// Frame Buffer viewer for PSYCHOS!  (Type "siocons auto" to run.)
//
// Ever point a video camera at the TV screen that's showing what
// the camera sees and wave it around?  If you have and PARTICULARLY
// enjoyed yourself then this 'game' is for you.  Just move the pad
// around and experience psychotic-tendancy-inducing nausea-floudering
// mayhem.  If you start saying 'wow' and words like 'infinity' it's
// time to stop.

// Originally I made it as a frame buffer viewer to see if TIMs/CLUTs etc
// have loaded into video RAM properly and in the right place but
// discovered that the SIOCONS tool thing wipes the whole thing, so
// you have to code it into your programs.  BUT it is a basic example
// of how to have a virtual screen on the FB, and how to have the visible
// screen anywhere you want. (in this case the middle of the FB).

// If you play around with the delightful wavyness for over 10 minutes
// you are guaranteed to have a migraine.  Oh, I should probably warn
// epileptics not to even try it..

// by James Shaughnessy james@manc.u-net.com
// http://www.netyaroze-europe.com/~shaughnj


#include <stdio.h>
#include <libps.h>

#include "pad.h"


extern DISPENV GsDISPENV;

void PaintFB();

main()
{
  u_long PadStatus = 0;
  RECT *scr;
  short inc, maxxpos = 768, maxypos = 256;

  // Setup graphics PAL
  SetVideoMode(MODE_PAL);
  GsInitGraph(256, 256, 4, 0, 0);
  GsDISPENV.screen.x = 0;
  GsDISPENV.screen.y = 20;
  GsDISPENV.screen.w = 256;
  GsDISPENV.screen.h = 256;
  GsDISPENV.disp.x = 384;
  GsDISPENV.disp.y = 136;
  GsDISPENV.disp.w = 256;
  GsDISPENV.disp.h = 256;
  //GsDISPENV.isinter = 1;
  //GsDISPENV.isrgb24 = 1;

  GsDefDispBuff(384, 136, 384, 136);

  PadInit();

  scr->x = 384;
  scr->y = 136;
  scr->w = 256;
  scr->h = 256;

  PaintFB();

  while(1)
  {
    PadStatus = PadRead();

    // Quit if both Select and Start pressed
    if (PadStatus & PAD1select && PadStatus & PAD1start) break;

    inc = 1;
    if (PadStatus & PAD1R1)
    {
      inc +=3;
      if (PadStatus & PAD1L1)
        inc +=4;
    }

    if (PadStatus & PAD1Lleft) scr->x-=inc;
    if (PadStatus & PAD1Lright) scr->x+=inc;
    if (PadStatus & PAD1Lup) scr->y-=inc;
    if (PadStatus & PAD1Ldown) scr->y+=inc;

    if (scr->x < 0) scr->x = 0; else if (scr->x > maxxpos) scr->x = maxxpos;
    if (scr->y < 0) scr->y = 0; else if (scr->y > maxypos) scr->y = maxypos;

    // Wait for a vertical blank
    VSync(0);

    // Copy virtual screen to visible area
    MoveImage(scr, 384, 136);
    DrawSync(0);

    GsSwapDispBuff();
  }

  ResetGraph(0);
}



void PaintFB()
{
  short x, y;

  RECT box, FB;

  FB.x = FB.y = 0;
  FB.w = 1024;
  FB.h = 512;
  ClearImage(&FB, 0, 0, 0);
  box.w = 4;
  box.h = 5;

  for (y=0; y < 512; y+=6) {
    for (x=0; x < 1024; x+=5) {
      box.x = x; box.y = y;
      ClearImage(&box, rand()%256, rand()%256, rand()%256);
    }
  }
}





// ****** PAD routines ******
// low-level pad buffers: never need to touch
volatile u_char *bb0, *bb1;

// call once only in program initialisation
void PadInit (void)
{
  GetPadBuf(&bb0, &bb1);
}

// call once per VSync(0)
// puts controller pad status into unsigned long integer
// please refer to the manuals if you want explanation 
// of the internals of this function
u_long PadRead(void)
{
  return(~(*(bb0+3) | *(bb0+2) << 8 | *(bb1+3) << 16 | *(bb1+2) << 24));
}