2 # Build time configuration of libpng
5 # Copyright: (c) John Bowler, 2013
7 # To the extent possible under law, the author has waived all copyright and
8 # related or neighboring rights to this work. This work is published from:
11 # Build libpng with basic read support. This enables the lowest level libpng
12 # read API - the one where the calling code has to use a loop to read each row.
13 # At present this is the API used by most programs.
15 # Support is enabled only for those chunks and transformations that are
16 # typically required - others can be added easily.
21 # The sequential read code is enabled here; the progressive code can be used
22 # instead but there is no point enabling both.
24 option SEQUENTIAL_READ on
26 # Likewise it is pointless enabling both fixed and floating point APIs. Choose
27 # one or the other for both the API and the internal math.
30 #option FIXED_POINT on
31 #option FLOATING_ARITHMETIC off
34 option FLOATING_POINT on
35 option FLOATING_ARITHMETIC on
37 # Basic error handling, IO and user memory support. The latter allows the
38 # application program to provide its own implementations of 'malloc' and 'free'.
43 # To read the full set of PNG images correctly interlace, transparency and
44 # 16-bit support is required. The application can implement interlace itself,
45 # but very few do and it's no longer possible to disable it when READ is
50 # Everything else is application dependent. This file assumes the app handles
51 # all the native PNG bit layouts, so it doesn't need any of layout change
52 # transforms, but needs libpng to perform gamma correction. It doesn't do any
53 # colorspace stuff and ignores the 'significant bit' information.
55 # If your app always expands the image to a limited set of bit layouts you
56 # probably want to consider using the simplified API instead of the low level
57 # one - see png.h and s_read.dfa.