FindImageMagick: Find arch include dir (#15007)

Modules/FindImageMagick.cmake

@@ -115,7 +115,19 @@ function(FIND_IMAGEMAGICK_API component header)
       "[HKEY_LOCAL_MACHINE\\SOFTWARE\\ImageMagick\\Current;BinPath]/include"
     PATH_SUFFIXES
       ImageMagick ImageMagick-6
-    DOC "Path to the ImageMagick include dir."
+    DOC "Path to the ImageMagick arch-independent include dir."
+    )
+  find_path(ImageMagick_${component}_ARCH_INCLUDE_DIR
+    NAMES magick/magick-baseconfig.h
+    HINTS
+      ${PC_${component}_INCLUDEDIR}
+      ${PC_${component}_INCLUDE_DIRS}
+    PATHS
+      ${ImageMagick_INCLUDE_DIRS}
+      "[HKEY_LOCAL_MACHINE\\SOFTWARE\\ImageMagick\\Current;BinPath]/include"
+    PATH_SUFFIXES
+      ImageMagick ImageMagick-6
+    DOC "Path to the ImageMagick arch-specific include dir."
     )
   find_library(ImageMagick_${component}_LIBRARY
     NAMES ${ARGN}
@@ -127,12 +139,17 @@ function(FIND_IMAGEMAGICK_API component header)
     DOC "Path to the ImageMagick Magick++ library."
     )
 
+  # old version have only indep dir
   if(ImageMagick_${component}_INCLUDE_DIR AND ImageMagick_${component}_LIBRARY)
     set(ImageMagick_${component}_FOUND TRUE PARENT_SCOPE)
 
     list(APPEND ImageMagick_INCLUDE_DIRS
       ${ImageMagick_${component}_INCLUDE_DIR}
       )
+    if(ImageMagick_${component}_ARCH_INCLUDE_DIR)
+      list(APPEND ImageMagick_INCLUDE_DIRS
+        ${ImageMagick_${component}_ARCH_INCLUDE_DIR})
+    endif()
     list(REMOVE_DUPLICATES ImageMagick_INCLUDE_DIRS)
     set(ImageMagick_INCLUDE_DIRS ${ImageMagick_INCLUDE_DIRS} PARENT_SCOPE)