/**
* Based on http://www.emagix.net/academic/mscs-project/item/camera-sync-with-css3-and-webgl-threejs
* @author mrdoob / http://mrdoob.com/
* @author yomotsu / https://yomotsu.net/
*/
THREE.CSS3DObject = function (element) {
THREE.Object3D.call(this);
this.element = element;
this.element.style.position = 'absolute';
this.addEventListener('removed', function () {
if (this.element.parentNode !== null) {
this.element.parentNode.removeChild(this.element);
}
});
};
THREE.CSS3DObject.prototype = Object.create(THREE.Object3D.prototype);
THREE.CSS3DObject.prototype.constructor = THREE.CSS3DObject;
THREE.CSS3DSprite = function (element) {
THREE.CSS3DObject.call(this, element);
};
THREE.CSS3DSprite.prototype = Object.create(THREE.CSS3DObject.prototype);
THREE.CSS3DSprite.prototype.constructor = THREE.CSS3DSprite;
//
THREE.CSS3DRenderer = function () {
console.log('THREE.CSS3DRenderer', THREE.REVISION);
var _width, _height;
var _widthHalf, _heightHalf;
var matrix = new THREE.Matrix4();
// 缓存
var cache = {
camera: { fov: 0, style: '' },
objects: new WeakMap()
};
var domElement = document.createElement('div');
domElement.style.overflow = 'hidden';
this.domElement = domElement;
// 该节点下的子节点都具有3D效果
var cameraElement = document.createElement('div');
// 该属性设置在父级元素中，它的子级元素具有3d效果
cameraElement.style.WebkitTransformStyle = 'preserve-3d';
cameraElement.style.transformStyle = 'preserve-3d';
domElement.appendChild(cameraElement);
var isIE = /Trident/i.test(navigator.userAgent);
this.getSize = function () {
return {
width: _width,
height: _height
};
};
this.setSize = function (width, height) {
_width = width;
_height = height;
_widthHalf = _width / 2;
_heightHalf = _height / 2;
domElement.style.width = width + 'px';
domElement.style.height = height + 'px';
cameraElement.style.width = width + 'px';
cameraElement.style.height = height + 'px';
};
function epsilon(value) {
return Math.abs(value) < 1e-10 ? 0 : value;
}
function getCameraCSSMatrix(matrix) {
var elements = matrix.elements;
return 'matrix3d(' +
epsilon(elements[0]) + ',' +
epsilon(- elements[1]) + ',' +
epsilon(elements[2]) + ',' +
epsilon(elements[3]) + ',' +
epsilon(elements[4]) + ',' +
epsilon(- elements[5]) + ',' +
epsilon(elements[6]) + ',' +
epsilon(elements[7]) + ',' +
epsilon(elements[8]) + ',' +
epsilon(- elements[9]) + ',' +
epsilon(elements[10]) + ',' +
epsilon(elements[11]) + ',' +
epsilon(elements[12]) + ',' +
epsilon(- elements[13]) + ',' +
epsilon(elements[14]) + ',' +
epsilon(elements[15]) +
')';
}
function getObjectCSSMatrix(matrix, cameraCSSMatrix, object) {
var elements = matrix.elements;
var matrix3d = 'matrix3d(' +
epsilon(elements[0]) + ',' +
epsilon(elements[1]) + ',' +
epsilon(elements[2]) + ',' +
epsilon(elements[3]) + ',' +
epsilon(- elements[4]) + ',' +
epsilon(- elements[5]) + ',' +
epsilon(- elements[6]) + ',' +
epsilon(- elements[7]) + ',' +
epsilon(elements[8]) + ',' +
epsilon(elements[9]) + ',' +
epsilon(elements[10]) + ',' +
epsilon(elements[11]) + ',' +
epsilon(elements[12]) + ',' +
epsilon(elements[13]) + ',' +
epsilon(elements[14]) + ',' +
epsilon(elements[15]) +
')';
if (isIE) {
return 'translate(-50%,-50%)' +
'translate(' + _widthHalf + 'px,' + _heightHalf + 'px)' +
cameraCSSMatrix +
matrix3d;
}
if (object.userData.anchor) {
return 'translate(-' + object.userData.anchor[0] * 100 + '%,-' + object.userData.anchor[1] * 100 + '%)' + matrix3d;
} else {
return 'translate(-50%,-50%)' + matrix3d;
}
}
function renderObject(object, camera, cameraCSSMatrix) {
if (object instanceof THREE.CSS3DObject) {
var style;
if (object instanceof THREE.CSS3DSprite) {
// http://swiftcoder.wordpress.com/2008/11/25/constructing-a-billboard-matrix/
matrix.copy(camera.matrixWorldInverse);
matrix.transpose();
matrix.copyPosition(object.matrixWorld);
matrix.scale(object.scale);
matrix.elements[3] = 0;
matrix.elements[7] = 0;
matrix.elements[11] = 0;
matrix.elements[15] = 1;
style = getObjectCSSMatrix(matrix, cameraCSSMatrix, object);
} else {
style = getObjectCSSMatrix(object.matrixWorld, cameraCSSMatrix, object);
}
var element = object.element;
var cachedObject = cache.objects.get(object);
if (cachedObject === undefined || cachedObject.style !== style) {
element.style.WebkitTransform = style;
element.style.transform = style;
if (object.userData.anchor) {
element.style.transformOrigin = object.userData.anchor[0] * 100 + '% ' + object.userData.anchor[1] * 100 + '%';// 有时间考虑一下为什么？
}
var objectData = { style: style };
if (isIE) {
objectData.distanceToCameraSquared = getDistanceToSquared(camera, object);
}
cache.objects.set(object, objectData);
}
if (element.parentNode !== cameraElement) {
cameraElement.appendChild(element);
}
}
for (var i = 0, l = object.children.length; i < l; i++) {
renderObject(object.children[i], camera, cameraCSSMatrix);
}
}
var getDistanceToSquared = function () {
var a = new THREE.Vector3();
var b = new THREE.Vector3();
return function (object1, object2) {
a.setFromMatrixPosition(object1.matrixWorld);
b.setFromMatrixPosition(object2.matrixWorld);
return a.distanceToSquared(b);
};
}();
function filterAndFlatten(scene) {
var result = [];
scene.traverse(function (object) {
if (object instanceof THREE.CSS3DObject) result.push(object);
});
return result;
}
function zOrder(scene) {
var sorted = filterAndFlatten(scene).sort(function (a, b) {
var distanceA = cache.objects.get(a).distanceToCameraSquared;
var distanceB = cache.objects.get(b).distanceToCameraSquared;
return distanceA - distanceB;
});
var zMax = sorted.length;
for (var i = 0, l = sorted.length; i < l; i++) {
sorted[i].element.style.zIndex = zMax - i;
}
}
this.render = function (scene, camera) {
// 计算设置fov
var fov = camera.projectionMatrix.elements[5] * _heightHalf;
if (cache.camera.fov !== fov) {
if (camera.isPerspectiveCamera) {
domElement.style.WebkitPerspective = fov + 'px';
domElement.style.perspective = fov + 'px';
}
cache.camera.fov = fov;
}
// 更新场景树矩阵
scene.updateMatrixWorld();
// 更新相机矩阵
if (camera.parent === null) camera.updateMatrixWorld();
if (camera.isOrthographicCamera) {
var tx = - (camera.right + camera.left) / 2;
var ty = (camera.top + camera.bottom) / 2;
}
// CSS 3D 相机矩阵（与ThreeJS相机联动）
var cameraCSSMatrix = camera.isOrthographicCamera ?
'scale(' + fov + ')' + 'translate(' + epsilon(tx) + 'px,' + epsilon(ty) + 'px)' + getCameraCSSMatrix(camera.matrixWorldInverse) :
'translateZ(' + fov + 'px)' + getCameraCSSMatrix(camera.matrixWorldInverse);
var style = cameraCSSMatrix +
'translate(' + _widthHalf + 'px,' + _heightHalf + 'px)';
if (cache.camera.style !== style && !isIE) {
cameraElement.style.WebkitTransform = style;
cameraElement.style.transform = style;
cache.camera.style = style;
}
renderObject(scene, camera, cameraCSSMatrix);
if (isIE) {
// IE10 and 11 does not support 'preserve-3d'.
// Thus, z-order in 3D will not work.
// We have to calc z-order manually and set CSS z-index for IE.
// FYI: z-index can't handle object intersection
zOrder(scene);
}
};
};