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);
};
it('can look east from a point on the equator', function() {
jasmine.addMatchers(CustomMatchers);
var view = CameraView.fromPositionHeadingPitchRoll(
Cartographic.fromDegrees(45, 0, 100),
CesiumMath.toRadians(90), 0, 0);
var cartographic = Ellipsoid.WGS84.cartesianToCartographic(view.position);
expect(cartographic.longitude).toEqualEpsilon(CesiumMath.toRadians(45), 1e-10);
expect(cartographic.latitude).toEqualEpsilon(0, 1e-10);
expect(cartographic.height).toEqualEpsilon(100.0, 1e-9);
var targetSurfaceNormal = Ellipsoid.WGS84.geodeticSurfaceNormalCartographic(Cartographic.fromDegrees(45, 0));
expect(Cartesian3.equalsEpsilon(view.up, targetSurfaceNormal, 1e-7)).toBe(true);
expect(Cartesian3.equalsEpsilon(Cartesian3.cross(Cartesian3.UNIT_Z, targetSurfaceNormal, new Cartesian3()), view.direction, 1e-7)).toBe(true);
});