--- /dev/null
+\r
+/* pngwutil.c - utilities to write a PNG file\r
+ *\r
+ * Last changed in libpng 1.2.30 [August 15, 2008]\r
+ * For conditions of distribution and use, see copyright notice in png.h\r
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson\r
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)\r
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)\r
+ */\r
+\r
+#define PNG_INTERNAL\r
+#include "png.h"\r
+#ifdef PNG_WRITE_SUPPORTED\r
+\r
+/* Place a 32-bit number into a buffer in PNG byte order. We work\r
+ * with unsigned numbers for convenience, although one supported\r
+ * ancillary chunk uses signed (two's complement) numbers.\r
+ */\r
+void PNGAPI\r
+png_save_uint_32(png_bytep buf, png_uint_32 i)\r
+{\r
+ buf[0] = (png_byte)((i >> 24) & 0xff);\r
+ buf[1] = (png_byte)((i >> 16) & 0xff);\r
+ buf[2] = (png_byte)((i >> 8) & 0xff);\r
+ buf[3] = (png_byte)(i & 0xff);\r
+}\r
+\r
+/* The png_save_int_32 function assumes integers are stored in two's\r
+ * complement format. If this isn't the case, then this routine needs to\r
+ * be modified to write data in two's complement format.\r
+ */\r
+void PNGAPI\r
+png_save_int_32(png_bytep buf, png_int_32 i)\r
+{\r
+ buf[0] = (png_byte)((i >> 24) & 0xff);\r
+ buf[1] = (png_byte)((i >> 16) & 0xff);\r
+ buf[2] = (png_byte)((i >> 8) & 0xff);\r
+ buf[3] = (png_byte)(i & 0xff);\r
+}\r
+\r
+/* Place a 16-bit number into a buffer in PNG byte order.\r
+ * The parameter is declared unsigned int, not png_uint_16,\r
+ * just to avoid potential problems on pre-ANSI C compilers.\r
+ */\r
+void PNGAPI\r
+png_save_uint_16(png_bytep buf, unsigned int i)\r
+{\r
+ buf[0] = (png_byte)((i >> 8) & 0xff);\r
+ buf[1] = (png_byte)(i & 0xff);\r
+}\r
+\r
+/* Simple function to write the signature. If we have already written\r
+ * the magic bytes of the signature, or more likely, the PNG stream is\r
+ * being embedded into another stream and doesn't need its own signature,\r
+ * we should call png_set_sig_bytes() to tell libpng how many of the\r
+ * bytes have already been written.\r
+ */\r
+void /* PRIVATE */\r
+png_write_sig(png_structp png_ptr)\r
+{\r
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};\r
+\r
+ /* write the rest of the 8 byte signature */\r
+ png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],\r
+ (png_size_t)(8 - png_ptr->sig_bytes));\r
+ if (png_ptr->sig_bytes < 3)\r
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;\r
+}\r
+\r
+/* Write a PNG chunk all at once. The type is an array of ASCII characters\r
+ * representing the chunk name. The array must be at least 4 bytes in\r
+ * length, and does not need to be null terminated. To be safe, pass the\r
+ * pre-defined chunk names here, and if you need a new one, define it\r
+ * where the others are defined. The length is the length of the data.\r
+ * All the data must be present. If that is not possible, use the\r
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()\r
+ * functions instead.\r
+ */\r
+void PNGAPI\r
+png_write_chunk(png_structp png_ptr, png_bytep chunk_name,\r
+ png_bytep data, png_size_t length)\r
+{\r
+ if (png_ptr == NULL) return;\r
+ png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);\r
+ png_write_chunk_data(png_ptr, data, (png_size_t)length);\r
+ png_write_chunk_end(png_ptr);\r
+}\r
+\r
+/* Write the start of a PNG chunk. The type is the chunk type.\r
+ * The total_length is the sum of the lengths of all the data you will be\r
+ * passing in png_write_chunk_data().\r
+ */\r
+void PNGAPI\r
+png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,\r
+ png_uint_32 length)\r
+{\r
+ png_byte buf[8];\r
+\r
+ png_debug2(0, "Writing %s chunk, length = %lu\n", chunk_name,\r
+ (unsigned long)length);\r
+ if (png_ptr == NULL) return;\r
+\r
+ /* write the length and the chunk name */\r
+ png_save_uint_32(buf, length);\r
+ png_memcpy(buf + 4, chunk_name, 4);\r
+ png_write_data(png_ptr, buf, (png_size_t)8);\r
+ /* put the chunk name into png_ptr->chunk_name */\r
+ png_memcpy(png_ptr->chunk_name, chunk_name, 4);\r
+ /* reset the crc and run it over the chunk name */\r
+ png_reset_crc(png_ptr);\r
+ png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);\r
+}\r
+\r
+/* Write the data of a PNG chunk started with png_write_chunk_start().\r
+ * Note that multiple calls to this function are allowed, and that the\r
+ * sum of the lengths from these calls *must* add up to the total_length\r
+ * given to png_write_chunk_start().\r
+ */\r
+void PNGAPI\r
+png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)\r
+{\r
+ /* write the data, and run the CRC over it */\r
+ if (png_ptr == NULL) return;\r
+ if (data != NULL && length > 0)\r
+ {\r
+ png_write_data(png_ptr, data, length);\r
+ /* update the CRC after writing the data,\r
+ * in case that the user I/O routine alters it.\r
+ */\r
+ png_calculate_crc(png_ptr, data, length);\r
+ }\r
+}\r
+\r
+/* Finish a chunk started with png_write_chunk_start(). */\r
+void PNGAPI\r
+png_write_chunk_end(png_structp png_ptr)\r
+{\r
+ png_byte buf[4];\r
+\r
+ if (png_ptr == NULL) return;\r
+\r
+ /* write the crc in a single operation */\r
+ png_save_uint_32(buf, png_ptr->crc);\r
+\r
+ png_write_data(png_ptr, buf, (png_size_t)4);\r
+}\r
+\r
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)\r
+/*\r
+ * This pair of functions encapsulates the operation of (a) compressing a\r
+ * text string, and (b) issuing it later as a series of chunk data writes.\r
+ * The compression_state structure is shared context for these functions\r
+ * set up by the caller in order to make the whole mess thread-safe.\r
+ */\r
+\r
+typedef struct\r
+{\r
+ char *input; /* the uncompressed input data */\r
+ int input_len; /* its length */\r
+ int num_output_ptr; /* number of output pointers used */\r
+ int max_output_ptr; /* size of output_ptr */\r
+ png_charpp output_ptr; /* array of pointers to output */\r
+} compression_state;\r
+\r
+/* compress given text into storage in the png_ptr structure */\r
+static int /* PRIVATE */\r
+png_text_compress(png_structp png_ptr,\r
+ png_charp text, png_size_t text_len, int compression,\r
+ compression_state *comp)\r
+{\r
+ int ret;\r
+\r
+ comp->num_output_ptr = 0;\r
+ comp->max_output_ptr = 0;\r
+ comp->output_ptr = NULL;\r
+ comp->input = NULL;\r
+ comp->input_len = 0;\r
+\r
+ /* we may just want to pass the text right through */\r
+ if (compression == PNG_TEXT_COMPRESSION_NONE)\r
+ {\r
+ comp->input = text;\r
+ comp->input_len = text_len;\r
+ return((int)text_len);\r
+ }\r
+\r
+ if (compression >= PNG_TEXT_COMPRESSION_LAST)\r
+ {\r
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)\r
+ char msg[50];\r
+ png_snprintf(msg, 50, "Unknown compression type %d", compression);\r
+ png_warning(png_ptr, msg);\r
+#else\r
+ png_warning(png_ptr, "Unknown compression type");\r
+#endif\r
+ }\r
+\r
+ /* We can't write the chunk until we find out how much data we have,\r
+ * which means we need to run the compressor first and save the\r
+ * output. This shouldn't be a problem, as the vast majority of\r
+ * comments should be reasonable, but we will set up an array of\r
+ * malloc'd pointers to be sure.\r
+ *\r
+ * If we knew the application was well behaved, we could simplify this\r
+ * greatly by assuming we can always malloc an output buffer large\r
+ * enough to hold the compressed text ((1001 * text_len / 1000) + 12)\r
+ * and malloc this directly. The only time this would be a bad idea is\r
+ * if we can't malloc more than 64K and we have 64K of random input\r
+ * data, or if the input string is incredibly large (although this\r
+ * wouldn't cause a failure, just a slowdown due to swapping).\r
+ */\r
+\r
+ /* set up the compression buffers */\r
+ png_ptr->zstream.avail_in = (uInt)text_len;\r
+ png_ptr->zstream.next_in = (Bytef *)text;\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;\r
+\r
+ /* this is the same compression loop as in png_write_row() */\r
+ do\r
+ {\r
+ /* compress the data */\r
+ ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);\r
+ if (ret != Z_OK)\r
+ {\r
+ /* error */\r
+ if (png_ptr->zstream.msg != NULL)\r
+ png_error(png_ptr, png_ptr->zstream.msg);\r
+ else\r
+ png_error(png_ptr, "zlib error");\r
+ }\r
+ /* check to see if we need more room */\r
+ if (!(png_ptr->zstream.avail_out))\r
+ {\r
+ /* make sure the output array has room */\r
+ if (comp->num_output_ptr >= comp->max_output_ptr)\r
+ {\r
+ int old_max;\r
+\r
+ old_max = comp->max_output_ptr;\r
+ comp->max_output_ptr = comp->num_output_ptr + 4;\r
+ if (comp->output_ptr != NULL)\r
+ {\r
+ png_charpp old_ptr;\r
+\r
+ old_ptr = comp->output_ptr;\r
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,\r
+ (png_uint_32)\r
+ (comp->max_output_ptr * png_sizeof(png_charpp)));\r
+ png_memcpy(comp->output_ptr, old_ptr, old_max\r
+ * png_sizeof(png_charp));\r
+ png_free(png_ptr, old_ptr);\r
+ }\r
+ else\r
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,\r
+ (png_uint_32)\r
+ (comp->max_output_ptr * png_sizeof(png_charp)));\r
+ }\r
+\r
+ /* save the data */\r
+ comp->output_ptr[comp->num_output_ptr] =\r
+ (png_charp)png_malloc(png_ptr,\r
+ (png_uint_32)png_ptr->zbuf_size);\r
+ png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,\r
+ png_ptr->zbuf_size);\r
+ comp->num_output_ptr++;\r
+\r
+ /* and reset the buffer */\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ }\r
+ /* continue until we don't have any more to compress */\r
+ } while (png_ptr->zstream.avail_in);\r
+\r
+ /* finish the compression */\r
+ do\r
+ {\r
+ /* tell zlib we are finished */\r
+ ret = deflate(&png_ptr->zstream, Z_FINISH);\r
+\r
+ if (ret == Z_OK)\r
+ {\r
+ /* check to see if we need more room */\r
+ if (!(png_ptr->zstream.avail_out))\r
+ {\r
+ /* check to make sure our output array has room */\r
+ if (comp->num_output_ptr >= comp->max_output_ptr)\r
+ {\r
+ int old_max;\r
+\r
+ old_max = comp->max_output_ptr;\r
+ comp->max_output_ptr = comp->num_output_ptr + 4;\r
+ if (comp->output_ptr != NULL)\r
+ {\r
+ png_charpp old_ptr;\r
+\r
+ old_ptr = comp->output_ptr;\r
+ /* This could be optimized to realloc() */\r
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,\r
+ (png_uint_32)(comp->max_output_ptr *\r
+ png_sizeof(png_charp)));\r
+ png_memcpy(comp->output_ptr, old_ptr,\r
+ old_max * png_sizeof(png_charp));\r
+ png_free(png_ptr, old_ptr);\r
+ }\r
+ else\r
+ comp->output_ptr = (png_charpp)png_malloc(png_ptr,\r
+ (png_uint_32)(comp->max_output_ptr *\r
+ png_sizeof(png_charp)));\r
+ }\r
+\r
+ /* save off the data */\r
+ comp->output_ptr[comp->num_output_ptr] =\r
+ (png_charp)png_malloc(png_ptr,\r
+ (png_uint_32)png_ptr->zbuf_size);\r
+ png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,\r
+ png_ptr->zbuf_size);\r
+ comp->num_output_ptr++;\r
+\r
+ /* and reset the buffer pointers */\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ }\r
+ }\r
+ else if (ret != Z_STREAM_END)\r
+ {\r
+ /* we got an error */\r
+ if (png_ptr->zstream.msg != NULL)\r
+ png_error(png_ptr, png_ptr->zstream.msg);\r
+ else\r
+ png_error(png_ptr, "zlib error");\r
+ }\r
+ } while (ret != Z_STREAM_END);\r
+\r
+ /* text length is number of buffers plus last buffer */\r
+ text_len = png_ptr->zbuf_size * comp->num_output_ptr;\r
+ if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)\r
+ text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;\r
+\r
+ return((int)text_len);\r
+}\r
+\r
+/* ship the compressed text out via chunk writes */\r
+static void /* PRIVATE */\r
+png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)\r
+{\r
+ int i;\r
+\r
+ /* handle the no-compression case */\r
+ if (comp->input)\r
+ {\r
+ png_write_chunk_data(png_ptr, (png_bytep)comp->input,\r
+ (png_size_t)comp->input_len);\r
+ return;\r
+ }\r
+\r
+ /* write saved output buffers, if any */\r
+ for (i = 0; i < comp->num_output_ptr; i++)\r
+ {\r
+ png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],\r
+ (png_size_t)png_ptr->zbuf_size);\r
+ png_free(png_ptr, comp->output_ptr[i]);\r
+ comp->output_ptr[i]=NULL;\r
+ }\r
+ if (comp->max_output_ptr != 0)\r
+ png_free(png_ptr, comp->output_ptr);\r
+ comp->output_ptr=NULL;\r
+ /* write anything left in zbuf */\r
+ if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)\r
+ png_write_chunk_data(png_ptr, png_ptr->zbuf,\r
+ (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));\r
+\r
+ /* reset zlib for another zTXt/iTXt or image data */\r
+ deflateReset(&png_ptr->zstream);\r
+ png_ptr->zstream.data_type = Z_BINARY;\r
+}\r
+#endif\r
+\r
+/* Write the IHDR chunk, and update the png_struct with the necessary\r
+ * information. Note that the rest of this code depends upon this\r
+ * information being correct.\r
+ */\r
+void /* PRIVATE */\r
+png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,\r
+ int bit_depth, int color_type, int compression_type, int filter_type,\r
+ int interlace_type)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_IHDR;\r
+#endif\r
+ int ret;\r
+\r
+ png_byte buf[13]; /* buffer to store the IHDR info */\r
+\r
+ png_debug(1, "in png_write_IHDR\n");\r
+ /* Check that we have valid input data from the application info */\r
+ switch (color_type)\r
+ {\r
+ case PNG_COLOR_TYPE_GRAY:\r
+ switch (bit_depth)\r
+ {\r
+ case 1:\r
+ case 2:\r
+ case 4:\r
+ case 8:\r
+ case 16: png_ptr->channels = 1; break;\r
+ default: png_error(png_ptr, "Invalid bit depth for grayscale image");\r
+ }\r
+ break;\r
+ case PNG_COLOR_TYPE_RGB:\r
+ if (bit_depth != 8 && bit_depth != 16)\r
+ png_error(png_ptr, "Invalid bit depth for RGB image");\r
+ png_ptr->channels = 3;\r
+ break;\r
+ case PNG_COLOR_TYPE_PALETTE:\r
+ switch (bit_depth)\r
+ {\r
+ case 1:\r
+ case 2:\r
+ case 4:\r
+ case 8: png_ptr->channels = 1; break;\r
+ default: png_error(png_ptr, "Invalid bit depth for paletted image");\r
+ }\r
+ break;\r
+ case PNG_COLOR_TYPE_GRAY_ALPHA:\r
+ if (bit_depth != 8 && bit_depth != 16)\r
+ png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");\r
+ png_ptr->channels = 2;\r
+ break;\r
+ case PNG_COLOR_TYPE_RGB_ALPHA:\r
+ if (bit_depth != 8 && bit_depth != 16)\r
+ png_error(png_ptr, "Invalid bit depth for RGBA image");\r
+ png_ptr->channels = 4;\r
+ break;\r
+ default:\r
+ png_error(png_ptr, "Invalid image color type specified");\r
+ }\r
+\r
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)\r
+ {\r
+ png_warning(png_ptr, "Invalid compression type specified");\r
+ compression_type = PNG_COMPRESSION_TYPE_BASE;\r
+ }\r
+\r
+ /* Write filter_method 64 (intrapixel differencing) only if\r
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and\r
+ * 2. Libpng did not write a PNG signature (this filter_method is only\r
+ * used in PNG datastreams that are embedded in MNG datastreams) and\r
+ * 3. The application called png_permit_mng_features with a mask that\r
+ * included PNG_FLAG_MNG_FILTER_64 and\r
+ * 4. The filter_method is 64 and\r
+ * 5. The color_type is RGB or RGBA\r
+ */\r
+ if (\r
+#if defined(PNG_MNG_FEATURES_SUPPORTED)\r
+ !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&\r
+ ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&\r
+ (color_type == PNG_COLOR_TYPE_RGB ||\r
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&\r
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&\r
+#endif\r
+ filter_type != PNG_FILTER_TYPE_BASE)\r
+ {\r
+ png_warning(png_ptr, "Invalid filter type specified");\r
+ filter_type = PNG_FILTER_TYPE_BASE;\r
+ }\r
+\r
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED\r
+ if (interlace_type != PNG_INTERLACE_NONE &&\r
+ interlace_type != PNG_INTERLACE_ADAM7)\r
+ {\r
+ png_warning(png_ptr, "Invalid interlace type specified");\r
+ interlace_type = PNG_INTERLACE_ADAM7;\r
+ }\r
+#else\r
+ interlace_type=PNG_INTERLACE_NONE;\r
+#endif\r
+\r
+ /* save off the relevent information */\r
+ png_ptr->bit_depth = (png_byte)bit_depth;\r
+ png_ptr->color_type = (png_byte)color_type;\r
+ png_ptr->interlaced = (png_byte)interlace_type;\r
+#if defined(PNG_MNG_FEATURES_SUPPORTED)\r
+ png_ptr->filter_type = (png_byte)filter_type;\r
+#endif\r
+ png_ptr->compression_type = (png_byte)compression_type;\r
+ png_ptr->width = width;\r
+ png_ptr->height = height;\r
+\r
+ png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);\r
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);\r
+ /* set the usr info, so any transformations can modify it */\r
+ png_ptr->usr_width = png_ptr->width;\r
+ png_ptr->usr_bit_depth = png_ptr->bit_depth;\r
+ png_ptr->usr_channels = png_ptr->channels;\r
+\r
+ /* pack the header information into the buffer */\r
+ png_save_uint_32(buf, width);\r
+ png_save_uint_32(buf + 4, height);\r
+ buf[8] = (png_byte)bit_depth;\r
+ buf[9] = (png_byte)color_type;\r
+ buf[10] = (png_byte)compression_type;\r
+ buf[11] = (png_byte)filter_type;\r
+ buf[12] = (png_byte)interlace_type;\r
+\r
+ /* write the chunk */\r
+ png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);\r
+\r
+ /* initialize zlib with PNG info */\r
+ png_ptr->zstream.zalloc = png_zalloc;\r
+ png_ptr->zstream.zfree = png_zfree;\r
+ png_ptr->zstream.opaque = (voidpf)png_ptr;\r
+ if (!(png_ptr->do_filter))\r
+ {\r
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||\r
+ png_ptr->bit_depth < 8)\r
+ png_ptr->do_filter = PNG_FILTER_NONE;\r
+ else\r
+ png_ptr->do_filter = PNG_ALL_FILTERS;\r
+ }\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))\r
+ {\r
+ if (png_ptr->do_filter != PNG_FILTER_NONE)\r
+ png_ptr->zlib_strategy = Z_FILTERED;\r
+ else\r
+ png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;\r
+ }\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))\r
+ png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))\r
+ png_ptr->zlib_mem_level = 8;\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))\r
+ png_ptr->zlib_window_bits = 15;\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))\r
+ png_ptr->zlib_method = 8;\r
+ ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,\r
+ png_ptr->zlib_method, png_ptr->zlib_window_bits,\r
+ png_ptr->zlib_mem_level, png_ptr->zlib_strategy);\r
+ if (ret != Z_OK)\r
+ {\r
+ if (ret == Z_VERSION_ERROR) png_error(png_ptr,\r
+ "zlib failed to initialize compressor -- version error");\r
+ if (ret == Z_STREAM_ERROR) png_error(png_ptr,\r
+ "zlib failed to initialize compressor -- stream error");\r
+ if (ret == Z_MEM_ERROR) png_error(png_ptr,\r
+ "zlib failed to initialize compressor -- mem error");\r
+ png_error(png_ptr, "zlib failed to initialize compressor");\r
+ }\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ /* libpng is not interested in zstream.data_type */\r
+ /* set it to a predefined value, to avoid its evaluation inside zlib */\r
+ png_ptr->zstream.data_type = Z_BINARY;\r
+\r
+ png_ptr->mode = PNG_HAVE_IHDR;\r
+}\r
+\r
+/* write the palette. We are careful not to trust png_color to be in the\r
+ * correct order for PNG, so people can redefine it to any convenient\r
+ * structure.\r
+ */\r
+void /* PRIVATE */\r
+png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_PLTE;\r
+#endif\r
+ png_uint_32 i;\r
+ png_colorp pal_ptr;\r
+ png_byte buf[3];\r
+\r
+ png_debug(1, "in png_write_PLTE\n");\r
+ if ((\r
+#if defined(PNG_MNG_FEATURES_SUPPORTED)\r
+ !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&\r
+#endif\r
+ num_pal == 0) || num_pal > 256)\r
+ {\r
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ png_error(png_ptr, "Invalid number of colors in palette");\r
+ }\r
+ else\r
+ {\r
+ png_warning(png_ptr, "Invalid number of colors in palette");\r
+ return;\r
+ }\r
+ }\r
+\r
+ if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))\r
+ {\r
+ png_warning(png_ptr,\r
+ "Ignoring request to write a PLTE chunk in grayscale PNG");\r
+ return;\r
+ }\r
+\r
+ png_ptr->num_palette = (png_uint_16)num_pal;\r
+ png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);\r
+\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,\r
+ (png_uint_32)(num_pal * 3));\r
+#ifndef PNG_NO_POINTER_INDEXING\r
+ for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)\r
+ {\r
+ buf[0] = pal_ptr->red;\r
+ buf[1] = pal_ptr->green;\r
+ buf[2] = pal_ptr->blue;\r
+ png_write_chunk_data(png_ptr, buf, (png_size_t)3);\r
+ }\r
+#else\r
+ /* This is a little slower but some buggy compilers need to do this instead */\r
+ pal_ptr=palette;\r
+ for (i = 0; i < num_pal; i++)\r
+ {\r
+ buf[0] = pal_ptr[i].red;\r
+ buf[1] = pal_ptr[i].green;\r
+ buf[2] = pal_ptr[i].blue;\r
+ png_write_chunk_data(png_ptr, buf, (png_size_t)3);\r
+ }\r
+#endif\r
+ png_write_chunk_end(png_ptr);\r
+ png_ptr->mode |= PNG_HAVE_PLTE;\r
+}\r
+\r
+/* write an IDAT chunk */\r
+void /* PRIVATE */\r
+png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_IDAT;\r
+#endif\r
+ png_debug(1, "in png_write_IDAT\n");\r
+\r
+ /* Optimize the CMF field in the zlib stream. */\r
+ /* This hack of the zlib stream is compliant to the stream specification. */\r
+ if (!(png_ptr->mode & PNG_HAVE_IDAT) &&\r
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)\r
+ {\r
+ unsigned int z_cmf = data[0]; /* zlib compression method and flags */\r
+ if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)\r
+ {\r
+ /* Avoid memory underflows and multiplication overflows. */\r
+ /* The conditions below are practically always satisfied;\r
+ however, they still must be checked. */\r
+ if (length >= 2 &&\r
+ png_ptr->height < 16384 && png_ptr->width < 16384)\r
+ {\r
+ png_uint_32 uncompressed_idat_size = png_ptr->height *\r
+ ((png_ptr->width *\r
+ png_ptr->channels * png_ptr->bit_depth + 15) >> 3);\r
+ unsigned int z_cinfo = z_cmf >> 4;\r
+ unsigned int half_z_window_size = 1 << (z_cinfo + 7);\r
+ while (uncompressed_idat_size <= half_z_window_size &&\r
+ half_z_window_size >= 256)\r
+ {\r
+ z_cinfo--;\r
+ half_z_window_size >>= 1;\r
+ }\r
+ z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);\r
+ if (data[0] != (png_byte)z_cmf)\r
+ {\r
+ data[0] = (png_byte)z_cmf;\r
+ data[1] &= 0xe0;\r
+ data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);\r
+ }\r
+ }\r
+ }\r
+ else\r
+ png_error(png_ptr,\r
+ "Invalid zlib compression method or flags in IDAT");\r
+ }\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);\r
+ png_ptr->mode |= PNG_HAVE_IDAT;\r
+}\r
+\r
+/* write an IEND chunk */\r
+void /* PRIVATE */\r
+png_write_IEND(png_structp png_ptr)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_IEND;\r
+#endif\r
+ png_debug(1, "in png_write_IEND\n");\r
+ png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,\r
+ (png_size_t)0);\r
+ png_ptr->mode |= PNG_HAVE_IEND;\r
+}\r
+\r
+#if defined(PNG_WRITE_gAMA_SUPPORTED)\r
+/* write a gAMA chunk */\r
+#ifdef PNG_FLOATING_POINT_SUPPORTED\r
+void /* PRIVATE */\r
+png_write_gAMA(png_structp png_ptr, double file_gamma)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_gAMA;\r
+#endif\r
+ png_uint_32 igamma;\r
+ png_byte buf[4];\r
+\r
+ png_debug(1, "in png_write_gAMA\n");\r
+ /* file_gamma is saved in 1/100,000ths */\r
+ igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);\r
+ png_save_uint_32(buf, igamma);\r
+ png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);\r
+}\r
+#endif\r
+#ifdef PNG_FIXED_POINT_SUPPORTED\r
+void /* PRIVATE */\r
+png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_gAMA;\r
+#endif\r
+ png_byte buf[4];\r
+\r
+ png_debug(1, "in png_write_gAMA\n");\r
+ /* file_gamma is saved in 1/100,000ths */\r
+ png_save_uint_32(buf, (png_uint_32)file_gamma);\r
+ png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);\r
+}\r
+#endif\r
+#endif\r
+\r
+#if defined(PNG_WRITE_sRGB_SUPPORTED)\r
+/* write a sRGB chunk */\r
+void /* PRIVATE */\r
+png_write_sRGB(png_structp png_ptr, int srgb_intent)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_sRGB;\r
+#endif\r
+ png_byte buf[1];\r
+\r
+ png_debug(1, "in png_write_sRGB\n");\r
+ if (srgb_intent >= PNG_sRGB_INTENT_LAST)\r
+ png_warning(png_ptr,\r
+ "Invalid sRGB rendering intent specified");\r
+ buf[0]=(png_byte)srgb_intent;\r
+ png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_iCCP_SUPPORTED)\r
+/* write an iCCP chunk */\r
+void /* PRIVATE */\r
+png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,\r
+ png_charp profile, int profile_len)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_iCCP;\r
+#endif\r
+ png_size_t name_len;\r
+ png_charp new_name;\r
+ compression_state comp;\r
+ int embedded_profile_len = 0;\r
+\r
+ png_debug(1, "in png_write_iCCP\n");\r
+\r
+ comp.num_output_ptr = 0;\r
+ comp.max_output_ptr = 0;\r
+ comp.output_ptr = NULL;\r
+ comp.input = NULL;\r
+ comp.input_len = 0;\r
+\r
+ if (name == NULL || (name_len = png_check_keyword(png_ptr, name,\r
+ &new_name)) == 0)\r
+ {\r
+ png_warning(png_ptr, "Empty keyword in iCCP chunk");\r
+ return;\r
+ }\r
+\r
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)\r
+ png_warning(png_ptr, "Unknown compression type in iCCP chunk");\r
+\r
+ if (profile == NULL)\r
+ profile_len = 0;\r
+\r
+ if (profile_len > 3)\r
+ embedded_profile_len =\r
+ ((*( (png_bytep)profile ))<<24) |\r
+ ((*( (png_bytep)profile + 1))<<16) |\r
+ ((*( (png_bytep)profile + 2))<< 8) |\r
+ ((*( (png_bytep)profile + 3)) );\r
+\r
+ if (profile_len < embedded_profile_len)\r
+ {\r
+ png_warning(png_ptr,\r
+ "Embedded profile length too large in iCCP chunk");\r
+ return;\r
+ }\r
+\r
+ if (profile_len > embedded_profile_len)\r
+ {\r
+ png_warning(png_ptr,\r
+ "Truncating profile to actual length in iCCP chunk");\r
+ profile_len = embedded_profile_len;\r
+ }\r
+\r
+ if (profile_len)\r
+ profile_len = png_text_compress(png_ptr, profile,\r
+ (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);\r
+\r
+ /* make sure we include the NULL after the name and the compression type */\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,\r
+ (png_uint_32)(name_len + profile_len + 2));\r
+ new_name[name_len + 1] = 0x00;\r
+ png_write_chunk_data(png_ptr, (png_bytep)new_name,\r
+ (png_size_t)(name_len + 2));\r
+\r
+ if (profile_len)\r
+ png_write_compressed_data_out(png_ptr, &comp);\r
+\r
+ png_write_chunk_end(png_ptr);\r
+ png_free(png_ptr, new_name);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_sPLT_SUPPORTED)\r
+/* write a sPLT chunk */\r
+void /* PRIVATE */\r
+png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_sPLT;\r
+#endif\r
+ png_size_t name_len;\r
+ png_charp new_name;\r
+ png_byte entrybuf[10];\r
+ int entry_size = (spalette->depth == 8 ? 6 : 10);\r
+ int palette_size = entry_size * spalette->nentries;\r
+ png_sPLT_entryp ep;\r
+#ifdef PNG_NO_POINTER_INDEXING\r
+ int i;\r
+#endif\r
+\r
+ png_debug(1, "in png_write_sPLT\n");\r
+ if (spalette->name == NULL || (name_len = png_check_keyword(png_ptr,\r
+ spalette->name, &new_name))==0)\r
+ {\r
+ png_warning(png_ptr, "Empty keyword in sPLT chunk");\r
+ return;\r
+ }\r
+\r
+ /* make sure we include the NULL after the name */\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,\r
+ (png_uint_32)(name_len + 2 + palette_size));\r
+ png_write_chunk_data(png_ptr, (png_bytep)new_name,\r
+ (png_size_t)(name_len + 1));\r
+ png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);\r
+\r
+ /* loop through each palette entry, writing appropriately */\r
+#ifndef PNG_NO_POINTER_INDEXING\r
+ for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)\r
+ {\r
+ if (spalette->depth == 8)\r
+ {\r
+ entrybuf[0] = (png_byte)ep->red;\r
+ entrybuf[1] = (png_byte)ep->green;\r
+ entrybuf[2] = (png_byte)ep->blue;\r
+ entrybuf[3] = (png_byte)ep->alpha;\r
+ png_save_uint_16(entrybuf + 4, ep->frequency);\r
+ }\r
+ else\r
+ {\r
+ png_save_uint_16(entrybuf + 0, ep->red);\r
+ png_save_uint_16(entrybuf + 2, ep->green);\r
+ png_save_uint_16(entrybuf + 4, ep->blue);\r
+ png_save_uint_16(entrybuf + 6, ep->alpha);\r
+ png_save_uint_16(entrybuf + 8, ep->frequency);\r
+ }\r
+ png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);\r
+ }\r
+#else\r
+ ep=spalette->entries;\r
+ for (i=0; i>spalette->nentries; i++)\r
+ {\r
+ if (spalette->depth == 8)\r
+ {\r
+ entrybuf[0] = (png_byte)ep[i].red;\r
+ entrybuf[1] = (png_byte)ep[i].green;\r
+ entrybuf[2] = (png_byte)ep[i].blue;\r
+ entrybuf[3] = (png_byte)ep[i].alpha;\r
+ png_save_uint_16(entrybuf + 4, ep[i].frequency);\r
+ }\r
+ else\r
+ {\r
+ png_save_uint_16(entrybuf + 0, ep[i].red);\r
+ png_save_uint_16(entrybuf + 2, ep[i].green);\r
+ png_save_uint_16(entrybuf + 4, ep[i].blue);\r
+ png_save_uint_16(entrybuf + 6, ep[i].alpha);\r
+ png_save_uint_16(entrybuf + 8, ep[i].frequency);\r
+ }\r
+ png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);\r
+ }\r
+#endif\r
+\r
+ png_write_chunk_end(png_ptr);\r
+ png_free(png_ptr, new_name);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_sBIT_SUPPORTED)\r
+/* write the sBIT chunk */\r
+void /* PRIVATE */\r
+png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_sBIT;\r
+#endif\r
+ png_byte buf[4];\r
+ png_size_t size;\r
+\r
+ png_debug(1, "in png_write_sBIT\n");\r
+ /* make sure we don't depend upon the order of PNG_COLOR_8 */\r
+ if (color_type & PNG_COLOR_MASK_COLOR)\r
+ {\r
+ png_byte maxbits;\r
+\r
+ maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :\r
+ png_ptr->usr_bit_depth);\r
+ if (sbit->red == 0 || sbit->red > maxbits ||\r
+ sbit->green == 0 || sbit->green > maxbits ||\r
+ sbit->blue == 0 || sbit->blue > maxbits)\r
+ {\r
+ png_warning(png_ptr, "Invalid sBIT depth specified");\r
+ return;\r
+ }\r
+ buf[0] = sbit->red;\r
+ buf[1] = sbit->green;\r
+ buf[2] = sbit->blue;\r
+ size = 3;\r
+ }\r
+ else\r
+ {\r
+ if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)\r
+ {\r
+ png_warning(png_ptr, "Invalid sBIT depth specified");\r
+ return;\r
+ }\r
+ buf[0] = sbit->gray;\r
+ size = 1;\r
+ }\r
+\r
+ if (color_type & PNG_COLOR_MASK_ALPHA)\r
+ {\r
+ if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)\r
+ {\r
+ png_warning(png_ptr, "Invalid sBIT depth specified");\r
+ return;\r
+ }\r
+ buf[size++] = sbit->alpha;\r
+ }\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_cHRM_SUPPORTED)\r
+/* write the cHRM chunk */\r
+#ifdef PNG_FLOATING_POINT_SUPPORTED\r
+void /* PRIVATE */\r
+png_write_cHRM(png_structp png_ptr, double white_x, double white_y,\r
+ double red_x, double red_y, double green_x, double green_y,\r
+ double blue_x, double blue_y)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_cHRM;\r
+#endif\r
+ png_byte buf[32];\r
+ png_uint_32 itemp;\r
+\r
+ png_debug(1, "in png_write_cHRM\n");\r
+ /* each value is saved in 1/100,000ths */\r
+ if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||\r
+ white_x + white_y > 1.0)\r
+ {\r
+ png_warning(png_ptr, "Invalid cHRM white point specified");\r
+#if !defined(PNG_NO_CONSOLE_IO)\r
+ fprintf(stderr, "white_x=%f, white_y=%f\n", white_x, white_y);\r
+#endif\r
+ return;\r
+ }\r
+ itemp = (png_uint_32)(white_x * 100000.0 + 0.5);\r
+ png_save_uint_32(buf, itemp);\r
+ itemp = (png_uint_32)(white_y * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 4, itemp);\r
+\r
+ if (red_x < 0 || red_y < 0 || red_x + red_y > 1.0)\r
+ {\r
+ png_warning(png_ptr, "Invalid cHRM red point specified");\r
+ return;\r
+ }\r
+ itemp = (png_uint_32)(red_x * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 8, itemp);\r
+ itemp = (png_uint_32)(red_y * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 12, itemp);\r
+\r
+ if (green_x < 0 || green_y < 0 || green_x + green_y > 1.0)\r
+ {\r
+ png_warning(png_ptr, "Invalid cHRM green point specified");\r
+ return;\r
+ }\r
+ itemp = (png_uint_32)(green_x * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 16, itemp);\r
+ itemp = (png_uint_32)(green_y * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 20, itemp);\r
+\r
+ if (blue_x < 0 || blue_y < 0 || blue_x + blue_y > 1.0)\r
+ {\r
+ png_warning(png_ptr, "Invalid cHRM blue point specified");\r
+ return;\r
+ }\r
+ itemp = (png_uint_32)(blue_x * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 24, itemp);\r
+ itemp = (png_uint_32)(blue_y * 100000.0 + 0.5);\r
+ png_save_uint_32(buf + 28, itemp);\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);\r
+}\r
+#endif\r
+#ifdef PNG_FIXED_POINT_SUPPORTED\r
+void /* PRIVATE */\r
+png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,\r
+ png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,\r
+ png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,\r
+ png_fixed_point blue_y)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_cHRM;\r
+#endif\r
+ png_byte buf[32];\r
+\r
+ png_debug(1, "in png_write_cHRM\n");\r
+ /* each value is saved in 1/100,000ths */\r
+ if (white_x > 80000L || white_y > 80000L || white_x + white_y > 100000L)\r
+ {\r
+ png_warning(png_ptr, "Invalid fixed cHRM white point specified");\r
+#if !defined(PNG_NO_CONSOLE_IO)\r
+ fprintf(stderr, "white_x=%ld, white_y=%ld\n", (unsigned long)white_x,\r
+ (unsigned long)white_y);\r
+#endif\r
+ return;\r
+ }\r
+ png_save_uint_32(buf, (png_uint_32)white_x);\r
+ png_save_uint_32(buf + 4, (png_uint_32)white_y);\r
+\r
+ if (red_x + red_y > 100000L)\r
+ {\r
+ png_warning(png_ptr, "Invalid cHRM fixed red point specified");\r
+ return;\r
+ }\r
+ png_save_uint_32(buf + 8, (png_uint_32)red_x);\r
+ png_save_uint_32(buf + 12, (png_uint_32)red_y);\r
+\r
+ if (green_x + green_y > 100000L)\r
+ {\r
+ png_warning(png_ptr, "Invalid fixed cHRM green point specified");\r
+ return;\r
+ }\r
+ png_save_uint_32(buf + 16, (png_uint_32)green_x);\r
+ png_save_uint_32(buf + 20, (png_uint_32)green_y);\r
+\r
+ if (blue_x + blue_y > 100000L)\r
+ {\r
+ png_warning(png_ptr, "Invalid fixed cHRM blue point specified");\r
+ return;\r
+ }\r
+ png_save_uint_32(buf + 24, (png_uint_32)blue_x);\r
+ png_save_uint_32(buf + 28, (png_uint_32)blue_y);\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);\r
+}\r
+#endif\r
+#endif\r
+\r
+#if defined(PNG_WRITE_tRNS_SUPPORTED)\r
+/* write the tRNS chunk */\r
+void /* PRIVATE */\r
+png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,\r
+ int num_trans, int color_type)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_tRNS;\r
+#endif\r
+ png_byte buf[6];\r
+\r
+ png_debug(1, "in png_write_tRNS\n");\r
+ if (color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)\r
+ {\r
+ png_warning(png_ptr, "Invalid number of transparent colors specified");\r
+ return;\r
+ }\r
+ /* write the chunk out as it is */\r
+ png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,\r
+ (png_size_t)num_trans);\r
+ }\r
+ else if (color_type == PNG_COLOR_TYPE_GRAY)\r
+ {\r
+ /* one 16 bit value */\r
+ if (tran->gray >= (1 << png_ptr->bit_depth))\r
+ {\r
+ png_warning(png_ptr,\r
+ "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");\r
+ return;\r
+ }\r
+ png_save_uint_16(buf, tran->gray);\r
+ png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);\r
+ }\r
+ else if (color_type == PNG_COLOR_TYPE_RGB)\r
+ {\r
+ /* three 16 bit values */\r
+ png_save_uint_16(buf, tran->red);\r
+ png_save_uint_16(buf + 2, tran->green);\r
+ png_save_uint_16(buf + 4, tran->blue);\r
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))\r
+ {\r
+ png_warning(png_ptr,\r
+ "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");\r
+ return;\r
+ }\r
+ png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);\r
+ }\r
+ else\r
+ {\r
+ png_warning(png_ptr, "Can't write tRNS with an alpha channel");\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_bKGD_SUPPORTED)\r
+/* write the background chunk */\r
+void /* PRIVATE */\r
+png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_bKGD;\r
+#endif\r
+ png_byte buf[6];\r
+\r
+ png_debug(1, "in png_write_bKGD\n");\r
+ if (color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ if (\r
+#if defined(PNG_MNG_FEATURES_SUPPORTED)\r
+ (png_ptr->num_palette ||\r
+ (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&\r
+#endif\r
+ back->index > png_ptr->num_palette)\r
+ {\r
+ png_warning(png_ptr, "Invalid background palette index");\r
+ return;\r
+ }\r
+ buf[0] = back->index;\r
+ png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);\r
+ }\r
+ else if (color_type & PNG_COLOR_MASK_COLOR)\r
+ {\r
+ png_save_uint_16(buf, back->red);\r
+ png_save_uint_16(buf + 2, back->green);\r
+ png_save_uint_16(buf + 4, back->blue);\r
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))\r
+ {\r
+ png_warning(png_ptr,\r
+ "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");\r
+ return;\r
+ }\r
+ png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);\r
+ }\r
+ else\r
+ {\r
+ if (back->gray >= (1 << png_ptr->bit_depth))\r
+ {\r
+ png_warning(png_ptr,\r
+ "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");\r
+ return;\r
+ }\r
+ png_save_uint_16(buf, back->gray);\r
+ png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_hIST_SUPPORTED)\r
+/* write the histogram */\r
+void /* PRIVATE */\r
+png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_hIST;\r
+#endif\r
+ int i;\r
+ png_byte buf[3];\r
+\r
+ png_debug(1, "in png_write_hIST\n");\r
+ if (num_hist > (int)png_ptr->num_palette)\r
+ {\r
+ png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist,\r
+ png_ptr->num_palette);\r
+ png_warning(png_ptr, "Invalid number of histogram entries specified");\r
+ return;\r
+ }\r
+\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_hIST,\r
+ (png_uint_32)(num_hist * 2));\r
+ for (i = 0; i < num_hist; i++)\r
+ {\r
+ png_save_uint_16(buf, hist[i]);\r
+ png_write_chunk_data(png_ptr, buf, (png_size_t)2);\r
+ }\r
+ png_write_chunk_end(png_ptr);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \\r
+ defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)\r
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,\r
+ * and if invalid, correct the keyword rather than discarding the entire\r
+ * chunk. The PNG 1.0 specification requires keywords 1-79 characters in\r
+ * length, forbids leading or trailing whitespace, multiple internal spaces,\r
+ * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.\r
+ *\r
+ * The new_key is allocated to hold the corrected keyword and must be freed\r
+ * by the calling routine. This avoids problems with trying to write to\r
+ * static keywords without having to have duplicate copies of the strings.\r
+ */\r
+png_size_t /* PRIVATE */\r
+png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)\r
+{\r
+ png_size_t key_len;\r
+ png_charp kp, dp;\r
+ int kflag;\r
+ int kwarn=0;\r
+\r
+ png_debug(1, "in png_check_keyword\n");\r
+ *new_key = NULL;\r
+\r
+ if (key == NULL || (key_len = png_strlen(key)) == 0)\r
+ {\r
+ png_warning(png_ptr, "zero length keyword");\r
+ return ((png_size_t)0);\r
+ }\r
+\r
+ png_debug1(2, "Keyword to be checked is '%s'\n", key);\r
+\r
+ *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));\r
+ if (*new_key == NULL)\r
+ {\r
+ png_warning(png_ptr, "Out of memory while procesing keyword");\r
+ return ((png_size_t)0);\r
+ }\r
+\r
+ /* Replace non-printing characters with a blank and print a warning */\r
+ for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)\r
+ {\r
+ if ((png_byte)*kp < 0x20 ||\r
+ ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))\r
+ {\r
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)\r
+ char msg[40];\r
+\r
+ png_snprintf(msg, 40,\r
+ "invalid keyword character 0x%02X", (png_byte)*kp);\r
+ png_warning(png_ptr, msg);\r
+#else\r
+ png_warning(png_ptr, "invalid character in keyword");\r
+#endif\r
+ *dp = ' ';\r
+ }\r
+ else\r
+ {\r
+ *dp = *kp;\r
+ }\r
+ }\r
+ *dp = '\0';\r
+\r
+ /* Remove any trailing white space. */\r
+ kp = *new_key + key_len - 1;\r
+ if (*kp == ' ')\r
+ {\r
+ png_warning(png_ptr, "trailing spaces removed from keyword");\r
+\r
+ while (*kp == ' ')\r
+ {\r
+ *(kp--) = '\0';\r
+ key_len--;\r
+ }\r
+ }\r
+\r
+ /* Remove any leading white space. */\r
+ kp = *new_key;\r
+ if (*kp == ' ')\r
+ {\r
+ png_warning(png_ptr, "leading spaces removed from keyword");\r
+\r
+ while (*kp == ' ')\r
+ {\r
+ kp++;\r
+ key_len--;\r
+ }\r
+ }\r
+\r
+ png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp);\r
+\r
+ /* Remove multiple internal spaces. */\r
+ for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)\r
+ {\r
+ if (*kp == ' ' && kflag == 0)\r
+ {\r
+ *(dp++) = *kp;\r
+ kflag = 1;\r
+ }\r
+ else if (*kp == ' ')\r
+ {\r
+ key_len--;\r
+ kwarn=1;\r
+ }\r
+ else\r
+ {\r
+ *(dp++) = *kp;\r
+ kflag = 0;\r
+ }\r
+ }\r
+ *dp = '\0';\r
+ if (kwarn)\r
+ png_warning(png_ptr, "extra interior spaces removed from keyword");\r
+\r
+ if (key_len == 0)\r
+ {\r
+ png_free(png_ptr, *new_key);\r
+ *new_key=NULL;\r
+ png_warning(png_ptr, "Zero length keyword");\r
+ }\r
+\r
+ if (key_len > 79)\r
+ {\r
+ png_warning(png_ptr, "keyword length must be 1 - 79 characters");\r
+ new_key[79] = '\0';\r
+ key_len = 79;\r
+ }\r
+\r
+ return (key_len);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_tEXt_SUPPORTED)\r
+/* write a tEXt chunk */\r
+void /* PRIVATE */\r
+png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,\r
+ png_size_t text_len)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_tEXt;\r
+#endif\r
+ png_size_t key_len;\r
+ png_charp new_key;\r
+\r
+ png_debug(1, "in png_write_tEXt\n");\r
+ if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)\r
+ {\r
+ png_warning(png_ptr, "Empty keyword in tEXt chunk");\r
+ return;\r
+ }\r
+\r
+ if (text == NULL || *text == '\0')\r
+ text_len = 0;\r
+ else\r
+ text_len = png_strlen(text);\r
+\r
+ /* make sure we include the 0 after the key */\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,\r
+ (png_uint_32)(key_len + text_len + 1));\r
+ /*\r
+ * We leave it to the application to meet PNG-1.0 requirements on the\r
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of\r
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.\r
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.\r
+ */\r
+ png_write_chunk_data(png_ptr, (png_bytep)new_key,\r
+ (png_size_t)(key_len + 1));\r
+ if (text_len)\r
+ png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);\r
+\r
+ png_write_chunk_end(png_ptr);\r
+ png_free(png_ptr, new_key);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_zTXt_SUPPORTED)\r
+/* write a compressed text chunk */\r
+void /* PRIVATE */\r
+png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,\r
+ png_size_t text_len, int compression)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_zTXt;\r
+#endif\r
+ png_size_t key_len;\r
+ char buf[1];\r
+ png_charp new_key;\r
+ compression_state comp;\r
+\r
+ png_debug(1, "in png_write_zTXt\n");\r
+\r
+ comp.num_output_ptr = 0;\r
+ comp.max_output_ptr = 0;\r
+ comp.output_ptr = NULL;\r
+ comp.input = NULL;\r
+ comp.input_len = 0;\r
+\r
+ if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)\r
+ {\r
+ png_warning(png_ptr, "Empty keyword in zTXt chunk");\r
+ png_free(png_ptr, new_key);\r
+ return;\r
+ }\r
+\r
+ if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)\r
+ {\r
+ png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);\r
+ png_free(png_ptr, new_key);\r
+ return;\r
+ }\r
+\r
+ text_len = png_strlen(text);\r
+\r
+ /* compute the compressed data; do it now for the length */\r
+ text_len = png_text_compress(png_ptr, text, text_len, compression,\r
+ &comp);\r
+\r
+ /* write start of chunk */\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,\r
+ (png_uint_32)(key_len+text_len + 2));\r
+ /* write key */\r
+ png_write_chunk_data(png_ptr, (png_bytep)new_key,\r
+ (png_size_t)(key_len + 1));\r
+ png_free(png_ptr, new_key);\r
+\r
+ buf[0] = (png_byte)compression;\r
+ /* write compression */\r
+ png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);\r
+ /* write the compressed data */\r
+ png_write_compressed_data_out(png_ptr, &comp);\r
+\r
+ /* close the chunk */\r
+ png_write_chunk_end(png_ptr);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_iTXt_SUPPORTED)\r
+/* write an iTXt chunk */\r
+void /* PRIVATE */\r
+png_write_iTXt(png_structp png_ptr, int compression, png_charp key,\r
+ png_charp lang, png_charp lang_key, png_charp text)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_iTXt;\r
+#endif\r
+ png_size_t lang_len, key_len, lang_key_len, text_len;\r
+ png_charp new_lang, new_key;\r
+ png_byte cbuf[2];\r
+ compression_state comp;\r
+\r
+ png_debug(1, "in png_write_iTXt\n");\r
+\r
+ comp.num_output_ptr = 0;\r
+ comp.max_output_ptr = 0;\r
+ comp.output_ptr = NULL;\r
+ comp.input = NULL;\r
+\r
+ if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)\r
+ {\r
+ png_warning(png_ptr, "Empty keyword in iTXt chunk");\r
+ return;\r
+ }\r
+ if (lang == NULL || (lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)\r
+ {\r
+ png_warning(png_ptr, "Empty language field in iTXt chunk");\r
+ new_lang = NULL;\r
+ lang_len = 0;\r
+ }\r
+\r
+ if (lang_key == NULL)\r
+ lang_key_len = 0;\r
+ else\r
+ lang_key_len = png_strlen(lang_key);\r
+\r
+ if (text == NULL)\r
+ text_len = 0;\r
+ else\r
+ text_len = png_strlen(text);\r
+\r
+ /* compute the compressed data; do it now for the length */\r
+ text_len = png_text_compress(png_ptr, text, text_len, compression-2,\r
+ &comp);\r
+\r
+\r
+ /* make sure we include the compression flag, the compression byte,\r
+ * and the NULs after the key, lang, and lang_key parts */\r
+\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,\r
+ (png_uint_32)(\r
+ 5 /* comp byte, comp flag, terminators for key, lang and lang_key */\r
+ + key_len\r
+ + lang_len\r
+ + lang_key_len\r
+ + text_len));\r
+\r
+ /*\r
+ * We leave it to the application to meet PNG-1.0 requirements on the\r
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of\r
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.\r
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.\r
+ */\r
+ png_write_chunk_data(png_ptr, (png_bytep)new_key,\r
+ (png_size_t)(key_len + 1));\r
+\r
+ /* set the compression flag */\r
+ if (compression == PNG_ITXT_COMPRESSION_NONE || \\r
+ compression == PNG_TEXT_COMPRESSION_NONE)\r
+ cbuf[0] = 0;\r
+ else /* compression == PNG_ITXT_COMPRESSION_zTXt */\r
+ cbuf[0] = 1;\r
+ /* set the compression method */\r
+ cbuf[1] = 0;\r
+ png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);\r
+\r
+ cbuf[0] = 0;\r
+ png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),\r
+ (png_size_t)(lang_len + 1));\r
+ png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),\r
+ (png_size_t)(lang_key_len + 1));\r
+ png_write_compressed_data_out(png_ptr, &comp);\r
+\r
+ png_write_chunk_end(png_ptr);\r
+ png_free(png_ptr, new_key);\r
+ png_free(png_ptr, new_lang);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_oFFs_SUPPORTED)\r
+/* write the oFFs chunk */\r
+void /* PRIVATE */\r
+png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,\r
+ int unit_type)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_oFFs;\r
+#endif\r
+ png_byte buf[9];\r
+\r
+ png_debug(1, "in png_write_oFFs\n");\r
+ if (unit_type >= PNG_OFFSET_LAST)\r
+ png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");\r
+\r
+ png_save_int_32(buf, x_offset);\r
+ png_save_int_32(buf + 4, y_offset);\r
+ buf[8] = (png_byte)unit_type;\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);\r
+}\r
+#endif\r
+#if defined(PNG_WRITE_pCAL_SUPPORTED)\r
+/* write the pCAL chunk (described in the PNG extensions document) */\r
+void /* PRIVATE */\r
+png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,\r
+ png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_pCAL;\r
+#endif\r
+ png_size_t purpose_len, units_len, total_len;\r
+ png_uint_32p params_len;\r
+ png_byte buf[10];\r
+ png_charp new_purpose;\r
+ int i;\r
+\r
+ png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams);\r
+ if (type >= PNG_EQUATION_LAST)\r
+ png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");\r
+\r
+ purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;\r
+ png_debug1(3, "pCAL purpose length = %d\n", (int)purpose_len);\r
+ units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);\r
+ png_debug1(3, "pCAL units length = %d\n", (int)units_len);\r
+ total_len = purpose_len + units_len + 10;\r
+\r
+ params_len = (png_uint_32p)png_malloc(png_ptr,\r
+ (png_uint_32)(nparams * png_sizeof(png_uint_32)));\r
+\r
+ /* Find the length of each parameter, making sure we don't count the\r
+ null terminator for the last parameter. */\r
+ for (i = 0; i < nparams; i++)\r
+ {\r
+ params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);\r
+ png_debug2(3, "pCAL parameter %d length = %lu\n", i,\r
+ (unsigned long) params_len[i]);\r
+ total_len += (png_size_t)params_len[i];\r
+ }\r
+\r
+ png_debug1(3, "pCAL total length = %d\n", (int)total_len);\r
+ png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);\r
+ png_write_chunk_data(png_ptr, (png_bytep)new_purpose,\r
+ (png_size_t)purpose_len);\r
+ png_save_int_32(buf, X0);\r
+ png_save_int_32(buf + 4, X1);\r
+ buf[8] = (png_byte)type;\r
+ buf[9] = (png_byte)nparams;\r
+ png_write_chunk_data(png_ptr, buf, (png_size_t)10);\r
+ png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);\r
+\r
+ png_free(png_ptr, new_purpose);\r
+\r
+ for (i = 0; i < nparams; i++)\r
+ {\r
+ png_write_chunk_data(png_ptr, (png_bytep)params[i],\r
+ (png_size_t)params_len[i]);\r
+ }\r
+\r
+ png_free(png_ptr, params_len);\r
+ png_write_chunk_end(png_ptr);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_sCAL_SUPPORTED)\r
+/* write the sCAL chunk */\r
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)\r
+void /* PRIVATE */\r
+png_write_sCAL(png_structp png_ptr, int unit, double width, double height)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_sCAL;\r
+#endif\r
+ char buf[64];\r
+ png_size_t total_len;\r
+\r
+ png_debug(1, "in png_write_sCAL\n");\r
+\r
+ buf[0] = (char)unit;\r
+#if defined(_WIN32_WCE)\r
+/* sprintf() function is not supported on WindowsCE */\r
+ {\r
+ wchar_t wc_buf[32];\r
+ size_t wc_len;\r
+ swprintf(wc_buf, TEXT("%12.12e"), width);\r
+ wc_len = wcslen(wc_buf);\r
+ WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + 1, wc_len, NULL, NULL);\r
+ total_len = wc_len + 2;\r
+ swprintf(wc_buf, TEXT("%12.12e"), height);\r
+ wc_len = wcslen(wc_buf);\r
+ WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + total_len, wc_len,\r
+ NULL, NULL);\r
+ total_len += wc_len;\r
+ }\r
+#else\r
+ png_snprintf(buf + 1, 63, "%12.12e", width);\r
+ total_len = 1 + png_strlen(buf + 1) + 1;\r
+ png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);\r
+ total_len += png_strlen(buf + total_len);\r
+#endif\r
+\r
+ png_debug1(3, "sCAL total length = %u\n", (unsigned int)total_len);\r
+ png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);\r
+}\r
+#else\r
+#ifdef PNG_FIXED_POINT_SUPPORTED\r
+void /* PRIVATE */\r
+png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,\r
+ png_charp height)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_sCAL;\r
+#endif\r
+ png_byte buf[64];\r
+ png_size_t wlen, hlen, total_len;\r
+\r
+ png_debug(1, "in png_write_sCAL_s\n");\r
+\r
+ wlen = png_strlen(width);\r
+ hlen = png_strlen(height);\r
+ total_len = wlen + hlen + 2;\r
+ if (total_len > 64)\r
+ {\r
+ png_warning(png_ptr, "Can't write sCAL (buffer too small)");\r
+ return;\r
+ }\r
+\r
+ buf[0] = (png_byte)unit;\r
+ png_memcpy(buf + 1, width, wlen + 1); /* append the '\0' here */\r
+ png_memcpy(buf + wlen + 2, height, hlen); /* do NOT append the '\0' here */\r
+\r
+ png_debug1(3, "sCAL total length = %u\n", (unsigned int)total_len);\r
+ png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);\r
+}\r
+#endif\r
+#endif\r
+#endif\r
+\r
+#if defined(PNG_WRITE_pHYs_SUPPORTED)\r
+/* write the pHYs chunk */\r
+void /* PRIVATE */\r
+png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,\r
+ png_uint_32 y_pixels_per_unit,\r
+ int unit_type)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_pHYs;\r
+#endif\r
+ png_byte buf[9];\r
+\r
+ png_debug(1, "in png_write_pHYs\n");\r
+ if (unit_type >= PNG_RESOLUTION_LAST)\r
+ png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");\r
+\r
+ png_save_uint_32(buf, x_pixels_per_unit);\r
+ png_save_uint_32(buf + 4, y_pixels_per_unit);\r
+ buf[8] = (png_byte)unit_type;\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_tIME_SUPPORTED)\r
+/* Write the tIME chunk. Use either png_convert_from_struct_tm()\r
+ * or png_convert_from_time_t(), or fill in the structure yourself.\r
+ */\r
+void /* PRIVATE */\r
+png_write_tIME(png_structp png_ptr, png_timep mod_time)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_tIME;\r
+#endif\r
+ png_byte buf[7];\r
+\r
+ png_debug(1, "in png_write_tIME\n");\r
+ if (mod_time->month > 12 || mod_time->month < 1 ||\r
+ mod_time->day > 31 || mod_time->day < 1 ||\r
+ mod_time->hour > 23 || mod_time->second > 60)\r
+ {\r
+ png_warning(png_ptr, "Invalid time specified for tIME chunk");\r
+ return;\r
+ }\r
+\r
+ png_save_uint_16(buf, mod_time->year);\r
+ buf[2] = mod_time->month;\r
+ buf[3] = mod_time->day;\r
+ buf[4] = mod_time->hour;\r
+ buf[5] = mod_time->minute;\r
+ buf[6] = mod_time->second;\r
+\r
+ png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);\r
+}\r
+#endif\r
+\r
+/* initializes the row writing capability of libpng */\r
+void /* PRIVATE */\r
+png_write_start_row(png_structp png_ptr)\r
+{\r
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */\r
+\r
+ /* start of interlace block */\r
+ int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};\r
+\r
+ /* offset to next interlace block */\r
+ int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};\r
+\r
+ /* start of interlace block in the y direction */\r
+ int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};\r
+\r
+ /* offset to next interlace block in the y direction */\r
+ int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};\r
+#endif\r
+#endif\r
+\r
+ png_size_t buf_size;\r
+\r
+ png_debug(1, "in png_write_start_row\n");\r
+ buf_size = (png_size_t)(PNG_ROWBYTES(\r
+ png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);\r
+\r
+ /* set up row buffer */\r
+ png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)buf_size);\r
+ png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;\r
+\r
+#ifndef PNG_NO_WRITE_FILTER\r
+ /* set up filtering buffer, if using this filter */\r
+ if (png_ptr->do_filter & PNG_FILTER_SUB)\r
+ {\r
+ png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(png_ptr->rowbytes + 1));\r
+ png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;\r
+ }\r
+\r
+ /* We only need to keep the previous row if we are using one of these. */\r
+ if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))\r
+ {\r
+ /* set up previous row buffer */\r
+ png_ptr->prev_row = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)buf_size);\r
+ png_memset(png_ptr->prev_row, 0, buf_size);\r
+\r
+ if (png_ptr->do_filter & PNG_FILTER_UP)\r
+ {\r
+ png_ptr->up_row = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(png_ptr->rowbytes + 1));\r
+ png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;\r
+ }\r
+\r
+ if (png_ptr->do_filter & PNG_FILTER_AVG)\r
+ {\r
+ png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(png_ptr->rowbytes + 1));\r
+ png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;\r
+ }\r
+\r
+ if (png_ptr->do_filter & PNG_FILTER_PAETH)\r
+ {\r
+ png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(png_ptr->rowbytes + 1));\r
+ png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;\r
+ }\r
+ }\r
+#endif /* PNG_NO_WRITE_FILTER */\r
+\r
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED\r
+ /* if interlaced, we need to set up width and height of pass */\r
+ if (png_ptr->interlaced)\r
+ {\r
+ if (!(png_ptr->transformations & PNG_INTERLACE))\r
+ {\r
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -\r
+ png_pass_ystart[0]) / png_pass_yinc[0];\r
+ png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -\r
+ png_pass_start[0]) / png_pass_inc[0];\r
+ }\r
+ else\r
+ {\r
+ png_ptr->num_rows = png_ptr->height;\r
+ png_ptr->usr_width = png_ptr->width;\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ png_ptr->num_rows = png_ptr->height;\r
+ png_ptr->usr_width = png_ptr->width;\r
+ }\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+}\r
+\r
+/* Internal use only. Called when finished processing a row of data. */\r
+void /* PRIVATE */\r
+png_write_finish_row(png_structp png_ptr)\r
+{\r
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */\r
+\r
+ /* start of interlace block */\r
+ int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};\r
+\r
+ /* offset to next interlace block */\r
+ int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};\r
+\r
+ /* start of interlace block in the y direction */\r
+ int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};\r
+\r
+ /* offset to next interlace block in the y direction */\r
+ int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};\r
+#endif\r
+#endif\r
+\r
+ int ret;\r
+\r
+ png_debug(1, "in png_write_finish_row\n");\r
+ /* next row */\r
+ png_ptr->row_number++;\r
+\r
+ /* see if we are done */\r
+ if (png_ptr->row_number < png_ptr->num_rows)\r
+ return;\r
+\r
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED\r
+ /* if interlaced, go to next pass */\r
+ if (png_ptr->interlaced)\r
+ {\r
+ png_ptr->row_number = 0;\r
+ if (png_ptr->transformations & PNG_INTERLACE)\r
+ {\r
+ png_ptr->pass++;\r
+ }\r
+ else\r
+ {\r
+ /* loop until we find a non-zero width or height pass */\r
+ do\r
+ {\r
+ png_ptr->pass++;\r
+ if (png_ptr->pass >= 7)\r
+ break;\r
+ png_ptr->usr_width = (png_ptr->width +\r
+ png_pass_inc[png_ptr->pass] - 1 -\r
+ png_pass_start[png_ptr->pass]) /\r
+ png_pass_inc[png_ptr->pass];\r
+ png_ptr->num_rows = (png_ptr->height +\r
+ png_pass_yinc[png_ptr->pass] - 1 -\r
+ png_pass_ystart[png_ptr->pass]) /\r
+ png_pass_yinc[png_ptr->pass];\r
+ if (png_ptr->transformations & PNG_INTERLACE)\r
+ break;\r
+ } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);\r
+\r
+ }\r
+\r
+ /* reset the row above the image for the next pass */\r
+ if (png_ptr->pass < 7)\r
+ {\r
+ if (png_ptr->prev_row != NULL)\r
+ png_memset(png_ptr->prev_row, 0,\r
+ (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*\r
+ png_ptr->usr_bit_depth, png_ptr->width)) + 1);\r
+ return;\r
+ }\r
+ }\r
+#endif\r
+\r
+ /* if we get here, we've just written the last row, so we need\r
+ to flush the compressor */\r
+ do\r
+ {\r
+ /* tell the compressor we are done */\r
+ ret = deflate(&png_ptr->zstream, Z_FINISH);\r
+ /* check for an error */\r
+ if (ret == Z_OK)\r
+ {\r
+ /* check to see if we need more room */\r
+ if (!(png_ptr->zstream.avail_out))\r
+ {\r
+ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ }\r
+ }\r
+ else if (ret != Z_STREAM_END)\r
+ {\r
+ if (png_ptr->zstream.msg != NULL)\r
+ png_error(png_ptr, png_ptr->zstream.msg);\r
+ else\r
+ png_error(png_ptr, "zlib error");\r
+ }\r
+ } while (ret != Z_STREAM_END);\r
+\r
+ /* write any extra space */\r
+ if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)\r
+ {\r
+ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -\r
+ png_ptr->zstream.avail_out);\r
+ }\r
+\r
+ deflateReset(&png_ptr->zstream);\r
+ png_ptr->zstream.data_type = Z_BINARY;\r
+}\r
+\r
+#if defined(PNG_WRITE_INTERLACING_SUPPORTED)\r
+/* Pick out the correct pixels for the interlace pass.\r
+ * The basic idea here is to go through the row with a source\r
+ * pointer and a destination pointer (sp and dp), and copy the\r
+ * correct pixels for the pass. As the row gets compacted,\r
+ * sp will always be >= dp, so we should never overwrite anything.\r
+ * See the default: case for the easiest code to understand.\r
+ */\r
+void /* PRIVATE */\r
+png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */\r
+\r
+ /* start of interlace block */\r
+ int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};\r
+\r
+ /* offset to next interlace block */\r
+ int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};\r
+#endif\r
+\r
+ png_debug(1, "in png_do_write_interlace\n");\r
+ /* we don't have to do anything on the last pass (6) */\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL && pass < 6)\r
+#else\r
+ if (pass < 6)\r
+#endif\r
+ {\r
+ /* each pixel depth is handled separately */\r
+ switch (row_info->pixel_depth)\r
+ {\r
+ case 1:\r
+ {\r
+ png_bytep sp;\r
+ png_bytep dp;\r
+ int shift;\r
+ int d;\r
+ int value;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ dp = row;\r
+ d = 0;\r
+ shift = 7;\r
+ for (i = png_pass_start[pass]; i < row_width;\r
+ i += png_pass_inc[pass])\r
+ {\r
+ sp = row + (png_size_t)(i >> 3);\r
+ value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;\r
+ d |= (value << shift);\r
+\r
+ if (shift == 0)\r
+ {\r
+ shift = 7;\r
+ *dp++ = (png_byte)d;\r
+ d = 0;\r
+ }\r
+ else\r
+ shift--;\r
+\r
+ }\r
+ if (shift != 7)\r
+ *dp = (png_byte)d;\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+ png_bytep sp;\r
+ png_bytep dp;\r
+ int shift;\r
+ int d;\r
+ int value;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ dp = row;\r
+ shift = 6;\r
+ d = 0;\r
+ for (i = png_pass_start[pass]; i < row_width;\r
+ i += png_pass_inc[pass])\r
+ {\r
+ sp = row + (png_size_t)(i >> 2);\r
+ value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;\r
+ d |= (value << shift);\r
+\r
+ if (shift == 0)\r
+ {\r
+ shift = 6;\r
+ *dp++ = (png_byte)d;\r
+ d = 0;\r
+ }\r
+ else\r
+ shift -= 2;\r
+ }\r
+ if (shift != 6)\r
+ *dp = (png_byte)d;\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ png_bytep sp;\r
+ png_bytep dp;\r
+ int shift;\r
+ int d;\r
+ int value;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ dp = row;\r
+ shift = 4;\r
+ d = 0;\r
+ for (i = png_pass_start[pass]; i < row_width;\r
+ i += png_pass_inc[pass])\r
+ {\r
+ sp = row + (png_size_t)(i >> 1);\r
+ value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;\r
+ d |= (value << shift);\r
+\r
+ if (shift == 0)\r
+ {\r
+ shift = 4;\r
+ *dp++ = (png_byte)d;\r
+ d = 0;\r
+ }\r
+ else\r
+ shift -= 4;\r
+ }\r
+ if (shift != 4)\r
+ *dp = (png_byte)d;\r
+ break;\r
+ }\r
+ default:\r
+ {\r
+ png_bytep sp;\r
+ png_bytep dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+ png_size_t pixel_bytes;\r
+\r
+ /* start at the beginning */\r
+ dp = row;\r
+ /* find out how many bytes each pixel takes up */\r
+ pixel_bytes = (row_info->pixel_depth >> 3);\r
+ /* loop through the row, only looking at the pixels that\r
+ matter */\r
+ for (i = png_pass_start[pass]; i < row_width;\r
+ i += png_pass_inc[pass])\r
+ {\r
+ /* find out where the original pixel is */\r
+ sp = row + (png_size_t)i * pixel_bytes;\r
+ /* move the pixel */\r
+ if (dp != sp)\r
+ png_memcpy(dp, sp, pixel_bytes);\r
+ /* next pixel */\r
+ dp += pixel_bytes;\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ /* set new row width */\r
+ row_info->width = (row_info->width +\r
+ png_pass_inc[pass] - 1 -\r
+ png_pass_start[pass]) /\r
+ png_pass_inc[pass];\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,\r
+ row_info->width);\r
+ }\r
+}\r
+#endif\r
+\r
+/* This filters the row, chooses which filter to use, if it has not already\r
+ * been specified by the application, and then writes the row out with the\r
+ * chosen filter.\r
+ */\r
+#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)\r
+#define PNG_HISHIFT 10\r
+#define PNG_LOMASK ((png_uint_32)0xffffL)\r
+#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))\r
+void /* PRIVATE */\r
+png_write_find_filter(png_structp png_ptr, png_row_infop row_info)\r
+{\r
+ png_bytep best_row;\r
+#ifndef PNG_NO_WRITE_FILTER\r
+ png_bytep prev_row, row_buf;\r
+ png_uint_32 mins, bpp;\r
+ png_byte filter_to_do = png_ptr->do_filter;\r
+ png_uint_32 row_bytes = row_info->rowbytes;\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ int num_p_filters = (int)png_ptr->num_prev_filters;\r
+#endif\r
+\r
+ png_debug(1, "in png_write_find_filter\n");\r
+ /* find out how many bytes offset each pixel is */\r
+ bpp = (row_info->pixel_depth + 7) >> 3;\r
+\r
+ prev_row = png_ptr->prev_row;\r
+#endif\r
+ best_row = png_ptr->row_buf;\r
+#ifndef PNG_NO_WRITE_FILTER\r
+ row_buf = best_row;\r
+ mins = PNG_MAXSUM;\r
+\r
+ /* The prediction method we use is to find which method provides the\r
+ * smallest value when summing the absolute values of the distances\r
+ * from zero, using anything >= 128 as negative numbers. This is known\r
+ * as the "minimum sum of absolute differences" heuristic. Other\r
+ * heuristics are the "weighted minimum sum of absolute differences"\r
+ * (experimental and can in theory improve compression), and the "zlib\r
+ * predictive" method (not implemented yet), which does test compressions\r
+ * of lines using different filter methods, and then chooses the\r
+ * (series of) filter(s) that give minimum compressed data size (VERY\r
+ * computationally expensive).\r
+ *\r
+ * GRR 980525: consider also\r
+ * (1) minimum sum of absolute differences from running average (i.e.,\r
+ * keep running sum of non-absolute differences & count of bytes)\r
+ * [track dispersion, too? restart average if dispersion too large?]\r
+ * (1b) minimum sum of absolute differences from sliding average, probably\r
+ * with window size <= deflate window (usually 32K)\r
+ * (2) minimum sum of squared differences from zero or running average\r
+ * (i.e., ~ root-mean-square approach)\r
+ */\r
+\r
+\r
+ /* We don't need to test the 'no filter' case if this is the only filter\r
+ * that has been chosen, as it doesn't actually do anything to the data.\r
+ */\r
+ if ((filter_to_do & PNG_FILTER_NONE) &&\r
+ filter_to_do != PNG_FILTER_NONE)\r
+ {\r
+ png_bytep rp;\r
+ png_uint_32 sum = 0;\r
+ png_uint_32 i;\r
+ int v;\r
+\r
+ for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)\r
+ {\r
+ v = *rp;\r
+ sum += (v < 128) ? v : 256 - v;\r
+ }\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ png_uint_32 sumhi, sumlo;\r
+ int j;\r
+ sumlo = sum & PNG_LOMASK;\r
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */\r
+\r
+ /* Reduce the sum if we match any of the previous rows */\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)\r
+ {\r
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ /* Factor in the cost of this filter (this is here for completeness,\r
+ * but it makes no sense to have a "cost" for the NONE filter, as\r
+ * it has the minimum possible computational cost - none).\r
+ */\r
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>\r
+ PNG_COST_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (sumhi > PNG_HIMASK)\r
+ sum = PNG_MAXSUM;\r
+ else\r
+ sum = (sumhi << PNG_HISHIFT) + sumlo;\r
+ }\r
+#endif\r
+ mins = sum;\r
+ }\r
+\r
+ /* sub filter */\r
+ if (filter_to_do == PNG_FILTER_SUB)\r
+ /* it's the only filter so no testing is needed */\r
+ {\r
+ png_bytep rp, lp, dp;\r
+ png_uint_32 i;\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;\r
+ i++, rp++, dp++)\r
+ {\r
+ *dp = *rp;\r
+ }\r
+ for (lp = row_buf + 1; i < row_bytes;\r
+ i++, rp++, lp++, dp++)\r
+ {\r
+ *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);\r
+ }\r
+ best_row = png_ptr->sub_row;\r
+ }\r
+\r
+ else if (filter_to_do & PNG_FILTER_SUB)\r
+ {\r
+ png_bytep rp, dp, lp;\r
+ png_uint_32 sum = 0, lmins = mins;\r
+ png_uint_32 i;\r
+ int v;\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ /* We temporarily increase the "minimum sum" by the factor we\r
+ * would reduce the sum of this filter, so that we can do the\r
+ * early exit comparison without scaling the sum each time.\r
+ */\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 lmhi, lmlo;\r
+ lmlo = lmins & PNG_LOMASK;\r
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)\r
+ {\r
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>\r
+ PNG_COST_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (lmhi > PNG_HIMASK)\r
+ lmins = PNG_MAXSUM;\r
+ else\r
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;\r
+ }\r
+#endif\r
+\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;\r
+ i++, rp++, dp++)\r
+ {\r
+ v = *dp = *rp;\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+ }\r
+ for (lp = row_buf + 1; i < row_bytes;\r
+ i++, rp++, lp++, dp++)\r
+ {\r
+ v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+\r
+ if (sum > lmins) /* We are already worse, don't continue. */\r
+ break;\r
+ }\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 sumhi, sumlo;\r
+ sumlo = sum & PNG_LOMASK;\r
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)\r
+ {\r
+ sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>\r
+ PNG_COST_SHIFT;\r
+ sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (sumhi > PNG_HIMASK)\r
+ sum = PNG_MAXSUM;\r
+ else\r
+ sum = (sumhi << PNG_HISHIFT) + sumlo;\r
+ }\r
+#endif\r
+\r
+ if (sum < mins)\r
+ {\r
+ mins = sum;\r
+ best_row = png_ptr->sub_row;\r
+ }\r
+ }\r
+\r
+ /* up filter */\r
+ if (filter_to_do == PNG_FILTER_UP)\r
+ {\r
+ png_bytep rp, dp, pp;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,\r
+ pp = prev_row + 1; i < row_bytes;\r
+ i++, rp++, pp++, dp++)\r
+ {\r
+ *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);\r
+ }\r
+ best_row = png_ptr->up_row;\r
+ }\r
+\r
+ else if (filter_to_do & PNG_FILTER_UP)\r
+ {\r
+ png_bytep rp, dp, pp;\r
+ png_uint_32 sum = 0, lmins = mins;\r
+ png_uint_32 i;\r
+ int v;\r
+\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 lmhi, lmlo;\r
+ lmlo = lmins & PNG_LOMASK;\r
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)\r
+ {\r
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>\r
+ PNG_COST_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (lmhi > PNG_HIMASK)\r
+ lmins = PNG_MAXSUM;\r
+ else\r
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;\r
+ }\r
+#endif\r
+\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,\r
+ pp = prev_row + 1; i < row_bytes; i++)\r
+ {\r
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+\r
+ if (sum > lmins) /* We are already worse, don't continue. */\r
+ break;\r
+ }\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 sumhi, sumlo;\r
+ sumlo = sum & PNG_LOMASK;\r
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)\r
+ {\r
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>\r
+ PNG_COST_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (sumhi > PNG_HIMASK)\r
+ sum = PNG_MAXSUM;\r
+ else\r
+ sum = (sumhi << PNG_HISHIFT) + sumlo;\r
+ }\r
+#endif\r
+\r
+ if (sum < mins)\r
+ {\r
+ mins = sum;\r
+ best_row = png_ptr->up_row;\r
+ }\r
+ }\r
+\r
+ /* avg filter */\r
+ if (filter_to_do == PNG_FILTER_AVG)\r
+ {\r
+ png_bytep rp, dp, pp, lp;\r
+ png_uint_32 i;\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,\r
+ pp = prev_row + 1; i < bpp; i++)\r
+ {\r
+ *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);\r
+ }\r
+ for (lp = row_buf + 1; i < row_bytes; i++)\r
+ {\r
+ *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))\r
+ & 0xff);\r
+ }\r
+ best_row = png_ptr->avg_row;\r
+ }\r
+\r
+ else if (filter_to_do & PNG_FILTER_AVG)\r
+ {\r
+ png_bytep rp, dp, pp, lp;\r
+ png_uint_32 sum = 0, lmins = mins;\r
+ png_uint_32 i;\r
+ int v;\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 lmhi, lmlo;\r
+ lmlo = lmins & PNG_LOMASK;\r
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)\r
+ {\r
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>\r
+ PNG_COST_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (lmhi > PNG_HIMASK)\r
+ lmins = PNG_MAXSUM;\r
+ else\r
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;\r
+ }\r
+#endif\r
+\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,\r
+ pp = prev_row + 1; i < bpp; i++)\r
+ {\r
+ v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+ }\r
+ for (lp = row_buf + 1; i < row_bytes; i++)\r
+ {\r
+ v = *dp++ =\r
+ (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+\r
+ if (sum > lmins) /* We are already worse, don't continue. */\r
+ break;\r
+ }\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 sumhi, sumlo;\r
+ sumlo = sum & PNG_LOMASK;\r
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)\r
+ {\r
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>\r
+ PNG_COST_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (sumhi > PNG_HIMASK)\r
+ sum = PNG_MAXSUM;\r
+ else\r
+ sum = (sumhi << PNG_HISHIFT) + sumlo;\r
+ }\r
+#endif\r
+\r
+ if (sum < mins)\r
+ {\r
+ mins = sum;\r
+ best_row = png_ptr->avg_row;\r
+ }\r
+ }\r
+\r
+ /* Paeth filter */\r
+ if (filter_to_do == PNG_FILTER_PAETH)\r
+ {\r
+ png_bytep rp, dp, pp, cp, lp;\r
+ png_uint_32 i;\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,\r
+ pp = prev_row + 1; i < bpp; i++)\r
+ {\r
+ *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);\r
+ }\r
+\r
+ for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)\r
+ {\r
+ int a, b, c, pa, pb, pc, p;\r
+\r
+ b = *pp++;\r
+ c = *cp++;\r
+ a = *lp++;\r
+\r
+ p = b - c;\r
+ pc = a - c;\r
+\r
+#ifdef PNG_USE_ABS\r
+ pa = abs(p);\r
+ pb = abs(pc);\r
+ pc = abs(p + pc);\r
+#else\r
+ pa = p < 0 ? -p : p;\r
+ pb = pc < 0 ? -pc : pc;\r
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;\r
+#endif\r
+\r
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;\r
+\r
+ *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);\r
+ }\r
+ best_row = png_ptr->paeth_row;\r
+ }\r
+\r
+ else if (filter_to_do & PNG_FILTER_PAETH)\r
+ {\r
+ png_bytep rp, dp, pp, cp, lp;\r
+ png_uint_32 sum = 0, lmins = mins;\r
+ png_uint_32 i;\r
+ int v;\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 lmhi, lmlo;\r
+ lmlo = lmins & PNG_LOMASK;\r
+ lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)\r
+ {\r
+ lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>\r
+ PNG_COST_SHIFT;\r
+ lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (lmhi > PNG_HIMASK)\r
+ lmins = PNG_MAXSUM;\r
+ else\r
+ lmins = (lmhi << PNG_HISHIFT) + lmlo;\r
+ }\r
+#endif\r
+\r
+ for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,\r
+ pp = prev_row + 1; i < bpp; i++)\r
+ {\r
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+ }\r
+\r
+ for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)\r
+ {\r
+ int a, b, c, pa, pb, pc, p;\r
+\r
+ b = *pp++;\r
+ c = *cp++;\r
+ a = *lp++;\r
+\r
+#ifndef PNG_SLOW_PAETH\r
+ p = b - c;\r
+ pc = a - c;\r
+#ifdef PNG_USE_ABS\r
+ pa = abs(p);\r
+ pb = abs(pc);\r
+ pc = abs(p + pc);\r
+#else\r
+ pa = p < 0 ? -p : p;\r
+ pb = pc < 0 ? -pc : pc;\r
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;\r
+#endif\r
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;\r
+#else /* PNG_SLOW_PAETH */\r
+ p = a + b - c;\r
+ pa = abs(p - a);\r
+ pb = abs(p - b);\r
+ pc = abs(p - c);\r
+ if (pa <= pb && pa <= pc)\r
+ p = a;\r
+ else if (pb <= pc)\r
+ p = b;\r
+ else\r
+ p = c;\r
+#endif /* PNG_SLOW_PAETH */\r
+\r
+ v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);\r
+\r
+ sum += (v < 128) ? v : 256 - v;\r
+\r
+ if (sum > lmins) /* We are already worse, don't continue. */\r
+ break;\r
+ }\r
+\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)\r
+ {\r
+ int j;\r
+ png_uint_32 sumhi, sumlo;\r
+ sumlo = sum & PNG_LOMASK;\r
+ sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;\r
+\r
+ for (j = 0; j < num_p_filters; j++)\r
+ {\r
+ if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)\r
+ {\r
+ sumlo = (sumlo * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_weights[j]) >>\r
+ PNG_WEIGHT_SHIFT;\r
+ }\r
+ }\r
+\r
+ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>\r
+ PNG_COST_SHIFT;\r
+ sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>\r
+ PNG_COST_SHIFT;\r
+\r
+ if (sumhi > PNG_HIMASK)\r
+ sum = PNG_MAXSUM;\r
+ else\r
+ sum = (sumhi << PNG_HISHIFT) + sumlo;\r
+ }\r
+#endif\r
+\r
+ if (sum < mins)\r
+ {\r
+ best_row = png_ptr->paeth_row;\r
+ }\r
+ }\r
+#endif /* PNG_NO_WRITE_FILTER */\r
+ /* Do the actual writing of the filtered row data from the chosen filter. */\r
+\r
+ png_write_filtered_row(png_ptr, best_row);\r
+\r
+#ifndef PNG_NO_WRITE_FILTER\r
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)\r
+ /* Save the type of filter we picked this time for future calculations */\r
+ if (png_ptr->num_prev_filters > 0)\r
+ {\r
+ int j;\r
+ for (j = 1; j < num_p_filters; j++)\r
+ {\r
+ png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];\r
+ }\r
+ png_ptr->prev_filters[j] = best_row[0];\r
+ }\r
+#endif\r
+#endif /* PNG_NO_WRITE_FILTER */\r
+}\r
+\r
+\r
+/* Do the actual writing of a previously filtered row. */\r
+void /* PRIVATE */\r
+png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)\r
+{\r
+ png_debug(1, "in png_write_filtered_row\n");\r
+ png_debug1(2, "filter = %d\n", filtered_row[0]);\r
+ /* set up the zlib input buffer */\r
+\r
+ png_ptr->zstream.next_in = filtered_row;\r
+ png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;\r
+ /* repeat until we have compressed all the data */\r
+ do\r
+ {\r
+ int ret; /* return of zlib */\r
+\r
+ /* compress the data */\r
+ ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);\r
+ /* check for compression errors */\r
+ if (ret != Z_OK)\r
+ {\r
+ if (png_ptr->zstream.msg != NULL)\r
+ png_error(png_ptr, png_ptr->zstream.msg);\r
+ else\r
+ png_error(png_ptr, "zlib error");\r
+ }\r
+\r
+ /* see if it is time to write another IDAT */\r
+ if (!(png_ptr->zstream.avail_out))\r
+ {\r
+ /* write the IDAT and reset the zlib output buffer */\r
+ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ }\r
+ /* repeat until all data has been compressed */\r
+ } while (png_ptr->zstream.avail_in);\r
+\r
+ /* swap the current and previous rows */\r
+ if (png_ptr->prev_row != NULL)\r
+ {\r
+ png_bytep tptr;\r
+\r
+ tptr = png_ptr->prev_row;\r
+ png_ptr->prev_row = png_ptr->row_buf;\r
+ png_ptr->row_buf = tptr;\r
+ }\r
+\r
+ /* finish row - updates counters and flushes zlib if last row */\r
+ png_write_finish_row(png_ptr);\r
+\r
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)\r
+ png_ptr->flush_rows++;\r
+\r
+ if (png_ptr->flush_dist > 0 &&\r
+ png_ptr->flush_rows >= png_ptr->flush_dist)\r
+ {\r
+ png_write_flush(png_ptr);\r
+ }\r
+#endif\r
+}\r
+#endif /* PNG_WRITE_SUPPORTED */\r
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