CMake: improve detection and configuration of image libs

Also: fix old (pre 3.13) link_directories() usage

1 files changed, 36 insertions, 15 deletions

diff --git a/jpeg/CMakeLists.txt b/jpeg/CMakeLists.txt
index 2e30f2d2e..16a423a81 100644
--- a/jpeg/CMakeLists.txt
+++ b/jpeg/CMakeLists.txt
@@ -1,36 +1,56 @@
+#
+# JPEG library CMake configuration for the Fast Light Toolkit (FLTK).
+#
+# Copyright 1998-2021 by Bill Spitzak and others.
+#
+# This library is free software. Distribution and use rights are outlined in
+# the file "COPYING" which should have been included with this file.  If this
+# file is missing or damaged, see the license at:
+#
+#     https://www.fltk.org/COPYING.php
+#
+# Please see the following page on how to report bugs and issues:
+#
+#     https://www.fltk.org/bugs.php
+#
 
 # memmgr back ends: compile only one of these into a working library
 # (For now, let's use the mode that requires the image fit into memory.
 # This is the recommended mode for Win32 anyway.)
-set(systemdependent_SRCS jmemnobs.c)
+
+set (systemdependent_SRCS jmemnobs.c)
 
 # library object files common to compression and decompression
-set(common_SRCS
-   jaricom.c jcomapi.c jutils.c jerror.c jmemmgr.c
+
+set (common_SRCS
+     jaricom.c jcomapi.c jutils.c jerror.c jmemmgr.c
 )
 
 # compression library object files
-set(compression_SRCS
-   jcapimin.c jcapistd.c jcarith.c jctrans.c jcparam.c jdatadst.c jcinit.c
-   jcmaster.c jcmarker.c jcmainct.c jcprepct.c jccoefct.c jccolor.c
-   jcsample.c jchuff.c jcdctmgr.c jfdctfst.c jfdctflt.c
-   jfdctint.c
+
+set (compression_SRCS
+     jcapimin.c jcapistd.c jcarith.c jctrans.c jcparam.c jdatadst.c jcinit.c
+     jcmaster.c jcmarker.c jcmainct.c jcprepct.c jccoefct.c jccolor.c
+     jcsample.c jchuff.c jcdctmgr.c jfdctfst.c jfdctflt.c
+     jfdctint.c
 )
 
 # decompression library object files
-set(decompression_SRCS
-   jdapimin.c jdapistd.c jdarith.c jdtrans.c jdatasrc.c jdmaster.c
-   jdinput.c jdmarker.c jdhuff.c jdmainct.c jdcoefct.c
-   jdpostct.c jddctmgr.c jidctfst.c jidctflt.c jidctint.c
-   jdsample.c jdcolor.c jquant1.c jquant2.c jdmerge.c
+
+set (decompression_SRCS
+     jdapimin.c jdapistd.c jdarith.c jdtrans.c jdatasrc.c jdmaster.c
+     jdinput.c jdmarker.c jdhuff.c jdmainct.c jdcoefct.c
+     jdpostct.c jddctmgr.c jidctfst.c jidctflt.c jidctint.c
+     jdsample.c jdcolor.c jquant1.c jquant2.c jdmerge.c
 )
 
-list(APPEND BUILD_SRCS "${systemdependent_SRCS};${common_SRCS}")
-list(APPEND BUILD_SRCS "${compression_SRCS};${decompression_SRCS}")
+list (APPEND BUILD_SRCS "${systemdependent_SRCS};${common_SRCS}")
+list (APPEND BUILD_SRCS "${compression_SRCS};${decompression_SRCS}")
 
 #######################################################################
 
 # Suppress some Visual Studio compiler warnings
+
 set (msvc_warnings /wd4267)
 
 #######################################################################
@@ -48,6 +68,7 @@ endif (MSVC)
 #######################################################################
 
 if (OPTION_BUILD_SHARED_LIBS)
+
   FL_ADD_LIBRARY (fltk_jpeg SHARED "${BUILD_SRCS}")
 
   if (MSVC)