/* png.h - header file for PNG reference library
*
- * libpng version 1.5.2 - March 31, 2011
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * libpng version 1.5.9 - February 18, 2012
+ * Copyright (c) 1998-2012 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.)
*
* Authors and maintainers:
* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- * libpng versions 0.97, January 1998, through 1.5.2 - March 31, 2011: Glenn
+ * libpng versions 0.97, January 1998, through 1.5.9 - February 18, 2012: Glenn
* See also "Contributing Authors", below.
*
* Note about libpng version numbers:
* 1.5.2beta01-03 15 10502 15.so.15.2[.0]
* 1.5.2rc01-03 15 10502 15.so.15.2[.0]
* 1.5.2 15 10502 15.so.15.2[.0]
+ * 1.5.3beta01-10 15 10503 15.so.15.3[.0]
+ * 1.5.3rc01-02 15 10503 15.so.15.3[.0]
+ * 1.5.3beta11 15 10503 15.so.15.3[.0]
+ * 1.5.3 [omitted]
+ * 1.5.4beta01-08 15 10504 15.so.15.4[.0]
+ * 1.5.4rc01 15 10504 15.so.15.4[.0]
+ * 1.5.4 15 10504 15.so.15.4[.0]
+ * 1.5.5beta01-08 15 10505 15.so.15.5[.0]
+ * 1.5.5rc01 15 10505 15.so.15.5[.0]
+ * 1.5.5 15 10505 15.so.15.5[.0]
+ * 1.5.6beta01-07 15 10506 15.so.15.6[.0]
+ * 1.5.6rc01-03 15 10506 15.so.15.6[.0]
+ * 1.5.6 15 10506 15.so.15.6[.0]
+ * 1.5.7beta01-05 15 10507 15.so.15.7[.0]
+ * 1.5.7rc01-03 15 10507 15.so.15.7[.0]
+ * 1.5.7 15 10507 15.so.15.7[.0]
+ * 1.5.8beta01 15 10508 15.so.15.8[.0]
+ * 1.5.8rc01 15 10508 15.so.15.8[.0]
+ * 1.5.8 15 10508 15.so.15.8[.0]
+ * 1.5.9beta01-02 15 10509 15.so.15.9[.0]
+ * 1.5.9rc01 15 10509 15.so.15.9[.0]
+ * 1.5.9 15 10509 15.so.15.9[.0]
*
* Henceforth the source version will match the shared-library major
* and minor numbers; the shared-library major version number will be
*
* This code is released under the libpng license.
*
- * libpng versions 1.2.6, August 15, 2004, through 1.5.2, March 31, 2011, are
- * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
+ * libpng versions 1.2.6, August 15, 2004, through 1.5.9, February 18, 2012, are
+ * Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are
* distributed according to the same disclaimer and license as libpng-1.2.5
* with the following individual added to the list of Contributing Authors:
*
* Y2K compliance in libpng:
* =========================
*
- * March 31, 2011
+ * February 18, 2012
*
* Since the PNG Development group is an ad-hoc body, we can't make
* an official declaration.
*
* This is your unofficial assurance that libpng from version 0.71 and
- * upward through 1.5.2 are Y2K compliant. It is my belief that
+ * upward through 1.5.9 are Y2K compliant. It is my belief that
* earlier versions were also Y2K compliant.
*
- * Libpng only has three year fields. One is a 2-byte unsigned integer
- * that will hold years up to 65535. The other two hold the date in text
+ * Libpng only has two year fields. One is a 2-byte unsigned integer
+ * that will hold years up to 65535. The other holds the date in text
* format, and will hold years up to 9999.
*
* The integer is
* "png_uint_16 year" in png_time_struct.
*
- * The strings are
- * "png_charp time_buffer" in png_struct and
- * "near_time_buffer", which is a local character string in png.c.
+ * The string is
+ * "png_char time_buffer" in png_struct
*
* There are seven time-related functions:
* png.c: png_convert_to_rfc_1123() in png.c
* describes how to use libpng, and the file example.c summarizes it
* with some code on which to build. This file is useful for looking
* at the actual function definitions and structure components.
+ *
+ * If you just need to read a PNG file and don't want to read the documentation
+ * skip to the end of this file and read the section entitled 'simplified API'.
*/
/* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.5.2"
+#define PNG_LIBPNG_VER_STRING "1.5.9"
#define PNG_HEADER_VERSION_STRING \
- " libpng version 1.5.2 - March 31, 2011\n"
+ " libpng version 1.5.9 - February 18, 2012\n"
#define PNG_LIBPNG_VER_SONUM 15
#define PNG_LIBPNG_VER_DLLNUM 15
/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
#define PNG_LIBPNG_VER_MAJOR 1
#define PNG_LIBPNG_VER_MINOR 5
-#define PNG_LIBPNG_VER_RELEASE 2
+#define PNG_LIBPNG_VER_RELEASE 9
+
/* This should match the numeric part of the final component of
* PNG_LIBPNG_VER_STRING, omitting any leading zero:
*/
* version 1.0.0 was mis-numbered 100 instead of 10000). From
* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
*/
-#define PNG_LIBPNG_VER 10502 /* 1.5.2 */
+#define PNG_LIBPNG_VER 10509 /* 1.5.9 */
/* Library configuration: these options cannot be changed after
* the library has been built.
/* This triggers a compiler error in png.c, if png.c and png.h
* do not agree upon the version number.
*/
-typedef char* png_libpng_version_1_5_2;
+typedef char* png_libpng_version_1_5_9;
/* Three color definitions. The order of the red, green, and blue, (and the
* exact size) is not important, although the size of the fields need to
#ifdef PNG_TEXT_SUPPORTED
/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
* and whether that contents is compressed or not. The "key" field
- * points to a regular zero-terminated C string. The "text", "lang", and
- * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
- * However, the * structure returned by png_get_text() will always contain
- * regular zero-terminated C strings (possibly empty), never NULL pointers,
- * so they can be safely used in printf() and other string-handling functions.
+ * points to a regular zero-terminated C string. The "text" fields can be a
+ * regular C string, an empty string, or a NULL pointer.
+ * However, the structure returned by png_get_text() will always contain
+ * the "text" field as a regular zero-terminated C string (possibly
+ * empty), never a NULL pointer, so it can be safely used in printf() and
+ * other string-handling functions. Note that the "itxt_length", "lang", and
+ * "lang_key" members of the structure only exist when the library is built
+ * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
+ * default without iTXt support. Also note that when iTXt *is* supported,
+ * the "lang" and "lang_key" fields contain NULL pointers when the
+ * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
+ * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
+ * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
+ * which is always 0 or 1, or its "compression method" which is always 0.
*/
typedef struct png_text_struct
{
/* libpng-using applications should NOT directly modify this byte. */
png_byte location; /* mode of operation at read time */
}
+
+
png_unknown_chunk;
typedef png_unknown_chunk FAR * png_unknown_chunkp;
typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
#endif
+/* Values for the unknown chunk location byte */
+
+#define PNG_HAVE_IHDR 0x01
+#define PNG_HAVE_PLTE 0x02
+#define PNG_AFTER_IDAT 0x08
+
+/* The complete definition of png_info has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications. Read libpng-manual.txt or libpng.3 for more info.
+ */
typedef struct png_info_def png_info;
typedef png_info FAR * png_infop;
typedef PNG_CONST png_info FAR * png_const_infop;
*/
#define PNG_FP_1 100000
#define PNG_FP_HALF 50000
+#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
+#define PNG_FP_MIN (-PNG_FP_MAX)
/* These describe the color_type field in png_info. */
/* color type masks */
#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
-#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */
/* This is used for the transformation routines, as some of them
* change these values for the row. It also should enable using
typedef png_row_info FAR * png_row_infop;
typedef png_row_info FAR * FAR * png_row_infopp;
+/* The complete definition of png_struct has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications. Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_struct_def png_struct;
+typedef PNG_CONST png_struct FAR * png_const_structp;
+typedef png_struct FAR * png_structp;
+
/* These are the function types for the I/O functions and for the functions
* that allow the user to override the default I/O functions with his or her
* own. The png_error_ptr type should match that of user-supplied warning
* modify the buffer it is passed. The 'read' function, on the other hand, is
* expected to return the read data in the buffer.
*/
-typedef struct png_struct_def png_struct;
-typedef PNG_CONST png_struct FAR * png_const_structp;
-typedef png_struct FAR * png_structp;
-
typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
#endif
#ifdef PNG_SETJMP_SUPPORTED
-/* This must match the function definition in <setjmp.h>, and the
- * application must include this before png.h to obtain the definition
- * of jmp_buf. The function is required to be PNG_NORETURN. (Note that
- * PNG_PTR_NORETURN is used here because current versions of the Microsoft
- * C compiler do not support the PNG_NORETURN attribute on a pointer.)
- *
- * If you get a type warning from the compiler when linking against this line
- * then your compiler has 'longjmp' that does not match the requirements of the
- * compiler that built libpng. You will have to write a wrapper function for
- * your compiler's longjmp and call png_set_longjmp_fn directly (not via the
- * png_jmpbuf macro.)
- *
- * If you get a warning here while building the library you will need to make
+/* This must match the function definition in <setjmp.h>, and the application
+ * must include this before png.h to obtain the definition of jmp_buf. The
+ * function is required to be PNG_NORETURN, but this is not checked. If the
+ * function does return the application will crash via an abort() or similar
+ * system level call.
+ *
+ * If you get a warning here while building the library you may need to make
* changes to ensure that pnglibconf.h records the calling convention used by
* your compiler. This may be very difficult - try using a different compiler
* to build the library!
*/
-typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
- PNG_PTR_NORETURN);
+PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
#endif
/* Transform masks for the high-level interface */
#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
/* Added to libpng-1.4.0 */
#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
+/* Added to libpng-1.5.4 */
+#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
+#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
/* Flags for MNG supported features */
#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
#endif
#ifdef PNG_READ_EXPAND_16_SUPPORTED
-/* Expand to 16 bit channels, forces conversion of palette to RGB and expansion
+/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
* of a tRNS chunk if present.
*/
PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
/* Reduce RGB to grayscale. */
+#define PNG_ERROR_ACTION_NONE 1
+#define PNG_ERROR_ACTION_WARN 2
+#define PNG_ERROR_ACTION_ERROR 3
+#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
+
PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr,
int error_action, double red, double green));
PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr,
png_ptr));
#endif
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
png_colorp palette));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* How the alpha channel is interpreted - this affects how the color channels of
+ * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
+ * file, is present.
+ *
+ * This has no effect on the way pixels are written into a PNG output
+ * datastream. The color samples in a PNG datastream are never premultiplied
+ * with the alpha samples.
+ *
+ * The default is to return data according to the PNG specification: the alpha
+ * channel is a linear measure of the contribution of the pixel to the
+ * corresponding composited pixel. The gamma encoded color channels must be
+ * scaled according to the contribution and to do this it is necessary to undo
+ * the encoding, scale the color values, perform the composition and reencode
+ * the values. This is the 'PNG' mode.
+ *
+ * The alternative is to 'associate' the alpha with the color information by
+ * storing color channel values that have been scaled by the alpha. The
+ * advantage is that the color channels can be resampled (the image can be
+ * scaled) in this form. The disadvantage is that normal practice is to store
+ * linear, not (gamma) encoded, values and this requires 16-bit channels for
+ * still images rather than the 8-bit channels that are just about sufficient if
+ * gamma encoding is used. In addition all non-transparent pixel values,
+ * including completely opaque ones, must be gamma encoded to produce the final
+ * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
+ * latter being the two common names for associated alpha color channels.)
+ *
+ * Since it is not necessary to perform arithmetic on opaque color values so
+ * long as they are not to be resampled and are in the final color space it is
+ * possible to optimize the handling of alpha by storing the opaque pixels in
+ * the PNG format (adjusted for the output color space) while storing partially
+ * opaque pixels in the standard, linear, format. The accuracy required for
+ * standard alpha composition is relatively low, because the pixels are
+ * isolated, therefore typically the accuracy loss in storing 8-bit linear
+ * values is acceptable. (This is not true if the alpha channel is used to
+ * simulate transparency over large areas - use 16 bits or the PNG mode in
+ * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
+ * treated as opaque only if the alpha value is equal to the maximum value.
+ *
+ * The final choice is to gamma encode the alpha channel as well. This is
+ * broken because, in practice, no implementation that uses this choice
+ * correctly undoes the encoding before handling alpha composition. Use this
+ * choice only if other serious errors in the software or hardware you use
+ * mandate it; the typical serious error is for dark halos to appear around
+ * opaque areas of the composited PNG image because of arithmetic overflow.
+ *
+ * The API function png_set_alpha_mode specifies which of these choices to use
+ * with an enumerated 'mode' value and the gamma of the required output:
+ */
+#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
+#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
+#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
+#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
+
+PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode,
+ double output_gamma));
+PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr,
+ int mode, png_fixed_point output_gamma));
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* The output_gamma value is a screen gamma in libpng terminology: it expresses
+ * how to decode the output values, not how they are encoded. The values used
+ * correspond to the normal numbers used to describe the overall gamma of a
+ * computer display system; for example 2.2 for an sRGB conformant system. The
+ * values are scaled by 100000 in the _fixed version of the API (so 220000 for
+ * sRGB.)
+ *
+ * The inverse of the value is always used to provide a default for the PNG file
+ * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
+ * to override the PNG gamma information.
+ *
+ * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
+ * opaque pixels however pixels with lower alpha values are not encoded,
+ * regardless of the output gamma setting.
+ *
+ * When the standard Porter Duff handling is requested with mode 1 the output
+ * encoding is set to be linear and the output_gamma value is only relevant
+ * as a default for input data that has no gamma information. The linear output
+ * encoding will be overridden if png_set_gamma() is called - the results may be
+ * highly unexpected!
+ *
+ * The following numbers are derived from the sRGB standard and the research
+ * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
+ * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
+ * correction required to take account of any differences in the color
+ * environment of the original scene and the intended display environment; the
+ * value expresses how to *decode* the image for display, not how the original
+ * data was *encoded*.
+ *
+ * sRGB provides a peg for the PNG standard by defining a viewing environment.
+ * sRGB itself, and earlier TV standards, actually use a more complex transform
+ * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
+ * limited to simple power laws.) By saying that an image for direct display on
+ * an sRGB conformant system should be stored with a gAMA chunk value of 45455
+ * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
+ * makes it possible to derive values for other display systems and
+ * environments.
+ *
+ * The Mac value is deduced from the sRGB based on an assumption that the actual
+ * extra viewing correction used in early Mac display systems was implemented as
+ * a power 1.45 lookup table.
+ *
+ * Any system where a programmable lookup table is used or where the behavior of
+ * the final display device characteristics can be changed requires system
+ * specific code to obtain the current characteristic. However this can be
+ * difficult and most PNG gamma correction only requires an approximate value.
+ *
+ * By default, if png_set_alpha_mode() is not called, libpng assumes that all
+ * values are unencoded, linear, values and that the output device also has a
+ * linear characteristic. This is only very rarely correct - it is invariably
+ * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
+ * default if you don't know what the right answer is!
+ *
+ * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
+ * 10.6) which used a correction table to implement a somewhat lower gamma on an
+ * otherwise sRGB system.
+ *
+ * Both these values are reserved (not simple gamma values) in order to allow
+ * more precise correction internally in the future.
+ *
+ * NOTE: the following values can be passed to either the fixed or floating
+ * point APIs, but the floating point API will also accept floating point
+ * values.
+ */
+#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
+#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
+#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
+#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
+#endif
+
+/* The following are examples of calls to png_set_alpha_mode to achieve the
+ * required overall gamma correction and, where necessary, alpha
+ * premultiplication.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * This is the default libpng handling of the alpha channel - it is not
+ * pre-multiplied into the color components. In addition the call states
+ * that the output is for a sRGB system and causes all PNG files without gAMA
+ * chunks to be assumed to be encoded using sRGB.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ * In this case the output is assumed to be something like an sRGB conformant
+ * display preceeded by a power-law lookup table of power 1.45. This is how
+ * early Mac systems behaved.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+ * This is the classic Jim Blinn approach and will work in academic
+ * environments where everything is done by the book. It has the shortcoming
+ * of assuming that input PNG data with no gamma information is linear - this
+ * is unlikely to be correct unless the PNG files where generated locally.
+ * Most of the time the output precision will be so low as to show
+ * significant banding in dark areas of the image.
+ *
+ * png_set_expand_16(pp);
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+ * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
+ * are assumed to have the sRGB encoding if not marked with a gamma value and
+ * the output is always 16 bits per component. This permits accurate scaling
+ * and processing of the data. If you know that your input PNG files were
+ * generated locally you might need to replace PNG_DEFAULT_sRGB with the
+ * correct value for your system.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+ * If you just need to composite the PNG image onto an existing background
+ * and if you control the code that does this you can use the optimization
+ * setting. In this case you just copy completely opaque pixels to the
+ * output. For pixels that are not completely transparent (you just skip
+ * those) you do the composition math using png_composite or png_composite_16
+ * below then encode the resultant 8-bit or 16-bit values to match the output
+ * encoding.
+ *
+ * Other cases
+ * If neither the PNG nor the standard linear encoding work for you because
+ * of the software or hardware you use then you have a big problem. The PNG
+ * case will probably result in halos around the image. The linear encoding
+ * will probably result in a washed out, too bright, image (it's actually too
+ * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
+ * substantially reduce the halos. Alternatively try:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+ * This option will also reduce the halos, but there will be slight dark
+ * halos round the opaque parts of the image where the background is light.
+ * In the OPTIMIZED mode the halos will be light halos where the background
+ * is dark. Take your pick - the halos are unavoidable unless you can get
+ * your hardware/software fixed! (The OPTIMIZED approach is slightly
+ * faster.)
+ *
+ * When the default gamma of PNG files doesn't match the output gamma.
+ * If you have PNG files with no gamma information png_set_alpha_mode allows
+ * you to provide a default gamma, but it also sets the ouput gamma to the
+ * matching value. If you know your PNG files have a gamma that doesn't
+ * match the output you can take advantage of the fact that
+ * png_set_alpha_mode always sets the output gamma but only sets the PNG
+ * default if it is not already set:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ * The first call sets both the default and the output gamma values, the
+ * second call overrides the output gamma without changing the default. This
+ * is easier than achieving the same effect with png_set_gamma. You must use
+ * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+ * fire if more than one call to png_set_alpha_mode and png_set_background is
+ * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+ * are ignored.
+ */
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
#endif
#ifdef PNG_READ_BACKGROUND_SUPPORTED
-/* Handle alpha and tRNS by replacing with a background color. */
+/* Handle alpha and tRNS by replacing with a background color. Prior to
+ * libpng-1.5.4 this API must not be called before the PNG file header has been
+ * read. Doing so will result in unexpected behavior and possible warnings or
+ * errors if the PNG file contains a bKGD chunk.
+ */
PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
png_const_color_16p background_color, int background_gamma_code,
int need_expand, double background_gamma));
# define PNG_BACKGROUND_GAMMA_UNIQUE 3
#endif
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale a 16-bit depth file down to 8-bit, accurately. */
+PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
/* Strip the second byte of information from a 16-bit depth file. */
PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
#endif
*/
#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
-/* Handle gamma correction. Screen_gamma=(display_exponent) */
+/* Handle gamma correction. Screen_gamma=(display_exponent).
+ * NOTE: this API simply sets the screen and file gamma values. It will
+ * therefore override the value for gamma in a PNG file if it is called after
+ * the file header has been read - use with care - call before reading the PNG
+ * file for best results!
+ *
+ * These routines accept the same gamma values as png_set_alpha_mode (described
+ * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
+ * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
+ * is the inverse of a 'screen gamma' value.
+ */
PNG_FP_EXPORT(50, void, png_set_gamma,
(png_structp png_ptr, double screen_gamma,
- double default_file_gamma));
+ double override_file_gamma));
PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
- png_fixed_point screen_gamma, png_fixed_point default_file_gamma));
+ png_fixed_point screen_gamma, png_fixed_point override_file_gamma));
#endif
#ifdef PNG_WRITE_FLUSH_SUPPORTED
#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
+#ifdef PNG_WRITE_SUPPORTED
/* Set the library compression level. Currently, valid values range from
* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
* (0 - no compression, 9 - "maximal" compression). Note that tests have
PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
int strategy));
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
int window_bits));
PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
int method));
+#endif
+
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+/* Also set zlib parameters for compressing non-IDAT chunks */
+PNG_EXPORT(222, void, png_set_text_compression_level,
+ (png_structp png_ptr, int level));
+
+PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr,
+ int mem_level));
+
+PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr,
+ int strategy));
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp
+ png_ptr, int window_bits));
+
+PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr,
+ int method));
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
/* These next functions are called for input/output, memory, and error
* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
*/
PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp));
+#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Function that combines rows. 'new_row' is a flag that should come from
* the callback and be non-NULL if anything needs to be done; the library
* stores its own version of the new data internally and ignores the passed
*/
PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr,
png_bytep old_row, png_const_bytep new_row));
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
PNG_EXPORTA(94, png_voidp, png_malloc,
PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
#endif
+#ifdef PNG_WARNINGS_SUPPORTED
/* Non-fatal error in libpng. Can continue, but may have a problem. */
PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
png_const_charp warning_message));
/* Non-fatal error in libpng, chunk name is prepended to message. */
PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
png_const_charp warning_message));
+#endif
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
/* Benign error in libpng. Can continue, but may have a problem.
png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
double *red_y, double *green_x, double *green_y, double *blue_x,
double *blue_y));
+PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr,
+ png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z,
+ double *green_X, double *green_Y, double *green_Z, double *blue_X,
+ double *blue_Y, double *blue_Z));
#ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
(png_const_structp png_ptr,
png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
png_fixed_point *int_blue_y));
#endif
+PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
+ (png_structp png_ptr, png_const_infop info_ptr,
+ png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+ png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+ png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+ png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+ png_fixed_point *int_blue_Z));
#endif
#ifdef PNG_cHRM_SUPPORTED
(png_structp png_ptr, png_infop info_ptr,
double white_x, double white_y, double red_x, double red_y, double green_x,
double green_y, double blue_x, double blue_y));
+PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr,
+ png_infop info_ptr, double red_X, double red_Y, double red_Z,
+ double green_X, double green_Y, double green_Z, double blue_X,
+ double blue_Y, double blue_Z));
PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
png_infop info_ptr, png_fixed_point int_white_x,
png_fixed_point int_white_y, png_fixed_point int_red_x,
png_fixed_point int_red_y, png_fixed_point int_green_x,
png_fixed_point int_green_y, png_fixed_point int_blue_x,
png_fixed_point int_blue_y));
+PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
+ png_fixed_point int_red_Z, png_fixed_point int_green_X,
+ png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+ png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+ png_fixed_point int_blue_Z));
#endif
#ifdef PNG_gAMA_SUPPORTED
/* Provide a list of chunks and how they are to be handled, if the built-in
handling or default unknown chunk handling is not desired. Any chunks not
listed will be handled in the default manner. The IHDR and IEND chunks
- must not be listed.
- keep = 0: follow default behaviour
- = 1: do not keep
- = 2: keep only if safe-to-copy
- = 3: keep even if unsafe-to-copy
+ must not be listed. Because this turns off the default handling for chunks
+ that would otherwise be recognized the behavior of libpng transformations may
+ well become incorrect!
+ keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
+ = 1: PNG_HANDLE_CHUNK_NEVER: do not keep
+ = 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy
+ = 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy
*/
PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
(png_structp png_ptr, int keep,
png_const_bytep chunk_list, int num_chunks));
+
+/* The handling code is returned; the result is therefore true (non-zero) if
+ * special handling is required, false for the default handling.
+ */
PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
png_const_bytep chunk_name));
#endif
* full, image which appears in a given pass. 'pass' is in the range 0
* to 6 and the result is in the range 0 to 7.
*/
-#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
-#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
+#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
+#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
+
+/* A macro to return the offset between pixels in the output row for a pair of
+ * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
+ * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
+ * COL_OFFSET is from one column to the next, within a row.
+ */
+#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
+#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
/* Two macros to help evaluate the number of rows or columns in each
* pass. This is expressed as a shift - effectively log2 of the number or
* the tile.
*/
#define PNG_PASS_MASK(pass,off) ( \
- ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
- ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
+ ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
+ ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
{ png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
* (png_uint_16)(alpha) \
+ (png_uint_16)(bg)*(png_uint_16)(255 \
- - (png_uint_16)(alpha)) + (png_uint_16)128); \
+ - (png_uint_16)(alpha)) + 128); \
(composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
# define png_composite_16(composite, fg, alpha, bg) \
{ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
* (png_uint_32)(alpha) \
- + (png_uint_32)(bg)*(png_uint_32)(65535L \
- - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
+ + (png_uint_32)(bg)*(65535 \
+ - (png_uint_32)(alpha)) + 32768); \
(composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
#else /* Standard method using integer division */
# define png_composite(composite, fg, alpha, bg) \
(composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
- (png_uint_16)127) / 255)
+ 127) / 255)
# define png_composite_16(composite, fg, alpha, bg) \
(composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
- (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
- (png_uint_32)32767) / (png_uint_32)65535L)
+ (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
+ 32767) / 65535)
#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
* scripts/symbols.def as well.
*/
#ifdef PNG_EXPORT_LAST_ORDINAL
- PNG_EXPORT_LAST_ORDINAL(221);
+ PNG_EXPORT_LAST_ORDINAL(233);
#endif
#ifdef __cplusplus
projects / apitrace / blobdiff