fixed sdlgpu for linux

Makefile

@@ -46,7 +46,8 @@ LINUX_INCLUDES= \
 LINUX_LIBS= \
 	$(GTK_LIBS) \
 	`sdl2-config --static-libs` \
-	-L$(3RD_PARTY)/wren-0.1.0/lib
+	-L$(3RD_PARTY)/wren-0.1.0/lib \
+	-L$(3RD_PARTY)/sdl-gpu/build/linux
 
 LINUX64_LIBS= \
 	$(GTK_LIBS) \
@@ -79,7 +80,9 @@ LINUX_LINKER_FLAGS= \
 	-lm \
 	-lpthread \
 	-lrt \
-	-lz
+	-lz \
+	-lsdlgpu \
+	-lGL
 
 MINGW_OUTPUT=$(BIN_NAME).exe
 

README.md

@@ -68,9 +68,8 @@ run the following commands in the Terminal
 ```
 sudo apt-get install git build-essential libgtk-3-dev libsdl2-dev lua5.3-dev zlib1g-dev
 git clone --recursive https://github.com/nesbox/TIC-80
-cd 3rd-party/wren-0.1.0/
-make static
-cd ../..
+make static -C 3rd-party/wren-0.1.0/
+make -C 3rd-party/sdl-gpu/build/linux/
 make linux
 ```