image.mod/png.mod/libpng/contrib/conftest/basic.dfa

# basic.dfa
#  Build time configuration of libpng
#
# Author: John Bowler
# Copyright: (c) John Bowler, 2024
# Usage rights:
#  To the extent possible under law, the author has waived all copyright and
#  related or neighboring rights to this work.  This work is published from:
#  United States.
#
# Build libpng with basic read and write support.  This enables the lowest
# level libpng read and write APIs - the "row-by-row" ones.
#
# Support is enabled only for those transformations that are observed to be
# required by widely used apps or are in the v3 specification.
#

everything = off

# The sequential read code is enabled here; the progressive code can be used
# instead but there is no point enabling both.

option READ on
option SEQUENTIAL_READ on
option EASY_ACCESS on
option SET_USER_LIMITS on
option INFO_IMAGE on
option READ_16BIT on

# Errors: these can be disabled but then there won't be any error messages
# just failures and the error messages are really needed for apps:
option WARNINGS on
option ERROR_TEXT on
option BENIGN_READ_ERRORS on

# Required for many display programs such as web browsers:
option PROGRESSIVE_READ on

# Switch on the write code - this makes a minimalist encoder but with
# interlace support turned on; otherwise png_read_png..png_write_png will
# fail on an interlaced image.
option WRITE on
option WRITE_INTERLACING on
option WRITE_16BIT on

# Usages of the 'fixed' APIs are relatively rare but they do occur
# one or the other for both the API and the internal math.

#Fixed point:
option FIXED_POINT on

#Floating point:
option FLOATING_POINT on
option FLOATING_ARITHMETIC on

# Basic error handling, IO and user memory support.  The latter allows the
# application program to provide its own implementations of 'malloc' and 'free'.
option SETJMP on
option STDIO on
option USER_MEM on

# Gamma handling: this needs to be on for the gamma handling
option READ_GAMMA on

# The supported chunks
chunk bKGD on
chunk cHRM on
chunk eXIf on
chunk gAMA on
chunk iCCP on
chunk iTXt on
chunk pHYs on
chunk sBIT on
chunk sRGB on
chunk tEXt on
chunk tIME on
chunk tRNS on
chunk zTXt on

# These don't seem to be used anywhere:
# chunk pCAL
# chunk sCAL
# chunk sPLT

# The rest of this is app dependent: none of these options are required for
# read/write of the full range of PNG files and the normal chunk handling on
# read.
option WRITE_CUSTOMIZE_ZTXT_COMPRESSION on
option WRITE_CUSTOMIZE_COMPRESSION on

option READ_EXPAND on
option READ_FILLER on
option READ_GRAY_TO_RGB on
option READ_INVERT on
option READ_PACK on
option READ_RGB_TO_GRAY on
option READ_SCALE_16_TO_8 on
option READ_SHIFT on
option READ_STRIP_16_TO_8 on
option READ_STRIP_ALPHA on
option READ_SWAP on

option CONVERT_tIME on

# optipng
option IO_STATE on
option STORE_UNKNOWN_CHUNKS on
option HANDLE_AS_UNKNOWN on

# pngcrush
option READ_USER_TRANSFORM on
option WRITE_FLUSH on

# pnmtopng
chunk hIST on

# cairo
option WRITE_PACKSWAP on
option WRITE_USER_TRANSFORM on

# graphicsmagick
option READ_USER_CHUNKS on

# Qt5.15 qtgui (gentoo package split) Qt6.6 qtbase
option READ_BGR on
option WRITE_BGR on
option READ_SWAP_ALPHA on
option WRITE_SWAP_ALPHA on
chunk oFFs on

# ghostscript-gpl
option WRITE_INVERT_ALPHA on
option WRITE_INVERT on