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| import Vector3 from './Vector3';
import BoundingBox from './BoundingBox';
import Plane from './Plane';
import glMatrix from '../dep/glmatrix';
var vec3 = glMatrix.vec3;
var vec3Set = vec3.set;
var vec3Copy = vec3.copy;
var vec3TranformMat4 = vec3.transformMat4;
var mathMin = Math.min;
var mathMax = Math.max;
/**
* @constructor
* @alias clay.Frustum
*/
var Frustum = function() {
/**
* Eight planes to enclose the frustum
* @type {clay.Plane[]}
*/
this.planes = [];
for (var i = 0; i < 6; i++) {
this.planes.push(new Plane());
}
/**
* Bounding box of frustum
* @type {clay.BoundingBox}
*/
this.boundingBox = new BoundingBox();
/**
* Eight vertices of frustum
* @type {Float32Array[]}
*/
this.vertices = [];
for (var i = 0; i < 8; i++) {
this.vertices[i] = vec3.fromValues(0, 0, 0);
}
};
Frustum.prototype = {
// http://web.archive.org/web/20120531231005/http://crazyjoke.free.fr/doc/3D/plane%20extraction.pdf
/**
* Set frustum from a projection matrix
* @param {clay.Matrix4} projectionMatrix
*/
setFromProjection: function(projectionMatrix) {
var planes = this.planes;
var m = projectionMatrix.array;
var m0 = m[0], m1 = m[1], m2 = m[2], m3 = m[3];
var m4 = m[4], m5 = m[5], m6 = m[6], m7 = m[7];
var m8 = m[8], m9 = m[9], m10 = m[10], m11 = m[11];
var m12 = m[12], m13 = m[13], m14 = m[14], m15 = m[15];
// Update planes
vec3Set(planes[0].normal.array, m3 - m0, m7 - m4, m11 - m8);
planes[0].distance = -(m15 - m12);
planes[0].normalize();
vec3Set(planes[1].normal.array, m3 + m0, m7 + m4, m11 + m8);
planes[1].distance = -(m15 + m12);
planes[1].normalize();
vec3Set(planes[2].normal.array, m3 + m1, m7 + m5, m11 + m9);
planes[2].distance = -(m15 + m13);
planes[2].normalize();
vec3Set(planes[3].normal.array, m3 - m1, m7 - m5, m11 - m9);
planes[3].distance = -(m15 - m13);
planes[3].normalize();
vec3Set(planes[4].normal.array, m3 - m2, m7 - m6, m11 - m10);
planes[4].distance = -(m15 - m14);
planes[4].normalize();
vec3Set(planes[5].normal.array, m3 + m2, m7 + m6, m11 + m10);
planes[5].distance = -(m15 + m14);
planes[5].normalize();
// Perspective projection
var boundingBox = this.boundingBox;
var vertices = this.vertices;
if (m15 === 0) {
var aspect = m5 / m0;
var zNear = -m14 / (m10 - 1);
var zFar = -m14 / (m10 + 1);
var farY = -zFar / m5;
var nearY = -zNear / m5;
// Update bounding box
boundingBox.min.set(-farY * aspect, -farY, zFar);
boundingBox.max.set(farY * aspect, farY, zNear);
// update vertices
//--- min z
// min x
vec3Set(vertices[0], -farY * aspect, -farY, zFar);
vec3Set(vertices[1], -farY * aspect, farY, zFar);
// max x
vec3Set(vertices[2], farY * aspect, -farY, zFar);
vec3Set(vertices[3], farY * aspect, farY, zFar);
//-- max z
vec3Set(vertices[4], -nearY * aspect, -nearY, zNear);
vec3Set(vertices[5], -nearY * aspect, nearY, zNear);
vec3Set(vertices[6], nearY * aspect, -nearY, zNear);
vec3Set(vertices[7], nearY * aspect, nearY, zNear);
}
else { // Orthographic projection
var left = (-1 - m12) / m0;
var right = (1 - m12) / m0;
var top = (1 - m13) / m5;
var bottom = (-1 - m13) / m5;
var near = (-1 - m14) / m10;
var far = (1 - m14) / m10;
boundingBox.min.set(Math.min(left, right), Math.min(bottom, top), Math.min(far, near));
boundingBox.max.set(Math.max(right, left), Math.max(top, bottom), Math.max(near, far));
var min = boundingBox.min.array;
var max = boundingBox.max.array;
//--- min z
// min x
vec3Set(vertices[0], min[0], min[1], min[2]);
vec3Set(vertices[1], min[0], max[1], min[2]);
// max x
vec3Set(vertices[2], max[0], min[1], min[2]);
vec3Set(vertices[3], max[0], max[1], min[2]);
//-- max z
vec3Set(vertices[4], min[0], min[1], max[2]);
vec3Set(vertices[5], min[0], max[1], max[2]);
vec3Set(vertices[6], max[0], min[1], max[2]);
vec3Set(vertices[7], max[0], max[1], max[2]);
}
},
/**
* Apply a affine transform matrix and set to the given bounding box
* @function
* @param {clay.BoundingBox}
* @param {clay.Matrix4}
* @return {clay.BoundingBox}
*/
getTransformedBoundingBox: (function() {
var tmpVec3 = vec3.create();
return function(bbox, matrix) {
var vertices = this.vertices;
var m4 = matrix.array;
var min = bbox.min;
var max = bbox.max;
var minArr = min.array;
var maxArr = max.array;
var v = vertices[0];
vec3TranformMat4(tmpVec3, v, m4);
vec3Copy(minArr, tmpVec3);
vec3Copy(maxArr, tmpVec3);
for (var i = 1; i < 8; i++) {
v = vertices[i];
vec3TranformMat4(tmpVec3, v, m4);
minArr[0] = mathMin(tmpVec3[0], minArr[0]);
minArr[1] = mathMin(tmpVec3[1], minArr[1]);
minArr[2] = mathMin(tmpVec3[2], minArr[2]);
maxArr[0] = mathMax(tmpVec3[0], maxArr[0]);
maxArr[1] = mathMax(tmpVec3[1], maxArr[1]);
maxArr[2] = mathMax(tmpVec3[2], maxArr[2]);
}
min._dirty = true;
max._dirty = true;
return bbox;
};
}) ()
};
export default Frustum;
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