# Configure a command to compile a single shader
# add_shader_cmd(
#	FILE file
#	OUTPUT output
#	TYPE type
#)
function (add_shader_cmd)
	cmake_parse_arguments(SHADER "" "FILE;OUTPUT;TYPE;LANG" "" ${ARGN})
	message(${SHADER_FILE} ${SHADER_OUTPUT} ${SHADER_TYPE} ${SHADER_LANG})

	set(BGFX_PATH ${CMAKE_CURRENT_SOURCE_DIR}/vendor/bgfx.cmake/bgfx)
	set(VARYING_DEF "C:/Users/romer/Documents/Projects/weasel/src/gfx/shader/varying.def.sc")

	message("checking platform")
	if(WIN32)
		set(SHADERC_PLATFORM_ARG WINDOWS)
		message("platform = " ${SHADERC_PLATFORM_ARG})
	elseif(APPLE)
		set(SHADERC_PLATFORM_ARG OSX)
	elseif(UNIX)
		set(SHADERC_PLATFORM_ARG LINUX)
	endif()

	# shaderc_parse(
	#	FILE filename
	#	OUTPUT filename
	#	FRAGMENT|VERTEX|COMPUTE
	#	ANDROID|ASM_JS|IOS|LINUX|NACL|OSX|WINDOWS
	#	[PROFILE profile]
	#	[O 0|1|2|3]
	#	[VARYINGDEF filename]
	#	[BIN2C filename]
	#	[INCLUDES include;include]
	#	[DEFINES include;include]
	#	[DEPENDS]
	#	[PREPROCESS]
	#	[RAW]
	#	[VERBOSE]
	#	[DEBUG]
	#	[DISASM]
	#	[WERROR]
	# )
	shaderc_parse(SHADERC_ARGS
		FILE ${SHADER_FILE}
		OUTPUT ${SHADER_OUTPUT}
		${SHADER_TYPE}
		${SHADERC_PLATFORM_ARG}
		PROFILE ${SHADER_LANG}
		VARYINGDEF ${VARYING_DEF}
		INCLUDES ${BGFX_PATH}/src
	)
	
	list( APPEND SHADER_COMPILE_CMD shaderc ${SHADERC_ARGS} )
	add_custom_command(
		OUTPUT ${SHADER_OUTPUT}
		COMMAND ${SHADER_COMPILE_CMD})
endfunction()