Rename float=64 build option to precision=double

[rburing]

This makes the build system consistent with Godot again; see godotengine/godot#67399.

TODO:

• Update CMake build file.

Also fixes the CMake build to define REAL_T_IS_DOUBLE when needed.

[akien-mga]

This begs for maybe refactoring further and changing the values from single|double to float|double to match what is used in the GDExtension config:

gdextension/extension_api.json
12:                     "build_configuration": "float_32",
173:                    "build_configuration": "float_64",
334:                    "build_configuration": "double_32",
495:                    "build_configuration": "double_64",
658:                    "build_configuration": "float_32",
973:                    "build_configuration": "float_64",
1288:                   "build_configuration": "double_32",
1603:                   "build_configuration": "double_64",

Would need to be done upstream too and break compat slightly again, but might be worth it?

[akien-mga]

CMake changes (untested), provided we'd do what I suggested above to change the default from single to float to match what should be passed to the bindings generator:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f3cf4fb..128d4a3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,7 @@
 # godot-cpp cmake arguments
 # GODOT_GDEXTENSION_DIR:	Path to the directory containing GDExtension interface header and API JSON file
 # GODOT_CUSTOM_API_FILE:	Path to a custom GDExtension API JSON file (takes precedence over `gdextension_dir`)
-# FLOAT_TYPE				Floating-point precision (32, 64)
+# FLOAT_PRECISION			Floating-point precision (float, double)
 #
 # Android cmake arguments
 # CMAKE_TOOLCHAIN_FILE:		The path to the android cmake toolchain ($ANDROID_NDK/build/cmake/android.toolchain.cmake)
@@ -45,11 +45,6 @@ if("${CMAKE_BUILD_TYPE}" STREQUAL "")
 	set(CMAKE_BUILD_TYPE Debug)
 endif()
 
-set(FLOAT_TYPE_FLAG "float" CACHE STRING "")
-if(FLOAT_TYPE EQUAL 64)
-	set(FLOAT_TYPE_FLAG "double" CACHE STRING "")
-endif(FLOAT_TYPE EQUAL 64)
-
 if(NOT DEFINED BITS)
 	set(BITS 32)
 	if(CMAKE_SIZEOF_VOID_P EQUAL 8)
@@ -60,6 +55,7 @@ endif()
 # Input from user for GDExtension interface header and the API JSON file
 set(GODOT_GDEXTENSION_DIR "gdextension" CACHE STRING "")
 set(GODOT_CUSTOM_API_FILE "" CACHE STRING "")
+set(FLOAT_PRECISION "float" CACHE STRING "")
 
 set(GODOT_GDEXTENSION_API_FILE "${GODOT_GDEXTENSION_DIR}/extension_api.json")
 if (NOT "${GODOT_CUSTOM_API_FILE}" STREQUAL "")  # User-defined override.
@@ -136,7 +132,7 @@ execute_process(COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator;
 )
 
 add_custom_command(OUTPUT ${GENERATED_FILES_LIST}
-		COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator; binding_generator.generate_bindings(\"${GODOT_GDEXTENSION_API_FILE}\", \"${GENERATE_BINDING_PARAMETERS}\", \"${BITS}\", \"${FLOAT_TYPE_FLAG}\", \"${CMAKE_CURRENT_BINARY_DIR}\")"
+		COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator; binding_generator.generate_bindings(\"${GODOT_GDEXTENSION_API_FILE}\", \"${GENERATE_BINDING_PARAMETERS}\", \"${BITS}\", \"${FLOAT_PRECISION}\", \"${CMAKE_CURRENT_BINARY_DIR}\")"
 		VERBATIM
 		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
 		MAIN_DEPENDENCY ${GODOT_GDEXTENSION_API_FILE}

Otherwise if we stick to single, it needs something like FLOAT_TYPE_FLAG re-added to do the extra conversion of single to float before passing to binding_generator.

[rburing]

I updated all the user-facing scripts to match the (current) Godot way of specifying precision=double. Internally we indeed still have build_configuration formatted differently. I would prefer to leave any further changes to a different PR. (Personally I prefer single|double to float|double.)

By the way, the CMake file never defines REAL_T_IS_DOUBLE (and I don't know how to do it), so I doubt it ever worked.

[akien-mga]

Fair enough, then further diff for CMake which should add REAL_T_IS_DOUBLE and handle the single->float conversion:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index dcf7475..2511a7e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,10 +52,17 @@ if(NOT DEFINED BITS)
 	endif(CMAKE_SIZEOF_VOID_P EQUAL 8)
 endif()
 
+set(FLOAT_PRECISION "single" CACHE STRING "")
+# "single" needs to be "float" for the binding generator.
+set(FLOAT_PRECISION_FLAG "float")
+if ("${FLOAT_PRECISION}" STREQUAL "double")
+	set(FLOAT_PRECISION_FLAG "double")
+	add_definitions(-DREAL_T_IS_DOUBLE)
+endif()
+
 # Input from user for GDExtension interface header and the API JSON file
 set(GODOT_GDEXTENSION_DIR "gdextension" CACHE STRING "")
 set(GODOT_CUSTOM_API_FILE "" CACHE STRING "")
-set(FLOAT_PRECISION "single" CACHE STRING "")
 
 set(GODOT_GDEXTENSION_API_FILE "${GODOT_GDEXTENSION_DIR}/extension_api.json")
 if (NOT "${GODOT_CUSTOM_API_FILE}" STREQUAL "")  # User-defined override.
@@ -132,7 +139,7 @@ execute_process(COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator;
 )
 
 add_custom_command(OUTPUT ${GENERATED_FILES_LIST}
-		COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator; binding_generator.generate_bindings(\"${GODOT_GDEXTENSION_API_FILE}\", \"${GENERATE_BINDING_PARAMETERS}\", \"${BITS}\", \"${FLOAT_PRECISION}\", \"${CMAKE_CURRENT_BINARY_DIR}\")"
+		COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator; binding_generator.generate_bindings(\"${GODOT_GDEXTENSION_API_FILE}\", \"${GENERATE_BINDING_PARAMETERS}\", \"${BITS}\", \"${FLOAT_PRECISION_FLAG}\", \"${CMAKE_CURRENT_BINARY_DIR}\")"
 		VERBATIM
 		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
 		MAIN_DEPENDENCY ${GODOT_GDEXTENSION_API_FILE}

[akien-mga]

Seems like your last push doesn't include all changes from my second diff. The FLOAT_PRECISION_FLAG intermediate variable is needed to pass float instead of single to the python script.

[rburing]

I changed generate_bindings to take precision instead (earlier). We can do it the other way if it is preferable.

[akien-mga]

Ah that's great then 👍

[akien-mga]

Thanks!