Merge pull request #462 from easyaspi314/doxygen-cleanup

[WIP] Doxygen and more detailed documentation

Doxyfile

@@ -0,0 +1,58 @@
+# Doxygen config for xxHash
+DOXYFILE_ENCODING      = UTF-8
+
+PROJECT_NAME           = "xxHash"
+PROJECT_NUMBER         = "0.8.0"
+PROJECT_BRIEF          = "Extremely fast non-cryptographic hash function"
+OUTPUT_DIRECTORY       = doxygen
+OUTPUT_LANGUAGE        = English
+
+# We already separate the internal docs.
+INTERNAL_DOCS          = YES
+# Consistency
+SORT_MEMBER_DOCS       = NO
+BRIEF_MEMBER_DESC      = YES
+REPEAT_BRIEF           = YES
+
+# Warnings
+QUIET                  = YES
+# Until we document everything
+WARN_IF_UNDOCUMENTED   = NO
+
+# TODO: Add the other files. It is just xxhash.h for now.
+FILE_PATTERNS          = xxhash.h
+# Note: xxHash's source files are technically ASCII only.
+INPUT_ENCODING         = UTF-8
+TAB_SIZE               = 4
+MARKDOWN_SUPPORT       = YES
+
+# xxHash is a C library
+OPTIMIZE_OUTPUT_FOR_C  = YES
+# So we can document the internals
+EXTRACT_STATIC         = YES
+# Document the macros
+MACRO_EXPANSION        = YES
+EXPAND_ONLY_PREDEF     = YES
+# Predefine some macros to clean up the output.
+PREDEFINED             = "XXH_DOXYGEN=" \
+                         "XXH_PUBLIC_API=" \
+                         "XXH_FORCE_INLINE=static inline" \
+                         "XXH_NO_INLINE=static" \
+                         "XXH_RESTRICT=restrict" \
+                         "XSUM_API=" \
+                         "XXH_STATIC_LINKING_ONLY" \
+                         "XXH_IMPLEMENTATION" \
+                         "XXH_ALIGN(N)=alignas(N)" \
+                         "XXH_ALIGN_MEMBER(align,type)=alignas(align) type"
+
+# We want HTML docs
+GENERATE_HTML          = YES
+HTML_OUTPUT            = html
+HTML_FILE_EXTENSION    = .html
+# Tweak the colors a bit
+HTML_COLORSTYLE_HUE    = 220
+HTML_COLORSTYLE_GAMMA  = 100
+HTML_COLORSTYLE_SAT    = 100
+
+# We don't want LaTeX.
+GENERATE_LATEX         = NO