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Diffstat (limited to 'Build/source/libs/libpng/libpng.txt')
| -rw-r--r-- | Build/source/libs/libpng/libpng.txt | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/Build/source/libs/libpng/libpng.txt b/Build/source/libs/libpng/libpng.txt index 9360f33b375..67c06537e04 100644 --- a/Build/source/libs/libpng/libpng.txt +++ b/Build/source/libs/libpng/libpng.txt @@ -1,9 +1,9 @@ libpng.txt - A description on how to use and modify libpng - libpng version 1.2.8 - December 3, 2004 + libpng version 1.2.14 - November 27, 2006 Updated and distributed by Glenn Randers-Pehrson <glennrp at users.sourceforge.net> - Copyright (c) 1998-2004 Glenn Randers-Pehrson + Copyright (c) 1998-2005 Glenn Randers-Pehrson For conditions of distribution and use, see copyright notice in png.h. @@ -392,7 +392,7 @@ dithering, and setting filler.) If this is the case, simply do this: png_read_png(png_ptr, info_ptr, png_transforms, NULL) -where png_transforms is an integer containing the logical OR of +where png_transforms is an integer containing the bitwise OR of some set of transformation flags. This call is equivalent to png_read_info(), followed the set of transformations indicated by the transform mask, then png_read_image(), and finally png_read_end(). @@ -787,7 +787,7 @@ viewing application that wishes to treat all images in the same way. png_set_palette_to_rgb(png_ptr); if (color_type == PNG_COLOR_TYPE_GRAY && - bit_depth < 8) png_set_gray_1_2_4_to_8(png_ptr); + bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); @@ -797,6 +797,11 @@ in libpng version 1.0.4, with the function names expanded to improve code readability. In some future version they may actually do different things. +As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was +added. It expands the sample depth without changing tRNS to alpha. +At the same time, png_set_gray_1_2_4_to_8() was deprecated, and it +will be removed from a future version. + PNG can have files with 16 bits per channel. If you only can handle 8 bits per channel, this will strip the pixels down to 8 bit. @@ -1248,8 +1253,8 @@ the second parameter NULL. Finishing a sequential read -After you are finished reading the image through either the high- or -low-level interfaces, you can finish reading the file. If you are +After you are finished reading the image through the +low-level interface, you can finish reading the file. If you are interested in comments or time, which may be stored either before or after the image data, you should pass the separate png_info struct if you want to keep the comments from before and after the image @@ -1267,7 +1272,7 @@ point to libpng-allocated storage with the following function: png_free_data(png_ptr, info_ptr, mask, seq) mask - identifies data to be freed, a mask - containing the logical OR of one or + containing the bitwise OR of one or more of PNG_FREE_PLTE, PNG_FREE_TRNS, PNG_FREE_HIST, PNG_FREE_ICCP, @@ -1329,7 +1334,7 @@ application instead of by libpng, you can use png_set_invalid(png_ptr, info_ptr, mask); mask - identifies the chunks to be made invalid, - containing the logical OR of one or + containing the bitwise OR of one or more of PNG_INFO_gAMA, PNG_INFO_sBIT, PNG_INFO_cHRM, PNG_INFO_PLTE, @@ -1596,6 +1601,14 @@ Libpng section below. png_init_io(png_ptr, fp); +If you are embedding your PNG into a datastream such as MNG, and don't +want libpng to write the 8-byte signature, or if you have already +written the signature in your application, use + + png_set_sig_bytes(png_ptr, 8); + +to inform libpng that it should not write a signature. + Write callbacks At this point, you can set up a callback function that will be @@ -1633,7 +1646,7 @@ types. /* turn on or off filtering, and/or choose specific filters. You can use either a single - PNG_FILTER_VALUE_NAME or the logical OR of one + PNG_FILTER_VALUE_NAME or the bitwise OR of one or more PNG_FILTER_NAME masks. */ png_set_filter(png_ptr, 0, PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE | @@ -2006,7 +2019,7 @@ png_set_rows() to put image data in the info structure), simply do this: png_write_png(png_ptr, info_ptr, png_transforms, NULL) -where png_transforms is an integer containing the logical OR of some set of +where png_transforms is an integer containing the bitwise OR of some set of transformation flags. This call is equivalent to png_write_info(), followed the set of transformations indicated by the transform mask, then png_write_image(), and finally png_write_end(). @@ -2266,7 +2279,7 @@ point to libpng-allocated storage with the following function: png_free_data(png_ptr, info_ptr, mask, seq) mask - identifies data to be freed, a mask - containing the logical OR of one or + containing the bitwise OR of one or more of PNG_FREE_PLTE, PNG_FREE_TRNS, PNG_FREE_HIST, PNG_FREE_ICCP, @@ -2459,7 +2472,7 @@ Custom chunks If you need to read or write custom chunks, you may need to get deeper into the libpng code. The library now has mechanisms for storing and writing chunks of unknown type; you can even declare callbacks -for custom chunks. Hoewver, this may not be good enough if the +for custom chunks. However, this may not be good enough if the library code itself needs to know about interactions between your chunk and existing `intrinsic' chunks. @@ -2810,7 +2823,7 @@ defined: #if defined(PNG_USE_PNGGCCRD) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) \ && defined(PNG_THREAD_UNSAFE_OK) /* Disable thread-unsafe features of pnggccrd */ - if (png_access_version() >= 10200) + if (png_access_version_number() >= 10200) { png_uint_32 mmx_disable_mask = 0; png_uint_32 asm_flags; @@ -2836,12 +2849,12 @@ Libpng can support some of these extensions. To enable them, use the png_permit_mng_features() function: feature_set = png_permit_mng_features(png_ptr, mask) - mask is a png_uint_32 containing the logical OR of the + mask is a png_uint_32 containing the bitwise OR of the features you want to enable. These include PNG_FLAG_MNG_EMPTY_PLTE PNG_FLAG_MNG_FILTER_64 PNG_ALL_MNG_FEATURES - feature_set is a png_uint_32 that is the logical AND of + feature_set is a png_uint_32 that is the bitwise AND of your mask with the set of MNG features that is supported by the version of libpng that you are using. @@ -2904,13 +2917,13 @@ application: IX. Y2K Compliance in libpng -December 3, 2004 +November 27, 2006 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 1.2.8 are Y2K compliant. It is my belief that earlier +upward through 1.2.14 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 |