From 940b627dedc8ed30122cb9b44702452f7767b7b3 Mon Sep 17 00:00:00 2001
From: "C. J. Howard" <cjhoward@cjhoward.org>
Date: Sun, 3 Dec 2023 17:14:45 +0800
Subject: [PATCH] Add support for --version and --help options

---
 CMakeLists.txt    | 10 ++++++++++
 README.md         | 14 +++++++++-----
 src/config.hpp.in | 17 +++++++++++++++++
 src/siafu.cpp     | 26 +++++++++++++++++++++++---
 4 files changed, 59 insertions(+), 8 deletions(-)
 create mode 100644 src/config.hpp.in

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e85e298..705ab77 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,6 +18,9 @@ file(GLOB_RECURSE SOURCE_FILES CONFIGURE_DEPENDS
 	${PROJECT_SOURCE_DIR}/src/*.cpp
 )
 
+# Generate config header
+configure_file(${PROJECT_SOURCE_DIR}/src/config.hpp.in ${PROJECT_BINARY_DIR}/src/config.hpp)
+
 if(CMAKE_SYSTEM_NAME MATCHES "Windows")
 	
 	# Generate Windows version-information resource file
@@ -40,6 +43,13 @@ set_target_properties(${PROJECT_NAME}
 		MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>"
 )
 
+# Set executable include directories
+target_include_directories(${PROJECT_NAME}
+	PRIVATE
+		${PROJECT_SOURCE_DIR}/src
+		${PROJECT_BINARY_DIR}/src
+)
+
 # Set executable compile options
 target_compile_options(${PROJECT_NAME}
 	PRIVATE
diff --git a/README.md b/README.md
index 4305355..88fbb78 100644
--- a/README.md
+++ b/README.md
@@ -30,14 +30,18 @@ cmake --build build --config Release --target install
 ## Usage
 
 ```bash
-siafu <volume_path> <isolevel> <output_file>
+usage: siafu [--version] [--help]
+             <volume_path> <isolevel> <output_file>
 ```
 
-### Parameters
-
 -   `volume_path`: Path to a sequence of uncompressed TIFF files.
--   `isolevel`: Floating-point threshold value for isosurface extraction.
--   `output_file`: Name and format of the output file. Supported file extensions include `.ply`, `.obj`, and `.stl`. If the file extension unrecognized, the `.ply` format will be used.
+-   `isolevel`: Threshold value for isosurface extraction.
+-   `output_file`: Output file path and format. Supported file formats include `.ply`, `.obj`, and `.stl`. If the output file extension is unrecognized, the `.ply` format will be used.
+
+### Options
+
+-   `--version`: Display the version number.
+-   `--help`: Display usage information.
 
 ### Examples
 
diff --git a/src/config.hpp.in b/src/config.hpp.in
new file mode 100644
index 0000000..0238a77
--- /dev/null
+++ b/src/config.hpp.in
@@ -0,0 +1,17 @@
+// SPDX-FileCopyrightText: 2023 C. J. Howard
+// SPDX-License-Identifier: MIT
+
+#ifndef CONFIG_HPP
+#define CONFIG_HPP
+
+#include <string_view>
+
+/// Siafu version string.
+inline constexpr std::string_view siafu_version_string = "siafu v@PROJECT_VERSION@";
+
+/// Siafu help string.
+inline constexpr std::string_view siafu_help_string =
+	"usage: siafu [--version] [--help]\n"
+	"             <volume_path> <isolevel> <output_file>";
+
+#endif // CONFIG_HPP
diff --git a/src/siafu.cpp b/src/siafu.cpp
index 15f6fbc..a73c3b6 100644
--- a/src/siafu.cpp
+++ b/src/siafu.cpp
@@ -2,26 +2,46 @@
 // SPDX-License-Identifier: MIT
 
 #include "siafu.hpp"
+#include "config.hpp"
 #include <fstream>
 #include <iostream>
 #include <format>
 #include <stdexcept>
+#include <string_view>
 
 int main(int argc, char* argv[])
 {
-	auto usage = [](){std::cerr << "usage: <volume_path> <isolevel> <output_file>\n";};
+	// Parse options
+	if (argc > 1)
+	{
+		std::string_view option(argv[1]);
+		
+		if (option == "--version")
+		{
+			std::cout << siafu_version_string << std::endl;
+			return 0;
+		}
+		else if (option == "--help")
+		{
+			std::cout << siafu_help_string << std::endl;
+			return 0;
+		}
+	}
 	
+	// Incorrect usage
 	if (argc != 4)
 	{
-		usage();
+		std::cerr << siafu_help_string << std::endl;
 		return 1;
 	}
 	
+	// Parse isolevel parameter
 	char* endptr;
 	f32 isolevel = std::strtof(argv[2], &endptr);
 	if (*endptr != '\0')
 	{
-		usage();
+		// NaN
+		std::cerr << siafu_help_string << std::endl;
 		return 1;
 	}