1th_show_ascii
arm-linux-gnueabihf-gcc -o show_ascii show_ascii.c
ִ./show_ascii 

2th_show_font
arm-linux-gnueabihf-gcc -o show_font show_font.c
ִ./show_font 

3th_freetype_show_font
arm-linux-gnueabihf-gcc -finput-charset=GBK -fexec-charset=GBK -o freetype_show_font freetype_show_font.c  -lfreetype -lm
ִ./freetype_show_font ../simsun.ttc

4th_freetype_show_font_angle
arm-linux-gnueabihf-gcc -finput-charset=GBK -fexec-charset=GBK -o freetype_show_font_angle freetype_show_font_angle.c  -lfreetype -lm
ִ./freetype_show_font_angle ../simsun.ttc 90
