/*global define*/
define([
'../Core/defined',
'../Core/defineProperties',
'../Core/DeveloperError',
'./PerspectiveOffCenterFrustum'
], function(
defined,
defineProperties,
DeveloperError,
PerspectiveOffCenterFrustum) {
'use strict';
/**
* The viewing frustum is defined by 6 planes.
* Each plane is represented by a {@link Cartesian4} object, where the x, y, and z components
* define the unit vector normal to the plane, and the w component is the distance of the
* plane from the origin/camera position.
*
* @alias PerspectiveFrustum
* @constructor
*
*
* @example
* var frustum = new Cesium.PerspectiveFrustum();
* frustum.aspectRatio = canvas.clientWidth / canvas.clientHeight;
* frustum.fov = Cesium.Math.PI_OVER_THREE;
* frustum.near = 1.0;
* frustum.far = 2.0;
*
* @see PerspectiveOffCenterFrustum
*/
function PerspectiveFrustum() {
this._offCenterFrustum = new PerspectiveOffCenterFrustum();
/**
* The angle of the field of view (FOV), in radians. This angle will be used
* as the horizontal FOV if the width is greater than the height, otherwise
* it will be the vertical FOV.
* @type {Number}
* @default undefined
*/
this.fov = undefined;
this._fov = undefined;
this._fovy = undefined;
this._sseDenominator = undefined;
/**
* The aspect ratio of the frustum's width to it's height.
* @type {Number}
* @default undefined
*/
this.aspectRatio = undefined;
this._aspectRatio = undefined;
/**
* The distance of the near plane.
* @type {Number}
* @default 1.0
*/
this.near = 1.0;
this._near = this.near;
/**
* The distance of the far plane.
* @type {Number}
* @default 500000000.0
*/
this.far = 500000000.0;
this._far = this.far;
/**
* Offsets the frustum in the x direction.
* @type {Number}
* @default 0.0
*/
this.xOffset = 0.0;
this._xOffset = this.xOffset;
/**
* Offsets the frustum in the y direction.
* @type {Number}
* @default 0.0
*/
this.yOffset = 0.0;
this._yOffset = this.yOffset;
}
function update(frustum) {
//>>includeStart('debug', pragmas.debug);
if (!defined(frustum.fov) || !defined(frustum.aspectRatio) || !defined(frustum.near) || !defined(frustum.far)) {
throw new DeveloperError('fov, aspectRatio, near, or far parameters are not set.');
}
//>>includeEnd('debug');
var f = frustum._offCenterFrustum;
if (frustum.fov !== frustum._fov || frustum.aspectRatio !== frustum._aspectRatio ||
frustum.near !== frustum._near || frustum.far !== frustum._far ||
frustum.xOffset !== frustum._xOffset || frustum.yOffset !== frustum._yOffset) {
//>>includeStart('debug', pragmas.debug);
if (frustum.fov < 0 || frustum.fov >= Math.PI) {
throw new DeveloperError('fov must be in the range [0, PI).');
}
if (frustum.aspectRatio < 0) {
throw new DeveloperError('aspectRatio must be positive.');
}
if (frustum.near < 0 || frustum.near > frustum.far) {
throw new DeveloperError('near must be greater than zero and less than far.');
}
//>>includeEnd('debug');
frustum._aspectRatio = frustum.aspectRatio;
frustum._fov = frustum.fov;
frustum._fovy = (frustum.aspectRatio <= 1) ? frustum.fov : Math.atan(Math.tan(frustum.fov * 0.5) / frustum.aspectRatio) * 2.0;
frustum._near = frustum.near;
frustum._far = frustum.far;
frustum._sseDenominator = 2.0 * Math.tan(0.5 * frustum._fovy);
frustum._xOffset = frustum.xOffset;
frustum._yOffset = frustum.yOffset;
f.top = frustum.near * Math.tan(0.5 * frustum._fovy);
f.bottom = -f.top;
f.right = frustum.aspectRatio * f.top;
f.left = -f.right;
f.near = frustum.near;
f.far = frustum.far;
f.right += frustum.xOffset;
f.left += frustum.xOffset;
f.top += frustum.yOffset;
f.bottom += frustum.yOffset;
}
}
defineProperties(PerspectiveFrustum.prototype, {
/**
* Gets the perspective projection matrix computed from the view frustum.
* @memberof PerspectiveFrustum.prototype
* @type {Matrix4}
* @readonly
*
* @see PerspectiveFrustum#infiniteProjectionMatrix
*/
projectionMatrix : {
get : function() {
update(this);
return this._offCenterFrustum.projectionMatrix;
}
},
/**
* The perspective projection matrix computed from the view frustum with an infinite far plane.
* @memberof PerspectiveFrustum.prototype
* @type {Matrix4}
* @readonly
*
* @see PerspectiveFrustum#projectionMatrix
*/
infiniteProjectionMatrix : {
get : function() {
update(this);
return this._offCenterFrustum.infiniteProjectionMatrix;
}
},
/**
* Gets the angle of the vertical field of view, in radians.
* @memberof PerspectiveFrustum.prototype
* @type {Number}
* @readonly
* @default undefined
*/
fovy : {
get : function() {
update(this);
return this._fovy;
}
},
/**
* @readonly
* @private
*/
sseDenominator : {
get : function () {
update(this);
return this._sseDenominator;
}
}
});
/**
* Creates a culling volume for this frustum.
*
* @param {Cartesian3} position The eye position.
* @param {Cartesian3} direction The view direction.
* @param {Cartesian3} up The up direction.
* @returns {CullingVolume} A culling volume at the given position and orientation.
*
* @example
* // Check if a bounding volume intersects the frustum.
* var cullingVolume = frustum.computeCullingVolume(cameraPosition, cameraDirection, cameraUp);
* var intersect = cullingVolume.computeVisibility(boundingVolume);
*/
PerspectiveFrustum.prototype.computeCullingVolume = function(position, direction, up) {
update(this);
return this._offCenterFrustum.computeCullingVolume(position, direction, up);
};
/**
* Returns the pixel's width and height in meters.
*
* @param {Number} drawingBufferWidth The width of the drawing buffer.
* @param {Number} drawingBufferHeight The height of the drawing buffer.
* @param {Number} distance The distance to the near plane in meters.
* @param {Cartesian2} result The object onto which to store the result.
* @returns {Cartesian2} The modified result parameter or a new instance of {@link Cartesian2} with the pixel's width and height in the x and y properties, respectively.
*
* @exception {DeveloperError} drawingBufferWidth must be greater than zero.
* @exception {DeveloperError} drawingBufferHeight must be greater than zero.
*
* @example
* // Example 1
* // Get the width and height of a pixel.
* var pixelSize = camera.frustum.getPixelDimensions(scene.drawingBufferWidth, scene.drawingBufferHeight, 1.0, new Cesium.Cartesian2());
*
* @example
* // Example 2
* // Get the width and height of a pixel if the near plane was set to 'distance'.
* // For example, get the size of a pixel of an image on a billboard.
* var position = camera.position;
* var direction = camera.direction;
* var toCenter = Cesium.Cartesian3.subtract(primitive.boundingVolume.center, position, new Cesium.Cartesian3()); // vector from camera to a primitive
* var toCenterProj = Cesium.Cartesian3.multiplyByScalar(direction, Cesium.Cartesian3.dot(direction, toCenter), new Cesium.Cartesian3()); // project vector onto camera direction vector
* var distance = Cesium.Cartesian3.magnitude(toCenterProj);
* var pixelSize = camera.frustum.getPixelDimensions(scene.drawingBufferWidth, scene.drawingBufferHeight, distance, new Cesium.Cartesian2());
*/
PerspectiveFrustum.prototype.getPixelDimensions = function(drawingBufferWidth, drawingBufferHeight, distance, result) {
update(this);
return this._offCenterFrustum.getPixelDimensions(drawingBufferWidth, drawingBufferHeight, distance, result);
};
/**
* Returns a duplicate of a PerspectiveFrustum instance.
*
* @param {PerspectiveFrustum} [result] The object onto which to store the result.
* @returns {PerspectiveFrustum} The modified result parameter or a new PerspectiveFrustum instance if one was not provided.
*/
PerspectiveFrustum.prototype.clone = function(result) {
if (!defined(result)) {
result = new PerspectiveFrustum();
}
result.aspectRatio = this.aspectRatio;
result.fov = this.fov;
result.near = this.near;
result.far = this.far;
// force update of clone to compute matrices
result._aspectRatio = undefined;
result._fov = undefined;
result._near = undefined;
result._far = undefined;
this._offCenterFrustum.clone(result._offCenterFrustum);
return result;
};
/**
* Compares the provided PerspectiveFrustum componentwise and returns
* <code>true</code> if they are equal, <code>false</code> otherwise.
*
* @param {PerspectiveFrustum} [other] The right hand side PerspectiveFrustum.
* @returns {Boolean} <code>true</code> if they are equal, <code>false</code> otherwise.
*/
PerspectiveFrustum.prototype.equals = function(other) {
if (!defined(other)) {
return false;
}
update(this);
update(other);
return (this.fov === other.fov &&
this.aspectRatio === other.aspectRatio &&
this.near === other.near &&
this.far === other.far &&
this._offCenterFrustum.equals(other._offCenterFrustum));
};
return PerspectiveFrustum;
});