From f00550899b083385325b8949ded3a2e6e666cc41 Mon Sep 17 00:00:00 2001
From: Wojciech Jarosz <wkjarosz@users.noreply.github.com>
Date: Tue, 4 Feb 2025 08:32:09 -0500
Subject: [PATCH] cmake work. requiring lcms2

---
 CMakeLists.txt                | 23 +++++++---
 cmake/modules/FindLCMS2.cmake | 79 +++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+), 6 deletions(-)
 create mode 100644 cmake/modules/FindLCMS2.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 491033f..62ede1e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -398,6 +398,10 @@ CPMAddPackage(
 )
 if(openexr_ADDED)
   message(STATUS "Building OpenEXR library with threading options: ${OPENEXR_THREADING_OPTIONS}")
+elseif(TARGET OpenEXR::OpenEXR)
+  message(STATUS "Will link against system-installed OpenEXR library")
+else()
+  message(FATAL_ERROR "OpenEXR library not found. Please install it.")
 endif()
 list(APPEND HDRVIEW_DEPENDENCIES "OpenEXR::OpenEXR")
 
@@ -417,9 +421,9 @@ if(HDRVIEW_ENABLE_UHDR)
             "UHDR_ENABLE_INTRINSICS OFF"
   )
   if(libuhdr_ADDED)
-    message(STATUS "Will build uhdr library with UHDR_BUILD_DEPS=${UHDR_BUILD_DEPS}")
+    message(STATUS "Building uhdr library with UHDR_BUILD_DEPS=${UHDR_BUILD_DEPS}")
   elseif(TARGET core)
-    message(STATUS "Using local uhdr library")
+    message(STATUS "Will link against system-installed uhdr library")
   else()
     message(FATAL_ERROR "uhdr library not found. Please install it or turn off HDRVIEW_ENABLE_UHDR.")
   endif()
@@ -451,9 +455,9 @@ if(HDRVIEW_ENABLE_JPEGXL)
             "EXCLUDE_FROM_ALL YES"
   )
   if(JXL_ADDED)
-    message(STATUS "Will build JPEG-XL library")
+    message(STATUS "Building JPEG-XL library")
   elseif(TARGET jxl)
-    message(STATUS "Using local JPEG-XL library")
+    message(STATUS "Using system-installed JPEG-XL library")
   else()
     message(FATAL_ERROR "JPEG-XL library not found. Please install it or turn off HDRVIEW_ENABLE_JPEGXL.")
   endif()
@@ -462,11 +466,18 @@ if(HDRVIEW_ENABLE_JPEGXL)
 endif()
 
 if(TARGET lcms2)
-  message(STATUS "Using local lcms2 library")
+  message(STATUS "Using lcms2 target already provided by one of the other dependencies")
   list(APPEND HDRVIEW_DEPENDENCIES "lcms2")
   list(APPEND HDRVIEW_DEFINITIONS HDRVIEW_ENABLE_LCMS2)
 else()
-  message(STATUS "lcms2 library not found.")
+  find_package(LCMS2 REQUIRED)
+  if(LCMS2_FOUND)
+    message(STATUS "Using system-installed lcms2 library")
+    list(APPEND HDRVIEW_DEPENDENCIES "lcms2")
+    list(APPEND HDRVIEW_DEFINITIONS HDRVIEW_ENABLE_LCMS2)
+  else()
+    message(FATAL_ERROR "lcms2 library not found.")
+  endif()
 endif()
 
 option(HDRVIEW_ENABLE_HEIF "Enable HEIF/AVIF support" OFF)
diff --git a/cmake/modules/FindLCMS2.cmake b/cmake/modules/FindLCMS2.cmake
new file mode 100644
index 0000000..d837bfe
--- /dev/null
+++ b/cmake/modules/FindLCMS2.cmake
@@ -0,0 +1,79 @@
+# cmake-format: off
+#
+# - Find LCMS2
+# Find the LCMS2 includes and library
+# 
+# This module defines
+#  LCMS2_INCLUDE_DIRS, where to find lcms2.h
+#  LCMS2_LIBRARIES, the libraries needed to use LCMS2.
+#  LCMS2_VERSION, The value of LCMS_VERSION defined in lcms2.h
+#  LCMS2_FOUND, If false, do not try to use LCMS2.
+# 
+# If found, it will also define an imported targets for the library:
+# - lcms2
+# 
+
+# Copyright (c) the JPEG XL Project Authors. All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+#
+# cmake-format: on
+
+find_package(PkgConfig QUIET)
+if(PkgConfig_FOUND)
+  pkg_check_modules(PC_LCMS2 QUIET libLCMS2)
+  set(LCMS2_VERSION ${PC_LCMS2_VERSION})
+endif()
+
+find_path(
+  LCMS2_INCLUDE_DIR
+  NAMES lcms2.h
+  HINTS ${PC_LCMS2_INCLUDEDIR} ${PC_LCMS2_INCLUDE_DIRS}
+)
+
+find_library(
+  LCMS2_LIBRARY
+  NAMES ${LCMS2_NAMES} lcms2 liblcms2 lcms-2 liblcms-2
+  HINTS ${PC_LCMS2_LIBDIR} ${PC_LCMS2_LIBRARY_DIRS}
+)
+
+if(LCMS2_INCLUDE_DIR AND NOT LCMS_VERSION)
+  file(READ ${LCMS2_INCLUDE_DIR}/lcms2.h LCMS2_VERSION_CONTENT)
+  string(REGEX MATCH "#define[ \t]+LCMS_VERSION[ \t]+([0-9]+)[ \t]*\n" LCMS2_VERSION_MATCH ${LCMS2_VERSION_CONTENT})
+  if(LCMS2_VERSION_MATCH)
+    string(SUBSTRING ${CMAKE_MATCH_1} 0 1 LCMS2_VERSION_MAJOR)
+    string(SUBSTRING ${CMAKE_MATCH_1} 1 2 LCMS2_VERSION_MINOR)
+    set(LCMS2_VERSION "${LCMS2_VERSION_MAJOR}.${LCMS2_VERSION_MINOR}")
+  endif()
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(
+  LCMS2
+  FOUND_VAR LCMS2_FOUND
+  REQUIRED_VARS LCMS2_LIBRARY LCMS2_INCLUDE_DIR
+  VERSION_VAR LCMS2_VERSION
+)
+
+if(LCMS2_LIBRARY AND NOT TARGET lcms2)
+  add_library(lcms2 INTERFACE IMPORTED GLOBAL)
+
+  if(CMAKE_VERSION VERSION_LESS "3.13.5")
+    set_property(TARGET lcms2 PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${LCMS2_INCLUDE_DIR})
+    target_link_libraries(lcms2 INTERFACE ${LCMS2_LIBRARY})
+    set_property(TARGET lcms2 PROPERTY INTERFACE_COMPILE_OPTIONS ${PC_LCMS2_CFLAGS_OTHER})
+  else()
+    target_include_directories(lcms2 INTERFACE ${LCMS2_INCLUDE_DIR})
+    target_link_libraries(lcms2 INTERFACE ${LCMS2_LIBRARY})
+    target_link_options(lcms2 INTERFACE ${PC_LCMS2_LDFLAGS_OTHER})
+    target_compile_options(lcms2 INTERFACE ${PC_LCMS2_CFLAGS_OTHER})
+  endif()
+endif()
+
+mark_as_advanced(LCMS2_INCLUDE_DIR LCMS2_LIBRARY)
+
+if(LCMS2_FOUND)
+  set(LCMS2_LIBRARIES ${LCMS2_LIBRARY})
+  set(LCMS2_INCLUDE_DIRS ${LCMS2_INCLUDE_DIR})
+endif()