start adding GL shaders, program, texture loading

Makefile

@@ -7,7 +7,7 @@ CFLAGS := $(shell freetype-config --cflags) $(shell sdl2-config --cflags)
 CXXFLAGS := $(CFLAGS)
 LDFLAGS := -l$(GL_LIB) -ldl -lfreetype $(shell sdl2-config --libs) $(shell freetype-config --libs)
 
-freetype2gl3: gl3w.o freetype2gl3.o
+freetype2gl3: gl3w.o freetype2gl3.o GLShader.o GLProgram.o
 	$(CXX) -o $@ $^ $(LDFLAGS)
 
 .PHONY: clean