/**
* Copyright 2013 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those of the
* authors and should not be interpreted as representing official policies, either expressed
* or implied, of JogAmp Community.
*/
package com.jogamp.newt.event;
import com.jogamp.nativewindow.NativeSurface;
import com.jogamp.newt.event.MouseEvent.PointerClass;
import jogamp.newt.Debug;
/**
* 2 pointer zoom, a.k.a. <i>pinch to zoom</i>, gesture handler processing {@link MouseEvent}s
* while producing {@link ZoomEvent}s if gesture is completed.
* <p>
* Zoom value lies within [0..2], with 1 as <i>1:1</i>.
* </p>
* <pre>
* - choosing the smallest surface edge (width/height -> x/y)
* - tolerating other fingers to be pressed and hence user to add functionality (scale, ..)
* </pre>
*/
public class PinchToZoomGesture implements GestureHandler {
public static final boolean DEBUG = Debug.debug("Window.MouseEvent");
/** A {@link GestureHandler.GestureEvent} denominating zoom. */
@SuppressWarnings("serial")
public static class ZoomEvent extends GestureEvent {
private final float zoom;
private final float delta;
private final float scale;
public ZoomEvent(final Object source, final long when, final int modifiers, final GestureHandler handler, final MouseEvent pe,
final float zoom, final float delta, final float scale) {
super(source, when, modifiers, handler, pe);
this.zoom = zoom;
this.delta = delta;
this.scale = scale;
}
/** Zoom value lies within [0..2], with 1 as <i>1:1</i>. */
public final float getZoom() { return zoom; }
/** Delta to last zoom value lies within [-1..1]. */
public final float getDelta() { return delta; }
/**
* Returns the scale used to determine the {@link #getZoom() zoom}
* and hence it's {@link #getDelta() delta} value,
* which semantics depends on the {@link #getPointerType() pointer type's} {@link PointerClass}.
* <p>
* For {@link PointerClass#Offscreen}, the scale is usually <code>1.0f</code> and denominates
* an abstract value without association to a physical value.
* </p>
* <p>
* For {@link PointerClass#Onscreen}, the scale varies and denominates
* the divisor of the distance the finger[s] have moved on the screen.
* Hence <code>scale * delta</code> reproduces the screen distance in pixels the finger[s] have moved.
* </p>
*/
public final float getScale() { return scale; }
public final String toString() {
return "ZoomEvent[zoom "+zoom+", delta "+delta+", scale "+scale+", trigger "+getTrigger()+", handler "+getHandler()+"]";
}
}
private final NativeSurface surface;
private final boolean allowMorePointer;
private float zoom;
private int zoomLastEdgeDist;
private boolean zoomFirstTouch;
private boolean zoomMode;
private ZoomEvent zoomEvent;
private final short[] pIds = new short[] { -1, -1 };
/**
* @param surface the {@link NativeSurface}, which size is used to compute the relative zoom factor
* @param allowMorePointer if false, allow only 2 pressed pointers (safe and recommended), otherwise accept other pointer to be pressed.
*/
public PinchToZoomGesture(final NativeSurface surface, final boolean allowMorePointer) {
clear(true);
this.surface = surface;
this.allowMorePointer = allowMorePointer;
this.zoom = 1f;
}
@Override
public String toString() {
return "PinchZoom[1stTouch "+zoomFirstTouch+", in "+isWithinGesture()+", has "+(null!=zoomEvent)+", zoom "+zoom+"]";
}
private int gesturePointers(final MouseEvent e, final int excludeIndex) {
int j = 0;
for(int i=e.getPointerCount()-1; i>=0; i--) {
if( excludeIndex != i ) {
final int id = e.getPointerId(i);
if( pIds[0] == id || pIds[1] == id ) {
j++;
}
}
}
return j;
}
@Override
public void clear(final boolean clearStarted) {
zoomEvent = null;
if( clearStarted ) {
zoomLastEdgeDist = 0;
zoomFirstTouch = true;
zoomMode = false;
pIds[0] = -1;
pIds[1] = -1;
}
}
@Override
public boolean isWithinGesture() {
return zoomMode;
}
@Override
public boolean hasGesture() {
return null != zoomEvent;
}
@Override
public InputEvent getGestureEvent() {
return zoomEvent;
}
/** Zoom value lies within [0..2], with 1 as <i>1:1</i>. */
public final float getZoom() {
return zoom;
}
/** Set zoom value within [0..2], with 1 as <i>1:1</i>. */
public final void setZoom(final float zoom) {
this.zoom=zoom;
}
@Override
public boolean process(final InputEvent in) {
if( null != zoomEvent || !(in instanceof MouseEvent) ) {
return true;
}
final MouseEvent pe = (MouseEvent)in;
final int pointerDownCount = pe.getPointerCount();
if( pe.getPointerType(0).getPointerClass() != MouseEvent.PointerClass.Onscreen ||
( !allowMorePointer && pointerDownCount > 2 ) ) {
return false;
}
final int eventType = pe.getEventType();
final boolean useY = surface.getSurfaceWidth() >= surface.getSurfaceHeight(); // use smallest dimension
switch ( eventType ) {
case MouseEvent.EVENT_MOUSE_PRESSED: {
if( 1 == pointerDownCount ) {
pIds[0] = pe.getPointerId(0);
pIds[1] = -1;
} else if ( 2 <= pointerDownCount ) { // && 1 == gesturePointers(pe, 0) /* w/o pressed pointer */) {
pIds[0] = pe.getPointerId(0);
pIds[1] = pe.getPointerId(1);
}
if(DEBUG) {
System.err.println("XXX1: id0 "+pIds[0]+" -> idx0 "+0+", id1 "+pIds[1]+" -> idx1 "+1);
System.err.println(this+".pressed: down "+pointerDownCount+", gPtr "+gesturePointers(pe, -1)+", event "+pe);
}
} break;
case MouseEvent.EVENT_MOUSE_RELEASED: {
final int gPtr = gesturePointers(pe, 0); // w/o lifted pointer
if ( 1 == gPtr ) {
zoomFirstTouch = true;
zoomMode = false;
} else if( 0 == gPtr ) {
// all lifted
clear(true);
}
if(DEBUG) {
System.err.println(this+".released: down "+pointerDownCount+", gPtr "+gPtr+", event "+pe);
}
} break;
case MouseEvent.EVENT_MOUSE_DRAGGED: {
if( 2 <= pointerDownCount ) {
final int gPtr = gesturePointers(pe, -1);
if( 2 == gPtr ) {
// same pointers
final int p0Idx = pe.getPointerIdx(pIds[0]);
final int p1Idx = pe.getPointerIdx(pIds[1]);
if( 0 <= p0Idx && 0 <= p1Idx ) {
final int edge0 = useY ? pe.getY(p0Idx) : pe.getX(p0Idx);
final int edge1 = useY ? pe.getY(p1Idx) : pe.getX(p1Idx);
// Diff. 1:1 Zoom: finger-distance to screen-coord
if(zoomFirstTouch) {
zoomLastEdgeDist = Math.abs(edge0-edge1);
zoomFirstTouch=false;
zoomMode = true;
} else if( zoomMode ) {
final int d = Math.abs(edge0-edge1);
final int dd = d - zoomLastEdgeDist;
final float screenEdge = useY ? surface.getSurfaceHeight() : surface.getSurfaceWidth();
final float delta = dd / screenEdge; // [-1..1]
if(DEBUG) {
System.err.println("XXX2: id0 "+pIds[0]+" -> idx0 "+p0Idx+", id1 "+pIds[1]+" -> idx1 "+p1Idx);
System.err.println("XXX3: d "+d+", ld "+zoomLastEdgeDist+", dd "+dd+", screen "+screenEdge+" -> incr "+delta+", zoom "+zoom+" -> "+(zoom+delta));
}
zoom += delta;
// clip value
if( 2f < zoom ) {
zoom = 2f;
} else if( 0 > zoom ) {
zoom = 0;
}
zoomLastEdgeDist = d;
zoomEvent = new ZoomEvent(pe.getSource(), pe.getWhen(), pe.getModifiers(), this, pe, zoom, delta, screenEdge);
}
}
}
if(DEBUG) {
System.err.println(this+".dragged: down "+pointerDownCount+", gPtr "+gPtr+", event "+pe);
}
}
} break;
default:
}
return null != zoomEvent;
}
}