Lesson 0: Linux Command Line

To build the projects on Linux we’ll be using a simple makefile that will setup the include and library dependencies for us. The makefile assumes that your SDL libraries are installed under /usr/local/lib and the headers are under /usr/local/include. These are the install locations if you built the project through cmake, some more detail on building from source can be found here. If you’ve installed it through your package manager or placed the libraries and headers elsewhere you may need to change these paths to match your installation. You can also check the output of sdl2-config with the --cflags and --libs switches to locate your install, assuming you haven’t moved it.

If you’re unfamiliar with Makefiles a basic introduction can be found here.

The Makefile

CXX = g++
# Update these paths to match your installation
# You may also need to update the linker option rpath, which sets where to look for
# the SDL2 libraries at runtime to match your install
SDL_LIB = -L/usr/local/lib -lSDL2 -Wl,-rpath=/usr/local/lib
SDL_INCLUDE = -I/usr/local/include
# You may need to change -std=c++11 to -std=c++0x if your compiler is a bit older
CXXFLAGS = -Wall -c -std=c++11 $(SDL_INCLUDE)
LDFLAGS = $(SDL_LIB)
EXE = SDL_Lesson0

all: $(EXE)

$(EXE): main.o
	$(CXX) $< $(LDFLAGS) -o $@

main.o: main.cpp
	$(CXX) $(CXXFLAGS) $< -o $@

clean:
	rm *.o && rm $(EXE)

The Test Program

The program we’re building for this lesson is a simple sanity check for SDL. It will initialize the SDL video subsystem, check for any errors and then quit. The source file should be titled main.cpp, or you can change the main.o build dependency in the makefile to match your source file.

#include <iostream>
#include <SDL2/SDL.h>

/*
 * Lesson 0: Test to make sure SDL is setup properly
 */
int main(int, char**){
	if (SDL_Init(SDL_INIT_VIDEO) != 0){
		std::cout << "SDL_Init Error: " << SDL_GetError() << std::endl;
		return 1;
	}
	SDL_Quit();
	return 0;
}

The program should run successfully but nothing should appear to happen if you’ve configured everything properly. If an error occurs make sure you’ve followed all the setup steps properly.

End of Lesson 0

If you’re having any trouble setting up SDL please send an email or tweet.

I’ll see you again soon in Postscript 0: Properly Finding Resource Paths!

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Published: 15 August 2013