wasm_build/Makefile: build objects seperately

wasm_build/.gitignore

@@ -2,3 +2,4 @@
 /jumpartifact.com_demo_0.js
 /jumpartifact.com_demo_0.wasm
 /jumpartifact.com_demo_0.data
+/objdir/

wasm_build/Makefile

@@ -4,6 +4,8 @@ else
 	OTHER_FLAGS = -Og
 endif
 
+OBJDIR = objdir
+
 SOURCES = \
 		../src/main.cc \
 		../src/ems.cc \
@@ -24,11 +26,13 @@ HEADERS = \
 		../src/3d_helpers.h \
 		../src/walker.h
 
+OBJECTS = $(addprefix ${OBJDIR}/,$(subst ..,PREVDIR,$(subst .cc,.cc.o,${SOURCES})))
+
 CXX = source ${HOME}/git/emsdk/emsdk_env.sh && em++
 
 all: | format jumpartifact.com_demo_0.html
 
-jumpartifact.com_demo_0.html: ${SOURCES} ${HEADERS}
+jumpartifact.com_demo_0.html: ${OBJECTS} ${HEADERS}
 	${CXX} -std=c++20 -o jumpartifact.com_demo_0.html \
 		-s USE_GLFW=3 -I../wasm_include -L../wasm_lib -lraylib \
 		--shell-file custom_shell.html \
@@ -36,7 +40,7 @@ jumpartifact.com_demo_0.html: ${SOURCES} ${HEADERS}
 		-sEXPORTED_RUNTIME_METHODS=ccall \
 		--preload-file ../res \
 		${OTHER_FLAGS} \
-		${SOURCES}
+		${OBJECTS}
 
 .PHONY: clean format
 
@@ -45,6 +49,13 @@ clean:
 	rm -f jumpartifact.com_demo_0.js
 	rm -f jumpartifact.com_demo_0.wasm
 	rm -f jumpartifact.com_demo_0.data
+	rm -rf "${OBJDIR}"
 
 format:
 	clang-format -i --style=google ${SOURCES} ${HEADERS}
+
+.SECONDEXPANSION:
+
+${OBJDIR}/%.cc.o: $$(subst PREVDIR,..,%.cc) ${HEADERS}
+	@mkdir -p "${OBJDIR}/$(dir $(subst ..,PREVDIR,$<))"
+	${CXX} -std=c++20 -I../wasm_include -c ${OTHER_FLAGS} -o $@ $<