gtkcurve.c

gtk是linux一款强大的夸平台的图形化开发工具

      if (c->curve_type != GTK_CURVE_TYPE_FREE)
	{
	  for (src = dst = 0; src < c->num_ctlpoints; ++src)
	    {
	      if (c->ctlpoint[src][0] >= min_x)
		{
		  memcpy (c->ctlpoint + dst, c->ctlpoint + src,
			  sizeof (*c->ctlpoint));
		  ++dst;
		}
	    }
	  if (dst < src)
	    {
	      c->num_ctlpoints -= (src - dst);
	      if (c->num_ctlpoints <= 0)
		{
		  c->num_ctlpoints = 1;
		  c->ctlpoint[0][0] = min_x;
		  c->ctlpoint[0][1] = c->min_y;
		  gtk_curve_interpolate (c, width, height);
		  gtk_curve_draw (c, width, height);
		}
	      c->ctlpoint =
		g_realloc (c->ctlpoint,
			   c->num_ctlpoints * sizeof (*c->ctlpoint));
	    }
	}
      new_type = GDK_FLEUR;
      c->grab_point = -1;
      break;

    case GDK_MOTION_NOTIFY:
      mevent = (GdkEventMotion *) event;

      switch (c->curve_type)
	{
	case GTK_CURVE_TYPE_LINEAR:
	case GTK_CURVE_TYPE_SPLINE:
	  if (c->grab_point == -1)
	    {
	      /* if no point is grabbed...  */
	      if (distance <= MIN_DISTANCE)
		new_type = GDK_FLEUR;
	      else
		new_type = GDK_TCROSS;
	    }
	  else
	    {
	      /* drag the grabbed point  */
	      new_type = GDK_TCROSS;

	      leftbound = -MIN_DISTANCE;
	      if (c->grab_point > 0)
		leftbound = project (c->ctlpoint[c->grab_point - 1][0],
				     min_x, c->max_x, width);

	      rightbound = width + RADIUS * 2 + MIN_DISTANCE;
	      if (c->grab_point + 1 < c->num_ctlpoints)
		rightbound = project (c->ctlpoint[c->grab_point + 1][0],
				      min_x, c->max_x, width);

	      if (tx <= leftbound || tx >= rightbound
		  || ty > height + RADIUS * 2 + MIN_DISTANCE
		  || ty < -MIN_DISTANCE)
		c->ctlpoint[c->grab_point][0] = min_x - 1.0;
	      else
		{
		  rx = unproject (x, min_x, c->max_x, width);
		  ry = unproject (height - y, c->min_y, c->max_y, height);
		  c->ctlpoint[c->grab_point][0] = rx;
		  c->ctlpoint[c->grab_point][1] = ry;
		}
	      gtk_curve_interpolate (c, width, height);
	      gtk_curve_draw (c, width, height);
	    }
	  break;

	case GTK_CURVE_TYPE_FREE:
	  if (c->grab_point != -1)
	    {
	      if (c->grab_point > x)
		{
		  x1 = x;
		  x2 = c->grab_point;
		  y1 = y;
		  y2 = c->last;
		}
	      else
		{
		  x1 = c->grab_point;
		  x2 = x;
		  y1 = c->last;
		  y2 = y;
		}

	      if (x2 != x1)
		for (i = x1; i <= x2; i++)
		  {
		    c->point[i].x = RADIUS + i;
		    c->point[i].y = RADIUS +
		      (y1 + ((y2 - y1) * (i - x1)) / (x2 - x1));
		  }
	      else
		{
		  c->point[x].x = RADIUS + x;
		  c->point[x].y = RADIUS + y;
		}
	      c->grab_point = x;
	      c->last = y;
	      gtk_curve_draw (c, width, height);
	    }
	  if (mevent->state & GDK_BUTTON1_MASK)
	    new_type = GDK_TCROSS;
	  else
	    new_type = GDK_PENCIL;
	  break;
	}
      if (new_type != (GdkCursorType) c->cursor_type)
	{
	  GdkCursor *cursor;

	  c->cursor_type = new_type;

	  cursor = gdk_cursor_new (c->cursor_type);
	  gdk_window_set_cursor (w->window, cursor);
	  gdk_cursor_destroy (cursor);
	}
      break;

    default:
      break;
    }
  return FALSE;
}

void
gtk_curve_set_curve_type (GtkCurve *c, GtkCurveType new_type)
{
  gfloat rx, dx;
  gint x, i;

  if (new_type != c->curve_type)
    {
      gint width, height;

      width  = GTK_WIDGET(c)->allocation.width - RADIUS * 2;
      height = GTK_WIDGET(c)->allocation.height - RADIUS * 2;

      if (new_type == GTK_CURVE_TYPE_FREE)
	{
	  gtk_curve_interpolate (c, width, height);
	  c->curve_type = new_type;
	}
      else if (c->curve_type == GTK_CURVE_TYPE_FREE)
	{
	  if (c->ctlpoint)
	    g_free (c->ctlpoint);
	  c->num_ctlpoints = 9;
	  c->ctlpoint = g_malloc (c->num_ctlpoints * sizeof (*c->ctlpoint));

	  rx = 0.0;
	  dx = (width - 1) / (gfloat) (c->num_ctlpoints - 1);

	  for (i = 0; i < c->num_ctlpoints; ++i, rx += dx)
	    {
	      x = (int) (rx + 0.5);
	      c->ctlpoint[i][0] =
		unproject (x, c->min_x, c->max_x, width);
	      c->ctlpoint[i][1] =
		unproject (RADIUS + height - c->point[x].y,
			   c->min_y, c->max_y, height);
	    }
	  c->curve_type = new_type;
	  gtk_curve_interpolate (c, width, height);
	}
      else
	{
	  c->curve_type = new_type;
	  gtk_curve_interpolate (c, width, height);
	}
      gtk_signal_emit (GTK_OBJECT (c), curve_type_changed_signal);
      gtk_curve_draw (c, width, height);
    }
}

static void
gtk_curve_size_graph (GtkCurve *curve)
{
  gint width, height;
  gfloat aspect;

  width  = (curve->max_x - curve->min_x) + 1;
  height = (curve->max_y - curve->min_y) + 1;
  aspect = width / (gfloat) height;
  if (width > gdk_screen_width () / 4)
    width  = gdk_screen_width () / 4;
  if (height > gdk_screen_height () / 4)
    height = gdk_screen_height () / 4;

  if (aspect < 1.0)
    width  = height * aspect;
  else
    height = width / aspect;

  gtk_drawing_area_size (GTK_DRAWING_AREA (curve),
			 width + RADIUS * 2, height + RADIUS * 2);
}

static void
gtk_curve_reset_vector (GtkCurve *curve)
{
  if (curve->ctlpoint)
    g_free (curve->ctlpoint);

  curve->num_ctlpoints = 2;
  curve->ctlpoint = g_malloc (2 * sizeof (curve->ctlpoint[0]));
  curve->ctlpoint[0][0] = curve->min_x;
  curve->ctlpoint[0][1] = curve->min_y;
  curve->ctlpoint[1][0] = curve->max_x;
  curve->ctlpoint[1][1] = curve->max_y;

  if (curve->pixmap)
    {
      gint width, height;

      width = GTK_WIDGET (curve)->allocation.width - RADIUS * 2;
      height = GTK_WIDGET (curve)->allocation.height - RADIUS * 2;

      if (curve->curve_type == GTK_CURVE_TYPE_FREE)
	{
	  curve->curve_type = GTK_CURVE_TYPE_LINEAR;
	  gtk_curve_interpolate (curve, width, height);
	  curve->curve_type = GTK_CURVE_TYPE_FREE;
	}
      else
	gtk_curve_interpolate (curve, width, height);
      gtk_curve_draw (curve, width, height);
    }
}

void
gtk_curve_reset (GtkCurve *c)
{
  GtkCurveType old_type;

  old_type = c->curve_type;
  c->curve_type = GTK_CURVE_TYPE_SPLINE;
  gtk_curve_reset_vector (c);

  if (old_type != GTK_CURVE_TYPE_SPLINE)
    gtk_signal_emit (GTK_OBJECT (c), curve_type_changed_signal);
}

void
gtk_curve_set_gamma (GtkCurve *c, gfloat gamma)
{
  gfloat x, one_over_gamma, height, one_over_width;
  GtkCurveType old_type;
  gint i;

  if (c->num_points < 2)
    return;

  old_type = c->curve_type;
  c->curve_type = GTK_CURVE_TYPE_FREE;

  if (gamma <= 0)
    one_over_gamma = 1.0;
  else
    one_over_gamma = 1.0 / gamma;
  one_over_width = 1.0 / (c->num_points - 1);
  height = c->height;
  for (i = 0; i < c->num_points; ++i)
    {
      x = (gfloat) i / (c->num_points - 1);
      c->point[i].x = RADIUS + i;
      c->point[i].y =
	RADIUS + (height * (1.0 - pow (x, one_over_gamma)) + 0.5);
    }

  if (old_type != GTK_CURVE_TYPE_FREE)
    gtk_signal_emit (GTK_OBJECT (c), curve_type_changed_signal);

  gtk_curve_draw (c, c->num_points, c->height);
}

void
gtk_curve_set_range (GtkCurve *curve,
		     gfloat min_x, gfloat max_x, gfloat min_y, gfloat max_y)
{
  curve->min_x = min_x;
  curve->max_x = max_x;
  curve->min_y = min_y;
  curve->max_y = max_y;

  gtk_curve_size_graph (curve);
  gtk_curve_reset_vector (curve);
}

void
gtk_curve_set_vector (GtkCurve *c, int veclen, gfloat vector[])
{
  GtkCurveType old_type;
  gfloat rx, dx, ry;
  gint i, height;

  old_type = c->curve_type;
  c->curve_type = GTK_CURVE_TYPE_FREE;

  if (c->point)
    height = GTK_WIDGET (c)->allocation.height - RADIUS * 2;
  else
    {
      height = (c->max_y - c->min_y);
      if (height > gdk_screen_height () / 4)
	height = gdk_screen_height () / 4;

      c->height = height;
      c->num_points = veclen;
      c->point = g_malloc (c->num_points * sizeof (c->point[0]));
    }
  rx = 0;
  dx = (veclen - 1.0) / (c->num_points - 1.0);

  for (i = 0; i < c->num_points; ++i, rx += dx)
    {
      ry = vector[(int) (rx + 0.5)];
      if (ry > c->max_y) ry = c->max_y;
      if (ry < c->min_y) ry = c->min_y;
      c->point[i].x = RADIUS + i;
      c->point[i].y =
	RADIUS + height - project (ry, c->min_y, c->max_y, height);
    }
  if (old_type != GTK_CURVE_TYPE_FREE)
    gtk_signal_emit (GTK_OBJECT (c), curve_type_changed_signal);

  gtk_curve_draw (c, c->num_points, height);
}

void
gtk_curve_get_vector (GtkCurve *c, int veclen, gfloat vector[])
{
  gfloat rx, ry, dx, dy, min_x, delta_x, *mem, *xv, *yv, *y2v, prev;
  gint dst, i, x, next, num_active_ctlpoints = 0, first_active = -1;

  min_x = c->min_x;

  if (c->curve_type != GTK_CURVE_TYPE_FREE)
    {
      /* count active points: */
      prev = min_x - 1.0;
      for (i = num_active_ctlpoints = 0; i < c->num_ctlpoints; ++i)
	if (c->ctlpoint[i][0] > prev)
	  {
	    if (first_active < 0)
	      first_active = i;
	    prev = c->ctlpoint[i][0];
	    ++num_active_ctlpoints;
	  }

      /* handle degenerate case: */
      if (num_active_ctlpoints < 2)
	{
	  if (num_active_ctlpoints > 0)
	    ry = c->ctlpoint[first_active][1];
	  else
	    ry = c->min_y;
	  if (ry < c->min_y) ry = c->min_y;
	  if (ry > c->max_y) ry = c->max_y;
	  for (x = 0; x < veclen; ++x)
	    vector[x] = ry;
	  return;
	}
    }

  switch (c->curve_type)
    {
    case GTK_CURVE_TYPE_SPLINE:
      mem = g_malloc (3 * num_active_ctlpoints * sizeof (gfloat));
      xv  = mem;
      yv  = mem + num_active_ctlpoints;
      y2v = mem + 2*num_active_ctlpoints;

      prev = min_x - 1.0;
      for (i = dst = 0; i < c->num_ctlpoints; ++i)
	if (c->ctlpoint[i][0] > prev)
	  {
	    prev    = c->ctlpoint[i][0];
	    xv[dst] = c->ctlpoint[i][0];
	    yv[dst] = c->ctlpoint[i][1];
	    ++dst;
	  }

      spline_solve (num_active_ctlpoints, xv, yv, y2v);

      rx = min_x;
      dx = (c->max_x - min_x) / (veclen - 1);
      for (x = 0; x < veclen; ++x, rx += dx)
	{
	  ry = spline_eval (num_active_ctlpoints, xv, yv, y2v, rx);
	  if (ry < c->min_y) ry = c->min_y;
	  if (ry > c->max_y) ry = c->max_y;
	  vector[x] = ry;
	}

      g_free (mem);
      break;

    case GTK_CURVE_TYPE_LINEAR:
      dx = (c->max_x - min_x) / (veclen - 1);
      rx = min_x;
      ry = c->min_y;
      dy = 0.0;
      i  = first_active;
      for (x = 0; x < veclen; ++x, rx += dx)
	{
	  if (rx >= c->ctlpoint[i][0])
	    {
	      if (rx > c->ctlpoint[i][0])
		ry = c->min_y;
	      dy = 0.0;
	      next = i + 1;
	      while (next < c->num_ctlpoints
		     && c->ctlpoint[next][0] <= c->ctlpoint[i][0])
		++next;
	      if (next < c->num_ctlpoints)
		{
		  delta_x = c->ctlpoint[next][0] - c->ctlpoint[i][0];
		  dy = ((c->ctlpoint[next][1] - c->ctlpoint[i][1])
			/ delta_x);
		  dy *= dx;
		  ry = c->ctlpoint[i][1];
		  i = next;
		}
	    }
	  vector[x] = ry;
	  ry += dy;
	}
      break;

    case GTK_CURVE_TYPE_FREE:
      if (c->point)
	{
	  rx = 0.0;
	  dx = c->num_points / (double) veclen;
	  for (x = 0; x < veclen; ++x, rx += dx)
	    vector[x] = unproject (RADIUS + c->height - c->point[(int) rx].y,
				   c->min_y, c->max_y,
				   c->height);
	}
      else
	memset (vector, 0, veclen * sizeof (vector[0]));
      break;
    }
}

GtkWidget*
gtk_curve_new (void)
{
  return gtk_type_new (gtk_curve_get_type ());
}

static void
gtk_curve_finalize (GtkObject *object)
{
  GtkCurve *curve;

  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_CURVE (object));

  curve = GTK_CURVE (object);
  if (curve->pixmap)
    gdk_pixmap_unref (curve->pixmap);
  if (curve->point)
    g_free (curve->point);
  if (curve->ctlpoint)
    g_free (curve->ctlpoint);

  (*GTK_OBJECT_CLASS (parent_class)->finalize) (object);
}