3 files changed, 22 insertions, 5 deletions

diff --git a/compiler/app/Main.hs b/compiler/app/Main.hs
index 404de4b..a4b6ae2 100644
--- a/compiler/app/Main.hs
+++ b/compiler/app/Main.hs
@@ -39,6 +39,7 @@ data ViewerConfig = ViewerConfig
 data Options = Options
   { inputDir :: FilePath
   , outputDir :: FilePath
+  , outputIndex :: FilePath
   , galleryConfig :: FilePath
   , rebuilAll :: Bool
   , cleanOutput :: Bool
@@ -59,6 +60,12 @@ options = Options
       &= name "output-dir"
       &= explicit
       &= help "Generated gallery output path (default=./out)"
+  , outputIndex = ""
+      &= typFile
+      &= name "x"
+      &= name "output-index"
+      &= explicit
+      &= help "Generated gallery index output path (default=$output-dir/index.json)"
   , galleryConfig = ""
       &= typFile
       &= name "g"
@@ -110,6 +117,7 @@ main =
             (galleryConfig opts)
             (inputDir opts)
             (galleryOutputDir opts)
+            (outputIndex opts)
             [outputDir opts]
             (rebuilAll opts)
             (cleanOutput opts)
diff --git a/compiler/ldgallery.1.md b/compiler/ldgallery.1.md
index 5524409..fd0355b 100644
--- a/compiler/ldgallery.1.md
+++ b/compiler/ldgallery.1.md
@@ -33,6 +33,10 @@ Available options are:
   Must be distinct from the source directory.
   Defaults to ./out.
 
+-x, \--output-index _FILE_
+: Generated gallery index output path.
+  Defaults to $output-dir/index.json.
+
 -g, \--gallery-config _FILE_
 : Gallery configuration file.
   Defaults to $input-dir/gallery.yaml.
@@ -45,6 +49,7 @@ Available options are:
 
 -w, \--with-viewer
 : Include the static web viewer in the output.
+  The compiled gallery itself is then placed in $output-dir/gallery.
 
 -h, \--help
 : Display help message.
diff --git a/compiler/src/Compiler.hs b/compiler/src/Compiler.hs
index 2970102..51f5065 100644
--- a/compiler/src/Compiler.hs
+++ b/compiler/src/Compiler.hs
@@ -51,8 +51,8 @@ import Processors
 defaultGalleryConf :: String
 defaultGalleryConf = "gallery.yaml"
 
-indexFile :: String
-indexFile = "index.json"
+defaultIndexFile :: String
+defaultIndexFile = "index.json"
 
 itemsDir :: String
 itemsDir = "items"
@@ -103,8 +103,8 @@ galleryDirFilter config excludedCanonicalDirs =
     isExcludedDir File{} = False
 
 
-compileGallery :: FilePath -> FilePath -> FilePath -> [FilePath] -> Bool -> Bool -> IO ()
-compileGallery configPath inputDirPath outputDirPath excludedDirs rebuildAll cleanOutput =
+compileGallery :: FilePath -> FilePath -> FilePath -> FilePath -> [FilePath] -> Bool -> Bool -> IO ()
+compileGallery configPath inputDirPath outputDirPath outputIndexPath excludedDirs rebuildAll cleanOutput =
   do
     config <- readConfig $ inputGalleryConf configPath
 
@@ -121,13 +121,17 @@ compileGallery configPath inputDirPath outputDirPath excludedDirs rebuildAll cle
     resources <- galleryBuilder inputTree
 
     when cleanOutput $ galleryCleanupResourceDir resources outputDirPath
-    writeJSON (outputDirPath </> indexFile) $ GalleryIndex (viewerConfig config) resources
+    writeJSON (outputGalleryIndex outputIndexPath) $ GalleryIndex (viewerConfig config) resources
 
   where
     inputGalleryConf :: FilePath -> FilePath
     inputGalleryConf "" = inputDirPath </> defaultGalleryConf
     inputGalleryConf file = file
 
+    outputGalleryIndex :: FilePath -> FilePath
+    outputGalleryIndex "" = outputDirPath </> defaultIndexFile
+    outputGalleryIndex file = file
+
     itemProcessor config cache =
       itemFileProcessor
         (pictureMaxResolution config) cache