# read.dfa

#  Build time configuration of libpng

#

# Author: John Bowler

# Copyright: (c) John Bowler, 2013

# 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 support.  This enables the lowest level libpng

# read API - the one where the calling code has to use a loop to read each row.

# At present this is the API used by most programs.

#

# Support is enabled only for those chunks and transformations that are

# typically required - others can be added easily.

#

everything = off

# The sequential read code is enabled here; the progressive code can be used

# instead but there is no point enabling both.

option SEQUENTIAL_READ on

# Likewise it is pointless enabling both fixed and floating point APIs.  Choose

# one or the other for both the API and the internal math.

#Fixed point:

#option FIXED_POINT on

#option FLOATING_ARITHMETIC off

#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

# To read the full set of PNG images correctly interlace, transparency and

# 16-bit support is required.  The application can implement interlace itself,

# but very few do and it's no longer possible to disable it when READ is

# enabled.

option READ_tRNS on

option READ_16BIT on

# Everything else is application dependent.  This file assumes the app handles

# all the native PNG bit layouts, so it doesn't need any of layout change

# transforms, but needs libpng to perform gamma correction.  It doesn't do any

# colorspace stuff and ignores the 'significant bit' information.

#

# If your app always expands the image to a limited set of bit layouts you

# probably want to consider using the simplified API instead of the low level

# one - see png.h and s_read.dfa.

option READ_GAMMA on