From b842e5821a453d5bfdb7f38a79ab15989597b37b Mon Sep 17 00:00:00 2001
From: Dominic Masters <dominic@domsplace.com>
Date: Wed, 12 Nov 2025 19:25:10 -0600
Subject: [PATCH] Add defs generator.

---
 cmake/modules/envtoh.cmake | 69 ++++++++++++++++++++++++++++++++++++++
 src/CMakeLists.txt         |  4 +++
 src/dawndefs.env           |  5 +++
 tools/CMakeLists.txt       | 17 ++++++++++
 4 files changed, 95 insertions(+)
 create mode 100644 cmake/modules/envtoh.cmake
 create mode 100644 src/dawndefs.env

diff --git a/cmake/modules/envtoh.cmake b/cmake/modules/envtoh.cmake
new file mode 100644
index 0000000..4c003e1
--- /dev/null
+++ b/cmake/modules/envtoh.cmake
@@ -0,0 +1,69 @@
+if(NOT DEFINED ENV_FILE)
+    message(FATAL_ERROR "ENV_FILE is not set")
+endif()
+
+if(NOT DEFINED OUT_HEADER)
+    message(FATAL_ERROR "OUT_HEADER is not set")
+endif()
+
+if(NOT EXISTS "${ENV_FILE}")
+    message(FATAL_ERROR ".env file not found: ${ENV_FILE}")
+endif()
+
+file(STRINGS "${ENV_FILE}" ENV_LINES)
+
+set(HEADER_CONTENT "#pragma once\n#include \"dusk.h\"\n\n")
+
+foreach(line IN LISTS ENV_LINES)
+  # Trim whitespace
+  string(REGEX REPLACE "^[ \t]*" "" line "${line}")
+  string(REGEX REPLACE "[ \t]*$" "" line "${line}")
+
+  # Skip comments and empty lines (allow whitespace before # or ;)
+  if(line STREQUAL "" OR line MATCHES "^[ \t]*[#;]")
+    continue()
+  endif()
+
+  # Expect KEY=VALUE
+  if(NOT line MATCHES "^[A-Za-z_][A-Za-z0-9_]*=")
+    message(WARNING "Skipping invalid line in ${ENV_FILE}: '${line}'")
+    continue()
+  endif()
+
+  # Extract key
+  string(REGEX MATCH "^[A-Za-z_][A-Za-z0-9_]*" KEY "${line}")
+  string(LENGTH "${KEY}" key_len)
+
+  # Extract value
+  string(SUBSTRING "${line}" ${key_len} -1 rest)
+  string(REGEX REPLACE "^[ \t]*=[ \t]*" "" RAW_VALUE "${rest}")
+
+  # Lowercase copy for boolean detection
+  string(TOLOWER "${RAW_VALUE}" VALUE_LC)
+  set(VALUE "${RAW_VALUE}")
+
+  # Determine type and format accordingly
+  if(VALUE_LC STREQUAL "true")
+    set(HEADER_CONTENT "${HEADER_CONTENT}#define ${KEY} true\n")
+
+  elseif(VALUE_LC STREQUAL "false")
+    set(HEADER_CONTENT "${HEADER_CONTENT}#define ${KEY} false\n")
+
+  elseif(VALUE MATCHES "^[+-]?[0-9]+$")
+    # Integer
+    set(HEADER_CONTENT "${HEADER_CONTENT}#define ${KEY} ${VALUE}\n")
+
+  elseif(VALUE MATCHES "^[+-]?[0-9]*\\.[0-9]+$")
+    # Float → append "f"
+    set(HEADER_CONTENT "${HEADER_CONTENT}#define ${KEY} ${VALUE}f\n")
+
+  else()
+    # String → escape for C literal
+    string(REPLACE "\\" "\\\\" VALUE_ESC "${VALUE}")
+    string(REPLACE "\"" "\\\"" VALUE_ESC "${VALUE_ESC}")
+    set(HEADER_CONTENT "${HEADER_CONTENT}#define ${KEY} \"${VALUE_ESC}\"\n")
+  endif()
+endforeach()
+
+file(WRITE "${OUT_HEADER}" "${HEADER_CONTENT}")
+message(STATUS "Generated header: ${OUT_HEADER}")
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 43bd8be..fcec72a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -6,6 +6,7 @@
 find_package(cglm REQUIRED)
 find_package(libzip REQUIRED)
 
+
 # Libs
 target_link_libraries(${DUSK_TARGET_NAME}
   PUBLIC
@@ -27,6 +28,9 @@ target_sources(${DUSK_TARGET_NAME}
     main.c
 )
 
+# Defs
+add_defs(dawndefs.env dawndefs.h)
+
 # Subdirs
 add_subdirectory(assert)
 add_subdirectory(asset)
diff --git a/src/dawndefs.env b/src/dawndefs.env
new file mode 100644
index 0000000..4864180
--- /dev/null
+++ b/src/dawndefs.env
@@ -0,0 +1,5 @@
+# Copyright (c) 2025 Dominic Masters
+# 
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 0ef1273..a9aacea 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -11,4 +11,21 @@ function(add_asset ASSET_TYPE ASSET_PATH)
     "${ASSET_TYPE}#${FULL_ASSET_PATH}#${ASSETS_ARGS}"
   )
   set(DUSK_ASSETS ${DUSK_ASSETS} CACHE INTERNAL ${DUSK_CACHE_TARGET})
+endfunction()
+
+function(add_defs INPUT_PATH OUTPUT_NAME_RELATIVE)
+  set(INPUT_FULL_PATH "${CMAKE_CURRENT_LIST_DIR}/${INPUT_PATH}")
+  set(OUTPUT_FULL_PATH "${DUSK_GENERATED_HEADERS_DIR}/${OUTPUT_NAME_RELATIVE}")
+
+  add_custom_command(
+    OUTPUT ${OUTPUT_FULL_PATH}
+    COMMAND ${CMAKE_COMMAND}
+      -DENV_FILE=${INPUT_FULL_PATH}
+      -DOUT_HEADER=${OUTPUT_FULL_PATH}
+      -P ${CMAKE_SOURCE_DIR}/cmake/modules/envtoh.cmake
+    DEPENDS ${INPUT_FULL_PATH} ${CMAKE_SOURCE_DIR}/cmake/modules/envtoh.cmake
+    COMMENT "Generating ${OUTPUT_NAME_RELATIVE}"
+  )
+  add_custom_target(${OUTPUT_NAME_RELATIVE}_header DEPENDS ${OUTPUT_FULL_PATH})
+  add_dependencies(${DUSK_TARGET_NAME} ${OUTPUT_NAME_RELATIVE}_header)
 endfunction()
\ No newline at end of file