tachometer.c

很好的一个gps daemon驱动,简单实用

     radius_y = center_y - w->tachometer.internal_border;

     if ((center_x==0) || (center_y==0) || (radius_x<=0) || (radius_y<=0))
	  return;	  /* can't draw anything */

     gc = w->tachometer.needle_GC;
     
     cur_theta1 = (double) (330 - (load * 3)) * PI / 180.0;
     cur_theta2 = (double) (330 - (load * 3) + 1) * PI / 180.0;
     cur_theta3 = (double) (330 - (load * 3) - 1) * PI / 180.0;
     cur_theta4 = (330.0 - ((double) load * 3.0) + 7.0) * PI / 180.0;
     cur_theta5 = (330.0 - ((double) load * 3.0) - 7.0) * PI / 180.0;

     points[0].x = sin(cur_theta1) * radius_x * 0.75 + center_x;
     points[0].y = cos(cur_theta1) * radius_y * 0.75 + center_y;
     points[1].x = sin(cur_theta2) * radius_x * 0.7 + center_x;
     points[1].y = cos(cur_theta2) * radius_y * 0.7 + center_y;
     points[2].x = sin(cur_theta4) * radius_x * 0.1 + center_x;
     points[2].y = cos(cur_theta4) * radius_y * 0.1 + center_y;
     points[3].x = sin(cur_theta5) * radius_x * 0.1 + center_x;
     points[3].y = cos(cur_theta5) * radius_y * 0.1 + center_y;
     points[4].x = sin(cur_theta3) * radius_x * 0.7 + center_x;
     points[4].y = cos(cur_theta3) * radius_y * 0.7 + center_y;
     points[5].x = points[0].x;
     points[5].y = points[0].y;

     XDrawLines(XtDisplay(w), XtWindow(w), gc, points, 6, CoordModeOrigin);
}

static void DrawNumbers(
    TachometerWidget w, int which, Cardinal x, Cardinal y)
{
     /* Draw Numbers	 */
     if (which == 10) {
	  DrawSingleNumber(w, 1, (Cardinal) ((double) x * 0.9), y);
	  DrawSingleNumber(w, 0, x, y);
     } else
	  DrawSingleNumber(w, which, x, y);
}

static void DrawSingleNumber(TachometerWidget w, int which, Cardinal x, Cardinal y)
{
     XSegment        segments[7];
     Cardinal        nsegments, width, height;
     unsigned char   count;
     
     width = (w->core.width / 2) - w->tachometer.internal_border;
     height = (w->core.height / 2) - w->tachometer.internal_border;
     if ((width <= 0) || (height <= 0))
	  return;

     for (count = 0, nsegments = 0; count < 7; count++)
	  if (num_segment[which].digit[count] == 1) {
	       segments[nsegments].x1 = (short)
		    (x + ((double)offset[count].x1 * ((double)width / 200.0)));
	       segments[nsegments].y1 = (short)
		    (y + ((double)offset[count].y1 * ((double)height / 200.0)));
	       segments[nsegments].x2 = (short)
		    (x + ((double)offset[count].x2 * ((double)width / 200.0)));
	       segments[nsegments].y2 = (short)
		    (y + ((double)offset[count].y2 * ((double)height / 200.0)));
	       nsegments++;
	  }

     XDrawSegments(XtDisplay(w), XtWindow(w), 
		   w->tachometer.scale_GC, segments, nsegments);
}

static void DrawLabelString(TachometerWidget w)
{
     XPoint          points[5];
     Cardinal        ry;
     unsigned char   char_count;
     unsigned char   data_count;
     Cardinal	center_x, center_y;
     Cardinal	radius_x, radius_y;
     GC gc;

     gc = w->tachometer.scale_GC;

     center_x = w->core.width / 2; center_y = w->core.height / 2;
     radius_x = center_x - w->tachometer.internal_border;
     radius_y = center_y - w->tachometer.internal_border;
     
     if (!(center_x && center_y && (radius_x > 0) && (radius_y > 0)))
	  return;
     
     ry = (double)  radius_y * 0.35 + center_y;

     for (char_count = 0; char_count < 4; char_count++) {
	  for (data_count = 0; data_count < char_data[char_count].nofline
	       ; data_count++) {
	       points[data_count].x = (double)
		    (char_data[char_count].point_list[data_count].x) *
			 (double) radius_x * 0.01 + center_x;
	       points[data_count].y = (double)
		    (char_data[char_count].point_list[data_count].y) *
			 (double) radius_y * 0.01 + ry;
	  }
	  XDrawLines(XtDisplay(w), XtWindow(w), gc, points,
		     char_data[char_count].nofline, CoordModeOrigin);
     }
}

static void MoveNeedle(TachometerWidget w, int new)
{
    int step, old, loop;

     old = w->tachometer.value;
     if (new > 100)
	  new = 100;
     if (old == new)
	  return;
     else if (old < new)
	  step = (w->tachometer.speed ? w->tachometer.speed : new - old);
     else
	  step = (w->tachometer.speed ? -w->tachometer.speed : new - old);

     if (old < new) {
	  for (loop = old; loop < new; loop += step)
	    DrawNeedle(w, loop);
	  for (loop = old + step; loop <= new; loop += step)
	    DrawNeedle(w, loop);
     } else {
	  for (loop = old; loop > new; loop += step)
	    DrawNeedle(w, loop);
	  for (loop = old + step; loop >= new; loop += step)
	    DrawNeedle(w, loop);
     }
	  
     if (loop != new + step) /* The final needle wasn't printed */
	  DrawNeedle(w, new);
     
     w->tachometer.value = new;
}

static void GetneedleGC(TachometerWidget ta)
{
    XGCValues	values;

    values.background	= ta->core.background_pixel;
    values.foreground	= ta->tachometer.needle ^ ta->core.background_pixel;
    values.function = GXxor;
    ta->tachometer.needle_GC = XtGetGC(
	(Widget)ta,
	(unsigned) GCFunction | GCBackground | GCForeground,
	&values);
}

static void GetscaleGC(TachometerWidget ta)
{
    XGCValues	values;

    values.foreground	= ta->tachometer.scale;
    values.background	= ta->core.background_pixel;
    ta->tachometer.scale_GC = XtGetGC(
	(Widget)ta,
	(unsigned) GCForeground | GCBackground,
	&values);
}

static void GetcircleGC(TachometerWidget ta)
{
    XGCValues	values;

    values.foreground	= ta->tachometer.circle;
    values.background	= ta->core.background_pixel;
    ta->tachometer.circle_GC = XtGetGC(
	(Widget)ta,
	(unsigned) GCForeground | GCBackground,
	&values);
}

static void GetbackgroundGC(TachometerWidget ta)
{
    XGCValues	values;

    values.foreground	= ta->core.background_pixel;
    values.background	= ta->core.background_pixel;
    ta->tachometer.background_GC = XtGetGC(
	(Widget)ta,
	(unsigned) GCForeground | GCBackground,
	&values);
}

static void Initialize(Widget request, Widget new)
{
    TachometerWidget ta = (TachometerWidget) new;
    
    GetneedleGC(ta);
    GetcircleGC(ta);
    GetscaleGC(ta);
    GetbackgroundGC(ta);
    ta->tachometer.width = ta->tachometer.height = 0;
} /* Initialize */

static void Realize(Widget w, Mask *valueMask, XSetWindowAttributes *attributes)
{
    *valueMask |= CWBitGravity;
    attributes->bit_gravity = NorthWestGravity;
    (*superclass->core_class.realize) (w, valueMask, attributes);
} /* Realize */

static void Redisplay(Widget w, XEvent *event, Region region)
/* Repaint the widget window */
{
     TachometerWidget ta = (TachometerWidget) w;

     if (event->xexpose.count == 0)
	  DrawTachometer(ta);
}

static void Resize(Widget w)
{
     TachometerWidget ta = (TachometerWidget) w;

     if ((ta->core.width == ta->tachometer.width) &&
	 (ta->core.height == ta->tachometer.height))
	  /* What resize?  We don't see a resize! */
	  return;

     XClearWindow(XtDisplay(w), XtWindow(w));
     
     if ((ta->core.width <= ta->tachometer.width) &&
	 (ta->core.height <= ta->tachometer.height))
	  /* Only redraw here if no expose events are going to be */
	  /* generated, i.e. if the window has not grown horizontally */
	  /* or vertically. */
	  DrawTachometer(ta);

     ta->tachometer.width = ta->core.width;
     ta->tachometer.height = ta->core.height;
}

static Boolean SetValues(Widget current, Widget request, Widget new)
/* Set specified arguments into widget */
{
    Boolean back, changed = False;
     
     TachometerWidget curta = (TachometerWidget) current;
     TachometerWidget newta = (TachometerWidget) new;

     back = (curta->core.background_pixel != newta->core.background_pixel);
     
     if (back || (curta->tachometer.needle != newta->tachometer.needle)) {
	  XtReleaseGC(new, newta->tachometer.needle_GC);
	  GetneedleGC(newta);
	  changed = True;
     }
     if (back || (curta->tachometer.scale != newta->tachometer.scale)) {
	  XtReleaseGC(new, newta->tachometer.scale_GC);
	  GetscaleGC(newta);
	  changed = True;
     }
     if (back || (curta->tachometer.circle != newta->tachometer.circle)) {
	  XtReleaseGC(new, newta->tachometer.circle_GC);
	  GetcircleGC(newta);
	  changed = True;
     }
     if (back) {
	  XtReleaseGC(new, newta->tachometer.background_GC);
	  GetbackgroundGC(newta);
	  changed = True;
     }
     if (curta->tachometer.value != newta->tachometer.value) {
	  MoveNeedle(newta, newta->tachometer.value);
	  changed = True;
     }

     return(changed);
}

static void Destroy(Widget w)
{
    TachometerWidget ta = (TachometerWidget) w;
     
    XtReleaseGC( w, ta->tachometer.needle_GC );
    XtReleaseGC( w, ta->tachometer.circle_GC );
    XtReleaseGC( w, ta->tachometer.scale_GC );
    XtReleaseGC( w, ta->tachometer.background_GC );
}

/***************************************************************
 *
 * Exported Procedures
 * 
 ***************************************************************/

int TachometerGetValue(Widget w)
{
     TachometerWidget ta = (TachometerWidget) w;

     return(ta->tachometer.value);
}

int TachometerSetValue(Widget w, int i)
{
     int old;
     TachometerWidget ta = (TachometerWidget) w;

     old = ta->tachometer.value;
     MoveNeedle(ta, i);
     
     return(old);
}