8 bits

Simple sample to show you how to use palettes.

Using library

GP2X minimal library by rlyeh, 2005

License

• Free for non-commercial projects (it would be nice receiving a mail from you).  Other cases, ask me first.
• GamePark Holdings is not allowed to use this library and/or use parts from it.

Source code

#include "minimal.h"

int main(int argc, char *argv[])
{
 gp2x_init(1000, 8, 11025,16,1,60, 1);

 //set & update color #1 (as white)
 gp2x_video_RGB_color8(255,255,255,1);
 gp2x_video_RGB_setpalette();

 while(1)
 {
  unsigned long  pad=gp2x_joystick_read(), R=0,G=0,B=0;

  if(pad & GP2X_VOL_DOWN) if(pad & GP2X_START) exit(0);

  if(pad & GP2X_A) R=255;
  if(pad & GP2X_X) G=255;
  if(pad & GP2X_B) B=255;

  //set & update color #0
  gp2x_video_RGB_color8(R,G,B,0);
  gp2x_video_RGB_setpalette();

  //put a white pixel (color #1) at center of screen (160,120)
  gp2x_video_RGB[0].screen8[160+120*320]=1;

  gp2x_video_RGB_flip(0);
 }
}

void gp2x_sound_frame(void *blah, void *buff, int samples) { }

Explanation

• Our gp2x_init line inits the whole library.  We set 1000 ticks per second, 8 bits video mode, 11025/16bits/stereo/60Hz sound mode, and solid font.
• Our gp2x_joystick_read line reads the joystick.  It is used to act properly to different button combinations.
• Our first gp2x_video_RGB_color8 line sets color entry 1 to white.
• Our second gp2x_video_RGB_color8 line sets color entry 0 to a determinated color.  Note that the whole screen defaults to entry 0, so this will change the entire screen.
• Our gp2x_video_RGB_setpalette line updates all gp2x_video_RGB_color8 changes.  So at this point exactly the screen color will change.
• Our gp2x_video_RGB [0].screen8 line will plot a white pixel (color #1) at center of screen.
• Our gp2x_sound_frame line fills our sound buffer.  Note that this function will not generate any sound since we have written a void function.

C Compilation

arm-linux-gcc minimal.c 8bits.c -static -lpthread -lm

C++ Compilation

arm-linux-g++ minimal.c 8bits.c -static -lpthread -lm

Output

• this program show different color patterns when you press buttons (pressing A,X and/or B changes the color).
• press volume down and start buttons to exit.