source: trunk/third/xscreensaver/hacks/apple2-main.c @ 20148

/* xscreensaver, Copyright (c) 1998-2003 Jamie Zawinski <jwz@jwz.org>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.  No representations are made about the suitability of this
 * software for any purpose.  It is provided "as is" without express or
 * implied warranty.
 *
 * Apple ][ CRT simulator, by Trevor Blackwell <tlb@tlb.org>
 * with additional work by Jamie Zawinski <jwz@jwz.org>
 */

#include <math.h>
#include "screenhack.h"
#include "apple2.h"
#include <X11/Xutil.h>
#include <X11/Intrinsic.h>
#include <ctype.h>

#undef countof
#define countof(x) (sizeof((x))/sizeof((*x)))

#define DEBUG

extern XtAppContext app;

Time subproc_relaunch_delay = 3000;


/* Given a bitmask, returns the position and width of the field.
 */
static void
decode_mask (unsigned int mask, unsigned int *pos_ret, unsigned int *size_ret)
{
  int i;
  for (i = 0; i < 32; i++)
    if (mask & (1L << i))
      {
        int j = 0;
        *pos_ret = i;
        for (; i < 32; i++, j++)
          if (! (mask & (1L << i)))
            break;
        *size_ret = j;
        return;
      }
}


/* Given a value and a field-width, expands the field to fill out 8 bits.
 */
static unsigned char
spread_bits (unsigned char value, unsigned char width)
{
  switch (width)
    {
    case 8: return value;
    case 7: return (value << 1) | (value >> 6);
    case 6: return (value << 2) | (value >> 4);
    case 5: return (value << 3) | (value >> 2);
    case 4: return (value << 4) | (value);
    case 3: return (value << 5) | (value << 2) | (value >> 2);
    case 2: return (value << 6) | (value << 4) | (value);
    default: abort(); break;
    }
}


/* Convert an XImage (of any size/depth/visual) to a 32bpp RGB array.
   Scales it (without dithering) to WxH.
 */
static void
scale_image (Display *dpy, Window window, XImage *in,
             int fromx, int fromy, int fromw, int fromh,
             unsigned int *out, int w, int h)
{
  float scale;
  int x, y, i;
  unsigned int rpos=0, gpos=0, bpos=0; /* bitfield positions */
  unsigned int rsiz=0, gsiz=0, bsiz=0;
  unsigned int rmsk=0, gmsk=0, bmsk=0;
  unsigned char spread_map[3][256];
  XWindowAttributes xgwa;
  XColor *colors = 0;

  if (fromx + fromw > in->width ||
      fromy + fromh > in->height)
    abort();

  XGetWindowAttributes (dpy, window, &xgwa);

  /* Compute the field offsets for RGB decoding in the XImage,
     when in TrueColor mode.  Otherwise we use the colormap.
   */
  if (visual_class (xgwa.screen, xgwa.visual) == PseudoColor ||
      visual_class (xgwa.screen, xgwa.visual) == GrayScale)
    {
      int ncolors = visual_cells (xgwa.screen, xgwa.visual);
      colors = (XColor *) calloc (sizeof (*colors), ncolors+1);
      for (i = 0; i < ncolors; i++)
        colors[i].pixel = i;
      XQueryColors (dpy, xgwa.colormap, colors, ncolors);
    }
  else
    {
      rmsk = xgwa.visual->red_mask;
      gmsk = xgwa.visual->green_mask;
      bmsk = xgwa.visual->blue_mask;
      decode_mask (rmsk, &rpos, &rsiz);
      decode_mask (gmsk, &gpos, &gsiz);
      decode_mask (bmsk, &bpos, &bsiz);

      for (i = 0; i < 256; i++)
        {
          spread_map[0][i] = spread_bits (i, rsiz);
          spread_map[1][i] = spread_bits (i, gsiz);
          spread_map[2][i] = spread_bits (i, bsiz);
        }
    }

  scale = (fromw > fromh
           ? (float) fromw / w
           : (float) fromh / h);

  /* Scale the pixmap from window size to Apple][ screen size (but 32bpp)
   */
  for (y = 0; y < h-1; y++)     /* iterate over dest pixels */
    for (x = 0; x < w-1; x++)
      {
        int xx, yy;
        unsigned int r=0, g=0, b=0;

        int xx1 = x * scale + fromx;
        int yy1 = y * scale + fromy;
        int xx2 = (x+1) * scale + fromx;
        int yy2 = (y+1) * scale + fromy;

        /* Iterate over the source pixels contributing to this one, and sum. */
        for (xx = xx1; xx < xx2; xx++)
          for (yy = yy1; yy < yy2; yy++)
            {
              unsigned char rr, gg, bb;
              unsigned long sp = ((xx > in->width || yy > in->height)
                                  ? 0 : XGetPixel (in, xx, yy));
              if (colors)
                {
                  rr = colors[sp].red   & 0xFF;
                  gg = colors[sp].green & 0xFF;
                  bb = colors[sp].blue  & 0xFF;
                }
              else
                {
                  rr = (sp & rmsk) >> rpos;
                  gg = (sp & gmsk) >> gpos;
                  bb = (sp & bmsk) >> bpos;
                  rr = spread_map[0][rr];
                  gg = spread_map[1][gg];
                  bb = spread_map[2][bb];
                }
              r += rr;
              g += gg;
              b += bb;
            }

        /* Scale summed pixel values down to 8/8/8 range */
        i = (xx2 - xx1) * (yy2 - yy1);
        if (i < 1) i = 1;
        r /= i;
        g /= i;
        b /= i;

        out[y * w + x] = (r << 16) | (g << 8) | b;
      }
}


/* Convert an XImage (of any size/depth/visual) to a 32bpp RGB array.
   Picks a random sub-image out of the source image, and scales it to WxH.
 */
static void
pick_a2_subimage (Display *dpy, Window window, XImage *in,
                  unsigned int *out, int w, int h)
{
  int fromx, fromy, fromw, fromh;
  if (in->width <= w || in->height <= h)
    {
      fromx = 0;
      fromy = 0;
      fromw = in->width;
      fromh = in->height;
    }
  else
    {
      int dw, dh;
      do {
        double scale = (0.5 + frand(0.7) + frand(0.7) + frand(0.7));
        fromw = w * scale;
        fromh = h * scale;
      } while (fromw > in->width ||
               fromh > in->height);

      dw = (in->width  - fromw) / 2;   /* near the center! */
      dh = (in->height - fromh) / 2;

      fromx = (random() % dw) + (dw/2);
      fromy = (random() % dh) + (dh/2);
    }

  scale_image (dpy, window, in,
               fromx, fromy, fromw, fromh,
               out, w, h);
}


/* Floyd-Steinberg dither.  Derived from ppmquant.c,
   Copyright (c) 1989, 1991 by Jef Poskanzer.
 */
static void
a2_dither (unsigned int *in, unsigned char *out, int w, int h)
{
  /*
    Apple ][ color map. Each pixel can only be 1 or 0, but what that
    means depends on whether it's an odd or even pixel, and whether
    the high bit in the byte is set or not. If it's 0, it's always
    black.
   */
  static const int a2_cmap[2][2][3] = {
    {
      /* hibit=0 */
      {/* odd pixels = blue */    0x00, 0x80, 0xff},
      {/* even pixels = red */    0xff, 0x80, 0x00}
    },
    {
      /* hibit=1 */
      {/* even pixels = purple */ 0xa0, 0x40, 0xa0},
      {/* odd pixels = green */   0x40, 0xff, 0x40}
    }
  };

  int x, y;
  unsigned int **pixels;
  unsigned int *pP;
  int maxval = 255;
  long *this_rerr;
  long *next_rerr;
  long *this_gerr;
  long *next_gerr;
  long *this_berr;
  long *next_berr;
  long *temp_err;
  int fs_scale = 1024;
  int brightness = 75;
  int fs_direction;

#if 0
  {
    FILE *pipe = popen ("xv -", "w");
    fprintf (pipe, "P6\n%d %d\n%d\n", w, h, 255);
    for (y = 0; y < h; y++)
      for (x = 0; x < w; x++)
        {
          unsigned int p = in[y * w + x];
          unsigned int r = (p >> 16) & 0xFF;
          unsigned int g = (p >>  8) & 0xFF;
          unsigned int b = (p      ) & 0xFF;
          fprintf(pipe, "%c%c%c", r, g, b);
        }
    fclose (pipe);
  }
#endif

  /* Initialize Floyd-Steinberg error vectors. */
  this_rerr = (long *) calloc (w + 2, sizeof(long));
  next_rerr = (long *) calloc (w + 2, sizeof(long));
  this_gerr = (long *) calloc (w + 2, sizeof(long));
  next_gerr = (long *) calloc (w + 2, sizeof(long));
  this_berr = (long *) calloc (w + 2, sizeof(long));
  next_berr = (long *) calloc (w + 2, sizeof(long));


  /* #### do we really need more than one element of "pixels" at once?
   */
  pixels = (unsigned int **) malloc (h * sizeof (unsigned int *));
  for (y = 0; y < h; y++)
    pixels[y] = (unsigned int *) malloc (w * sizeof (unsigned int));

  for (x = 0; x < w + 2; ++x)
    {
      this_rerr[x] = random() % (fs_scale * 2) - fs_scale;
      this_gerr[x] = random() % (fs_scale * 2) - fs_scale;
      this_berr[x] = random() % (fs_scale * 2) - fs_scale;
      /* (random errors in [-1 .. 1]) */
    }
  fs_direction = 1;

  for (y = 0; y < h; y++)
    for (x = 0; x < w; x++)
      pixels[y][x] = in[y * w + x];

  for (y = 0; y < h; y++)
    {
      int xbyte;
      int err;
      int prev_byte=0;

      for (x = 0; x < w + 2; x++)
        next_rerr[x] = next_gerr[x] = next_berr[x] = 0;

      /* It's too complicated to go back and forth on alternate rows,
         so we always go left-right here. It doesn't change the result
         very much.

         For each group of 7 pixels, we have to try it both with the
         high bit=0 and =1. For each high bit value, we add up the
         total error and pick the best one.

         Because we have to go through each group of bits twice, we
         don't propagate the error values through this_[rgb]err since
         it would add them twice. So we keep seperate local_[rgb]err
         variables for propagating error within the 7-pixel group.
      */

      pP = pixels[y];
      for (xbyte=0; xbyte<280; xbyte+=7)
        {
          int best_byte=0;
          int best_error=2000000000;
          int hibit;
          int sr, sg, sb;
          int r2, g2, b2;
          int local_rerr=0, local_gerr=0, local_berr=0;

          for (hibit=0; hibit<2; hibit++)
            {
              int byte = hibit<<7;
              int tot_error=0;

              for (x=xbyte; x<xbyte+7; x++)
                {
                  int dist0, dist1;

                  /* Use Floyd-Steinberg errors to adjust actual color. */
                  sr = ((pP[x] >> 16) & 0xFF) * brightness/256;
                  sg = ((pP[x] >>  8) & 0xFF) * brightness/256;
                  sb = ((pP[x]      ) & 0xFF) * brightness/256;
                  sr += (this_rerr[x + 1] + local_rerr) / fs_scale;
                  sg += (this_gerr[x + 1] + local_gerr) / fs_scale;
                  sb += (this_berr[x + 1] + local_berr) / fs_scale;

                  if  (sr < 0) sr = 0;
                  else if  (sr > maxval) sr = maxval;
                  if  (sg < 0) sg = 0;
                  else if  (sg > maxval) sg = maxval;
                  if  (sb < 0) sb = 0;
                  else if  (sb > maxval) sb = maxval;

                  /* This is the color we'd get if we set the bit 1. For 0,
                     we get black */
                  r2=a2_cmap[hibit][x&1][0];
                  g2=a2_cmap[hibit][x&1][1];
                  b2=a2_cmap[hibit][x&1][2];

                  /*
                     dist0 and dist1 are the error (Minkowski 2-metric
                     distances in the color space) for choosing 0 and
                     1 respectively. 0 is black, 1 is the color r2,g2,b2.
                  */
                  dist1= (sr-r2)*(sr-r2) + (sg-g2)*(sg-g2) + (sb-b2)*(sb-b2);
                  dist0= sr*sr + sg*sg + sb*sb;

                  if (dist1<dist0)
                    {
                      byte |= 1 << (x-xbyte);
                      tot_error += dist1;

                      /* Wanted sr but got r2, so propagate sr-r2 */
                      local_rerr =  (sr - r2) * fs_scale * 7/16;
                      local_gerr =  (sg - g2) * fs_scale * 7/16;
                      local_berr =  (sb - b2) * fs_scale * 7/16;
                    }
                  else
                    {
                      tot_error += dist0;

                      /* Wanted sr but got 0, so propagate sr */
                      local_rerr =  sr * fs_scale * 7/16;
                      local_gerr =  sg * fs_scale * 7/16;
                      local_berr =  sb * fs_scale * 7/16;
                    }
                }

              if (tot_error < best_error)
                {
                  best_byte = byte;
                  best_error = tot_error;
                }
            }

          /* Avoid alternating 7f and ff in all-white areas, because it makes
             regular pink vertical lines */
          if ((best_byte&0x7f)==0x7f && (prev_byte&0x7f)==0x7f)
            best_byte=prev_byte;
          prev_byte=best_byte;

        /*
          Now that we've chosen values for all 8 bits of the byte, we
          have to fill in the real pixel values into pP and propagate
          all the error terms. We end up repeating a lot of the code
          above.
         */

        for (x=xbyte; x<xbyte+7; x++)
          {
            int bit=(best_byte>>(x-xbyte))&1;
            hibit=(best_byte>>7)&1;

            sr = (pP[x] >> 16) & 0xFF;
            sg = (pP[x] >>  8) & 0xFF;
            sb = (pP[x]      ) & 0xFF;
            sr += this_rerr[x + 1] / fs_scale;
            sg += this_gerr[x + 1] / fs_scale;
            sb += this_berr[x + 1] / fs_scale;

            if  (sr < 0) sr = 0;
            else if  (sr > maxval) sr = maxval;
            if  (sg < 0) sg = 0;
            else if  (sg > maxval) sg = maxval;
            if  (sb < 0) sb = 0;
            else if  (sb > maxval) sb = maxval;

            r2=a2_cmap[hibit][x&1][0] * bit;
            g2=a2_cmap[hibit][x&1][1] * bit;
            b2=a2_cmap[hibit][x&1][2] * bit;

            pP[x] = (r2<<16) | (g2<<8) | (b2);

            /* Propagate Floyd-Steinberg error terms. */
            err =  (sr - r2) * fs_scale;
            this_rerr[x + 2] +=  (err * 7) / 16;
            next_rerr[x    ] +=  (err * 3) / 16;
            next_rerr[x + 1] +=  (err * 5) / 16;
            next_rerr[x + 2] +=  (err    ) / 16;
            err =  (sg - g2) * fs_scale;
            this_gerr[x + 2] +=  (err * 7) / 16;
            next_gerr[x    ] +=  (err * 3) / 16;
            next_gerr[x + 1] +=  (err * 5) / 16;
            next_gerr[x + 2] +=  (err    ) / 16;
            err =  (sb - b2) * fs_scale;
            this_berr[x + 2] +=  (err * 7) / 16;
            next_berr[x    ] +=  (err * 3) / 16;
            next_berr[x + 1] +=  (err * 5) / 16;
            next_berr[x + 2] +=  (err    ) / 16;
          }

        /*
          And put the actual byte into out.
        */

        out[y*(w/7) + xbyte/7] = best_byte;

        }

      temp_err  = this_rerr;
      this_rerr = next_rerr;
      next_rerr = temp_err;
      temp_err  = this_gerr;
      this_gerr = next_gerr;
      next_gerr = temp_err;
      temp_err  = this_berr;
      this_berr = next_berr;
      next_berr = temp_err;
    }

  free (this_rerr);
  free (next_rerr);
  free (this_gerr);
  free (next_gerr);
  free (this_berr);
  free (next_berr);

  for (y=0; y<h; y++)
    free (pixels[y]);
  free (pixels);

#if 0
  {
    /* let's see what we got... */
    FILE *pipe = popen ("xv -", "w");
    fprintf (pipe, "P6\n%d %d\n%d\n", w, h, 255);
    for (y = 0; y < h; y++)
      for (x = 0; x < w; x++)
        {
          unsigned int r = (pixels[y][x]>>16)&0xff;
          unsigned int g = (pixels[y][x]>>8)&0xff;
          unsigned int b = (pixels[y][x]>>0)&0xff;
          fprintf(pipe, "%c%c%c", r, g, b);
        }
    fclose (pipe);
  }
#endif
}


static unsigned char *
load_image (Display *dpy, Window window, char **image_filename_r)
{
  XWindowAttributes xgwa;
  Pixmap p;

  int w = 280;
  int h = 192;
  XImage *image;
  unsigned int  *buf32 = (unsigned int  *) calloc (w, h * 4);
  unsigned char *buf8  = (unsigned char *) calloc (w/7, h);

  if (!buf32 || !buf8)
    {
      fprintf (stderr, "%s: out of memory (%dx%d)\n", progname, w, h);
      exit (1);
    }

  XGetWindowAttributes (dpy, window, &xgwa);
  p = XCreatePixmap (dpy, window, xgwa.width, xgwa.height, xgwa.depth);
  load_random_image (xgwa.screen, window, p, image_filename_r);
  image = XGetImage (dpy, p, 0, 0, xgwa.width, xgwa.height, ~0, ZPixmap);
  XFreePixmap (dpy, p);
  p = 0;

  /* Make sure the window's background is not set to None, and get the
     grabbed bits (if any) off it as soon as possible. */
  XSetWindowBackground (dpy, window,
                        get_pixel_resource ("background", "Background",
                                            dpy, xgwa.colormap));
  XClearWindow (dpy, window);

  /* Scale the XImage down to Apple][ size, and convert it to a 32bpp
     image (regardless of whether it started as TrueColor/PseudoColor.)
   */
  pick_a2_subimage (dpy, window, image, buf32, w, h);

  /* Then dither the 32bpp image to a 6-color Apple][ colormap.
   */
  a2_dither (buf32, buf8, w, h);

  free (buf32);
  return buf8;
}


char *progclass = "Apple2";

char *defaults [] = {
  "*mode:                  random",
  "*duration:              20",
  ANALOGTV_DEFAULTS
  0
};

XrmOptionDescRec options [] = {
  { "-slideshow",       ".mode",                XrmoptionNoArg, "slideshow" },
  { "-basic",           ".mode",                XrmoptionNoArg, "basic" },
  { "-text",            ".mode",                XrmoptionNoArg, "text" },
  { "-program",         ".program",             XrmoptionSepArg, 0 },
  { "-duration",        ".duration",            XrmoptionSepArg, 0 },
  ANALOGTV_OPTIONS
  { 0, 0, 0, 0 }
};

/*
  TODO: this should load 10 images at startup time, then cycle through them
  to avoid the pause while it loads.
 */

void slideshow_controller(apple2_sim_t *sim, int *stepno,
                          double *next_actiontime)
{
  apple2_state_t *st=sim->st;
  int i;
  struct mydata {
    int slideno;
    int render_img_lineno;
    u_char *render_img;
    char *img_filename;
  } *mine;

  if (!sim->controller_data)
    sim->controller_data = calloc(sizeof(struct mydata),1);
  mine=(struct mydata *) sim->controller_data;

  switch(*stepno) {

  case 0:
    a2_invalidate(st);
    a2_clear_hgr(st);
    a2_cls(st);
    sim->typing_rate = 0.3;
    sim->dec->powerup=0.0;

    a2_goto(st, 0, 16);
    a2_prints(st, "APPLE ][");
    a2_goto(st,23,0);
    a2_printc(st,']');

    *next_actiontime += 4.0;
    *stepno=10;

  case 10:
    mine->render_img = load_image (sim->dpy, sim->window, &mine->img_filename);
    if (st->gr_mode) {
      *stepno=30;
    } else {
      *stepno=20;
    }
    *next_actiontime += 3.0;
    break;

  case 20:
    sim->typing="HGR\n";
    *stepno=29;
    break;

  case 29:
    sim->printing="]";
    *stepno=30;
    break;

  case 30:
    st->gr_mode=A2_GR_HIRES;
    if (mine->img_filename) {
      char *basename, *tmp;
      char *s;

      basename = tmp = strdup (mine->img_filename);
      while (1)
        {
          char *slash = strchr(basename, '/');
          if (!slash || !slash[1]) break;
          basename = slash+1;
        }
      {
        char *dot=strchr(basename,'.');
        if (dot) *dot=0;
      }
      if (strlen(basename)>20) basename[20]=0;
      for (s=basename; *s; s++) *s = toupper (*s);
      sprintf(sim->typing_buf, "BLOAD %s\n", basename);
      sim->typing = sim->typing_buf;

      free(tmp);
    } else {
      sim->typing = "BLOAD IMAGE\n";
    }
    mine->render_img_lineno=0;

    *stepno=35;
    break;

  case 35:
    *next_actiontime += 0.7;
    *stepno=40;
    break;

  case 40:
    if (mine->render_img_lineno>=192) {
      sim->printing="]";
      sim->typing="POKE 49234,0\n";
      *stepno=50;
      return;
    }

    for (i=0; i<6 && mine->render_img_lineno<192; i++) {
      a2_display_image_loading(st, mine->render_img,
                               mine->render_img_lineno++);
    }

    /* The disk would have to seek every 13 sectors == 78 lines.
       (This ain't no newfangled 16-sector operating system) */
    if ((mine->render_img_lineno%78)==0) {
      *next_actiontime += 0.5;
    } else {
      *next_actiontime += 0.08;
    }
    break;

  case 50:
    st->gr_mode |= A2_GR_FULL;
    *stepno=60;
    *next_actiontime += sim->delay;
    break;

  case 60:
    sim->printing="]";
    sim->typing="POKE 49235,0\n";
    *stepno=70;
    break;

  case 70:
    sim->printing="]";
    st->gr_mode &= ~A2_GR_FULL;
    if (mine->render_img) {
      free(mine->render_img);
      mine->render_img=NULL;
    }
    if (mine->img_filename) {
      free(mine->img_filename);
      mine->img_filename=NULL;
    }
    *stepno=10;
    break;

  case A2CONTROLLER_FREE:
    free(mine->render_img);
    free(mine->img_filename);
    free(mine);
    return;

  }
}

struct terminal_controller_data {
  FILE *pipe;
  int pipe_id;
  int input_available_p;
  XtIntervalId timeout_id;
  char curword[256];
  unsigned char lastc;
  int fake_nl;
  double last_emit_time;
};

static void
subproc_cb (XtPointer closure, int *source, XtInputId *id)
{
  struct terminal_controller_data *mine =
    (struct terminal_controller_data *) closure;
  mine->input_available_p = True;
}

static void
launch_text_generator (struct terminal_controller_data *mine)
{
  char *oprogram = get_string_resource ("program", "Program");
  char *program;

  if (!oprogram || !*oprogram)
    oprogram = FORTUNE_PROGRAM;

  program = (char *) malloc (strlen (oprogram) + 10);

  strcpy (program, "( ");
  strcat (program, oprogram);
  strcat (program, " ) 2>&1");

  if (mine->pipe) abort();
  if ((mine->pipe = popen (program, "r")))
    {
      if (mine->pipe_id) abort();
      mine->pipe_id =
        XtAppAddInput (app, fileno (mine->pipe),
                       (XtPointer) (XtInputReadMask | XtInputExceptMask),
                       subproc_cb, (XtPointer) mine);
    }
  else
    {
      perror (program);
    }
}

static void
relaunch_generator_timer (XtPointer closure, XtIntervalId *id)
{
  struct terminal_controller_data *mine =
    (struct terminal_controller_data *) closure;
  mine->timeout_id=0;
  launch_text_generator (mine);
}

static void
terminal_closegen(struct terminal_controller_data *mine)
{
  if (mine->pipe_id) {
    XtRemoveInput (mine->pipe_id);
    mine->pipe_id = 0;
  }
  if (mine->pipe) {
    pclose (mine->pipe);
    mine->pipe = 0;
  }
  if (mine->timeout_id) {
    XtRemoveTimeOut(mine->timeout_id);
    mine->timeout_id=0;
  }
}

static int
terminal_read(struct terminal_controller_data *mine, unsigned char *buf, int n)
{
  int rc;
  if (mine->fake_nl) {
    buf[0]='\n';
    mine->fake_nl=0;
    return 1;
  }

  if (!mine->input_available_p) return 0;

  rc=read (fileno (mine->pipe), (void *) buf, n);
  if (rc>0) mine->lastc=buf[rc-1];

  if (rc<=0)
    {
      terminal_closegen(mine);

      if (mine->lastc != '\n') { /* add a newline at eof if there wasn't one */
        mine->fake_nl=1;
      }

      /* Set up a timer to re-launch the subproc in a bit. */
      mine->timeout_id =
        XtAppAddTimeOut(app, subproc_relaunch_delay,
                        relaunch_generator_timer,
                        (XtPointer) mine);
    }

  mine->input_available_p = False;

  return rc;
}


/*
  It's fun to put things like "gdb" as the command. For one, it's
  amusing how the standard mumble (version, no warranty, it's
  GNU/Linux dammit) occupies an entire screen on the Apple ][.
*/

void
terminal_controller(apple2_sim_t *sim, int *stepno, double *next_actiontime)
{
  apple2_state_t *st=sim->st;
  int c;
  int i;

  struct terminal_controller_data *mine;
  if (!sim->controller_data)
    sim->controller_data=calloc(sizeof(struct terminal_controller_data),1);
  mine=(struct terminal_controller_data *) sim->controller_data;

  switch(*stepno) {

  case 0:
    if (random()%2)
      st->gr_mode |= A2_GR_FULL; /* Turn on color mode even through it's
                                    showing text */
    a2_cls(st);
    a2_goto(st,0,16);
    a2_prints(st, "APPLE ][");
    a2_goto(st,2,0);

    if (! mine->pipe)
      launch_text_generator(mine);

    *next_actiontime += 4.0;
    *stepno = 10;
    break;

  case 10:
    {
      unsigned char buf[5];
      int nr,nwant;
      double elapsed;

      elapsed=sim->curtime - mine->last_emit_time;
      mine->last_emit_time=sim->curtime;
      nwant=elapsed*25.0;
      if (elapsed>1.0) nwant=1;
      if (nwant<1) nwant=1;
      if (nwant>4) nwant=4;

      nr=terminal_read(mine, buf, nwant);
      for (i=0; i<nr; i++) {
        c=buf[i];
        if (c < 0)
          ;
        else if (c >= 'a' && c <= 'z')            /* upcase lower-case chars */
          {
            a2_printc(st, c&0xDF);
          }
        else if ((c >= 'A'+128) ||                    /* upcase and blink */
                 (c < ' ' && c != 014 &&              /* high-bit & ctl chrs */
                  c != '\r' && c != '\n' && c!='\t'))
          {
            a2_printc(st, (c & 0x1F) | 0x80);
          }
        else if (c >= 'A' && c <= 'Z')            /* invert upper-case chars */
          {
            a2_printc(st, c | 0x80);
          }
        else {
          a2_printc(st, c);
        }
      }
    }
    break;

  case A2CONTROLLER_FREE:
    terminal_closegen(mine);
    free(mine);
    return;
  }
}

struct basic_controller_data {
  int prog_line;
  int x,y,k;
  char **progtext;
  int progstep;
  char *rep_str;
  int rep_pos;
  double prog_start_time;
  char error_buf[256];
};

/*
  Adding more programs is easy. Just add a listing here and to all_programs,
  then add the state machine to actually execute it to basic_controller.
 */
static char *moire_program[]={
  "10 HGR2\n",
  "20 FOR Y = 0 TO 191 STEP 2\n",
  "30 HCOLOR=4 : REM BLACK\n",
  "40 HLINE 0,191-Y TO 279,Y\n",
  "60 HCOLOR=7 : REM WHITE\n",
  "80 HLINE 0,190-Y TO 279,Y+1\n",
  "90 NEXT Y\n",
  "100 FOR X = 0 TO 279 STEP 3\n",
  "110 HCOLOR=4\n",
  "120 HLINE 279-X,0 TO X,192\n",
  "140 HCOLOR=7\n",
  "150 HLINE 278-X,0 TO X+1,192\n",
  "160 NEXT X\n",
  NULL
};

static char *sinewave_program[] = {
  "10 HGR\n",
  "25 K=0\n",
  "30 FOR X = 0 TO 279\n",
  "32 HCOLOR= 0\n",
  "35 HLINE X,0 TO X,159\n",
  "38 HCOLOR= 3\n",
  "40 Y = 80 + SIN(15*(X-K)/279)\n",
  "50 HPLOT X,Y\n",
  "60 NEXT X\n",
  "70 K=K+4\n",
  "80 GOTO 30\n",
  NULL
};

#if 0
static char *dumb_program[]={
  "10 PRINT \"APPLE ][ ROOLZ! TRS-80 DROOLZ!\"\n",
  "20 GOTO 10\n",
  NULL
};
#endif

static char *random_lores_program[]={
  "1 REM APPLE ][ SCREEN SAVER\n",
  "10 GR\n",
  "100 COLOR= RND(1)*16\n",

  "110 X=RND(1)*40\n",
  "120 Y1=RND(1)*48\n",
  "130 Y2=RND(1)*48\n",
  "140 FOR Y = Y1 TO Y2\n",
  "150 PLOT X,Y\n",
  "160 NEXT Y\n",

  "210 Y=RND(1)*48\n",
  "220 X1=RND(1)*40\n",
  "230 X2=RND(1)*40\n",
  "240 FOR X = X1 TO X2\n",
  "250 PLOT X,Y\n",
  "260 NEXT X\n",
  "300 GOTO 100\n",

  NULL
};

static char typo_map[256];

int make_typo(char *out_buf, char *orig, char *err_buf)
{
  int i,j;
  int errc;
  int success=0;
  err_buf[0]=0;

  typo_map['A']='Q';
  typo_map['S']='A';
  typo_map['D']='S';
  typo_map['F']='G';
  typo_map['G']='H';
  typo_map['H']='J';
  typo_map['J']='H';
  typo_map['K']='L';
  typo_map['L']=';';

  typo_map['Q']='1';
  typo_map['W']='Q';
  typo_map['E']='3';
  typo_map['R']='T';
  typo_map['T']='Y';
  typo_map['Y']='U';
  typo_map['U']='Y';
  typo_map['I']='O';
  typo_map['O']='P';
  typo_map['P']='[';

  typo_map['Z']='X';
  typo_map['X']='C';
  typo_map['C']='V';
  typo_map['V']='C';
  typo_map['B']='N';
  typo_map['N']='B';
  typo_map['M']='N';
  typo_map[',']='.';
  typo_map['.']=',';

  typo_map['!']='1';
  typo_map['@']='2';
  typo_map['#']='3';
  typo_map['$']='4';
  typo_map['%']='5';
  typo_map['^']='6';
  typo_map['&']='7';
  typo_map['*']='8';
  typo_map['(']='9';
  typo_map[')']='0';

  typo_map['1']='Q';
  typo_map['2']='W';
  typo_map['3']='E';
  typo_map['4']='R';
  typo_map['5']='T';
  typo_map['6']='Y';
  typo_map['7']='U';
  typo_map['8']='I';
  typo_map['9']='O';
  typo_map['0']='-';

  strcpy(out_buf, orig);
  for (i=0; out_buf[i]; i++) {
    char *p = out_buf+i;

    if (i>2 && p[-2]=='R' && p[-1]=='E' && p[0]=='M')
      break;

    if (isalpha(p[0]) &&
        isalpha(p[1]) &&
        p[0] != p[1] &&
        random()%15==0)
      {
        int tmp=p[1];
        p[1]=p[0];
        p[0]=tmp;
        success=1;
        sprintf(err_buf,"?SYNTAX ERROR\n");
        break;
      }

    if (random()%10==0 && strlen(p)>=4 && (errc=typo_map[(int)(u_char)p[0]])) {
      int remain=strlen(p);
      int past=random()%(remain-2)+1;
      memmove(p+past+past, p, remain+1);
      p[0]=errc;
      for (j=0; j<past; j++) {
        p[past+j]=010;
      }
      break;
    }
  }
  return success;
}

struct {
  char **progtext;
  int progstep;
} all_programs[]={
  {moire_program, 100},
  /*{dumb_program, 200}, */
  {sinewave_program, 400},
  {random_lores_program, 500},
};

void
basic_controller(apple2_sim_t *sim, int *stepno, double *next_actiontime)
{
  apple2_state_t *st=sim->st;
  int i;

  struct basic_controller_data *mine;
  if (!sim->controller_data)
    sim->controller_data=calloc(sizeof(struct basic_controller_data),1);
  mine=(struct basic_controller_data *) sim->controller_data;

  switch (*stepno) {
  case 0:
    st->gr_mode=0;
    a2_cls(st);
    a2_goto(st,0,16);
    a2_prints(st, "APPLE ][");
    a2_goto(st,23,0);
    a2_printc(st,']');
    sim->typing_rate=0.2;

    i=random()%countof(all_programs);
    mine->progtext=all_programs[i].progtext;
    mine->progstep=all_programs[i].progstep;
    mine->prog_line=0;

    *next_actiontime += 1.0;
    *stepno=10;
    break;

  case 10:
    if (st->cursx==0) a2_printc(st,']');
    if (mine->progtext[mine->prog_line]) {
      if (random()%4==0) {
        int err=make_typo(sim->typing_buf,
                          mine->progtext[mine->prog_line],
                          mine->error_buf);
        sim->typing=sim->typing_buf;
        if (err) {
          *stepno=11;
        } else {
          mine->prog_line++;
        }
      } else {
        sim->typing=mine->progtext[mine->prog_line++];
      }
    } else {
      *stepno=15;
    }
    break;

  case 11:
    sim->printing=mine->error_buf;
    *stepno=12;
    break;

  case 12:
    if (st->cursx==0) a2_printc(st,']');
    *next_actiontime+=1.0;
    *stepno=10;
    break;

  case 15:
    sim->typing="RUN\n";
    mine->y=0;
    mine->x=0;
    mine->k=0;
    mine->prog_start_time=*next_actiontime;
    *stepno=mine->progstep;
    break;

    /* moire_program */
  case 100:
    st->gr_mode=A2_GR_HIRES|A2_GR_FULL;
    for (i=0; i<24 && mine->y<192; i++)
      {
        a2_hline(st, 4, 0, 191-mine->y, 279, mine->y);
        a2_hline(st, 7, 0, 191-mine->y-1, 279, mine->y+1);
        mine->y += 2;
      }
    if (mine->y>=192) {
      mine->x = 0;
      *stepno = 110;
    }
    break;

  case 110:
    for (i=0; i<24 && mine->x<280; i++)
      {
        a2_hline(st, 4, 279-mine->x, 0, mine->x, 192);
        a2_hline(st, 7, 279-mine->x-1, 0, mine->x+1, 192);
        mine->x+=3;
      }
    if (mine->x >= 280) *stepno=120;
    break;

  case 120:
    if (*next_actiontime > mine->prog_start_time+sim->delay) *stepno=999;
    break;

    /* dumb_program */
  case 200:
    mine->rep_str="\nAPPLE ][ ROOLZ! TRS-80 DROOLZ!";
    for (i=0; i<30; i++) {
      a2_prints(st, mine->rep_str);
    }
    *stepno=210;
    break;

  case 210:
    i=random()%strlen(mine->rep_str);
    while (mine->rep_pos != i) {
      a2_printc(st, mine->rep_str[mine->rep_pos]);
      mine->rep_pos++;
      if (!mine->rep_str[mine->rep_pos]) mine->rep_pos=0;
    }
    if (*next_actiontime > mine->prog_start_time+sim->delay) *stepno=999;
    break;

    /* sinewave_program */
  case 400:
    st->gr_mode=A2_GR_HIRES;
    *stepno=410;
    break;

  case 410:
    for (i=0; i<48; i++) {
      int y=80 + (int)(75.0*sin(15.0*(mine->x-mine->k)/279.0));
      a2_hline(st, 0, mine->x, 0, mine->x, 159);
      a2_hplot(st, 3, mine->x, y);
      mine->x += 1;
      if (mine->x>=279) {
        mine->x=0;
        mine->k+=4;
      }
    }
    if (*next_actiontime > mine->prog_start_time+sim->delay) *stepno=999;
    break;

  case 420:
    a2_prints(st, "]");
    *stepno=999;
    break;

    /* random_lores_program */
  case 500:
    st->gr_mode=A2_GR_LORES|A2_GR_FULL;
    a2_clear_gr(st);
    *stepno=510;

  case 510:
    for (i=0; i<10; i++) {
      int color,x,y,x1,x2,y1,y2;

      color=random()%15;
      x=random()%40;
      y1=random()%48;
      y2=random()%48;
      for (y=y1; y<y2; y++) a2_plot(st, color, x, y);

      x1=random()%40;
      x2=random()%40;
      y=random()%48;
      for (x=x1; x<x2; x++) a2_plot(st, color, x, y);
    }
    if (*next_actiontime > mine->prog_start_time+sim->delay) *stepno=999;
    break;

  case 999:
    *stepno=0;
    break;

  case A2CONTROLLER_FREE:
    free(mine);
    break;
  }

}

void (*controllers[])(apple2_sim_t *sim, int *stepno,
                      double *next_actiontime) = {
  slideshow_controller,
  terminal_controller,
  basic_controller
};

void
screenhack (Display *dpy, Window window)
{
  int duration = get_integer_resource ("duration", "Integer");
  char *s;
  void (*controller)(apple2_sim_t *sim, int *stepno, double *next_actiontime);

  if (duration < 1) duration = 1;

  s = get_string_resource ("mode", "Mode");
  if (!s || !*s || !strcasecmp(s, "random"))
    controller = controllers[random() % (countof(controllers))];
  else if (!strcasecmp(s, "text"))
     controller = terminal_controller;
  else if (!strcasecmp(s, "slideshow"))
     controller = slideshow_controller;
  else if (!strcasecmp(s, "basic"))
     controller = basic_controller;
  else
    {
      fprintf (stderr, "%s: mode must be text, slideshow, or random; not %s\n",
               progname, s);
      exit (1);
    }

  if (!get_boolean_resource ("root", "Boolean"))
    {
      XWindowAttributes xgwa;
      XGetWindowAttributes (dpy, window, &xgwa);
      XSelectInput (dpy, window,
                    xgwa.your_event_mask |
                    KeyPressMask | ButtonPressMask | ExposureMask);
    }

  apple2 (dpy, window, duration, controller);
  XSync (dpy, False);
}