Built SDL2_image and _mixer static

libsdl2_image/external/libpng-1.6.37/libpngpf.3

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+.TH LIBPNGPF 3 "April 14, 2019"
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.37
+(private functions)
+
+.SH SYNOPSIS
+\fB#include \fI"pngpriv.h"
+
+\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer
+\fP\fImaintained\fP\fB, now that the private function prototypes are hidden in
+\fP\fIpngpriv.h\fP\fB and not accessible to applications. Look in
+\fP\fIpngpriv.h\fP\fB for the prototypes and a short description of each
+function.
+
+.SH DESCRIPTION
+The functions previously listed here are used privately by libpng and are not
+available for use by applications.  They are not "exported" to applications
+using shared libraries.
+
+.SH "SEE ALSO"
+.BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
+
+.SH AUTHORS
+Cosmin Truta, Glenn Randers-Pehrson