GitBucket
Newer
/**
* Cesium - https://github.com/CesiumGS/cesium
*
* Copyright 2011-2020 Cesium Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Columbus View (Pat. Pend.)
*
* Portions licensed separately.
* See https://github.com/CesiumGS/cesium/blob/master/LICENSE.md for full licensing details.
*/
define(['exports', './when-8d13db60', './Check-70bec281', './Math-61ede240', './Cartographic-f2a06374', './Cartesian2-16a61632'], function (exports, when, Check, _Math, Cartographic, Cartesian2) { 'use strict';
var RIGHT_SHIFT = 1.0 / 256.0;
var LEFT_SHIFT = 256.0;
/**
* Attribute compression and decompression functions.
*
* @exports AttributeCompression
*
* @private
*/
var AttributeCompression = {};
/**
* Encodes a normalized vector into 2 SNORM values in the range of [0-rangeMax] following the 'oct' encoding.
*
* Oct encoding is a compact representation of unit length vectors.
* The 'oct' encoding is described in "A Survey of Efficient Representations of Independent Unit Vectors",
* Cigolle et al 2014: {@link http://jcgt.org/published/0003/02/01/}
*
* @param {Cartesian3} vector The normalized vector to be compressed into 2 component 'oct' encoding.
* @param {Cartesian2} result The 2 component oct-encoded unit length vector.
* @param {Number} rangeMax The maximum value of the SNORM range. The encoded vector is stored in log2(rangeMax+1) bits.
* @returns {Cartesian2} The 2 component oct-encoded unit length vector.
*
* @exception {DeveloperError} vector must be normalized.
*
* @see AttributeCompression.octDecodeInRange
*/
AttributeCompression.octEncodeInRange = function(vector, rangeMax, result) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('vector', vector);
Check.Check.defined('result', result);
var magSquared = Cartographic.Cartesian3.magnitudeSquared(vector);
if (Math.abs(magSquared - 1.0) > _Math.CesiumMath.EPSILON6) {
throw new Check.DeveloperError('vector must be normalized.');
}
//>>includeEnd('debug');
result.x = vector.x / (Math.abs(vector.x) + Math.abs(vector.y) + Math.abs(vector.z));
result.y = vector.y / (Math.abs(vector.x) + Math.abs(vector.y) + Math.abs(vector.z));
if (vector.z < 0) {
var x = result.x;
var y = result.y;
result.x = (1.0 - Math.abs(y)) * _Math.CesiumMath.signNotZero(x);
result.y = (1.0 - Math.abs(x)) * _Math.CesiumMath.signNotZero(y);
}
result.x = _Math.CesiumMath.toSNorm(result.x, rangeMax);
result.y = _Math.CesiumMath.toSNorm(result.y, rangeMax);
return result;
};
/**
* Encodes a normalized vector into 2 SNORM values in the range of [0-255] following the 'oct' encoding.
*
* @param {Cartesian3} vector The normalized vector to be compressed into 2 byte 'oct' encoding.
* @param {Cartesian2} result The 2 byte oct-encoded unit length vector.
* @returns {Cartesian2} The 2 byte oct-encoded unit length vector.
*
* @exception {DeveloperError} vector must be normalized.
*
* @see AttributeCompression.octEncodeInRange
* @see AttributeCompression.octDecode
*/
AttributeCompression.octEncode = function(vector, result) {
return AttributeCompression.octEncodeInRange(vector, 255, result);
};
var octEncodeScratch = new Cartesian2.Cartesian2();
var uint8ForceArray = new Uint8Array(1);
function forceUint8(value) {
uint8ForceArray[0] = value;
return uint8ForceArray[0];
}
/**
* @param {Cartesian3} vector The normalized vector to be compressed into 4 byte 'oct' encoding.
* @param {Cartesian4} result The 4 byte oct-encoded unit length vector.
* @returns {Cartesian4} The 4 byte oct-encoded unit length vector.
*
* @exception {DeveloperError} vector must be normalized.
*
* @see AttributeCompression.octEncodeInRange
* @see AttributeCompression.octDecodeFromCartesian4
*/
AttributeCompression.octEncodeToCartesian4 = function(vector, result) {
AttributeCompression.octEncodeInRange(vector, 65535, octEncodeScratch);
result.x = forceUint8(octEncodeScratch.x * RIGHT_SHIFT);
result.y = forceUint8(octEncodeScratch.x);
result.z = forceUint8(octEncodeScratch.y * RIGHT_SHIFT);
result.w = forceUint8(octEncodeScratch.y);
return result;
};
/**
* Decodes a unit-length vector in 'oct' encoding to a normalized 3-component vector.
*
* @param {Number} x The x component of the oct-encoded unit length vector.
* @param {Number} y The y component of the oct-encoded unit length vector.
* @param {Number} rangeMax The maximum value of the SNORM range. The encoded vector is stored in log2(rangeMax+1) bits.
* @param {Cartesian3} result The decoded and normalized vector
* @returns {Cartesian3} The decoded and normalized vector.
*
* @exception {DeveloperError} x and y must be unsigned normalized integers between 0 and rangeMax.
*
* @see AttributeCompression.octEncodeInRange
*/
AttributeCompression.octDecodeInRange = function(x, y, rangeMax, result) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('result', result);
if (x < 0 || x > rangeMax || y < 0 || y > rangeMax) {
throw new Check.DeveloperError('x and y must be unsigned normalized integers between 0 and ' + rangeMax);
}
//>>includeEnd('debug');
result.x = _Math.CesiumMath.fromSNorm(x, rangeMax);
result.y = _Math.CesiumMath.fromSNorm(y, rangeMax);
result.z = 1.0 - (Math.abs(result.x) + Math.abs(result.y));
if (result.z < 0.0)
{
var oldVX = result.x;
result.x = (1.0 - Math.abs(result.y)) * _Math.CesiumMath.signNotZero(oldVX);
result.y = (1.0 - Math.abs(oldVX)) * _Math.CesiumMath.signNotZero(result.y);
}
return Cartographic.Cartesian3.normalize(result, result);
};
/**
* Decodes a unit-length vector in 2 byte 'oct' encoding to a normalized 3-component vector.
*
* @param {Number} x The x component of the oct-encoded unit length vector.
* @param {Number} y The y component of the oct-encoded unit length vector.
* @param {Cartesian3} result The decoded and normalized vector.
* @returns {Cartesian3} The decoded and normalized vector.
*
* @exception {DeveloperError} x and y must be an unsigned normalized integer between 0 and 255.
*
* @see AttributeCompression.octDecodeInRange
*/
AttributeCompression.octDecode = function(x, y, result) {
return AttributeCompression.octDecodeInRange(x, y, 255, result);
};
/**
* Decodes a unit-length vector in 4 byte 'oct' encoding to a normalized 3-component vector.
*
* @param {Cartesian4} encoded The oct-encoded unit length vector.
* @param {Cartesian3} result The decoded and normalized vector.
* @returns {Cartesian3} The decoded and normalized vector.
*
* @exception {DeveloperError} x, y, z, and w must be unsigned normalized integers between 0 and 255.
*
* @see AttributeCompression.octDecodeInRange
* @see AttributeCompression.octEncodeToCartesian4
*/
AttributeCompression.octDecodeFromCartesian4 = function(encoded, result) {
//>>includeStart('debug', pragmas.debug);
Check.Check.typeOf.object('encoded', encoded);
Check.Check.typeOf.object('result', result);
//>>includeEnd('debug');
var x = encoded.x;
var y = encoded.y;
var z = encoded.z;
var w = encoded.w;
//>>includeStart('debug', pragmas.debug);
if (x < 0 || x > 255 || y < 0 || y > 255 || z < 0 || z > 255 || w < 0 || w > 255) {
throw new Check.DeveloperError('x, y, z, and w must be unsigned normalized integers between 0 and 255');
}
//>>includeEnd('debug');
var xOct16 = x * LEFT_SHIFT + y;
var yOct16 = z * LEFT_SHIFT + w;
return AttributeCompression.octDecodeInRange(xOct16, yOct16, 65535, result);
};
/**
* Packs an oct encoded vector into a single floating-point number.
*
* @param {Cartesian2} encoded The oct encoded vector.
* @returns {Number} The oct encoded vector packed into a single float.
*
*/
AttributeCompression.octPackFloat = function(encoded) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('encoded', encoded);
//>>includeEnd('debug');
return 256.0 * encoded.x + encoded.y;
};
var scratchEncodeCart2 = new Cartesian2.Cartesian2();
/**
* Encodes a normalized vector into 2 SNORM values in the range of [0-255] following the 'oct' encoding and
* stores those values in a single float-point number.
*
* @param {Cartesian3} vector The normalized vector to be compressed into 2 byte 'oct' encoding.
* @returns {Number} The 2 byte oct-encoded unit length vector.
*
* @exception {DeveloperError} vector must be normalized.
*/
AttributeCompression.octEncodeFloat = function(vector) {
AttributeCompression.octEncode(vector, scratchEncodeCart2);
return AttributeCompression.octPackFloat(scratchEncodeCart2);
};
/**
* Decodes a unit-length vector in 'oct' encoding packed in a floating-point number to a normalized 3-component vector.
*
* @param {Number} value The oct-encoded unit length vector stored as a single floating-point number.
* @param {Cartesian3} result The decoded and normalized vector
* @returns {Cartesian3} The decoded and normalized vector.
*
*/
AttributeCompression.octDecodeFloat = function(value, result) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('value', value);
//>>includeEnd('debug');
var temp = value / 256.0;
var x = Math.floor(temp);
var y = (temp - x) * 256.0;
return AttributeCompression.octDecode(x, y, result);
};
/**
* Encodes three normalized vectors into 6 SNORM values in the range of [0-255] following the 'oct' encoding and
* packs those into two floating-point numbers.
*
* @param {Cartesian3} v1 A normalized vector to be compressed.
* @param {Cartesian3} v2 A normalized vector to be compressed.
* @param {Cartesian3} v3 A normalized vector to be compressed.
* @param {Cartesian2} result The 'oct' encoded vectors packed into two floating-point numbers.
* @returns {Cartesian2} The 'oct' encoded vectors packed into two floating-point numbers.
*
*/
AttributeCompression.octPack = function(v1, v2, v3, result) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('v1', v1);
Check.Check.defined('v2', v2);
Check.Check.defined('v3', v3);
Check.Check.defined('result', result);
//>>includeEnd('debug');
var encoded1 = AttributeCompression.octEncodeFloat(v1);
var encoded2 = AttributeCompression.octEncodeFloat(v2);
var encoded3 = AttributeCompression.octEncode(v3, scratchEncodeCart2);
result.x = 65536.0 * encoded3.x + encoded1;
result.y = 65536.0 * encoded3.y + encoded2;
return result;
};
/**
* Decodes three unit-length vectors in 'oct' encoding packed into a floating-point number to a normalized 3-component vector.
*
* @param {Cartesian2} packed The three oct-encoded unit length vectors stored as two floating-point number.
* @param {Cartesian3} v1 One decoded and normalized vector.
* @param {Cartesian3} v2 One decoded and normalized vector.
* @param {Cartesian3} v3 One decoded and normalized vector.
*/
AttributeCompression.octUnpack = function(packed, v1, v2, v3) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('packed', packed);
Check.Check.defined('v1', v1);
Check.Check.defined('v2', v2);
Check.Check.defined('v3', v3);
//>>includeEnd('debug');
var temp = packed.x / 65536.0;
var x = Math.floor(temp);
var encodedFloat1 = (temp - x) * 65536.0;
temp = packed.y / 65536.0;
var y = Math.floor(temp);
var encodedFloat2 = (temp - y) * 65536.0;
AttributeCompression.octDecodeFloat(encodedFloat1, v1);
AttributeCompression.octDecodeFloat(encodedFloat2, v2);
AttributeCompression.octDecode(x, y, v3);
};
/**
* Pack texture coordinates into a single float. The texture coordinates will only preserve 12 bits of precision.
*
* @param {Cartesian2} textureCoordinates The texture coordinates to compress. Both coordinates must be in the range 0.0-1.0.
* @returns {Number} The packed texture coordinates.
*
*/
AttributeCompression.compressTextureCoordinates = function(textureCoordinates) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('textureCoordinates', textureCoordinates);
//>>includeEnd('debug');
// Move x and y to the range 0-4095;
var x = (textureCoordinates.x * 4095.0) | 0;
var y = (textureCoordinates.y * 4095.0) | 0;
return 4096.0 * x + y;
};
/**
* Decompresses texture coordinates that were packed into a single float.
*
* @param {Number} compressed The compressed texture coordinates.
* @param {Cartesian2} result The decompressed texture coordinates.
* @returns {Cartesian2} The modified result parameter.
*
*/
AttributeCompression.decompressTextureCoordinates = function(compressed, result) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('compressed', compressed);
Check.Check.defined('result', result);
//>>includeEnd('debug');
var temp = compressed / 4096.0;
var xZeroTo4095 = Math.floor(temp);
result.x = xZeroTo4095 / 4095.0;
result.y = (compressed - xZeroTo4095 * 4096) / 4095;
return result;
};
function zigZagDecode(value) {
return (value >> 1) ^ (-(value & 1));
}
/**
* Decodes delta and ZigZag encoded vertices. This modifies the buffers in place.
*
* @param {Uint16Array} uBuffer The buffer view of u values.
* @param {Uint16Array} vBuffer The buffer view of v values.
* @param {Uint16Array} [heightBuffer] The buffer view of height values.
*
* @see {@link https://github.com/AnalyticalGraphicsInc/quantized-mesh|quantized-mesh-1.0 terrain format}
*/
AttributeCompression.zigZagDeltaDecode = function(uBuffer, vBuffer, heightBuffer) {
//>>includeStart('debug', pragmas.debug);
Check.Check.defined('uBuffer', uBuffer);
Check.Check.defined('vBuffer', vBuffer);
Check.Check.typeOf.number.equals('uBuffer.length', 'vBuffer.length', uBuffer.length, vBuffer.length);
if (when.defined(heightBuffer)) {
Check.Check.typeOf.number.equals('uBuffer.length', 'heightBuffer.length', uBuffer.length, heightBuffer.length);
}
//>>includeEnd('debug');
var count = uBuffer.length;
var u = 0;
var v = 0;
var height = 0;
for (var i = 0; i < count; ++i) {
u += zigZagDecode(uBuffer[i]);
v += zigZagDecode(vBuffer[i]);
uBuffer[i] = u;
vBuffer[i] = v;
if (when.defined(heightBuffer)) {
height += zigZagDecode(heightBuffer[i]);
heightBuffer[i] = height;
}
}
};
// 将oct压缩的short转化为float
AttributeCompression.octShortToFloat = function(s){
//var tempF = s * 1.0 / ((1 << 15) - 1);
return _Math.CesiumMath.clamp(s * 0.00003051850947599719, -1.0, 1.0);
};
// 将oct压缩的两个short解压为三个float
AttributeCompression.octShortDecode = function(x, y, result) {
Check.Check.defined('result', result);
result.x = AttributeCompression.octShortToFloat(x);
result.y = AttributeCompression.octShortToFloat(y);
result.z = 1.0 - (Math.abs(result.x) + Math.abs(result.y));
if (result.z < 0.0)
{
var oldVX = result.x;
result.x = (1.0 - Math.abs(result.y)) * _Math.CesiumMath.signNotZero(oldVX);
result.y = (1.0 - Math.abs(oldVX)) * _Math.CesiumMath.signNotZero(result.y);
}
return Cartographic.Cartesian3.normalize(result, result);
};
exports.AttributeCompression = AttributeCompression;
});