Updated README: build options

1 files changed, 9 insertions, 2 deletions

diff --git a/README.md b/README.md
index b4f05592..4cb6f03b 100644
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+++ b/README.md
@@ -63,10 +63,17 @@ This will also install an XDG .desktop file for launching the app.
 | CMake Option | Description |
 | ------------ | ----------- |
 | `ENABLE_BINCAT_SH` | Merge resource files (fonts, etc.) together using a Bash shell script. By default this is **OFF**, so _res/bincat.c_ is compiled as a native executable for this purpose. However, when cross-compiling, native binaries built during the CMake run may be targeted for the wrong architecture. Set this to **ON** if you are having problems with bincat while running CMake. |
+| `ENABLE_CUSTOM_FRAME` | Draw a custom window frame. (Only on Microsoft Windows.) The custom frame is more in line with the visual style of the rest of the UI, but does not implement all of the native window behaviors (e.g., snapping, system menu). |
+| `ENABLE_DOWNLOAD_EDIT` | Allow changing the Downloads directory via the Preferences dialog. This should be set to **OFF** in sandboxed environments where  downloaded files must be saved into a specific place. |
 | `ENABLE_IDLE_SLEEP` | Sleep in the main thread instead of waiting for events. On some platforms, `SDL_WaitEvent()` may have a relatively high CPU usage. Setting this to **ON** polls for events periodically but otherwise keeps the main thread sleeping, reducing CPU usage. The drawback is that there is a slightly increased latency reacting to new events after idle mode ends. |
-| `ENABLE_HARFBUZZ` | Use the HarfBuzz library for shaping Unicode text. This is required for correctly rendering complex scripts and composite glyphs. If disabled, a simplified text shaping algorithm is used that only works for left-to-right languages like English. |
-| `ENABLE_KERNING` | Use kerning information in the fonts to adjust glyph placement. Setting this **ON** improves text appearance in subtle ways but slows down text rendering. It may be a good idea to set this to **OFF** when running on a slow CPU. |
+| `ENABLE_FRIBIDI` | Use the GNU FriBidi library for processing bidirectional text. FriBidi implements the Unicode Bidirectional Algorithm to determine text directions. |
+| `ENABLE_FRIBIDI_BUILD` | Compile the GNU FriBidi library as part of the build. If set to **OFF**, `pkg-config` is used instead to locate the library. |
+| `ENABLE_HARFBUZZ` | Use the HarfBuzz library for shaping Unicode text. This is required for correctly rendering complex scripts and composite glyphs. If disabled, a simplified text shaping algorithm is used that only works for non-complex languages like English. |
+| `ENABLE_HARFBUZZ_MINIMAL` | Build the HarfBuzz library with all dependencies disabled. Useful when building the application for distribution so that the number of deployed dependencies will be minimized. A system-provided version of HarfBuzz is likely built with dependencies on FreeType and ICU at least. If set to **OFF**, `pkg-config` will be used to find HarfBuzz. | 
+| `ENABLE_IPC` | Instances of the Lagrange executable communicate via signals or (on Windows) a system-provided IPC mechanism. This is used for controlling an existing Lagrange window via the CLI. If set to **OFF**, each instance of the application runs without knowledge of other instances. This may cause them to overwrite each other's runtime files. |
+| `ENABLE_KERNING` | Use kerning information in the fonts to adjust glyph placement. Setting this **ON** improves text appearance in subtle ways but slows down text rendering. It may be a good idea to set this to **OFF** when running on a slow CPU. This option only affects the simple built-in text renderer, and has no effect on HarfBuzz. |
 | `ENABLE_MPG123` | Use the mpg123 library for decoding MPEG audio files. |
+| `ENABLE_RELATIVE_EMBED` | Locate resources only in relation to the executable. Useful when any system/predefined directories are not supposed to be accessed, e.g., in the Windows portable build. |
 | `ENABLE_RESOURCE_EMBED` | Embed all resource files into the Lagrange executable instead of keeping them in a separate file that gets loaded at launch. Setting this **ON** makes it much slower to run CMake and to compile Lagrange. |
 | `ENABLE_WINDOWPOS_FIX` | Set correct window position after the window has already been shown. This may be necessary on some platforms to prevent the window from being restored to the wrong position. |
 | `ENABLE_X11_SWRENDER` | Default to software rendering when running under X11. By default Lagrange attempts to use the GPU for rendering the user interface. You can also use the `--sw` option at launch to force software rendering. |