libraries/libspng: Added (Portable Network PNG C library)

Signed-off-by: bedlam <dave@slackbuilds.org>

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

libraries/libspng/README

@@ -0,0 +1,12 @@
+lib**spng** (**s**imple **png**) is a C library for reading and
+writing Portable Network Graphics (PNG) format files with a focus on
+security and ease of use.
+
+libspng is an alternative to libpng, the projects are separate and the
+APIs are not compatible.
+
+The goal is to provide a fast PNG library with a simpler API than
+https://github.com/glennrp/libpng/blob/libpng16/png.h, it outperforms
+the reference implementation in common use cases.
+
+libspng can be used by xpra for better speed.

libraries/libspng/libspng.SlackBuild

@@ -0,0 +1,112 @@
+#!/bin/bash
+
+# Slackware build script for libspng
+
+# Copyright 2023 Lockywolf
+# All rights reserved.
+#
+# Redistribution and use of this script, with or without modification, is
+# permitted provided that the following conditions are met:
+#
+# 1. Redistributions of this script must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
+#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
+#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cd $(dirname $0) ; CWD=$(pwd)
+
+PRGNAM=libspng
+VERSION=${VERSION:-0.7.4}
+BUILD=${BUILD:-1}
+TAG=${TAG:-_SBo}
+PKGTYPE=${PKGTYPE:-tgz}
+
+if [ -z "$ARCH" ]; then
+  case "$( uname -m )" in
+    i?86) ARCH=i586 ;;
+    arm*) ARCH=arm ;;
+       *) ARCH=$( uname -m ) ;;
+  esac
+fi
+
+# If the variable PRINT_PACKAGE_NAME is set, then this script will report what
+# the name of the created package would be, and then exit. This information
+# could be useful to other scripts.
+if [ ! -z "${PRINT_PACKAGE_NAME}" ]; then
+  echo "$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.$PKGTYPE"
+  exit 0
+fi
+
+TMP=${TMP:-/tmp/SBo}
+PKG=$TMP/package-$PRGNAM
+OUTPUT=${OUTPUT:-/tmp}
+
+if [ "$ARCH" = "i586" ]; then
+  SLKCFLAGS="-O2 -march=i586 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "i686" ]; then
+  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "x86_64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+else
+  SLKCFLAGS="-O2"
+  LIBDIRSUFFIX=""
+fi
+
+set -e
+
+rm -rf $PKG
+mkdir -p $TMP $PKG $OUTPUT
+cd $TMP
+rm -rf $PRGNAM-$VERSION
+tar xvf $CWD/$PRGNAM-$VERSION.tar.gz
+cd $PRGNAM-$VERSION
+chown -R root:root .
+find -L . \
+ \( -perm 777 -o -perm 775 -o -perm 750 -o -perm 711 -o -perm 555 \
+  -o -perm 511 \) -exec chmod 755 {} \; -o \
+ \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
+  -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
+
+mkdir -p build
+cd build
+  cmake \
+    -DCMAKE_C_FLAGS:STRING="$SLKCFLAGS" \
+    -DCMAKE_CXX_FLAGS:STRING="$SLKCFLAGS" \
+    -DCMAKE_INSTALL_PREFIX=/usr \
+    -DLIB_SUFFIX=${LIBDIRSUFFIX} \
+    -DMAN_INSTALL_DIR=/usr/man \
+    -DBUILD_EXAMPLES=OFF \
+    -DSPNG_STATIC=FALSE \
+    -DCMAKE_BUILD_TYPE=Release ..
+  make
+  make install/strip DESTDIR=$PKG
+cd ..
+
+rm -f $PKG/{,usr/}lib${LIBDIRSUFFIX}/*.la
+
+find $PKG -print0 | xargs -0 file | grep -e "executable" -e "shared object" | grep ELF \
+  | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null || true
+
+mkdir -p $PKG/usr/doc/$PRGNAM-$VERSION
+cp -a \
+  README.md \
+  $PKG/usr/doc/$PRGNAM-$VERSION
+cat $CWD/$PRGNAM.SlackBuild > $PKG/usr/doc/$PRGNAM-$VERSION/$PRGNAM.SlackBuild
+
+mkdir -p $PKG/install
+cat $CWD/slack-desc > $PKG/install/slack-desc
+
+cd $PKG
+/sbin/makepkg -l y -c n $OUTPUT/$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.$PKGTYPE

libraries/libspng/libspng.info

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+PRGNAM="libspng"
+VERSION="0.7.4"
+HOMEPAGE="https://libspng.org/download/"
+DOWNLOAD="https://github.com/randy408/libspng/archive/v0.7.4/libspng-0.7.4.tar.gz"
+MD5SUM="5072ee5d309c593080ea5f43e81e61e4"
+DOWNLOAD_x86_64=""
+MD5SUM_x86_64=""
+REQUIRES=""
+MAINTAINER="Lockywolf"
+EMAIL="for_sbo.spng_2023-06-01@lockywolf.net"

libraries/libspng/slack-desc

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+# HOW TO EDIT THIS FILE:
+# The "handy ruler" below makes it easier to edit a package description.
+# Line up the first '|' above the ':' following the base package name, and
+# the '|' on the right side marks the last column you can put a character in.
+# You must make exactly 11 lines for the formatting to be correct.  It's also
+# customary to leave one space after the ':' except on otherwise blank lines.
+
+       |-----handy-ruler------------------------------------------------------|
+libspng: libspng (C library for reading and writing Portable Network PNG)
+libspng:
+libspng: libspng is an alternative to libpng, the projects are separate and
+libspng: the APIs are not compatible.
+libspng:
+libspng: The goal is to provide a fast PNG library with a simpler API than
+libspng: png.h
+libspng:
+libspng: libspng can be used by xpra for better speed.
+libspng:
+libspng: