--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/libpng-1.2.32/pngwrite.c Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,1547 @@
+
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Last changed in libpng 1.2.31 [August 19, 2008]
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2008 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.)
+ */
+
+/* get internal access to png.h */
+#define PNG_INTERNAL
+#include "png.h"
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Writes all the PNG information. This is the suggested way to use the
+ * library. If you have a new chunk to add, make a function to write it,
+ * and put it in the correct location here. If you want the chunk written
+ * after the image data, put it in png_write_end(). I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
+ * the chunk, as that will keep the code from breaking if you want to just
+ * write a plain PNG file. If you have long comments, I suggest writing
+ * them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_write_info_before_PLTE\n");
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+ if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+ {
+ png_write_sig(png_ptr); /* write PNG signature */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+ if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
+ {
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+ png_ptr->mng_features_permitted=0;
+ }
+#endif
+ /* write IHDR information. */
+ png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
+ info_ptr->filter_type,
+#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+ info_ptr->interlace_type);
+#else
+ 0);
+#endif
+ /* the rest of these check to see if the valid field has the appropriate
+ flag set, and if it does, writes the chunk. */
+#if defined(PNG_WRITE_gAMA_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_gAMA)
+ {
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_write_gAMA(png_ptr, info_ptr->gamma);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
+# endif
+#endif
+ }
+#endif
+#if defined(PNG_WRITE_sRGB_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_sRGB)
+ png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
+#endif
+#if defined(PNG_WRITE_iCCP_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_iCCP)
+ png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
+ info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
+#endif
+#if defined(PNG_WRITE_sBIT_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_sBIT)
+ png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+#endif
+#if defined(PNG_WRITE_cHRM_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_cHRM)
+ {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_write_cHRM(png_ptr,
+ info_ptr->x_white, info_ptr->y_white,
+ info_ptr->x_red, info_ptr->y_red,
+ info_ptr->x_green, info_ptr->y_green,
+ info_ptr->x_blue, info_ptr->y_blue);
+#else
+# ifdef PNG_FIXED_POINT_SUPPORTED
+ png_write_cHRM_fixed(png_ptr,
+ info_ptr->int_x_white, info_ptr->int_y_white,
+ info_ptr->int_x_red, info_ptr->int_y_red,
+ info_ptr->int_x_green, info_ptr->int_y_green,
+ info_ptr->int_x_blue, info_ptr->int_y_blue);
+# endif
+#endif
+ }
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_unknown_chunk *up;
+
+ png_debug(5, "writing extra chunks\n");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ up++)
+ {
+ int keep=png_handle_as_unknown(png_ptr, up->name);
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ up->location && !(up->location & PNG_HAVE_PLTE) &&
+ !(up->location & PNG_HAVE_IDAT) &&
+ ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+ {
+ if (up->size == 0)
+ png_warning(png_ptr, "Writing zero-length unknown chunk");
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+#endif
+ png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+ }
+}
+
+void PNGAPI
+png_write_info(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+ int i;
+#endif
+
+ png_debug(1, "in png_write_info\n");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+
+ if (info_ptr->valid & PNG_INFO_PLTE)
+ png_write_PLTE(png_ptr, info_ptr->palette,
+ (png_uint_32)info_ptr->num_palette);
+ else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Valid palette required for paletted images");
+
+#if defined(PNG_WRITE_tRNS_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_tRNS)
+ {
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+ /* invert the alpha channel (in tRNS) */
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
+ info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ int j;
+ for (j=0; j<(int)info_ptr->num_trans; j++)
+ info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
+ }
+#endif
+ png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
+ info_ptr->num_trans, info_ptr->color_type);
+ }
+#endif
+#if defined(PNG_WRITE_bKGD_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_bKGD)
+ png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+#if defined(PNG_WRITE_hIST_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_hIST)
+ png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+#if defined(PNG_WRITE_oFFs_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+ info_ptr->offset_unit_type);
+#endif
+#if defined(PNG_WRITE_pCAL_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_pCAL)
+ png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+ info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+ info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+#if defined(PNG_WRITE_sCAL_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_sCAL)
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
+ png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_s_width, info_ptr->scal_s_height);
+#else
+ png_warning(png_ptr,
+ "png_write_sCAL not supported; sCAL chunk not written.");
+#endif
+#endif
+#endif
+#if defined(PNG_WRITE_pHYs_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+ info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif
+#if defined(PNG_WRITE_tIME_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_tIME)
+ {
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+ png_ptr->mode |= PNG_WROTE_tIME;
+ }
+#endif
+#if defined(PNG_WRITE_sPLT_SUPPORTED)
+ if (info_ptr->valid & PNG_INFO_sPLT)
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif
+#if defined(PNG_WRITE_TEXT_SUPPORTED)
+ /* Check to see if we need to write text chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing header text chunk %d, type %d\n", i,
+ info_ptr->text[i].compression);
+ /* an internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#if defined(PNG_WRITE_iTXt_SUPPORTED)
+ /* write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ /* If we want a compressed text chunk */
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+ {
+#if defined(PNG_WRITE_zTXt_SUPPORTED)
+ /* write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0,
+ info_ptr->text[i].compression);
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+ }
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#if defined(PNG_WRITE_tEXt_SUPPORTED)
+ /* write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text,
+ 0);
+#else
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ }
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_unknown_chunk *up;
+
+ png_debug(5, "writing extra chunks\n");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ up++)
+ {
+ int keep=png_handle_as_unknown(png_ptr, up->name);
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ up->location && (up->location & PNG_HAVE_PLTE) &&
+ !(up->location & PNG_HAVE_IDAT) &&
+ ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+ {
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+#endif
+}
+
+/* Writes the end of the PNG file. If you don't want to write comments or
+ * time information, you can pass NULL for info. If you already wrote these
+ * in png_write_info(), do not write them again here. If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_write_end\n");
+ if (png_ptr == NULL)
+ return;
+ if (!(png_ptr->mode & PNG_HAVE_IDAT))
+ png_error(png_ptr, "No IDATs written into file");
+
+ /* see if user wants us to write information chunks */
+ if (info_ptr != NULL)
+ {
+#if defined(PNG_WRITE_TEXT_SUPPORTED)
+ int i; /* local index variable */
+#endif
+#if defined(PNG_WRITE_tIME_SUPPORTED)
+ /* check to see if user has supplied a time chunk */
+ if ((info_ptr->valid & PNG_INFO_tIME) &&
+ !(png_ptr->mode & PNG_WROTE_tIME))
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+#endif
+#if defined(PNG_WRITE_TEXT_SUPPORTED)
+ /* loop through comment chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
+ info_ptr->text[i].compression);
+ /* an internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#if defined(PNG_WRITE_iTXt_SUPPORTED)
+ /* write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+ {
+#if defined(PNG_WRITE_zTXt_SUPPORTED)
+ /* write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0,
+ info_ptr->text[i].compression);
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+ }
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#if defined(PNG_WRITE_tEXt_SUPPORTED)
+ /* write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0);
+#else
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ }
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_unknown_chunk *up;
+
+ png_debug(5, "writing extra chunks\n");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ up++)
+ {
+ int keep=png_handle_as_unknown(png_ptr, up->name);
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ up->location && (up->location & PNG_AFTER_IDAT) &&
+ ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+ {
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+#endif
+ }
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* write end of PNG file */
+ png_write_IEND(png_ptr);
+ /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+ * and restored again in libpng-1.2.30, may cause some applications that
+ * do not set png_ptr->output_flush_fn to crash. If your application
+ * experiences a problem, please try building libpng with
+ * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+ * png-mng-implement at lists.sf.net . This kludge will be removed
+ * from libpng-1.4.0.
+ */
+#if defined(PNG_WRITE_FLUSH_SUPPORTED) && \
+ defined(PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED)
+ png_flush(png_ptr);
+#endif
+}
+
+#if defined(PNG_WRITE_tIME_SUPPORTED)
+#if !defined(_WIN32_WCE)
+/* "time.h" functions are not supported on WindowsCE */
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
+{
+ png_debug(1, "in png_convert_from_struct_tm\n");
+ ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+ ptime->month = (png_byte)(ttime->tm_mon + 1);
+ ptime->day = (png_byte)ttime->tm_mday;
+ ptime->hour = (png_byte)ttime->tm_hour;
+ ptime->minute = (png_byte)ttime->tm_min;
+ ptime->second = (png_byte)ttime->tm_sec;
+}
+
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+ struct tm *tbuf;
+
+ png_debug(1, "in png_convert_from_time_t\n");
+ tbuf = gmtime(&ttime);
+ png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+#endif
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+png_structp PNGAPI
+png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+ return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
+}
+
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+png_structp PNGAPI
+png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+#ifdef PNG_SETJMP_SUPPORTED
+ volatile
+#endif
+ png_structp png_ptr;
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+ jmp_buf jmpbuf;
+#endif
+#endif
+ int i;
+ png_debug(1, "in png_create_write_struct\n");
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+ (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
+#else
+ png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+#endif /* PNG_USER_MEM_SUPPORTED */
+ if (png_ptr == NULL)
+ return (NULL);
+
+ /* added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
+ png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+ if (setjmp(jmpbuf))
+#else
+ if (setjmp(png_ptr->jmpbuf))
+#endif
+ {
+ png_free(png_ptr, png_ptr->zbuf);
+ png_ptr->zbuf=NULL;
+ png_destroy_struct(png_ptr);
+ return (NULL);
+ }
+#ifdef USE_FAR_KEYWORD
+ png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
+#endif
+#endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif /* PNG_USER_MEM_SUPPORTED */
+ png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
+
+ if (user_png_ver)
+ {
+ i=0;
+ do
+ {
+ if (user_png_ver[i] != png_libpng_ver[i])
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+ } while (png_libpng_ver[i++]);
+ }
+
+ if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
+ {
+ /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
+ * we must recompile any applications that use any older library version.
+ * For versions after libpng 1.0, we will be compatible, so we need
+ * only check the first digit.
+ */
+ if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
+ (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
+ (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+ {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ char msg[80];
+ if (user_png_ver)
+ {
+ png_snprintf(msg, 80,
+ "Application was compiled with png.h from libpng-%.20s",
+ user_png_ver);
+ png_warning(png_ptr, msg);
+ }
+ png_snprintf(msg, 80,
+ "Application is running with png.c from libpng-%.20s",
+ png_libpng_ver);
+ png_warning(png_ptr, msg);
+#endif
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags=0;
+#endif
+ png_error(png_ptr,
+ "Incompatible libpng version in application and library");
+ }
+ }
+
+ /* initialize zbuf - compression buffer */
+ png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+ png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)png_ptr->zbuf_size);
+
+ png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
+ png_flush_ptr_NULL);
+
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+ png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
+ 1, png_doublep_NULL, png_doublep_NULL);
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* Applications that neglect to set up their own setjmp() and then encounter
+ a png_error() will longjmp here. Since the jmpbuf is then meaningless we
+ abort instead of returning. */
+#ifdef USE_FAR_KEYWORD
+ if (setjmp(jmpbuf))
+ PNG_ABORT();
+ png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
+#else
+ if (setjmp(png_ptr->jmpbuf))
+ PNG_ABORT();
+#endif
+#endif
+ return (png_ptr);
+}
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
+/* Deprecated. */
+#undef png_write_init
+void PNGAPI
+png_write_init(png_structp png_ptr)
+{
+ /* We only come here via pre-1.0.7-compiled applications */
+ png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
+}
+
+void PNGAPI
+png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
+ png_size_t png_struct_size, png_size_t png_info_size)
+{
+ /* We only come here via pre-1.0.12-compiled applications */
+ if (png_ptr == NULL) return;
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ if (png_sizeof(png_struct) > png_struct_size ||
+ png_sizeof(png_info) > png_info_size)
+ {
+ char msg[80];
+ png_ptr->warning_fn=NULL;
+ if (user_png_ver)
+ {
+ png_snprintf(msg, 80,
+ "Application was compiled with png.h from libpng-%.20s",
+ user_png_ver);
+ png_warning(png_ptr, msg);
+ }
+ png_snprintf(msg, 80,
+ "Application is running with png.c from libpng-%.20s",
+ png_libpng_ver);
+ png_warning(png_ptr, msg);
+ }
+#endif
+ if (png_sizeof(png_struct) > png_struct_size)
+ {
+ png_ptr->error_fn=NULL;
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags=0;
+#endif
+ png_error(png_ptr,
+ "The png struct allocated by the application for writing is too small.");
+ }
+ if (png_sizeof(png_info) > png_info_size)
+ {
+ png_ptr->error_fn=NULL;
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags=0;
+#endif
+ png_error(png_ptr,
+ "The info struct allocated by the application for writing is too small.");
+ }
+ png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
+}
+#endif /* PNG_1_0_X || PNG_1_2_X */
+
+
+void PNGAPI
+png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
+ png_size_t png_struct_size)
+{
+ png_structp png_ptr=*ptr_ptr;
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf tmp_jmp; /* to save current jump buffer */
+#endif
+
+ int i = 0;
+
+ if (png_ptr == NULL)
+ return;
+
+ do
+ {
+ if (user_png_ver[i] != png_libpng_ver[i])
+ {
+#ifdef PNG_LEGACY_SUPPORTED
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+#else
+ png_ptr->warning_fn=NULL;
+ png_warning(png_ptr,
+ "Application uses deprecated png_write_init() and should be recompiled.");
+ break;
+#endif
+ }
+ } while (png_libpng_ver[i++]);
+
+ png_debug(1, "in png_write_init_3\n");
+
+#ifdef PNG_SETJMP_SUPPORTED
+ /* save jump buffer and error functions */
+ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
+#endif
+
+ if (png_sizeof(png_struct) > png_struct_size)
+ {
+ png_destroy_struct(png_ptr);
+ png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+ *ptr_ptr = png_ptr;
+ }
+
+ /* reset all variables to 0 */
+ png_memset(png_ptr, 0, png_sizeof(png_struct));
+
+ /* added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
+ png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ /* restore jump buffer */
+ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+
+ png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
+ png_flush_ptr_NULL);
+
+ /* initialize zbuf - compression buffer */
+ png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+ png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)png_ptr->zbuf_size);
+
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+ png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
+ 1, png_doublep_NULL, png_doublep_NULL);
+#endif
+}
+
+/* Write a few rows of image data. If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structp png_ptr, png_bytepp row,
+ png_uint_32 num_rows)
+{
+ png_uint_32 i; /* row counter */
+ png_bytepp rp; /* row pointer */
+
+ png_debug(1, "in png_write_rows\n");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* loop through the rows */
+ for (i = 0, rp = row; i < num_rows; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+}
+
+/* Write the image. You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structp png_ptr, png_bytepp image)
+{
+ png_uint_32 i; /* row index */
+ int pass, num_pass; /* pass variables */
+ png_bytepp rp; /* points to current row */
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug(1, "in png_write_image\n");
+#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+ /* intialize interlace handling. If image is not interlaced,
+ this will set pass to 1 */
+ num_pass = png_set_interlace_handling(png_ptr);
+#else
+ num_pass = 1;
+#endif
+ /* loop through passes */
+ for (pass = 0; pass < num_pass; pass++)
+ {
+ /* loop through image */
+ for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+ }
+}
+
+/* called by user to write a row of image data */
+void PNGAPI
+png_write_row(png_structp png_ptr, png_bytep row)
+{
+ if (png_ptr == NULL)
+ return;
+ png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
+ png_ptr->row_number, png_ptr->pass);
+
+ /* initialize transformations and other stuff if first time */
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* make sure we wrote the header info */
+ if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+ png_error(png_ptr,
+ "png_write_info was never called before png_write_row.");
+
+ /* check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
+#endif
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & PNG_FILLER)
+ png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
+#endif
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACK)
+ png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
+#endif
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
+#endif
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+ if (png_ptr->transformations & PNG_BGR)
+ png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
+#endif
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
+#endif
+
+ png_write_start_row(png_ptr);
+ }
+
+#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+ /* if interlaced and not interested in row, return */
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if (png_ptr->row_number & 0x07)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 1:
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 3:
+ if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 4:
+ if ((png_ptr->row_number & 0x03) != 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 5:
+ if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ case 6:
+ if (!(png_ptr->row_number & 0x01))
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+ }
+ }
+#endif
+
+ /* set up row info for transformations */
+ png_ptr->row_info.color_type = png_ptr->color_type;
+ png_ptr->row_info.width = png_ptr->usr_width;
+ png_ptr->row_info.channels = png_ptr->usr_channels;
+ png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
+ png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
+ png_ptr->row_info.channels);
+
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+
+ png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
+ png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
+ png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
+ png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
+ png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
+ png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
+
+ /* Copy user's row into buffer, leaving room for filter byte. */
+ png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
+ png_ptr->row_info.rowbytes);
+
+#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+ /* handle interlacing */
+ if (png_ptr->interlaced && png_ptr->pass < 6 &&
+ (png_ptr->transformations & PNG_INTERLACE))
+ {
+ png_do_write_interlace(&(png_ptr->row_info),
+ png_ptr->row_buf + 1, png_ptr->pass);
+ /* this should always get caught above, but still ... */
+ if (!(png_ptr->row_info.width))
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ }
+#endif
+
+ /* handle other transformations */
+ if (png_ptr->transformations)
+ png_do_write_transformations(png_ptr);
+
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+ /* 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 ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ }
+#endif
+
+ /* Find a filter if necessary, filter the row and write it out. */
+ png_write_find_filter(png_ptr, &(png_ptr->row_info));
+
+ if (png_ptr->write_row_fn != NULL)
+ (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structp png_ptr, int nrows)
+{
+ png_debug(1, "in png_set_flush\n");
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
+}
+
+/* flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structp png_ptr)
+{
+ int wrote_IDAT;
+
+ png_debug(1, "in png_write_flush\n");
+ if (png_ptr == NULL)
+ return;
+ /* We have already written out all of the data */
+ if (png_ptr->row_number >= png_ptr->num_rows)
+ return;
+
+ do
+ {
+ int ret;
+
+ /* compress the data */
+ ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+ wrote_IDAT = 0;
+
+ /* 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");
+ }
+
+ 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;
+ wrote_IDAT = 1;
+ }
+ } while(wrote_IDAT == 1);
+
+ /* If there is any data left to be output, write it into a new IDAT */
+ if (png_ptr->zbuf_size != 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.avail_out);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ }
+ png_ptr->flush_rows = 0;
+ png_flush(png_ptr);
+}
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+
+/* free all memory used by the write */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+ png_structp png_ptr = NULL;
+ png_infop info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn = NULL;
+ png_voidp mem_ptr = NULL;
+#endif
+
+ png_debug(1, "in png_destroy_write_struct\n");
+ if (png_ptr_ptr != NULL)
+ {
+ png_ptr = *png_ptr_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+ mem_ptr = png_ptr->mem_ptr;
+#endif
+ }
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr != NULL)
+ {
+ free_fn = png_ptr->free_fn;
+ mem_ptr = png_ptr->mem_ptr;
+ }
+#endif
+
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (info_ptr != NULL)
+ {
+ if (png_ptr != NULL)
+ {
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+ if (png_ptr->num_chunk_list)
+ {
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list=NULL;
+ png_ptr->num_chunk_list = 0;
+ }
+#endif
+ }
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)info_ptr);
+#endif
+ *info_ptr_ptr = NULL;
+ }
+
+ if (png_ptr != NULL)
+ {
+ png_write_destroy(png_ptr);
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)png_ptr);
+#endif
+ *png_ptr_ptr = NULL;
+ }
+}
+
+
+/* Free any memory used in png_ptr struct (old method) */
+void /* PRIVATE */
+png_write_destroy(png_structp png_ptr)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf tmp_jmp; /* save jump buffer */
+#endif
+ png_error_ptr error_fn;
+ png_error_ptr warning_fn;
+ png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn;
+#endif
+
+ png_debug(1, "in png_write_destroy\n");
+ /* free any memory zlib uses */
+ deflateEnd(&png_ptr->zstream);
+
+ /* free our memory. png_free checks NULL for us. */
+ png_free(png_ptr, png_ptr->zbuf);
+ png_free(png_ptr, png_ptr->row_buf);
+#ifndef PNG_NO_WRITE_FILTER
+ png_free(png_ptr, png_ptr->prev_row);
+ png_free(png_ptr, png_ptr->sub_row);
+ png_free(png_ptr, png_ptr->up_row);
+ png_free(png_ptr, png_ptr->avg_row);
+ png_free(png_ptr, png_ptr->paeth_row);
+#endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+ png_free(png_ptr, png_ptr->time_buffer);
+#endif
+
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+ png_free(png_ptr, png_ptr->prev_filters);
+ png_free(png_ptr, png_ptr->filter_weights);
+ png_free(png_ptr, png_ptr->inv_filter_weights);
+ png_free(png_ptr, png_ptr->filter_costs);
+ png_free(png_ptr, png_ptr->inv_filter_costs);
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ /* reset structure */
+ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
+#endif
+
+ error_fn = png_ptr->error_fn;
+ warning_fn = png_ptr->warning_fn;
+ error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+#endif
+
+ png_memset(png_ptr, 0, png_sizeof(png_struct));
+
+ png_ptr->error_fn = error_fn;
+ png_ptr->warning_fn = warning_fn;
+ png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr->free_fn = free_fn;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+}
+
+/* Allow the application to select one or more row filters to use. */
+void PNGAPI
+png_set_filter(png_structp png_ptr, int method, int filters)
+{
+ png_debug(1, "in png_set_filter\n");
+ if (png_ptr == NULL)
+ return;
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (method == PNG_INTRAPIXEL_DIFFERENCING))
+ method = PNG_FILTER_TYPE_BASE;
+#endif
+ if (method == PNG_FILTER_TYPE_BASE)
+ {
+ switch (filters & (PNG_ALL_FILTERS | 0x07))
+ {
+#ifndef PNG_NO_WRITE_FILTER
+ case 5:
+ case 6:
+ case 7: png_warning(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_NO_WRITE_FILTER */
+ case PNG_FILTER_VALUE_NONE:
+ png_ptr->do_filter=PNG_FILTER_NONE; break;
+#ifndef PNG_NO_WRITE_FILTER
+ case PNG_FILTER_VALUE_SUB:
+ png_ptr->do_filter=PNG_FILTER_SUB; break;
+ case PNG_FILTER_VALUE_UP:
+ png_ptr->do_filter=PNG_FILTER_UP; break;
+ case PNG_FILTER_VALUE_AVG:
+ png_ptr->do_filter=PNG_FILTER_AVG; break;
+ case PNG_FILTER_VALUE_PAETH:
+ png_ptr->do_filter=PNG_FILTER_PAETH; break;
+ default: png_ptr->do_filter = (png_byte)filters; break;
+#else
+ default: png_warning(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_NO_WRITE_FILTER */
+ }
+
+ /* If we have allocated the row_buf, this means we have already started
+ * with the image and we should have allocated all of the filter buffers
+ * that have been selected. If prev_row isn't already allocated, then
+ * it is too late to start using the filters that need it, since we
+ * will be missing the data in the previous row. If an application
+ * wants to start and stop using particular filters during compression,
+ * it should start out with all of the filters, and then add and
+ * remove them after the start of compression.
+ */
+ if (png_ptr->row_buf != NULL)
+ {
+#ifndef PNG_NO_WRITE_FILTER
+ if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
+ {
+ png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Up filter after starting");
+ png_ptr->do_filter &= ~PNG_FILTER_UP;
+ }
+ else
+ {
+ 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 == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Average filter after starting");
+ png_ptr->do_filter &= ~PNG_FILTER_AVG;
+ }
+ else
+ {
+ 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 == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Paeth filter after starting");
+ png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
+ }
+ else
+ {
+ png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+ }
+ }
+
+ if (png_ptr->do_filter == PNG_NO_FILTERS)
+#endif /* PNG_NO_WRITE_FILTER */
+ png_ptr->do_filter = PNG_FILTER_NONE;
+ }
+ }
+ else
+ png_error(png_ptr, "Unknown custom filter method");
+}
+
+/* This allows us to influence the way in which libpng chooses the "best"
+ * filter for the current scanline. While the "minimum-sum-of-absolute-
+ * differences metric is relatively fast and effective, there is some
+ * question as to whether it can be improved upon by trying to keep the
+ * filtered data going to zlib more consistent, hopefully resulting in
+ * better compression.
+ */
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
+void PNGAPI
+png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
+ int num_weights, png_doublep filter_weights,
+ png_doublep filter_costs)
+{
+ int i;
+
+ png_debug(1, "in png_set_filter_heuristics\n");
+ if (png_ptr == NULL)
+ return;
+ if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
+ {
+ png_warning(png_ptr, "Unknown filter heuristic method");
+ return;
+ }
+
+ if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
+ {
+ heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
+ }
+
+ if (num_weights < 0 || filter_weights == NULL ||
+ heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
+ {
+ num_weights = 0;
+ }
+
+ png_ptr->num_prev_filters = (png_byte)num_weights;
+ png_ptr->heuristic_method = (png_byte)heuristic_method;
+
+ if (num_weights > 0)
+ {
+ if (png_ptr->prev_filters == NULL)
+ {
+ png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_byte) * num_weights));
+
+ /* To make sure that the weighting starts out fairly */
+ for (i = 0; i < num_weights; i++)
+ {
+ png_ptr->prev_filters[i] = 255;
+ }
+ }
+
+ if (png_ptr->filter_weights == NULL)
+ {
+ png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+
+ png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+ for (i = 0; i < num_weights; i++)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+ }
+
+ for (i = 0; i < num_weights; i++)
+ {
+ if (filter_weights[i] < 0.0)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+ else
+ {
+ png_ptr->inv_filter_weights[i] =
+ (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
+ png_ptr->filter_weights[i] =
+ (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
+ }
+ }
+ }
+
+ /* If, in the future, there are other filter methods, this would
+ * need to be based on png_ptr->filter.
+ */
+ if (png_ptr->filter_costs == NULL)
+ {
+ png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+
+ png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+ {
+ png_ptr->inv_filter_costs[i] =
+ png_ptr->filter_costs[i] = PNG_COST_FACTOR;
+ }
+ }
+
+ /* Here is where we set the relative costs of the different filters. We
+ * should take the desired compression level into account when setting
+ * the costs, so that Paeth, for instance, has a high relative cost at low
+ * compression levels, while it has a lower relative cost at higher
+ * compression settings. The filter types are in order of increasing
+ * relative cost, so it would be possible to do this with an algorithm.
+ */
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+ {
+ if (filter_costs == NULL || filter_costs[i] < 0.0)
+ {
+ png_ptr->inv_filter_costs[i] =
+ png_ptr->filter_costs[i] = PNG_COST_FACTOR;
+ }
+ else if (filter_costs[i] >= 1.0)
+ {
+ png_ptr->inv_filter_costs[i] =
+ (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
+ png_ptr->filter_costs[i] =
+ (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
+ }
+ }
+}
+#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+
+void PNGAPI
+png_set_compression_level(png_structp png_ptr, int level)
+{
+ png_debug(1, "in png_set_compression_level\n");
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
+ png_ptr->zlib_level = level;
+}
+
+void PNGAPI
+png_set_compression_mem_level(png_structp png_ptr, int mem_level)
+{
+ png_debug(1, "in png_set_compression_mem_level\n");
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
+ png_ptr->zlib_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_compression_strategy(png_structp png_ptr, int strategy)
+{
+ png_debug(1, "in png_set_compression_strategy\n");
+ if (png_ptr == NULL)
+ return;
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
+ png_ptr->zlib_strategy = strategy;
+}
+
+void PNGAPI
+png_set_compression_window_bits(png_structp png_ptr, int window_bits)
+{
+ if (png_ptr == NULL)
+ return;
+ if (window_bits > 15)
+ png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ else if (window_bits < 8)
+ png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+#ifndef WBITS_8_OK
+ /* avoid libpng bug with 256-byte windows */
+ if (window_bits == 8)
+ {
+ png_warning(png_ptr, "Compression window is being reset to 512");
+ window_bits=9;
+ }
+#endif
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
+ png_ptr->zlib_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_compression_method(png_structp png_ptr, int method)
+{
+ png_debug(1, "in png_set_compression_method\n");
+ if (png_ptr == NULL)
+ return;
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
+ png_ptr->zlib_method = method;
+}
+
+void PNGAPI
+png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+ png_ptr->write_row_fn = write_row_fn;
+}
+
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+ write_user_transform_fn)
+{
+ png_debug(1, "in png_set_write_user_transform_fn\n");
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+void PNGAPI
+png_write_png(png_structp png_ptr, png_infop info_ptr,
+ int transforms, voidp params)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+ /* invert the alpha channel from opacity to transparency */
+ if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+ png_set_invert_alpha(png_ptr);
+#endif
+
+ /* Write the file header information. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* ------ these transformations don't touch the info structure ------- */
+
+#if defined(PNG_WRITE_INVERT_SUPPORTED)
+ /* invert monochrome pixels */
+ if (transforms & PNG_TRANSFORM_INVERT_MONO)
+ png_set_invert_mono(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_SHIFT_SUPPORTED)
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT)
+ && (info_ptr->valid & PNG_INFO_sBIT))
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#endif
+
+#if defined(PNG_WRITE_PACK_SUPPORTED)
+ /* pack pixels into bytes */
+ if (transforms & PNG_TRANSFORM_PACKING)
+ png_set_packing(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+ /* swap location of alpha bytes from ARGB to RGBA */
+ if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+ png_set_swap_alpha(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED)
+ /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
+ * RGB (4 channels -> 3 channels). The second parameter is not used.
+ */
+ if (transforms & PNG_TRANSFORM_STRIP_FILLER)
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#endif
+
+#if defined(PNG_WRITE_BGR_SUPPORTED)
+ /* flip BGR pixels to RGB */
+ if (transforms & PNG_TRANSFORM_BGR)
+ png_set_bgr(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_SWAP_SUPPORTED)
+ /* swap bytes of 16-bit files to most significant byte first */
+ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+ png_set_swap(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+ /* swap bits of 1, 2, 4 bit packed pixel formats */
+ if (transforms & PNG_TRANSFORM_PACKSWAP)
+ png_set_packswap(png_ptr);
+#endif
+
+ /* ----------------------- end of transformations ------------------- */
+
+ /* write the bits */
+ if (info_ptr->valid & PNG_INFO_IDAT)
+ png_write_image(png_ptr, info_ptr->row_pointers);
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ transforms = transforms; /* quiet compiler warnings */
+ params = params;
+}
+#endif
+#endif /* PNG_WRITE_SUPPORTED */