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@duhaime
Created March 6, 2020 20:57
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Zoom to cursor with Trackball controls
<!DOCTYPE html>
<html>
<head>
<meta charset='UTF-8'>
<style>* {margin: 0; padding: 0; height: 100%; width: 100%;}</style>
</head>
<body>
<script src='https://cdnjs.cloudflare.com/ajax/libs/three.js/110/three.min.js'></script>
<script src='trackball.js'></script>
<script>
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
camera.position.z = 50;
var renderer = new THREE.WebGLRenderer({antialias: true});
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
var controls = new THREE.TrackballControls(camera, document.body);
// geom
var geometry = new THREE.BoxGeometry( 1, 1, 1 );
var material = new THREE.MeshPhongMaterial({ color: 0xffff00 })
var cube = new THREE.Mesh( geometry, material );
scene.add( cube );
// light
var light = new THREE.PointLight( 0xffffff, .7, 0 );
light.position.set(1, 1, 100 );
scene.add(light)
// main
function animate() {
requestAnimationFrame( animate );
renderer.render( scene, camera );
cube.rotation.y += 0.01;
cube.rotation.z += 0.01;
controls.update();
}
animate();
</script>
</body>
</html>
/**
* @author Eberhard Graether / http://egraether.com/
* @author Mark Lundin / http://mark-lundin.com
* @author Simone Manini / http://daron1337.github.io
* @author Luca Antiga / http://lantiga.github.io
* @modified by Cello / http://milletforall.com
*/
THREE.TrackballControls = function ( object, domElement ) {
var _this = window.inner = this;
var STATE = { NONE: - 1, ROTATE: 2, ZOOM: 1, PAN: 0, TOUCH_ROTATE: 3, TOUCH_ZOOM_PAN: 4 };
// the camera
this.object = object;
// the dom element that holds the canvas
this.domElement = ( domElement !== undefined ) ? domElement : document;
// API
this.enabled = true;
this.screen = { left: 0, top: 0, width: 0, height: 0 };
this.rotateSpeed = 1.0;
this.zoomSpeed = 1.2;
this.panSpeed = 0.7;
this.noRotate = false;
this.noZoom = false;
this.noPan = false;
this.staticMoving = false;
this.dynamicDampingFactor = 0.2;
this.minDistance = 0;
this.maxDistance = Infinity;
this.keys = [ 65 /*A*/, 83 /*S*/, 68 /*D*/ ];
// internals
this.target = new THREE.Vector3();
var EPS = 0.000001;
var lastPosition = new THREE.Vector3();
var _state = STATE.NONE,
_prevState = STATE.NONE,
_eye = new THREE.Vector3(),
_movePrev = new THREE.Vector2(),
_moveCurr = new THREE.Vector2(),
_lastAxis = new THREE.Vector3(),
_lastAngle = 0,
_zoomStart = new THREE.Vector2(),
_zoomEnd = new THREE.Vector2(),
_touchZoomDistanceStart = 0,
_touchZoomDistanceEnd = 0,
_panStart = new THREE.Vector2(),
_panEnd = new THREE.Vector2(),
_mouseWheelLocation = new THREE.Vector2();
// for reset
this.target0 = this.target.clone();
this.position0 = this.object.position.clone();
this.up0 = this.object.up.clone();
// events
var changeEvent = { type: 'change' };
var startEvent = { type: 'start' };
var endEvent = { type: 'end' };
// methods
this.handleResize = function () {
if ( this.domElement === document ) {
this.screen.left = 0;
this.screen.top = 0;
this.screen.width = window.innerWidth;
this.screen.height = window.innerHeight;
} else {
var box = this.domElement.getBoundingClientRect();
// adjustments come from similar code in the jquery offset() function
var d = this.domElement.ownerDocument.documentElement;
this.screen.left = box.left + window.pageXOffset - d.clientLeft;
this.screen.top = box.top + window.pageYOffset - d.clientTop;
this.screen.width = box.width;
this.screen.height = box.height;
}
};
this.handleEvent = function ( event ) {
if ( typeof this[ event.type ] == 'function' ) {
this[ event.type ]( event );
}
};
var getMouseOnScreen = ( function () {
var vector = new THREE.Vector2();
return function getMouseOnScreen( pageX, pageY ) {
vector.set(
( pageX - _this.screen.left ) / _this.screen.width,
( pageY - _this.screen.top ) / _this.screen.height
);
return vector;
};
}() );
var getMouseOnCircle = ( function () {
var vector = new THREE.Vector2();
return function getMouseOnCircle( pageX, pageY ) {
vector.set(
( ( pageX - _this.screen.width * 0.5 - _this.screen.left ) / ( _this.screen.width * 0.5 ) ),
( ( _this.screen.height + 2 * ( _this.screen.top - pageY ) ) / _this.screen.width ) // screen.width intentional
);
return vector;
};
}());
function getMouseClipCoords(event) {
var rect = event.target.getBoundingClientRect(),
dx = event.clientX - rect.left,
dy = event.clientY - rect.top,
// convert from event to clip space
x = (dx / _this.domElement.clientWidth) * 2 - 1,
y = -(dy / _this.domElement.clientHeight) * 2 + 1;
return new THREE.Vector2(x, y);
}
this.rotateCamera = ( function() {
var axis = new THREE.Vector3(),
quaternion = new THREE.Quaternion(),
eyeDirection = new THREE.Vector3(),
objectUpDirection = new THREE.Vector3(),
objectSidewaysDirection = new THREE.Vector3(),
moveDirection = new THREE.Vector3(),
angle;
return function rotateCamera() {
moveDirection.set( _moveCurr.x - _movePrev.x, _moveCurr.y - _movePrev.y, 0 );
angle = moveDirection.length();
if ( angle ) {
_eye.copy( _this.object.position ).sub( _this.target );
eyeDirection.copy( _eye ).normalize();
objectUpDirection.copy( _this.object.up ).normalize();
objectSidewaysDirection.crossVectors( objectUpDirection, eyeDirection ).normalize();
objectUpDirection.setLength( _moveCurr.y - _movePrev.y );
objectSidewaysDirection.setLength( _moveCurr.x - _movePrev.x );
moveDirection.copy( objectUpDirection.add( objectSidewaysDirection ) );
axis.crossVectors( moveDirection, _eye ).normalize();
angle *= _this.rotateSpeed;
quaternion.setFromAxisAngle( axis, angle );
_eye.applyQuaternion( quaternion );
_this.object.up.applyQuaternion( quaternion );
_lastAxis.copy( axis );
_lastAngle = angle;
} else if ( ! _this.staticMoving && _lastAngle ) {
_lastAngle *= Math.sqrt( 1.0 - _this.dynamicDampingFactor );
_eye.copy( _this.object.position ).sub( _this.target );
quaternion.setFromAxisAngle( _lastAxis, _lastAngle );
_eye.applyQuaternion( quaternion );
_this.object.up.applyQuaternion( quaternion );
}
_movePrev.copy( _moveCurr );
};
}());
this.zoomCamera = function () {
var factor;
if ( _state === STATE.TOUCH_ZOOM_PAN ) {
factor = _touchZoomDistanceStart / _touchZoomDistanceEnd;
_touchZoomDistanceStart = _touchZoomDistanceEnd;
_eye.multiplyScalar( factor );
} else {
factor = 1.0 + ( _zoomEnd.y - _zoomStart.y ) * _this.zoomSpeed;
if ( factor !== 1.0 && factor > 0.0 ) {
// set the direction toward the location the user mousewheeled
var loc = _mouseWheelLocation;
var factor = factor || 1.0 + ( _zoomEnd.y - _zoomStart.y ) * _this.zoomSpeed;
var vector = new THREE.Vector3(loc.x, loc.y, 1);
vector.unproject(_this.object);
vector.sub(_this.object.position);
vector.setLength(factor);
_this.target.addVectors(_this.target, vector);
// sets the actual zoom scalar
_eye.multiplyScalar( factor );
}
if ( _this.staticMoving ) {
_zoomStart.copy( _zoomEnd );
} else {
_zoomStart.y += ( _zoomEnd.y - _zoomStart.y ) * this.dynamicDampingFactor;
}
}
};
this.panCamera = ( function() {
var mouseChange = new THREE.Vector2(),
objectUp = new THREE.Vector3(),
pan = new THREE.Vector3();
return function panCamera() {
mouseChange.copy( _panEnd ).sub( _panStart );
if ( mouseChange.lengthSq() ) {
mouseChange.multiplyScalar( _eye.length() * _this.panSpeed );
pan.copy( _eye ).cross( _this.object.up ).setLength( mouseChange.x );
pan.add( objectUp.copy( _this.object.up ).setLength( mouseChange.y ) );
_this.object.position.add( pan );
_this.target.add( pan );
if ( _this.staticMoving ) {
_panStart.copy( _panEnd );
} else {
_panStart.add( mouseChange.subVectors( _panEnd, _panStart ).multiplyScalar( _this.dynamicDampingFactor ) );
}
}
};
}());
this.checkDistances = function () {
if ( ! _this.noZoom || ! _this.noPan ) {
if ( _eye.lengthSq() > _this.maxDistance * _this.maxDistance ) {
_this.object.position.addVectors( _this.target, _eye.setLength( _this.maxDistance ) );
_zoomStart.copy( _zoomEnd );
}
if ( _eye.lengthSq() < _this.minDistance * _this.minDistance ) {
_this.object.position.addVectors( _this.target, _eye.setLength( _this.minDistance ) );
_zoomStart.copy( _zoomEnd );
}
}
};
this.update = function () {
_eye.subVectors( _this.object.position, _this.target );
if ( ! _this.noRotate ) {
_this.rotateCamera();
}
if ( ! _this.noZoom ) {
_this.zoomCamera();
}
if ( ! _this.noPan ) {
_this.panCamera();
}
_this.object.position.addVectors( _this.target, _eye );
_this.checkDistances();
_this.object.lookAt( _this.target );
if ( lastPosition.distanceToSquared( _this.object.position ) > EPS ) {
_this.dispatchEvent( changeEvent );
lastPosition.copy( _this.object.position );
}
};
this.reset = function () {
_state = STATE.NONE;
_prevState = STATE.NONE;
_this.target.copy( _this.target0 );
_this.object.position.copy( _this.position0 );
_this.object.up.copy( _this.up0 );
_eye.subVectors( _this.object.position, _this.target );
_this.object.lookAt( _this.target );
_this.dispatchEvent( changeEvent );
lastPosition.copy( _this.object.position );
};
// listeners
function keydown( event ) {
if ( _this.enabled === false ) return;
window.removeEventListener( 'keydown', keydown, eventBindType );
_prevState = _state;
if ( _state !== STATE.NONE ) {
return;
} else if ( event.keyCode === _this.keys[ STATE.ROTATE ] && ! _this.noRotate ) {
_state = STATE.ROTATE;
} else if ( event.keyCode === _this.keys[ STATE.ZOOM ] && ! _this.noZoom ) {
_state = STATE.ZOOM;
} else if ( event.keyCode === _this.keys[ STATE.PAN ] && ! _this.noPan ) {
_state = STATE.PAN;
}
}
function keyup( event ) {
if ( _this.enabled === false ) return;
_state = _prevState;
window.addEventListener( 'keydown', keydown, eventBindType );
}
function mousedown( event ) {
if ( _this.enabled === false ) return;
if ( _state === STATE.NONE ) {
_state = event.button;
}
if ( _state === STATE.ROTATE && ! _this.noRotate ) {
_moveCurr.copy( getMouseOnCircle( event.pageX, event.pageY ) );
_movePrev.copy( _moveCurr );
} else if ( _state === STATE.ZOOM && ! _this.noZoom ) {
_zoomStart.copy( getMouseOnScreen( event.pageX, event.pageY ) );
_zoomEnd.copy( _zoomStart );
} else if ( _state === STATE.PAN && ! _this.noPan ) {
_panStart.copy( getMouseOnScreen( event.pageX, event.pageY ) );
_panEnd.copy( _panStart );
}
document.addEventListener( 'mousemove', mousemove, eventBindType );
document.addEventListener( 'mouseup', mouseup, eventBindType );
_this.dispatchEvent( startEvent );
}
function mousemove( event ) {
if ( _this.enabled === false ) return;
if ( _state === STATE.ROTATE && ! _this.noRotate ) {
_movePrev.copy( _moveCurr );
_moveCurr.copy( getMouseOnCircle( event.pageX, event.pageY ) );
} else if ( _state === STATE.ZOOM && ! _this.noZoom ) {
_zoomEnd.copy( getMouseOnScreen( event.pageX, event.pageY ) );
} else if ( _state === STATE.PAN && ! _this.noPan ) {
_panEnd.copy( getMouseOnScreen( event.pageX, event.pageY ) );
}
}
function mouseup( event ) {
if ( _this.enabled === false ) return;
_state = STATE.NONE;
document.removeEventListener( 'mousemove', mousemove, eventBindType );
document.removeEventListener( 'mouseup', mouseup, eventBindType );
_this.dispatchEvent( endEvent );
}
function mousewheel( event ) {
if ( _this.enabled === false ) return;
// store the location where the user ran the mousewheel
_mouseWheelLocation.copy( getMouseClipCoords( event ) );
switch ( event.deltaMode ) {
case 2:
// Zoom in pages
_zoomStart.y -= event.deltaY * 0.025;
break;
case 1:
// Zoom in lines
_zoomStart.y -= event.deltaY * 0.01;
break;
default:
// undefined, 0, assume pixels
_zoomStart.y -= event.deltaY * 0.00025;
break;
}
_this.dispatchEvent( startEvent );
_this.dispatchEvent( endEvent );
}
function touchstart( event ) {
if ( _this.enabled === false ) return;
switch ( event.touches.length ) {
case 1:
_state = STATE.TOUCH_ROTATE;
_moveCurr.copy( getMouseOnCircle( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY ) );
_movePrev.copy( _moveCurr );
break;
default: // 2 or more
_state = STATE.TOUCH_ZOOM_PAN;
var dx = event.touches[ 0 ].pageX - event.touches[ 1 ].pageX;
var dy = event.touches[ 0 ].pageY - event.touches[ 1 ].pageY;
_touchZoomDistanceEnd = _touchZoomDistanceStart = Math.sqrt( dx * dx + dy * dy );
var x = ( event.touches[ 0 ].pageX + event.touches[ 1 ].pageX ) / 2;
var y = ( event.touches[ 0 ].pageY + event.touches[ 1 ].pageY ) / 2;
_panStart.copy( getMouseOnScreen( x, y ) );
_panEnd.copy( _panStart );
break;
}
_this.dispatchEvent( startEvent );
}
function touchmove( event ) {
if ( _this.enabled === false ) return;
switch ( event.touches.length ) {
case 1:
_movePrev.copy( _moveCurr );
_moveCurr.copy( getMouseOnCircle( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY ) );
break;
default: // 2 or more
var dx = event.touches[ 0 ].pageX - event.touches[ 1 ].pageX;
var dy = event.touches[ 0 ].pageY - event.touches[ 1 ].pageY;
_touchZoomDistanceEnd = Math.sqrt( dx * dx + dy * dy );
var x = ( event.touches[ 0 ].pageX + event.touches[ 1 ].pageX ) / 2;
var y = ( event.touches[ 0 ].pageY + event.touches[ 1 ].pageY ) / 2;
_panEnd.copy( getMouseOnScreen( x, y ) );
break;
}
}
function touchend( event ) {
if ( _this.enabled === false ) return;
switch ( event.touches.length ) {
case 0:
_state = STATE.NONE;
break;
case 1:
_state = STATE.TOUCH_ROTATE;
_moveCurr.copy( getMouseOnCircle( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY ) );
_movePrev.copy( _moveCurr );
break;
}
_this.dispatchEvent( endEvent );
}
function contextmenu( event ) {
if ( _this.enabled === false ) return;
event.preventDefault();
}
this.dispose = function() {
this.domElement.removeEventListener( 'contextmenu', contextmenu, eventBindType );
this.domElement.removeEventListener( 'mousedown', mousedown, eventBindType );
this.domElement.removeEventListener( 'wheel', mousewheel, eventBindType );
this.domElement.removeEventListener( 'touchstart', touchstart, eventBindType );
this.domElement.removeEventListener( 'touchend', touchend, eventBindType );
this.domElement.removeEventListener( 'touchmove', touchmove, eventBindType );
document.removeEventListener( 'mousemove', mousemove, eventBindType );
document.removeEventListener( 'mouseup', mouseup, eventBindType );
window.removeEventListener( 'keydown', keydown, eventBindType );
window.removeEventListener( 'keyup', keyup, eventBindType );
};
this.domElement.addEventListener( 'contextmenu', contextmenu, eventBindType );
this.domElement.addEventListener( 'mousedown', mousedown, eventBindType );
this.domElement.addEventListener( 'wheel', mousewheel, eventBindType );
this.domElement.addEventListener( 'touchstart', touchstart, eventBindType );
this.domElement.addEventListener( 'touchend', touchend, eventBindType );
this.domElement.addEventListener( 'touchmove', touchmove, eventBindType );
window.addEventListener( 'keydown', keydown, eventBindType );
window.addEventListener( 'keyup', keyup, eventBindType );
this.handleResize();
// force an update at start
this.update();
};
THREE.TrackballControls.prototype = Object.create( THREE.EventDispatcher.prototype );
THREE.TrackballControls.prototype.constructor = THREE.TrackballControls;
/**
* Determine whether browser supports passive event listener binding
**/
var supportsPassive = false;
try {
var opts = Object.defineProperty({}, 'passive', {
get: function() {
supportsPassive = true;
}
});
window.addEventListener('testPassive', null, opts);
window.removeEventListener('testPassive', null, opts);
} catch (e) {}
var eventBindType = supportsPassive ? { passive: true } : false;
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