_write_chunk_data(png_ptr, (png_bytep)new_name, - (png_size_t)(name_len + 2)); - - if (profile_len) - png_write_compressed_data_out(png_ptr, &comp); - - png_write_chunk_end(png_ptr); - png_free(png_ptr, new_name); -} -#endif - -#ifdef PNG_WRITE_sPLT_SUPPORTED -/* Write a sPLT chunk */ -void /* PRIVATE */ -png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) -{ - PNG_sPLT; - png_size_t name_len; - png_charp new_name; - png_byte entrybuf[10]; - png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); - png_size_t palette_size = entry_size * spalette->nentries; - png_sPLT_entryp ep; -#ifndef PNG_POINTER_INDEXING_SUPPORTED - int i; -#endif - - png_debug(1, "in png_write_sPLT"); - - if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) - return; - - /* Make sure we include the NULL after the name */ - png_write_chunk_start(png_ptr, png_sPLT, - (png_uint_32)(name_len + 2 + palette_size)); - - png_write_chunk_data(png_ptr, (png_bytep)new_name, - (png_size_t)(name_len + 1)); - - png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); - - /* Loop through each palette entry, writing appropriately */ -#ifdef PNG_POINTER_INDEXING_SUPPORTED - for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) - { - if (spalette->depth == 8) - { - entrybuf[0] = (png_byte)ep->red; - entrybuf[1] = (png_byte)ep->green; - entrybuf[2] = (png_byte)ep->blue; - entrybuf[3] = (png_byte)ep->alpha; - png_save_uint_16(entrybuf + 4, ep->frequency); - } - - else - { - png_save_uint_16(entrybuf + 0, ep->red); - png_save_uint_16(entrybuf + 2, ep->green); - png_save_uint_16(entrybuf + 4, ep->blue); - png_save_uint_16(entrybuf + 6, ep->alpha); - png_save_uint_16(entrybuf + 8, ep->frequency); - } - - png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); - } -#else - ep=spalette->entries; - for (i = 0; i>spalette->nentries; i++) - { - if (spalette->depth == 8) - { - entrybuf[0] = (png_byte)ep[i].red; - entrybuf[1] = (png_byte)ep[i].green; - entrybuf[2] = (png_byte)ep[i].blue; - entrybuf[3] = (png_byte)ep[i].alpha; - png_save_uint_16(entrybuf + 4, ep[i].frequency); - } - - else - { - png_save_uint_16(entrybuf + 0, ep[i].red); - png_save_uint_16(entrybuf + 2, ep[i].green); - png_save_uint_16(entrybuf + 4, ep[i].blue); - png_save_uint_16(entrybuf + 6, ep[i].alpha); - png_save_uint_16(entrybuf + 8, ep[i].frequency); - } - - png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); - } -#endif - - png_write_chunk_end(png_ptr); - png_free(png_ptr, new_name); -} -#endif - -#ifdef PNG_WRITE_sBIT_SUPPORTED -/* Write the sBIT chunk */ -void /* PRIVATE */ -png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) -{ - PNG_sBIT; - png_byte buf[4]; - png_size_t size; - - png_debug(1, "in png_write_sBIT"); - - /* Make sure we don't depend upon the order of PNG_COLOR_8 */ - if (color_type & PNG_COLOR_MASK_COLOR) - { - png_byte maxbits; - - maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : - png_ptr->usr_bit_depth); - - if (sbit->red == 0 || sbit->red > maxbits || - sbit->green == 0 || sbit->green > maxbits || - sbit->blue == 0 || sbit->blue > maxbits) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[0] = sbit->red; - buf[1] = sbit->green; - buf[2] = sbit->blue; - size = 3; - } - - else - { - if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[0] = sbit->gray; - size = 1; - } - - if (color_type & PNG_COLOR_MASK_ALPHA) - { - if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[size++] = sbit->alpha; - } - - png_write_chunk(png_ptr, png_sBIT, buf, size); -} -#endif - -#ifdef PNG_WRITE_cHRM_SUPPORTED -/* Write the cHRM chunk */ -void /* PRIVATE */ -png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, - png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, - png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, - png_fixed_point blue_y) -{ - PNG_cHRM; - png_byte buf[32]; - - png_debug(1, "in png_write_cHRM"); - - /* Each value is saved in 1/100,000ths */ -#ifdef PNG_CHECK_cHRM_SUPPORTED - if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, - green_x, green_y, blue_x, blue_y)) -#endif - { - png_save_uint_32(buf, (png_uint_32)white_x); - png_save_uint_32(buf + 4, (png_uint_32)white_y); - - png_save_uint_32(buf + 8, (png_uint_32)red_x); - png_save_uint_32(buf + 12, (png_uint_32)red_y); - - png_save_uint_32(buf + 16, (png_uint_32)green_x); - png_save_uint_32(buf + 20, (png_uint_32)green_y); - - png_save_uint_32(buf + 24, (png_uint_32)blue_x); - png_save_uint_32(buf + 28, (png_uint_32)blue_y); - - png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); - } -} -#endif - -#ifdef PNG_WRITE_tRNS_SUPPORTED -/* Write the tRNS chunk */ -void /* PRIVATE */ -png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, - png_const_color_16p tran, int num_trans, int color_type) -{ - PNG_tRNS; - png_byte buf[6]; - - png_debug(1, "in png_write_tRNS"); - - if (color_type == PNG_COLOR_TYPE_PALETTE) - { - if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) - { - png_warning(png_ptr, "Invalid number of transparent colors specified"); - return; - } - - /* Write the chunk out as it is */ - png_write_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); - } - - else if (color_type == PNG_COLOR_TYPE_GRAY) - { - /* One 16 bit value */ - if (tran->gray >= (1 << png_ptr->bit_depth)) - { - png_warning(png_ptr, - "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); - - return; - } - - png_save_uint_16(buf, tran->gray); - png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); - } - - else if (color_type == PNG_COLOR_TYPE_RGB) - { - /* Three 16 bit values */ - png_save_uint_16(buf, tran->red); - png_save_uint_16(buf + 2, tran->green); - png_save_uint_16(buf + 4, tran->blue); -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) -#else - if (buf[0] | buf[2] | buf[4]) -#endif - { - png_warning(png_ptr, - "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); - return; - } - - png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); - } - - else - { - png_warning(png_ptr, "Can't write tRNS with an alpha channel"); - } -} -#endif - -#ifdef PNG_WRITE_bKGD_SUPPORTED -/* Write the background chunk */ -void /* PRIVATE */ -png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) -{ - PNG_bKGD; - png_byte buf[6]; - - png_debug(1, "in png_write_bKGD"); - - if (color_type == PNG_COLOR_TYPE_PALETTE) - { - if ( -#ifdef PNG_MNG_FEATURES_SUPPORTED - (png_ptr->num_palette || - (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && -#endif - back->index >= png_ptr->num_palette) - { - png_warning(png_ptr, "Invalid background palette index"); - return; - } - - buf[0] = back->index; - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); - } - - else if (color_type & PNG_COLOR_MASK_COLOR) - { - png_save_uint_16(buf, back->red); - png_save_uint_16(buf + 2, back->green); - png_save_uint_16(buf + 4, back->blue); -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) -#else - if (buf[0] | buf[2] | buf[4]) -#endif - { - png_warning(png_ptr, - "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); - - return; - } - - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); - } - - else - { - if (back->gray >= (1 << png_ptr->bit_depth)) - { - png_warning(png_ptr, - "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); - - return; - } - - png_save_uint_16(buf, back->gray); - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); - } -} -#endif - -#ifdef PNG_WRITE_hIST_SUPPORTED -/* Write the histogram */ -void /* PRIVATE */ -png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) -{ - PNG_hIST; - int i; - png_byte buf[3]; - - png_debug(1, "in png_write_hIST"); - - if (num_hist > (int)png_ptr->num_palette) - { - png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, - png_ptr->num_palette); - - png_warning(png_ptr, "Invalid number of histogram entries specified"); - return; - } - - png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); - - for (i = 0; i < num_hist; i++) - { - png_save_uint_16(buf, hist[i]); - png_write_chunk_data(png_ptr, buf, (png_size_t)2); - } - - png_write_chunk_end(png_ptr); -} -#endif - -#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ - defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) -/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, - * and if invalid, correct the keyword rather than discarding the entire - * chunk. The PNG 1.0 specification requires keywords 1-79 characters in - * length, forbids leading or trailing whitespace, multiple internal spaces, - * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. - * - * The new_key is allocated to hold the corrected keyword and must be freed - * by the calling routine. This avoids problems with trying to write to - * static keywords without having to have duplicate copies of the strings. - */ -png_size_t /* PRIVATE */ -png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) -{ - png_size_t key_len; - png_const_charp ikp; - png_charp kp, dp; - int kflag; - int kwarn=0; - - png_debug(1, "in png_check_keyword"); - - *new_key = NULL; - - if (key == NULL || (key_len = png_strlen(key)) == 0) - { - png_warning(png_ptr, "zero length keyword"); - return ((png_size_t)0); - } - - png_debug1(2, "Keyword to be checked is '%s'", key); - - *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); - - if (*new_key == NULL) - { - png_warning(png_ptr, "Out of memory while procesing keyword"); - return ((png_size_t)0); - } - - /* Replace non-printing characters with a blank and print a warning */ - for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++) - { - if ((png_byte)*ikp < 0x20 || - ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) - { -#ifdef PNG_CONSOLE_IO_SUPPORTED - char msg[40]; - - png_snprintf(msg, 40, - "invalid keyword character 0x%02X", (png_byte)*ikp); - png_warning(png_ptr, msg); -#else - png_warning(png_ptr, "invalid character in keyword"); -#endif - *dp = ' '; - } - - else - { - *dp = *ikp; - } - } - *dp = '\0'; - - /* Remove any trailing white space. */ - kp = *new_key + key_len - 1; - if (*kp == ' ') - { - png_warning(png_ptr, "trailing spaces removed from keyword"); - - while (*kp == ' ') - { - *(kp--) = '\0'; - key_len--; - } - } - - /* Remove any leading white space. */ - kp = *new_key; - if (*kp == ' ') - { - png_warning(png_ptr, "leading spaces removed from keyword"); - - while (*kp == ' ') - { - kp++; - key_len--; - } - } - - png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); - - /* Remove multiple internal spaces. */ - for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) - { - if (*kp == ' ' && kflag == 0) - { - *(dp++) = *kp; - kflag = 1; - } - - else if (*kp == ' ') - { - key_len--; - kwarn = 1; - } - - else - { - *(dp++) = *kp; - kflag = 0; - } - } - *dp = '\0'; - if (kwarn) - png_warning(png_ptr, "extra interior spaces removed from keyword"); - - if (key_len == 0) - { - png_free(png_ptr, *new_key); - png_warning(png_ptr, "Zero length keyword"); - } - - if (key_len > 79) - { - png_warning(png_ptr, "keyword length must be 1 - 79 characters"); - (*new_key)[79] = '\0'; - key_len = 79; - } - - return (key_len); -} -#endif - -#ifdef PNG_WRITE_tEXt_SUPPORTED -/* Write a tEXt chunk */ -void /* PRIVATE */ -png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, - png_size_t text_len) -{ - PNG_tEXt; - png_size_t key_len; - png_charp new_key; - - png_debug(1, "in png_write_tEXt"); - - if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) - return; - - if (text == NULL || *text == '\0') - text_len = 0; - - else - text_len = png_strlen(text); - - /* Make sure we include the 0 after the key */ - png_write_chunk_start(png_ptr, png_tEXt, - (png_uint_32)(key_len + text_len + 1)); - /* - * We leave it to the application to meet PNG-1.0 requirements on the - * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of - * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. - * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. - */ - png_write_chunk_data(png_ptr, (png_bytep)new_key, - (png_size_t)(key_len + 1)); - - if (text_len) - png_write_chunk_data(png_ptr, (png_const_bytep)text, - (png_size_t)text_len); - - png_write_chunk_end(png_ptr); - png_free(png_ptr, new_key); -} -#endif - -#ifdef PNG_WRITE_zTXt_SUPPORTED -/* Write a compressed text chunk */ -void /* PRIVATE */ -png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, - png_size_t text_len, int compression) -{ - PNG_zTXt; - png_size_t key_len; - png_byte buf; - png_charp new_key; - compression_state comp; - - png_debug(1, "in png_write_zTXt"); - - comp.num_output_ptr = 0; - comp.max_output_ptr = 0; - comp.output_ptr = NULL; - comp.input = NULL; - comp.input_len = 0; - - if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) - { - png_free(png_ptr, new_key); - return; - } - - if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) - { - png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); - png_free(png_ptr, new_key); - return; - } - - text_len = png_strlen(text); - - /* Compute the compressed data; do it now for the length */ - text_len = png_text_compress(png_ptr, text, text_len, compression, - &comp); - - /* Write start of chunk */ - png_write_chunk_start(png_ptr, png_zTXt, - (png_uint_32)(key_len+text_len + 2)); - - /* Write key */ - png_write_chunk_data(png_ptr, (png_bytep)new_key, - (png_size_t)(key_len + 1)); - - png_free(png_ptr, new_key); - - buf = (png_byte)compression; - - /* Write compression */ - png_write_chunk_data(png_ptr, &buf, (png_size_t)1); - - /* Write the compressed data */ - png_write_compressed_data_out(png_ptr, &comp); - - /* Close the chunk */ - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_iTXt_SUPPORTED -/* Write an iTXt chunk */ -void /* PRIVATE */ -png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, - png_const_charp lang, png_const_charp lang_key, png_const_charp text) -{ - PNG_iTXt; - png_size_t lang_len, key_len, lang_key_len, text_len; - png_charp new_lang; - png_charp new_key = NULL; - png_byte cbuf[2]; - compression_state comp; - - png_debug(1, "in png_write_iTXt"); - - comp.num_output_ptr = 0; - comp.max_output_ptr = 0; - comp.output_ptr = NULL; - comp.input = NULL; - - if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) - return; - - if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0) - { - png_warning(png_ptr, "Empty language field in iTXt chunk"); - new_lang = NULL; - lang_len = 0; - } - - if (lang_key == NULL) - lang_key_len = 0; - - else - lang_key_len = png_strlen(lang_key); - - if (text == NULL) - text_len = 0; - - else - text_len = png_strlen(text); - - /* Compute the compressed data; do it now for the length */ - text_len = png_text_compress(png_ptr, text, text_len, compression - 2, - &comp); - - - /* Make sure we include the compression flag, the compression byte, - * and the NULs after the key, lang, and lang_key parts - */ - - png_write_chunk_start(png_ptr, png_iTXt, (png_uint_32)( - 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ - + key_len - + lang_len - + lang_key_len - + text_len)); - - /* We leave it to the application to meet PNG-1.0 requirements on the - * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of - * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. - * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. - */ - png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1)); - - /* Set the compression flag */ - if (compression == PNG_ITXT_COMPRESSION_NONE || - compression == PNG_TEXT_COMPRESSION_NONE) - cbuf[0] = 0; - - else /* compression == PNG_ITXT_COMPRESSION_zTXt */ - cbuf[0] = 1; - - /* Set the compression method */ - cbuf[1] = 0; - - png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); - - cbuf[0] = 0; - png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf), - (png_size_t)(lang_len + 1)); - - png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), - (png_size_t)(lang_key_len + 1)); - - png_write_compressed_data_out(png_ptr, &comp); - - png_write_chunk_end(png_ptr); - - png_free(png_ptr, new_key); - png_free(png_ptr, new_lang); -} -#endif - -#ifdef PNG_WRITE_oFFs_SUPPORTED -/* Write the oFFs chunk */ -void /* PRIVATE */ -png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, - int unit_type) -{ - PNG_oFFs; - png_byte buf[9]; - - png_debug(1, "in png_write_oFFs"); - - if (unit_type >= PNG_OFFSET_LAST) - png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); - - png_save_int_32(buf, x_offset); - png_save_int_32(buf + 4, y_offset); - buf[8] = (png_byte)unit_type; - - png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); -} -#endif -#ifdef PNG_WRITE_pCAL_SUPPORTED -/* Write the pCAL chunk (described in the PNG extensions document) */ -void /* PRIVATE */ -png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, - png_int_32 X1, int type, int nparams, png_const_charp units, - png_charpp params) -{ - PNG_pCAL; - png_size_t purpose_len, units_len, total_len; - png_uint_32p params_len; - png_byte buf[10]; - png_charp new_purpose; - int i; - - png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); - - if (type >= PNG_EQUATION_LAST) - png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); - - purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; - png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); - units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); - png_debug1(3, "pCAL units length = %d", (int)units_len); - total_len = purpose_len + units_len + 10; - - params_len = (png_uint_32p)png_malloc(png_ptr, - (png_alloc_size_t)(nparams * png_sizeof(png_uint_32))); - - /* Find the length of each parameter, making sure we don't count the - * null terminator for the last parameter. - */ - for (i = 0; i < nparams; i++) - { - params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); - png_debug2(3, "pCAL parameter %d length = %lu", i, - (unsigned long)params_len[i]); - total_len += (png_size_t)params_len[i]; - } - - png_debug1(3, "pCAL total length = %d", (int)total_len); - png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); - png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, - (png_size_t)purpose_len); - png_save_int_32(buf, X0); - png_save_int_32(buf + 4, X1); - buf[8] = (png_byte)type; - buf[9] = (png_byte)nparams; - png_write_chunk_data(png_ptr, buf, (png_size_t)10); - png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); - - png_free(png_ptr, new_purpose); - - for (i = 0; i < nparams; i++) - { - png_write_chunk_data(png_ptr, (png_const_bytep)params[i], - (png_size_t)params_len[i]); - } - - png_free(png_ptr, params_len); - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sCAL_SUPPORTED -/* Write the sCAL chunk */ -void /* PRIVATE */ -png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, - png_const_charp height) -{ - PNG_sCAL; - png_byte buf[64]; - png_size_t wlen, hlen, total_len; - - png_debug(1, "in png_write_sCAL_s"); - - wlen = png_strlen(width); - hlen = png_strlen(height); - total_len = wlen + hlen + 2; - - if (total_len > 64) - { - png_warning(png_ptr, "Can't write sCAL (buffer too small)"); - return; - } - - buf[0] = (png_byte)unit; - png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ - png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ - - png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); - png_write_chunk(png_ptr, png_sCAL, buf, total_len); -} -#endif - -#ifdef PNG_WRITE_pHYs_SUPPORTED -/* Write the pHYs chunk */ -void /* PRIVATE */ -png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, - png_uint_32 y_pixels_per_unit, - int unit_type) -{ - PNG_pHYs; - png_byte buf[9]; - - png_debug(1, "in png_write_pHYs"); - - if (unit_type >= PNG_RESOLUTION_LAST) - png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); - - png_save_uint_32(buf, x_pixels_per_unit); - png_save_uint_32(buf + 4, y_pixels_per_unit); - buf[8] = (png_byte)unit_type; - - png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); -} -#endif - -#ifdef PNG_WRITE_tIME_SUPPORTED -/* Write the tIME chunk. Use either png_convert_from_struct_tm() - * or png_convert_from_time_t(), or fill in the structure yourself. - */ -void /* PRIVATE */ -png_write_tIME(png_structp png_ptr, png_const_timep mod_time) -{ - PNG_tIME; - png_byte buf[7]; - - png_debug(1, "in png_write_tIME"); - - if (mod_time->month > 12 || mod_time->month < 1 || - mod_time->day > 31 || mod_time->day < 1 || - mod_time->hour > 23 || mod_time->second > 60) - { - png_warning(png_ptr, "Invalid time specified for tIME chunk"); - return; - } - - png_save_uint_16(buf, mod_time->year); - buf[2] = mod_time->month; - buf[3] = mod_time->day; - buf[4] = mod_time->hour; - buf[5] = mod_time->minute; - buf[6] = mod_time->second; - - png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7); -} -#endif - -/* Initializes the row writing capability of libpng */ -void /* PRIVATE */ -png_write_start_row(png_structp png_ptr) -{ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - png_size_t buf_size; - - png_debug(1, "in png_write_start_row"); - - buf_size = (png_size_t)(PNG_ROWBYTES( - png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1); - - /* Set up row buffer */ - png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, - (png_alloc_size_t)buf_size); - - png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; - -#ifdef PNG_WRITE_FILTER_SUPPORTED - /* Set up filtering buffer, if using this filter */ - if (png_ptr->do_filter & PNG_FILTER_SUB) - { - png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); - - png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; - } - - /* We only need to keep the previous row if we are using one of these. */ - if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) - { - /* Set up previous row buffer */ - png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, - (png_alloc_size_t)buf_size); - - if (png_ptr->do_filter & PNG_FILTER_UP) - { - png_ptr->up_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); - - png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; - } - - if (png_ptr->do_filter & PNG_FILTER_AVG) - { - png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); - - png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; - } - - if (png_ptr->do_filter & PNG_FILTER_PAETH) - { - png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); - - png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; - } - } -#endif /* PNG_WRITE_FILTER_SUPPORTED */ - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced, we need to set up width and height of pass */ - if (png_ptr->interlaced) - { - if (!(png_ptr->transformations & PNG_INTERLACE)) - { - png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - - png_pass_ystart[0]) / png_pass_yinc[0]; - - png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - - png_pass_start[0]) / png_pass_inc[0]; - } - - else - { - png_ptr->num_rows = png_ptr->height; - png_ptr->usr_width = png_ptr->width; - } - } - - else -#endif - { - png_ptr->num_rows = png_ptr->height; - png_ptr->usr_width = png_ptr->width; - } - - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->zstream.next_out = png_ptr->zbuf; -} - -/* Internal use only. Called when finished processing a row of data. */ -void /* PRIVATE */ -png_write_finish_row(png_structp png_ptr) -{ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - int ret; - - png_debug(1, "in png_write_finish_row"); - - /* Next row */ - png_ptr->row_number++; - - /* See if we are done */ - if (png_ptr->row_number < png_ptr->num_rows) - return; - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced, go to next pass */ - if (png_ptr->interlaced) - { - png_ptr->row_number = 0; - if (png_ptr->transformations & PNG_INTERLACE) - { - png_ptr->pass++; - } - - else - { - /* Loop until we find a non-zero width or height pass */ - do - { - png_ptr->pass++; - - if (png_ptr->pass >= 7) - break; - - png_ptr->usr_width = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; - - png_ptr->num_rows = (png_ptr->height + - png_pass_yinc[png_ptr->pass] - 1 - - png_pass_ystart[png_ptr->pass]) / - png_pass_yinc[png_ptr->pass]; - - if (png_ptr->transformations & PNG_INTERLACE) - break; - - } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); - - } - - /* Reset the row above the image for the next pass */ - if (png_ptr->pass < 7) - { - if (png_ptr->prev_row != NULL) - png_memset(png_ptr->prev_row, 0, - (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* - png_ptr->usr_bit_depth, png_ptr->width)) + 1); - - return; - } - } -#endif - - /* If we get here, we've just written the last row, so we need - to flush the compressor */ - do - { - /* Tell the compressor we are done */ - ret = deflate(&png_ptr->zstream, Z_FINISH); - - /* Check for an error */ - if (ret == Z_OK) - { - /* Check to see if we need more room */ - if (!(png_ptr->zstream.avail_out)) - { - png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } - } - - else if (ret != Z_STREAM_END) - { - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); - - else - png_error(png_ptr, "zlib error"); - } - } while (ret != Z_STREAM_END); - - /* Write any extra space */ - if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) - { - png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - - png_ptr->zstream.avail_out); - } - - deflateReset(&png_ptr->zstream); - png_ptr->zstream.data_type = Z_BINARY; -} - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED -/* Pick out the correct pixels for the interlace pass. - * The basic idea here is to go through the row with a source - * pointer and a destination pointer (sp and dp), and copy the - * correct pixels for the pass. As the row gets compacted, - * sp will always be >= dp, so we should never overwrite anything. - * See the default: case for the easiest code to understand. - */ -void /* PRIVATE */ -png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - png_debug(1, "in png_do_write_interlace"); - - /* We don't have to do anything on the last pass (6) */ - if (pass < 6) - { - /* Each pixel depth is handled separately */ - switch (row_info->pixel_depth) - { - case 1: - { - png_bytep sp; - png_bytep dp; - int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - d = 0; - shift = 7; - - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 3); - value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; - d |= (value << shift); - - if (shift == 0) - { - shift = 7; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift--; - - } - if (shift != 7) - *dp = (png_byte)d; - - break; - } - - case 2: - { - png_bytep sp; - png_bytep dp; - int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - shift = 6; - d = 0; - - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 2); - value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; - d |= (value << shift); - - if (shift == 0) - { - shift = 6; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift -= 2; - } - if (shift != 6) - *dp = (png_byte)d; - - break; - } - - case 4: - { - png_bytep sp; - png_bytep dp; - int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - shift = 4; - d = 0; - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 1); - value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; - d |= (value << shift); - - if (shift == 0) - { - shift = 4; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift -= 4; - } - if (shift != 4) - *dp = (png_byte)d; - - break; - } - - default: - { - png_bytep sp; - png_bytep dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - png_size_t pixel_bytes; - - /* Start at the beginning */ - dp = row; - - /* Find out how many bytes each pixel takes up */ - pixel_bytes = (row_info->pixel_depth >> 3); - - /* Loop through the row, only looking at the pixels that matter */ - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - /* Find out where the original pixel is */ - sp = row + (png_size_t)i * pixel_bytes; - - /* Move the pixel */ - if (dp != sp) - png_memcpy(dp, sp, pixel_bytes); - - /* Next pixel */ - dp += pixel_bytes; - } - break; - } - } - /* Set new row width */ - row_info->width = (row_info->width + - png_pass_inc[pass] - 1 - - png_pass_start[pass]) / - png_pass_inc[pass]; - - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, - row_info->width); - } -} -#endif - -/* This filters the row, chooses which filter to use, if it has not already - * been specified by the application, and then writes the row out with the - * chosen filter. - */ -#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) -#define PNG_HISHIFT 10 -#define PNG_LOMASK ((png_uint_32)0xffffL) -#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) -void /* PRIVATE */ -png_write_find_filter(png_structp png_ptr, png_row_infop row_info) -{ - png_bytep best_row; -#ifdef PNG_WRITE_FILTER_SUPPORTED - png_bytep prev_row, row_buf; - png_uint_32 mins, bpp; - png_byte filter_to_do = png_ptr->do_filter; - png_size_t row_bytes = row_info->rowbytes; -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - int num_p_filters = (int)png_ptr->num_prev_filters; -#endif - - png_debug(1, "in png_write_find_filter"); - -#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) - { - /* These will never be selected so we need not test them. */ - filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); - } -#endif - - /* Find out how many bytes offset each pixel is */ - bpp = (row_info->pixel_depth + 7) >> 3; - - prev_row = png_ptr->prev_row; -#endif - best_row = png_ptr->row_buf; -#ifdef PNG_WRITE_FILTER_SUPPORTED - row_buf = best_row; - mins = PNG_MAXSUM; - - /* The prediction method we use is to find which method provides the - * smallest value when summing the absolute values of the distances - * from zero, using anything >= 128 as negative numbers. This is known - * as the "minimum sum of absolute differences" heuristic. Other - * heuristics are the "weighted minimum sum of absolute differences" - * (experimental and can in theory improve compression), and the "zlib - * predictive" method (not implemented yet), which does test compressions - * of lines using different filter methods, and then chooses the - * (series of) filter(s) that give minimum compressed data size (VERY - * computationally expensive). - * - * GRR 980525: consider also - * - * (1) minimum sum of absolute differences from running average (i.e., - * keep running sum of non-absolute differences & count of bytes) - * [track dispersion, too? restart average if dispersion too large?] - * - * (1b) minimum sum of absolute differences from sliding average, probably - * with window size <= deflate window (usually 32K) - * - * (2) minimum sum of squared differences from zero or running average - * (i.e., ~ root-mean-square approach) - */ - - - /* We don't need to test the 'no filter' case if this is the only filter - * that has been chosen, as it doesn't actually do anything to the data. - */ - if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE) - { - png_bytep rp; - png_uint_32 sum = 0; - png_size_t i; - int v; - - for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) - { - v = *rp; - sum += (v < 128) ? v : 256 - v; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - png_uint_32 sumhi, sumlo; - int j; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ - - /* Reduce the sum if we match any of the previous rows */ - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - /* Factor in the cost of this filter (this is here for completeness, - * but it makes no sense to have a "cost" for the NONE filter, as - * it has the minimum possible computational cost - none). - */ - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - mins = sum; - } - - /* Sub filter */ - if (filter_to_do == PNG_FILTER_SUB) - /* It's the only filter so no testing is needed */ - { - png_bytep rp, lp, dp; - png_size_t i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; - i++, rp++, dp++) - { - *dp = *rp; - } - - for (lp = row_buf + 1; i < row_bytes; - i++, rp++, lp++, dp++) - { - *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); - } - - best_row = png_ptr->sub_row; - } - - else if (filter_to_do & PNG_FILTER_SUB) - { - png_bytep rp, dp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - /* We temporarily increase the "minimum sum" by the factor we - * would reduce the sum of this filter, so that we can do the - * early exit comparison without scaling the sum each time. - */ - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; - i++, rp++, dp++) - { - v = *dp = *rp; - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = row_buf + 1; i < row_bytes; - i++, rp++, lp++, dp++) - { - v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) - { - sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->sub_row; - } - } - - /* Up filter */ - if (filter_to_do == PNG_FILTER_UP) - { - png_bytep rp, dp, pp; - png_size_t i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, - pp = prev_row + 1; i < row_bytes; - i++, rp++, pp++, dp++) - { - *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); - } - - best_row = png_ptr->up_row; - } - - else if (filter_to_do & PNG_FILTER_UP) - { - png_bytep rp, dp, pp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, - pp = prev_row + 1; i < row_bytes; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->up_row; - } - } - - /* Avg filter */ - if (filter_to_do == PNG_FILTER_AVG) - { - png_bytep rp, dp, pp, lp; - png_uint_32 i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); - } - - for (lp = row_buf + 1; i < row_bytes; i++) - { - *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) - & 0xff); - } - best_row = png_ptr->avg_row; - } - - else if (filter_to_do & PNG_FILTER_AVG) - { - png_bytep rp, dp, pp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = row_buf + 1; i < row_bytes; i++) - { - v = *dp++ = - (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->avg_row; - } - } - - /* Paeth filter */ - if (filter_to_do == PNG_FILTER_PAETH) - { - png_bytep rp, dp, pp, cp, lp; - png_size_t i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - } - - for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) - { - int a, b, c, pa, pb, pc, p; - - b = *pp++; - c = *cp++; - a = *lp++; - - p = b - c; - pc = a - c; - -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - - p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; - - *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); - } - best_row = png_ptr->paeth_row; - } - - else if (filter_to_do & PNG_FILTER_PAETH) - { - png_bytep rp, dp, pp, cp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) - { - int a, b, c, pa, pb, pc, p; - - b = *pp++; - c = *cp++; - a = *lp++; - -#ifndef PNG_SLOW_PAETH - p = b - c; - pc = a - c; -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; -#else /* PNG_SLOW_PAETH */ - p = a + b - c; - pa = abs(p - a); - pb = abs(p - b); - pc = abs(p - c); - - if (pa <= pb && pa <= pc) - p = a; - - else if (pb <= pc) - p = b; - - else - p = c; -#endif /* PNG_SLOW_PAETH */ - - v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - best_row = png_ptr->paeth_row; - } - } -#endif /* PNG_WRITE_FILTER_SUPPORTED */ - /* Do the actual writing of the filtered row data from the chosen filter. */ - - png_write_filtered_row(png_ptr, best_row); - -#ifdef PNG_WRITE_FILTER_SUPPORTED -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - /* Save the type of filter we picked this time for future calculations */ - if (png_ptr->num_prev_filters > 0) - { - int j; - - for (j = 1; j < num_p_filters; j++) - { - png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; - } - - png_ptr->prev_filters[j] = best_row[0]; - } -#endif -#endif /* PNG_WRITE_FILTER_SUPPORTED */ -} - - -/* Do the actual writing of a previously filtered row. */ -void /* PRIVATE */ -png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) -{ - png_size_t avail; - - png_debug(1, "in png_write_filtered_row"); - - png_debug1(2, "filter = %d", filtered_row[0]); - /* Set up the zlib input buffer */ - - png_ptr->zstream.next_in = filtered_row; - png_ptr->zstream.avail_in = 0; - avail = png_ptr->row_info.rowbytes + 1; - /* Repeat until we have compressed all the data */ - do - { - int ret; /* Return of zlib */ - - /* Record the number of bytes available - zlib supports at least 65535 - * bytes at one step, depending on the size of the zlib type 'uInt', the - * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h). - * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e. - * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a - * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called - * with smaller chunks of data. - */ - if (png_ptr->zstream.avail_in == 0) - { - if (avail > ZLIB_IO_MAX) - { - png_ptr->zstream.avail_in = ZLIB_IO_MAX; - avail -= ZLIB_IO_MAX; - } - - else - { - /* So this will fit in the available uInt space: */ - png_ptr->zstream.avail_in = (uInt)avail; - avail = 0; - } - } - - /* Compress the data */ - ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); - - /* Check for compression errors */ - if (ret != Z_OK) - { - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); - - else - png_error(png_ptr, "zlib error"); - } - - /* See if it is time to write another IDAT */ - if (!(png_ptr->zstream.avail_out)) - { - /* Write the IDAT and reset the zlib output buffer */ - png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } - /* Repeat until all data has been compressed */ - } while (avail > 0 || png_ptr->zstream.avail_in > 0); - - /* Swap the current and previous rows */ - if (png_ptr->prev_row != NULL) - { - png_bytep tptr; - - tptr = png_ptr->prev_row; - png_ptr->prev_row = png_ptr->row_buf; - png_ptr->row_buf = tptr; - } - - /* Finish row - updates counters and flushes zlib if last row */ - png_write_finish_row(png_ptr); - -#ifdef PNG_WRITE_FLUSH_SUPPORTED - png_ptr->flush_rows++; - - if (png_ptr->flush_dist > 0 && - png_ptr->flush_rows >= png_ptr->flush_dist) - { - png_write_flush(png_ptr); - } -#endif -} -#endif /* PNG_WRITE_SUPPORTED */ |