/*global define*/
define([
'../Core/Cartesian2',
'../Core/Cartesian3',
'../Core/Cartesian4',
'../Core/defaultValue',
'../Core/defined',
'../Core/defineProperties',
'../Core/DeveloperError',
'../Core/Matrix4',
'./CullingVolume'
], function(
Cartesian2,
Cartesian3,
Cartesian4,
defaultValue,
defined,
defineProperties,
DeveloperError,
Matrix4,
CullingVolume) {
'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 PerspectiveOffCenterFrustum
* @constructor
*
*
* @example
* var frustum = new Cesium.PerspectiveOffCenterFrustum();
* frustum.right = 1.0;
* frustum.left = -1.0;
* frustum.top = 1.0;
* frustum.bottom = -1.0;
* frustum.near = 1.0;
* frustum.far = 2.0;
*
* @see PerspectiveFrustum
*/
function PerspectiveOffCenterFrustum() {
/**
* Defines the left clipping plane.
* @type {Number}
* @default undefined
*/
this.left = undefined;
this._left = undefined;
/**
* Defines the right clipping plane.
* @type {Number}
* @default undefined
*/
this.right = undefined;
this._right = undefined;
/**
* Defines the top clipping plane.
* @type {Number}
* @default undefined
*/
this.top = undefined;
this._top = undefined;
/**
* Defines the bottom clipping plane.
* @type {Number}
* @default undefined
*/
this.bottom = undefined;
this._bottom = 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;
this._cullingVolume = new CullingVolume();
this._perspectiveMatrix = new Matrix4();
this._infinitePerspective = new Matrix4();
}
function update(frustum) {
//>>includeStart('debug', pragmas.debug);
if (!defined(frustum.right) || !defined(frustum.left) ||
!defined(frustum.top) || !defined(frustum.bottom) ||
!defined(frustum.near) || !defined(frustum.far)) {
throw new DeveloperError('right, left, top, bottom, near, or far parameters are not set.');
}
//>>includeEnd('debug');
var t = frustum.top;
var b = frustum.bottom;
var r = frustum.right;
var l = frustum.left;
var n = frustum.near;
var f = frustum.far;
if (t !== frustum._top || b !== frustum._bottom ||
l !== frustum._left || r !== frustum._right ||
n !== frustum._near || f !== frustum._far) {
//>>includeStart('debug', pragmas.debug);
if (frustum.near <= 0 || frustum.near > frustum.far) {
throw new DeveloperError('near must be greater than zero and less than far.');
}
//>>includeEnd('debug');
frustum._left = l;
frustum._right = r;
frustum._top = t;
frustum._bottom = b;
frustum._near = n;
frustum._far = f;
frustum._perspectiveMatrix = Matrix4.computePerspectiveOffCenter(l, r, b, t, n, f, frustum._perspectiveMatrix);
frustum._infinitePerspective = Matrix4.computeInfinitePerspectiveOffCenter(l, r, b, t, n, frustum._infinitePerspective);
}
}
defineProperties(PerspectiveOffCenterFrustum.prototype, {
/**
* Gets the perspective projection matrix computed from the view frustum.
* @memberof PerspectiveOffCenterFrustum.prototype
* @type {Matrix4}
* @readonly
*
* @see PerspectiveOffCenterFrustum#infiniteProjectionMatrix
*/
projectionMatrix : {
get : function() {
update(this);
return this._perspectiveMatrix;
}
},
/**
* Gets the perspective projection matrix computed from the view frustum with an infinite far plane.
* @memberof PerspectiveOffCenterFrustum.prototype
* @type {Matrix4}
* @readonly
*
* @see PerspectiveOffCenterFrustum#projectionMatrix
*/
infiniteProjectionMatrix : {
get : function() {
update(this);
return this._infinitePerspective;
}
}
});
var getPlanesRight = new Cartesian3();
var getPlanesNearCenter = new Cartesian3();
var getPlanesFarCenter = new Cartesian3();
var getPlanesNormal = new Cartesian3();
/**
* 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);
*/
PerspectiveOffCenterFrustum.prototype.computeCullingVolume = function(position, direction, up) {
//>>includeStart('debug', pragmas.debug);
if (!defined(position)) {
throw new DeveloperError('position is required.');
}
if (!defined(direction)) {
throw new DeveloperError('direction is required.');
}
if (!defined(up)) {
throw new DeveloperError('up is required.');
}
//>>includeEnd('debug');
var planes = this._cullingVolume.planes;
var t = this.top;
var b = this.bottom;
var r = this.right;
var l = this.left;
var n = this.near;
var f = this.far;
var right = Cartesian3.cross(direction, up, getPlanesRight);
var nearCenter = getPlanesNearCenter;
Cartesian3.multiplyByScalar(direction, n, nearCenter);
Cartesian3.add(position, nearCenter, nearCenter);
var farCenter = getPlanesFarCenter;
Cartesian3.multiplyByScalar(direction, f, farCenter);
Cartesian3.add(position, farCenter, farCenter);
var normal = getPlanesNormal;
//Left plane computation
Cartesian3.multiplyByScalar(right, l, normal);
Cartesian3.add(nearCenter, normal, normal);
Cartesian3.subtract(normal, position, normal);
Cartesian3.normalize(normal, normal);
Cartesian3.cross(normal, up, normal);
var plane = planes[0];
if (!defined(plane)) {
plane = planes[0] = new Cartesian4();
}
plane.x = normal.x;
plane.y = normal.y;
plane.z = normal.z;
plane.w = -Cartesian3.dot(normal, position);
//Right plane computation
Cartesian3.multiplyByScalar(right, r, normal);
Cartesian3.add(nearCenter, normal, normal);
Cartesian3.subtract(normal, position, normal);
Cartesian3.normalize(normal, normal);
Cartesian3.cross(up, normal, normal);
plane = planes[1];
if (!defined(plane)) {
plane = planes[1] = new Cartesian4();
}
plane.x = normal.x;
plane.y = normal.y;
plane.z = normal.z;
plane.w = -Cartesian3.dot(normal, position);
//Bottom plane computation
Cartesian3.multiplyByScalar(up, b, normal);
Cartesian3.add(nearCenter, normal, normal);
Cartesian3.subtract(normal, position, normal);
Cartesian3.normalize(normal, normal);
Cartesian3.cross(right, normal, normal);
plane = planes[2];
if (!defined(plane)) {
plane = planes[2] = new Cartesian4();
}
plane.x = normal.x;
plane.y = normal.y;
plane.z = normal.z;
plane.w = -Cartesian3.dot(normal, position);
//Top plane computation
Cartesian3.multiplyByScalar(up, t, normal);
Cartesian3.add(nearCenter, normal, normal);
Cartesian3.subtract(normal, position, normal);
Cartesian3.normalize(normal, normal);
Cartesian3.cross(normal, right, normal);
plane = planes[3];
if (!defined(plane)) {
plane = planes[3] = new Cartesian4();
}
plane.x = normal.x;
plane.y = normal.y;
plane.z = normal.z;
plane.w = -Cartesian3.dot(normal, position);
//Near plane computation
plane = planes[4];
if (!defined(plane)) {
plane = planes[4] = new Cartesian4();
}
plane.x = direction.x;
plane.y = direction.y;
plane.z = direction.z;
plane.w = -Cartesian3.dot(direction, nearCenter);
//Far plane computation
Cartesian3.negate(direction, normal);
plane = planes[5];
if (!defined(plane)) {
plane = planes[5] = new Cartesian4();
}
plane.x = normal.x;
plane.y = normal.y;
plane.z = normal.z;
plane.w = -Cartesian3.dot(normal, farCenter);
return this._cullingVolume;
};
/**
* 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());
*/
PerspectiveOffCenterFrustum.prototype.getPixelDimensions = function(drawingBufferWidth, drawingBufferHeight, distance, result) {
update(this);
//>>includeStart('debug', pragmas.debug);
if (!defined(drawingBufferWidth) || !defined(drawingBufferHeight)) {
throw new DeveloperError('Both drawingBufferWidth and drawingBufferHeight are required.');
}
if (drawingBufferWidth <= 0) {
throw new DeveloperError('drawingBufferWidth must be greater than zero.');
}
if (drawingBufferHeight <= 0) {
throw new DeveloperError('drawingBufferHeight must be greater than zero.');
}
if (!defined(distance)) {
throw new DeveloperError('distance is required.');
}
if (!defined(result)) {
throw new DeveloperError('A result object is required.');
}
//>>includeEnd('debug');
var inverseNear = 1.0 / this.near;
var tanTheta = this.top * inverseNear;
var pixelHeight = 2.0 * distance * tanTheta / drawingBufferHeight;
tanTheta = this.right * inverseNear;
var pixelWidth = 2.0 * distance * tanTheta / drawingBufferWidth;
result.x = pixelWidth;
result.y = pixelHeight;
return result;
};
/**
* Returns a duplicate of a PerspectiveOffCenterFrustum instance.
*
* @param {PerspectiveOffCenterFrustum} [result] The object onto which to store the result.
* @returns {PerspectiveOffCenterFrustum} The modified result parameter or a new PerspectiveFrustum instance if one was not provided.
*/
PerspectiveOffCenterFrustum.prototype.clone = function(result) {
if (!defined(result)) {
result = new PerspectiveOffCenterFrustum();
}
result.right = this.right;
result.left = this.left;
result.top = this.top;
result.bottom = this.bottom;
result.near = this.near;
result.far = this.far;
// force update of clone to compute matrices
result._left = undefined;
result._right = undefined;
result._top = undefined;
result._bottom = undefined;
result._near = undefined;
result._far = undefined;
return result;
};
/**
* Compares the provided PerspectiveOffCenterFrustum componentwise and returns
* <code>true</code> if they are equal, <code>false</code> otherwise.
*
* @param {PerspectiveOffCenterFrustum} [other] The right hand side PerspectiveOffCenterFrustum.
* @returns {Boolean} <code>true</code> if they are equal, <code>false</code> otherwise.
*/
PerspectiveOffCenterFrustum.prototype.equals = function(other) {
return (defined(other) &&
this.right === other.right &&
this.left === other.left &&
this.top === other.top &&
this.bottom === other.bottom &&
this.near === other.near &&
this.far === other.far);
};
return PerspectiveOffCenterFrustum;
});