'use strict';
/*global require*/
var Cartesian3 = require('terriajs-cesium/Source/Core/Cartesian3');
var Cartographic = require('terriajs-cesium/Source/Core/Cartographic');
var CesiumMath = require('terriajs-cesium/Source/Core/Math');
var defined = require('terriajs-cesium/Source/Core/defined');
var defineProperties = require('terriajs-cesium/Source/Core/defineProperties');
var DeveloperError = require('terriajs-cesium/Source/Core/DeveloperError');
var Ellipsoid = require('terriajs-cesium/Source/Core/Ellipsoid');
var HeadingPitchRange = require('terriajs-cesium/Source/Core/HeadingPitchRange');
var HeadingPitchRoll = require('terriajs-cesium/Source/Core/HeadingPitchRoll');
var Matrix3 = require('terriajs-cesium/Source/Core/Matrix3');
var Matrix4 = require('terriajs-cesium/Source/Core/Matrix4');
var Quaternion = require('terriajs-cesium/Source/Core/Quaternion');
var Rectangle = require('terriajs-cesium/Source/Core/Rectangle');
var Transforms = require('terriajs-cesium/Source/Core/Transforms');
/**
* Holds a camera view parameters, expressed as a rectangular extent and/or as a camera position, direction,
* and up vector.
*
* @alias CameraView
* @constructor
*/
var CameraView = function(rectangle, position, direction, up) {
if (!defined(rectangle)) {
throw new DeveloperError('rectangle is required.');
}
if (defined(position) || defined(direction) || defined(up)) {
if (!defined(position) || !defined(direction) || !defined(up)) {
throw new DeveloperError('If any of position, direction, or up are specified, all must be specified.');
}
}
this._rectangle = rectangle;
this._position = position;
this._direction = direction;
this._up = up;
};
defineProperties(CameraView.prototype, {
/**
* Gets the rectangular extent of the view. If {@link CameraView#position}, {@link CameraView#direction},
* and {@link CameraView#up} are specified, this property will be ignored for viewers that support those parameters
* (e.g. Cesium). This property must always be supplied, however, for the benefit of viewers that do not understand
* these parameters (e.g. Leaflet).
* @type {Rectangle}
*/
rectangle: {
get: function() {
return this._rectangle;
}
},
/**
* Gets the position of the camera in the Earth-centered Fixed frame.
* @type {Cartesian3}
*/
position: {
get: function() {
return this._position;
}
},
/**
* Gets the look direction of the camera in the Earth-centered Fixed frame.
* @type {Cartesian3}
*/
direction: {
get: function() {
return this._direction;
}
},
/**
* Gets the up vector direction of the camera in the Earth-centered Fixed frame.
* @type {Cartesian3}
*/
up: {
get: function() {
return this._up;
}
}
});
/**
* Constructs a {@link CameraView} from json. All angles must be specified in degrees.
* If neither json.lookAt nor json.positionHeadingPitchRoll is present, then json should have the keys position, direction, up, west, south, east, north.
* @param {Object} json The JSON description. The JSON should be in the form of an object literal, not a string.
* @param {Object} [json.lookAt] If present, must include keys targetLongitude, targetLatitude, targetHeight, heading, pitch, range.
* @param {Object} [json.positionHeadingPitchRoll] If present, must include keys cameraLongitude, cameraLatitude, cameraHeight, heading, pitch, roll.
* @return {CameraView} The camera view.
*/
CameraView.fromJson = function(json) {
if (defined(json.lookAt)) {
var targetPosition = Cartographic.fromDegrees(json.lookAt.targetLongitude, json.lookAt.targetLatitude, json.lookAt.targetHeight);
var headingPitchRange = new HeadingPitchRange(CesiumMath.toRadians(json.lookAt.heading), CesiumMath.toRadians(json.lookAt.pitch), json.lookAt.range);
return CameraView.fromLookAt(targetPosition, headingPitchRange);
} else if (defined(json.positionHeadingPitchRoll)) {
var cameraPosition = Cartographic.fromDegrees(json.positionHeadingPitchRoll.cameraLongitude, json.positionHeadingPitchRoll.cameraLatitude, json.positionHeadingPitchRoll.cameraHeight);
return CameraView.fromPositionHeadingPitchRoll(cameraPosition,
CesiumMath.toRadians(json.positionHeadingPitchRoll.heading),
CesiumMath.toRadians(json.positionHeadingPitchRoll.pitch),
CesiumMath.toRadians(json.positionHeadingPitchRoll.roll));
} else if (defined(json.position) && defined(json.direction) && defined(json.up)) {
return new CameraView(
Rectangle.fromDegrees(json.west, json.south, json.east, json.north),
new Cartesian3(json.position.x, json.position.y, json.position.z),
new Cartesian3(json.direction.x, json.direction.y, json.direction.z),
new Cartesian3(json.up.x, json.up.y, json.up.z));
} else {
return new CameraView(Rectangle.fromDegrees(json.west, json.south, json.east, json.north));
}
};
var scratchPosition = new Cartesian3();
var scratchOffset = new Cartesian3();
var scratchDirection = new Cartesian3();
var scratchRight = new Cartesian3();
var scratchUp = new Cartesian3();
var scratchTarget = new Cartesian3();
var scratchMatrix4 = new Matrix4();
/**
* Constructs a {@link CameraView} from a "look at" description.
* @param {Cartographic} targetPosition The position to look at.
* @param {HeadingPitchRange} headingPitchRange The offset of the camera from the target position.
* @return {CameraView} The camera view.
*/
CameraView.fromLookAt = function(targetPosition, headingPitchRange) {
if (!defined(targetPosition)) {
throw new DeveloperError('targetPosition is required.');
}
if (!defined(headingPitchRange)) {
throw new DeveloperError('headingPitchRange is required.');
}
var positionENU = offsetFromHeadingPitchRange(headingPitchRange.heading, -headingPitchRange.pitch, headingPitchRange.range, scratchPosition);
var directionENU = Cartesian3.normalize(Cartesian3.negate(positionENU, scratchDirection), scratchDirection);
var rightENU = Cartesian3.cross(directionENU, Cartesian3.UNIT_Z, scratchRight);
if (Cartesian3.magnitudeSquared(rightENU) < CesiumMath.EPSILON10) {
Cartesian3.clone(Cartesian3.UNIT_X, rightENU);
}
Cartesian3.normalize(rightENU, rightENU);
var upENU = Cartesian3.cross(rightENU, directionENU, scratchUp);
Cartesian3.normalize(upENU, upENU);
var targetCartesian = Ellipsoid.WGS84.cartographicToCartesian(targetPosition, scratchTarget);
var transform = Transforms.eastNorthUpToFixedFrame(targetCartesian, Ellipsoid.WGS84, scratchMatrix4);
var offsetECF = Matrix4.multiplyByPointAsVector(transform, positionENU, scratchOffset);
var position = Cartesian3.add(targetCartesian, offsetECF, new Cartesian3());
var direction = Cartesian3.normalize(Cartesian3.negate(offsetECF, new Cartesian3()), new Cartesian3());
var up = Matrix4.multiplyByPointAsVector(transform, upENU, new Cartesian3());
// Estimate a rectangle for this view.
var fieldOfViewHalfAngle = CesiumMath.toRadians(30);
var groundDistance = Math.tan(fieldOfViewHalfAngle) * (headingPitchRange.range + targetPosition.height);
var angle = groundDistance / Ellipsoid.WGS84.minimumRadius;
var extent = new Rectangle(targetPosition.longitude - angle, targetPosition.latitude - angle, targetPosition.longitude + angle, targetPosition.latitude + angle);
return new CameraView(extent, position, direction, up);
};
var scratchQuaternion = new Quaternion();
var scratchMatrix3 = new Matrix3();
/**
* Constructs a {@link CameraView} from a camera position and heading, pitch, and roll angles for the camera.
* @param {Cartographic} cameraPosition The position of the camera.
* @param {Number} heading The heading of the camera in radians measured from North toward East.
* @param {Number} pitch The pitch of the camera in radians measured from the local horizontal. Positive angles look up, negative angles look down.
* @param {Number} roll The roll of the camera in radians counterclockwise.
*/
CameraView.fromPositionHeadingPitchRoll = function(cameraPosition, heading, pitch, roll) {
if (!defined(cameraPosition)) {
throw new DeveloperError('cameraPosition is required.');
}
if (!defined(heading)) {
throw new DeveloperError('heading is required.');
}
if (!defined(pitch)) {
throw new DeveloperError('pitch is required.');
}
if (!defined(roll)) {
throw new DeveloperError('roll is required.');
}
var hpr = new HeadingPitchRoll(heading - CesiumMath.PI_OVER_TWO, pitch, roll);
var rotQuat = Quaternion.fromHeadingPitchRoll(hpr, scratchQuaternion);
var rotMat = Matrix3.fromQuaternion(rotQuat, scratchMatrix3);
var directionENU = Matrix3.getColumn(rotMat, 0, scratchDirection);
var upENU = Matrix3.getColumn(rotMat, 2, scratchUp);
var positionECF = Ellipsoid.WGS84.cartographicToCartesian(cameraPosition, scratchTarget);
var transform = Transforms.eastNorthUpToFixedFrame(positionECF, Ellipsoid.WGS84, scratchMatrix4);
var directionECF = Matrix4.multiplyByPointAsVector(transform, directionENU, new Cartesian3());
var upECF = Matrix4.multiplyByPointAsVector(transform, upENU, new Cartesian3());
// Estimate a rectangle for this view.
var fieldOfViewHalfAngle = CesiumMath.toRadians(30);
var groundDistance = Math.tan(fieldOfViewHalfAngle) * cameraPosition.height;
var angle = groundDistance / Ellipsoid.WGS84.minimumRadius;
var extent = new Rectangle(cameraPosition.longitude - angle, cameraPosition.latitude - angle, cameraPosition.longitude + angle, cameraPosition.latitude + angle);
return new CameraView(extent, positionECF, directionECF, upECF);
};
var scratchLookAtHeadingPitchRangeQuaternion1 = new Quaternion();
var scratchLookAtHeadingPitchRangeQuaternion2 = new Quaternion();
var scratchHeadingPitchRangeMatrix3 = new Matrix3();
function offsetFromHeadingPitchRange(heading, pitch, range, result) {
pitch = CesiumMath.clamp(pitch, -CesiumMath.PI_OVER_TWO, CesiumMath.PI_OVER_TWO);
heading = CesiumMath.zeroToTwoPi(heading) - CesiumMath.PI_OVER_TWO;
var pitchQuat = Quaternion.fromAxisAngle(Cartesian3.UNIT_Y, -pitch, scratchLookAtHeadingPitchRangeQuaternion1);
var headingQuat = Quaternion.fromAxisAngle(Cartesian3.UNIT_Z, -heading, scratchLookAtHeadingPitchRangeQuaternion2);
var rotQuat = Quaternion.multiply(headingQuat, pitchQuat, headingQuat);
var rotMatrix = Matrix3.fromQuaternion(rotQuat, scratchHeadingPitchRangeMatrix3);
var offset = Cartesian3.clone(Cartesian3.UNIT_X, result);
Matrix3.multiplyByVector(rotMatrix, offset, offset);
Cartesian3.negate(offset, offset);
Cartesian3.multiplyByScalar(offset, range, offset);
return offset;
}
module.exports = CameraView;