Compilation errors

[bztsrc]

Cmake doesn't work. Thanks to dulsi who pointed out the error, this modification to CMakeLists.txt fixed it:

- find_package(SDL2_Image REQUIRED)
- find_package(SDL2_Mixer REQUIRED)
+ find_package(SDL2_image REQUIRED)
+ find_package(SDL2_mixer REQUIRED)

Otherwise I've created a Cmake-free version too, put this to "src/Makefile", It Just Works™.

TARGET=../openggs
SRCS=$(wildcard *.cpp)
OBJS=$(SRCS:.cpp=.o)
CFLAGS=-I/usr/include/SDL2
LIBS=-lSDL2 -lSDL2_mixer -lSDL2_image

all: $(OBJS) $(TARGET)

%.o: %.cpp
	g++ $(CFLAGS) -c $<

$(TARGET): $(OBJS)
	g++ $(OBJS) -o $(TARGET) $(LIBS)

clean:
	rm *.o $(TARGET)

BTW, you should change the includes in the sources, for example

- #include <SDL.h>
+ #include <SDL2/SDL.h>

and then there's no need for the CFLAGS variable, and it will work on any configuration too (headers could be installed in /usr/local/include too for example).

Finally, it wouldn't hurt to add this to the README:

Compilation
-----------

GNU/make: go to the "src" directory and run
\```
make
\```

CMake: in the project's directory, run
\```
cmake .
make
\```

Otherwise awesome rewrite, thank you very much! Very nostalgic!!!

Cheers,
bzt