@xeokit/xeokit-sdk
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3D BIM IFC Viewer SDK for AEC engineering applications. Open Source JavaScript Toolkit based on pure WebGL for top performance, real-world coordinates and full double precision
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JavaScript
import {math} from '../math/math.js';
import {Component} from '../Component.js';
import {RenderState} from '../webgl/RenderState.js';
/**
* @desc Defines its {@link Camera}'s perspective projection using a field-of-view angle.
*
* * Located at {@link Camera#perspective}.
* * Implicitly sets the left, right, top, bottom frustum planes using {@link Perspective#fov}.
* * {@link Perspective#near} and {@link Perspective#far} specify the distances to the WebGL clipping planes.
*/
class Perspective extends Component {
/**
@private
*/
get type() {
return "Perspective";
}
/**
* @constructor
* @private
*/
constructor(camera, cfg = {}) {
super(camera, cfg);
/**
* The Camera this Perspective belongs to.
*
* @property camera
* @type {Camera}
* @final
*/
this.camera = camera;
this._state = new RenderState({
matrix: math.mat4(),
inverseMatrix: math.mat4(),
transposedMatrix: math.mat4(),
near: 0.1,
far: 10000.0
});
this._inverseMatrixDirty = true;
this._transposedMatrixDirty = true;
this._fov = 60.0;
// Recompute aspect from change in canvas size
this._canvasResized = this.scene.canvas.on("boundary", this._needUpdate, this);
this.fov = cfg.fov;
this.fovAxis = cfg.fovAxis;
this.near = cfg.near;
this.far = cfg.far;
}
_update() {
const WIDTH_INDEX = 2;
const HEIGHT_INDEX = 3;
const boundary = this.scene.canvas.boundary;
const aspect = boundary[WIDTH_INDEX] / boundary[HEIGHT_INDEX];
const fovAxis = this._fovAxis;
let fov = this._fov;
if (fovAxis === "x" || (fovAxis === "min" && aspect < 1) || (fovAxis === "max" && aspect > 1)) {
fov = fov / aspect;
}
fov = Math.min(fov, 120);
math.perspectiveMat4(fov * (Math.PI / 180.0), aspect, this._state.near, this._state.far, this._state.matrix);
this._inverseMatrixDirty = true;
this._transposedMatrixDirty = true;
this.glRedraw();
this.camera._updateScheduled = true;
this.fire("matrix", this._state.matrix);
}
/**
* Sets the Perspective's field-of-view angle (FOV).
*
* Fires an "fov" event on change.
* Default value is ````60.0````.
*
* @param {Number} value New field-of-view.
*/
set fov(value) {
value = (value !== undefined && value !== null) ? value : 60.0;
if (value === this._fov) {
return;
}
this._fov = value;
this._needUpdate(0); // Ensure matrix built on next "tick"
this.fire("fov", this._fov);
}
/**
* Gets the Perspective's field-of-view angle (FOV).
*
* Default value is ````60.0````.
*
* @returns {Number} Current field-of-view.
*/
get fov() {
return this._fov;
}
/**
* Sets the Perspective's FOV axis.
*
* Options are ````"x"````, ````"y"```` or ````"min"````, to use the minimum axis.
*
* Fires an "fovAxis" event on change.
* Default value ````"min"````.
*
* @param {String} value New FOV axis value.
*/
set fovAxis(value) {
value = value || "min";
if (this._fovAxis === value) {
return;
}
if (value !== "x" && value !== "y" && value !== "min") {
this.error("Unsupported value for 'fovAxis': " + value + " - defaulting to 'min'");
value = "min";
}
this._fovAxis = value;
this._needUpdate(0); // Ensure matrix built on next "tick"
this.fire("fovAxis", this._fovAxis);
}
/**
* Gets the Perspective's FOV axis.
*
* Options are ````"x"````, ````"y"```` or ````"min"````, to use the minimum axis.
*
* Fires an "fovAxis" event on change.
* Default value is ````"min"````.
*
* @returns {String} The current FOV axis value.
*/
get fovAxis() {
return this._fovAxis;
}
/**
* Sets the position of the Perspective's near plane on the positive View-space Z-axis.
*
* Fires a "near" event on change.
*
* Default value is ````0.1````.
*
* @param {Number} value New Perspective near plane position.
*/
set near(value) {
const near = (value !== undefined && value !== null) ? value : 0.1;
if (this._state.near === near) {
return;
}
this._state.near = near;
this._needUpdate(0); // Ensure matrix built on next "tick"
this.fire("near", this._state.near);
}
/**
* Gets the position of the Perspective's near plane on the positive View-space Z-axis.
*
* Fires an "emits" emits on change.
*
* Default value is ````0.1````.
*
* @returns The Perspective's near plane position.
*/
get near() {
return this._state.near;
}
/**
* Sets the position of this Perspective's far plane on the positive View-space Z-axis.
*
* Fires a "far" event on change.
*
* Default value is ````10000.0````.
*
* @param {Number} value New Perspective far plane position.
*/
set far(value) {
const far = (value !== undefined && value !== null) ? value : 10000.0;
if (this._state.far === far) {
return;
}
this._state.far = far;
this._needUpdate(0); // Ensure matrix built on next "tick"
this.fire("far", this._state.far);
}
/**
* Gets the position of this Perspective's far plane on the positive View-space Z-axis.
*
* Default value is ````10000.0````.
*
* @return {Number} The Perspective's far plane position.
*/
get far() {
return this._state.far;
}
/**
* Gets the Perspective's projection transform matrix.
*
* Fires a "matrix" event on change.
*
* Default value is ````[1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]````.
*
* @returns {Number[]} The Perspective's projection matrix.
*/
get matrix() {
if (this._updateScheduled) {
this._doUpdate();
}
return this._state.matrix;
}
/**
* Gets the inverse of {@link Perspective#matrix}.
*
* @returns {Number[]} The inverse of {@link Perspective#matrix}.
*/
get inverseMatrix() {
if (this._updateScheduled) {
this._doUpdate();
}
if (this._inverseMatrixDirty) {
math.inverseMat4(this._state.matrix, this._state.inverseMatrix);
this._inverseMatrixDirty = false;
}
return this._state.inverseMatrix;
}
/**
* Gets the transpose of {@link Perspective#matrix}.
*
* @returns {Number[]} The transpose of {@link Perspective#matrix}.
*/
get transposedMatrix() {
if (this._updateScheduled) {
this._doUpdate();
}
if (this._transposedMatrixDirty) {
math.transposeMat4(this._state.matrix, this._state.transposedMatrix);
this._transposedMatrixDirty = false;
}
return this._state.transposedMatrix;
}
/**
* Un-projects the given Canvas-space coordinates and Screen-space depth, using this Perspective projection.
*
* @param {Number[]} canvasPos Inputs 2D Canvas-space coordinates.
* @param {Number} screenZ Inputs Screen-space Z coordinate.
* @param {Number[]} screenPos Outputs 3D Screen/Clip-space coordinates.
* @param {Number[]} viewPos Outputs un-projected 3D View-space coordinates.
* @param {Number[]} worldPos Outputs un-projected 3D World-space coordinates.
*/
unproject(canvasPos, screenZ, screenPos, viewPos, worldPos) {
const canvas = this.scene.canvas.canvas;
const halfCanvasWidth = canvas.offsetWidth / 2.0;
const halfCanvasHeight = canvas.offsetHeight / 2.0;
screenPos[0] = (canvasPos[0] - halfCanvasWidth) / halfCanvasWidth;
screenPos[1] = (canvasPos[1] - halfCanvasHeight) / halfCanvasHeight;
screenPos[2] = screenZ;
screenPos[3] = 1.0;
math.mulMat4v4(this.inverseMatrix, screenPos, viewPos);
math.mulVec3Scalar(viewPos, 1.0 / viewPos[3]);
viewPos[3] = 1.0;
viewPos[1] *= -1;
math.mulMat4v4(this.camera.inverseViewMatrix, viewPos, worldPos);
return worldPos;
}
/** @private
*
*/
destroy() {
super.destroy();
this._state.destroy();
this.scene.canvas.off(this._canvasResized);
}
}
export {Perspective};