X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=hacks%2Fvfeedback.c;fp=hacks%2Fvfeedback.c;h=5b482a7b947a70c778571d9d74eaf2a3d1c986fb;hp=0000000000000000000000000000000000000000;hb=c85f503f5793839a6be4c818332aca4a96927bb2;hpb=78add6e627ee5f10e1fa6f3852602ea5066eee5a

diff --git a/hacks/vfeedback.c b/hacks/vfeedback.c
new file mode 100644
index 00000000..5b482a7b
--- /dev/null
+++ b/hacks/vfeedback.c
@@ -0,0 +1,628 @@
+/* vfeedback, Copyright (c) 2018 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.
+ *
+ * Simulates video feedback: pointing a video camera at an NTSC television.
+ *
+ * Created: 4-Aug-2018.
+ *
+ * TODO:
+ *
+ * - Figure out better UI gestures on mobile to pan, zoom and rotate.
+ *
+ * - When zoomed in really far, grab_rectangle should decompose pixels
+ *   into RGB phosphor dots.
+ *
+ * - Maybe load an image and chroma-key it, letting transparency bleed,
+ *   for that Amiga Genlock, Cabaret Voltaire look.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#include "screenhack.h"
+#include "analogtv.h"
+
+#include <time.h>
+
+#undef DEBUG
+#undef DARKEN
+
+#ifdef DEBUG
+# include "ximage-loader.h"
+# include "images/gen/testcard_bbcf_png.h"
+#endif
+
+#undef countof
+#define countof(x) (sizeof((x))/sizeof((*x)))
+
+#define RANDSIGN() ((random() & 1) ? 1 : -1)
+
+struct state {
+  Display *dpy;
+  Window window;
+  XWindowAttributes xgwa;
+  int w, h;
+  Pixmap pix;
+  GC gc;
+  double start, last_time;
+  double noise;
+  double zoom, rot;
+  double value, svalue, speed, dx, dy, ds, dth;
+
+  struct { double x, y, w, h, th; } rect, orect;
+  struct { int x, y, s; } specular;
+
+  enum { POWERUP, IDLE, MOVE } state;
+  analogtv *tv;
+  analogtv_reception rec;
+  Bool button_down_p;
+  int mouse_x, mouse_y;
+  double mouse_th;
+  Bool dragmode;
+
+# ifdef DEBUG
+  XImage *tcimg;
+# endif
+
+};
+
+
+static void
+twiddle_knobs (struct state *st)
+{
+  st->rec.ofs = random() % ANALOGTV_SIGNAL_LEN;		/* roll picture once */
+  st->rec.level = 0.8 + frand(1.0);  /* signal strength (low = dark, static) */
+  st->tv->color_control    = frand(1.0) * RANDSIGN();
+  st->tv->contrast_control = 0.4 + frand(1.0);
+  st->tv->tint_control     = frand(360);
+}
+
+
+static void
+twiddle_camera (struct state *st)
+{
+# if 0
+  st->rect.x  = 0;
+  st->rect.y  = 0;
+  st->rect.w  = 1;
+  st->rect.h  = 1;
+  st->rect.th = 0;
+# else
+  st->rect.x = frand(0.1) * RANDSIGN();
+  st->rect.y = frand(0.1) * RANDSIGN();
+  st->rect.w = st->rect.h = 1 + frand(0.4) * RANDSIGN();
+  st->rect.th = 0.2 + frand(1.0) * RANDSIGN();
+# endif
+}
+
+
+static void *
+vfeedback_init (Display *dpy, Window window)
+{
+  struct state *st = (struct state *) calloc (1, sizeof(*st));
+  XGCValues gcv;
+
+  st->dpy = dpy;
+  st->window = window;
+  st->tv = analogtv_allocate (st->dpy, st->window);
+  analogtv_set_defaults (st->tv, "");
+  st->tv->need_clear = 1;
+  st->rec.input = analogtv_input_allocate();
+  analogtv_setup_sync (st->rec.input, 1, 0);
+  st->tv->use_color = 1;
+  st->tv->powerup = 0;
+  st->rec.multipath = 0;
+  twiddle_camera (st);
+  twiddle_knobs (st);
+  st->noise = get_float_resource (st->dpy, "noise", "Float");
+  st->speed = get_float_resource (st->dpy, "speed", "Float");
+
+  XGetWindowAttributes (dpy, window, &st->xgwa);
+
+  st->state = POWERUP;
+  st->value = 0;
+
+  st->w = 640;
+  st->h = 480;
+  gcv.foreground = get_pixel_resource (st->dpy, st->xgwa.colormap,
+                                       "foreground", "Foreground");
+  st->gc = XCreateGC (dpy, st->window, GCForeground, &gcv);
+
+  st->orect = st->rect;
+
+# ifdef DEBUG
+  {
+    int w, h;
+    Pixmap p;
+    p = image_data_to_pixmap (dpy, window,
+                              testcard_bbcf_png, sizeof(testcard_bbcf_png),
+                              &w, &h, 0);
+    st->tcimg = XGetImage (dpy, p, 0, 0, w, h, ~0L, ZPixmap);
+    XFreePixmap (dpy, p);
+  }
+# endif
+
+# ifndef HAVE_JWXYZ
+  XSelectInput (dpy, window,
+                PointerMotionMask | st->xgwa.your_event_mask);
+# endif
+
+  return st;
+}
+
+
+static double
+ease_fn (double r)
+{
+  return cos ((r/2 + 1) * M_PI) + 1; /* Smooth curve up, end at slope 1. */
+}
+
+
+static double
+ease_ratio (double r)
+{
+  double ease = 0.5;
+  if      (r <= 0)     return 0;
+  else if (r >= 1)     return 1;
+  else if (r <= ease)  return     ease * ease_fn (r / ease);
+  else if (r > 1-ease) return 1 - ease * ease_fn ((1 - r) / ease);
+  else                 return r;
+}
+
+
+static XImage *
+grab_rectangle (struct state *st)
+{
+  XImage *in, *out;
+
+  /* Under XQuartz we can't just do XGetImage on the Window, we have to
+     go through an intermediate Pixmap first.  I don't understand why.
+   */
+  if (! st->pix)
+    st->pix = XCreatePixmap (st->dpy, st->window, 
+                             st->xgwa.width, st->xgwa.height, st->xgwa.depth);
+
+  XCopyArea (st->dpy, st->window, st->pix, st->gc, 0, 0,
+             st->xgwa.width, st->xgwa.height, 0, 0);
+
+  if (st->specular.s)
+    {
+      double p = 0.2;
+      double r = (st->svalue <    p ? st->svalue/p :
+                  st->svalue >= 1-p ? (1-st->svalue)/p :
+                  1);
+      double s = st->specular.s * ease_ratio (r * 2);
+      XFillArc (st->dpy, st->pix, st->gc,
+                st->specular.x - s/2,
+                st->specular.y - s/2,
+                s, s, 0, 360*64);
+    }
+
+# ifdef DEBUG
+  in = st->tcimg;
+# else
+  in = XGetImage (st->dpy, st->pix,
+                  0, 0, st->xgwa.width, st->xgwa.height,
+                  ~0L, ZPixmap);
+  /* Could actually use st->tv->image here, except we don't have the
+     subrectangle being used (overall_top, usewidth, etc.) */
+# endif
+
+  out = XCreateImage (st->dpy, st->xgwa.visual, st->xgwa.depth,
+                      ZPixmap, 0, NULL,
+                      st->w, st->h, 8, 0);
+
+  if (! in) abort();
+  if (! out) abort();
+  out->data = (char *) calloc (out->height, out->bytes_per_line);
+  if (! out->data) abort();
+
+  {
+    double C = cos (st->rect.th);
+    double S = sin (st->rect.th);
+    unsigned long black = BlackPixelOfScreen (st->xgwa.screen);
+    int ox, oy;
+    for (oy = 0; oy < out->height; oy++)
+      {
+        double doy = (double) oy / out->height;
+        double diy = st->rect.h * doy + st->rect.y - 0.5;
+
+        float dix_mul = (float) st->rect.w / out->width;
+        float dix_add = (-0.5 + st->rect.x) * st->rect.w;
+        float ix_add = (-diy * S + 0.5) * in->width;
+        float iy_add = ( diy * C + 0.5) * in->height;
+        float ix_mul = C * in->width;
+        float iy_mul = S * in->height;
+
+        ix_add += dix_add * ix_mul;
+        iy_add += dix_add * iy_mul;
+        ix_mul *= dix_mul;
+        iy_mul *= dix_mul;
+
+        if (in->bits_per_pixel == 32 &&
+            out->bits_per_pixel == 32)
+          {
+            /* Unwrapping XGetPixel and XPutPixel gains us several FPS here */
+            uint32_t *out_line =
+              (uint32_t *) (out->data + out->bytes_per_line * oy);
+            for (ox = 0; ox < out->width; ox++)
+              {
+                float dix = ox;
+                int ix = dix * ix_mul + ix_add;
+                int iy = dix * iy_mul + iy_add;
+                unsigned long p = (ix >= 0 && ix < in->width &&
+                                   iy >= 0 && iy < in->height
+                                   ? ((uint32_t *)
+                                      (in->data + in->bytes_per_line * iy))[ix]
+                                   : black);
+# ifdef HAVE_JWXYZ
+                p |= black;   /* We get 0 instead of BlackPixel... */
+# endif
+                out_line[ox] = p;
+              }
+          }
+        else
+          for (ox = 0; ox < out->width; ox++)
+            {
+              float dix = ox;
+              int ix = dix * ix_mul + ix_add;
+              int iy = dix * iy_mul + iy_add;
+              unsigned long p = (ix >= 0 && ix < in->width &&
+                                 iy >= 0 && iy < in->height
+                                 ? XGetPixel (in, ix, iy)
+                                 : black);
+# ifdef HAVE_JWXYZ
+              p |= black;   /* We get 0 instead of BlackPixel... */
+# endif
+              XPutPixel (out, ox, oy, p);
+            }
+      }
+  }
+
+# ifndef DEBUG
+  XDestroyImage (in);
+# endif
+
+  return out;
+}
+
+
+static double
+double_time (void)
+{
+  struct timeval now;
+# ifdef GETTIMEOFDAY_TWO_ARGS
+  struct timezone tzp;
+  gettimeofday(&now, &tzp);
+# else
+  gettimeofday(&now);
+# endif
+
+  return (now.tv_sec + ((double) now.tv_usec * 0.000001));
+}
+
+
+static unsigned long
+vfeedback_draw (Display *dpy, Window window, void *closure)
+{
+  struct state *st = (struct state *) closure;
+  const analogtv_reception *rec = &st->rec;
+  double then = double_time(), now, timedelta;
+  XImage *img = 0;
+
+  switch (st->state) {
+  case POWERUP: case IDLE: break;
+  case MOVE:
+    st->rect.x  = st->orect.x  + st->dx  * ease_ratio (st->value);
+    st->rect.y  = st->orect.y  + st->dy  * ease_ratio (st->value);
+    st->rect.th = st->orect.th + st->dth * ease_ratio (st->value);
+    st->rect.w  = st->orect.w * (1 + (st->ds * ease_ratio (st->value)));
+    st->rect.h  = st->orect.h * (1 + (st->ds * ease_ratio (st->value)));
+    break;
+  default:
+    abort();
+    break;
+  }
+
+  if (! st->button_down_p)
+    {
+      st->value  += 0.03 * st->speed;
+      if (st->value > 1 || st->state == POWERUP)
+        {
+          st->orect = st->rect;
+          st->value = 0;
+          st->dx = st->dy = st->ds = st->dth = 0;
+
+          switch (st->state) {
+          case POWERUP:
+            /* Wait until the monitor has warmed up before turning on
+               the camcorder? */
+            /* if (st->tv->powerup > 4.0) */
+              st->state = IDLE;
+            break;
+          case IDLE:
+            st->state = MOVE;
+            if (! (random() % 5))
+              st->ds = frand(0.2) * RANDSIGN();		/* zoom */
+            if (! (random() % 3))
+              st->dth = frand(0.2) * RANDSIGN();	/* rotate */
+            if (! (random() % 8))
+              st->dx = frand(0.05) * RANDSIGN(),	/* pan */
+              st->dy = frand(0.05) * RANDSIGN();
+            if (! (random() % 2000))
+              {
+                twiddle_knobs (st);
+                if (! (random() % 10))
+                  twiddle_camera (st);
+              }
+            break;
+          case MOVE:
+            st->state = IDLE;
+            st->value = 0.3;
+            break;
+          default:
+            abort();
+            break;
+          }
+        }
+
+      /* Draw a specular reflection somewhere on the screen, to mix it up
+         with a little noise from environmental light.
+       */
+      if (st->specular.s)
+        {
+          st->svalue += 0.01 * st->speed;
+          if (st->svalue > 1)
+            {
+              st->svalue = 0;
+              st->specular.s = 0;
+            }
+        }
+      else if (! (random() % 300))
+        {
+# if 1
+          /* Center on the monitor's screen, depth 1 */
+          int cx = st->xgwa.width / 2;
+          int cy = st->xgwa.height / 2;
+# else
+          /* Center on the monitor's screen, depth 0 -- but this clips. */
+          int cx = (st->rect.x + st->rect.w / 2) * st->xgwa.width;
+          int cy = (st->rect.y + st->rect.h / 2) * st->xgwa.height;
+# endif
+          int ww = 4 + (st->rect.h * st->xgwa.height) / 12;
+          st->specular.x = cx + (random() % ww) * RANDSIGN();
+          st->specular.y = cy + (random() % ww) * RANDSIGN();
+          st->specular.s = ww * (0.8 + frand(0.4));
+          st->svalue = 0;
+        }
+    }
+
+  if (st->last_time == 0)
+    st->start = then;
+
+  if (st->state != POWERUP)
+    {
+      img = grab_rectangle (st);
+      analogtv_load_ximage (st->tv, st->rec.input, img, 0, 0, 0, 0, 0);
+    }
+
+  analogtv_reception_update (&st->rec);
+  analogtv_draw (st->tv, st->noise, &rec, 1);
+  if (img)
+    XDestroyImage (img);
+
+  now = double_time();
+  timedelta = (1 / 29.97) - (now - then);
+
+  st->tv->powerup = then - st->start;
+  st->last_time = then;
+
+  return timedelta > 0 ? timedelta * 1000000 : 0;
+}
+
+
+static void
+vfeedback_reshape (Display *dpy, Window window, void *closure, 
+                    unsigned int w, unsigned int h)
+{
+  struct state *st = (struct state *) closure;
+  analogtv_reconfigure (st->tv);
+  XGetWindowAttributes (dpy, window, &st->xgwa);
+
+  if (st->pix)
+    {
+      XFreePixmap (dpy, st->pix);
+      st->pix = 0;
+    }
+}
+
+
+static Bool
+vfeedback_event (Display *dpy, Window window, void *closure, XEvent *event)
+{
+  struct state *st = (struct state *) closure;
+  double i = 0.02;
+
+  /* Pan with left button and no modifier keys.
+     Rotate with other buttons, or left-with-modifiers.
+   */
+  if (event->xany.type == ButtonPress &&
+      (event->xbutton.button == Button1 ||
+       event->xbutton.button == Button2 ||
+       event->xbutton.button == Button3))
+    {
+      st->button_down_p = True;
+      st->mouse_x = event->xbutton.x;
+      st->mouse_y = event->xbutton.y;
+      st->mouse_th = st->rect.th;
+      st->dragmode = (event->xbutton.button == Button1 && 
+                      !event->xbutton.state);
+      return True;
+    }
+  else if (event->xany.type == ButtonRelease &&
+           (event->xbutton.button == Button1 ||
+            event->xbutton.button == Button2 ||
+            event->xbutton.button == Button3))
+    {
+      st->button_down_p = False;
+      return True;
+    }
+  else if (event->xany.type == MotionNotify && st->button_down_p)
+    {
+      if (st->dragmode)
+        {
+          double dx = st->mouse_x - event->xmotion.x;
+          double dy = st->mouse_y - event->xmotion.y;
+          st->rect.x += dx / st->xgwa.width  * st->rect.w;
+          st->rect.y += dy / st->xgwa.height * st->rect.h;
+          st->mouse_x = event->xmotion.x;
+          st->mouse_y = event->xmotion.y;
+        }
+      else
+        {
+          /* Angle between center and initial click */
+          double a1 = -atan2 (st->mouse_y - st->xgwa.height / 2,
+                              st->mouse_x - st->xgwa.width  / 2);
+          /* Angle between center and drag position */
+          double a2 = -atan2 (event->xmotion.y - st->xgwa.height / 2,
+                              event->xmotion.x - st->xgwa.width  / 2);
+          /* Cumulatively rotate by difference between them */
+          st->rect.th = a2 - a1 + st->mouse_th;
+        }
+      goto OK;
+    }
+
+  /* Zoom with mouse wheel */
+
+  else if (event->xany.type == ButtonPress &&
+           (event->xbutton.button == Button4 ||
+            event->xbutton.button == Button6))
+    {
+      i = 1-i;
+      goto ZZ;
+    }
+  else if (event->xany.type == ButtonPress &&
+           (event->xbutton.button == Button5 ||
+            event->xbutton.button == Button7))
+    {
+      i = 1+i;
+      goto ZZ;
+    }
+  else if (event->type == KeyPress)
+    {
+      KeySym keysym;
+      char c = 0;
+      XLookupString (&event->xkey, &c, 1, &keysym, 0);
+      switch (keysym) {
+        /* pan with arrow keys */
+      case XK_Up:    st->rect.y += i; goto OK; break;
+      case XK_Down:  st->rect.y -= i; goto OK; break;
+      case XK_Left:  st->rect.x += i; goto OK; break;
+      case XK_Right: st->rect.x -= i; goto OK; break;
+      default: break;
+      }
+      switch (c) {
+
+        /* rotate with <> */
+      case '<': case ',': st->rect.th += i; goto OK; break;
+      case '>': case '.': st->rect.th -= i; goto OK; break;
+
+        /* zoom with += */
+      case '-': case '_':
+        i = 1+i;
+        goto ZZ;
+      case '=': case '+':
+        i = 1-i;
+      ZZ:
+        st->orect = st->rect;
+        st->rect.w *= i;
+        st->rect.h *= i;
+        st->rect.x += (st->orect.w - st->rect.w) / 2;
+        st->rect.y += (st->orect.h - st->rect.h) / 2;
+        goto OK;
+        break;
+
+        /* tv controls with T, C, B, O */
+      case 't': st->tv->tint_control       += 5;    goto OK; break;
+      case 'T': st->tv->tint_control       -= 5;    goto OK; break;
+      case 'c': st->tv->color_control      += 0.1;  goto OK; break;
+      case 'C': st->tv->color_control      -= 0.1;  goto OK; break;
+      case 'b': st->tv->brightness_control += 0.01; goto OK; break;
+      case 'B': st->tv->brightness_control -= 0.01; goto OK; break;
+      case 'o': st->tv->contrast_control   += 0.1;  goto OK; break;
+      case 'O': st->tv->contrast_control   -= 0.1;  goto OK; break;
+      case 'r': st->rec.level              += 0.01; goto OK; break;
+      case 'R': st->rec.level              -= 0.01; goto OK; break;
+      default: break;
+      }
+      goto NOPE;
+    OK:
+# if 0
+      fprintf (stderr, " %.6f x %.6f @ %.6f, %.6f %.6f\t",
+               st->rect.w, st->rect.h,
+               st->rect.x, st->rect.y, st->rect.th);
+      fprintf (stderr," T=%.2f C=%.2f B=%.2f O=%.2f R=%.3f\n",
+               st->tv->tint_control,
+               st->tv->color_control/* * 100*/,
+               st->tv->brightness_control/* * 100*/,
+               st->tv->contrast_control/* * 100*/,
+               st->rec.level);
+# endif
+      st->value = 0;
+      st->state = IDLE;
+      st->orect = st->rect;
+      return True;
+    }
+
+ NOPE:
+  if (screenhack_event_helper (dpy, window, event))
+    {
+      /* SPC or RET re-randomize the TV controls. */
+      twiddle_knobs (st);
+      goto OK;
+    }
+
+  return False;
+}
+
+
+static void
+vfeedback_free (Display *dpy, Window window, void *closure)
+{
+  struct state *st = (struct state *) closure;
+  analogtv_release (st->tv);
+  if (st->pix)
+    XFreePixmap (dpy, st->pix);
+  XFreeGC (dpy, st->gc);
+  free (st);
+}
+
+
+static const char *vfeedback_defaults [] = {
+
+  ".foreground:  #CCCC44",
+  ".background:  #000000",
+  "*noise:       0.02",
+  "*speed:       1.0",
+  ANALOGTV_DEFAULTS
+  "*TVBrightness: 1.5",
+  "*TVContrast:   150",
+  0
+};
+
+static XrmOptionDescRec vfeedback_options [] = {
+  { "-noise",           ".noise",     XrmoptionSepArg, 0 },
+  { "-speed",           ".speed",     XrmoptionSepArg, 0 },
+  ANALOGTV_OPTIONS
+  { 0, 0, 0, 0 }
+};
+
+XSCREENSAVER_MODULE ("VFeedback", vfeedback)