cesiumDemo/Source/Scene/ModelAnimationCache.js

import Cartesian3 from '../Core/Cartesian3.js';
import ComponentDatatype from '../Core/ComponentDatatype.js';
import defaultValue from '../Core/defaultValue.js';
import defined from '../Core/defined.js';
import LinearSpline from '../Core/LinearSpline.js';
import Matrix4 from '../Core/Matrix4.js';
import Quaternion from '../Core/Quaternion.js';
import QuaternionSpline from '../Core/QuaternionSpline.js';
import WebGLConstants from '../Core/WebGLConstants.js';
import WeightSpline from '../Core/WeightSpline.js';
import getAccessorByteStride from '../ThirdParty/GltfPipeline/getAccessorByteStride.js';
import numberOfComponentsForType from '../ThirdParty/GltfPipeline/numberOfComponentsForType.js';
import AttributeType from './AttributeType.js';

    /**
     * @private
     */
    function ModelAnimationCache() {
    }

    var dataUriRegex = /^data\:/i;

    function getAccessorKey(model, accessor) {
        var gltf = model.gltf;
        var buffers = gltf.buffers;
        var bufferViews = gltf.bufferViews;

        var bufferView = bufferViews[accessor.bufferView];
        var buffer = buffers[bufferView.buffer];

        var byteOffset = bufferView.byteOffset + accessor.byteOffset;
        var byteLength = accessor.count * numberOfComponentsForType(accessor.type);

        var uriKey = dataUriRegex.test(buffer.uri) ? '' : buffer.uri;
        return model.cacheKey + '//' + uriKey + '/' + byteOffset + '/' + byteLength;
    }

    var cachedAnimationParameters = {
    };

    ModelAnimationCache.getAnimationParameterValues = function(model, accessor) {
        var key = getAccessorKey(model, accessor);
        var values = cachedAnimationParameters[key];

        if (!defined(values)) {
            // Cache miss
            var gltf = model.gltf;

            var buffers = gltf.buffers;
            var bufferViews = gltf.bufferViews;

            var bufferView = bufferViews[accessor.bufferView];
            var bufferId = bufferView.buffer;
            var buffer = buffers[bufferId];
            var source = buffer.extras._pipeline.source;

            var componentType = accessor.componentType;
            var type = accessor.type;
            var numberOfComponents = numberOfComponentsForType(type);
            var count = accessor.count;
            var byteStride = getAccessorByteStride(gltf, accessor);

            values = new Array(count);
            var accessorByteOffset = defaultValue(accessor.byteOffset, 0);
            var byteOffset = bufferView.byteOffset + accessorByteOffset;
            for (var i = 0; i < count; i++) {
                var typedArrayView = ComponentDatatype.createArrayBufferView(componentType, source.buffer, source.byteOffset + byteOffset, numberOfComponents);
                if (type === 'SCALAR') {
                    values[i] = typedArrayView[0];
                } else if (type === 'VEC3') {
                    values[i] = Cartesian3.fromArray(typedArrayView);
                } else if (type === 'VEC4') {
                    values[i] = Quaternion.unpack(typedArrayView);
                }
                byteOffset += byteStride;
            }
            // GLTF_SPEC: Support more parameter types when glTF supports targeting materials. https://github.com/KhronosGroup/glTF/issues/142

            if (defined(model.cacheKey)) {
                // Only cache when we can create a unique id
                cachedAnimationParameters[key] = values;
            }
        }

        return values;
    };

    var cachedAnimationSplines = {
    };

    function getAnimationSplineKey(model, animationName, samplerName) {
        return model.cacheKey + '//' + animationName + '/' + samplerName;
    }

    function ConstantSpline(value) {
        this._value = value;
    }
    ConstantSpline.prototype.evaluate = function(time, result) {
        return this._value;
    };
    ConstantSpline.prototype.wrapTime = function(time) {
        return 0.0;
    };
    ConstantSpline.prototype.clampTime = function(time) {
        return 0.0;
    };

    ModelAnimationCache.getAnimationSpline = function(model, animationName, animation, samplerName, sampler, input, path, output) {
        var key = getAnimationSplineKey(model, animationName, samplerName);
        var spline = cachedAnimationSplines[key];

        if (!defined(spline)) {
            var times = input;
            var controlPoints = output;

            if ((times.length === 1) && (controlPoints.length === 1)) {
                spline = new ConstantSpline(controlPoints[0]);
            } else if (sampler.interpolation === 'LINEAR') {
                if (path === 'translation' || path === 'scale') {
                    spline = new LinearSpline({
                        times : times,
                        points : controlPoints
                    });
                } else if (path === 'rotation') {
                    spline = new QuaternionSpline({
                        times : times,
                        points : controlPoints
                    });
                } else if (path === 'weights') {
                    spline = new WeightSpline({
                        times : times,
                        weights : controlPoints
                    });
                }
                // GLTF_SPEC: Support more parameter types when glTF supports targeting materials. https://github.com/KhronosGroup/glTF/issues/142
            }

            if (defined(model.cacheKey)) {
                // Only cache when we can create a unique id
                cachedAnimationSplines[key] = spline;
            }
        }

        return spline;
    };

    var cachedSkinInverseBindMatrices = {
    };

    ModelAnimationCache.getSkinInverseBindMatrices = function(model, accessor) {
        var key = getAccessorKey(model, accessor);
        var matrices = cachedSkinInverseBindMatrices[key];

        if (!defined(matrices)) {
            // Cache miss
            var gltf = model.gltf;
            var buffers = gltf.buffers;
            var bufferViews = gltf.bufferViews;

            var bufferViewId = accessor.bufferView;
            var bufferView = bufferViews[bufferViewId];
            var bufferId = bufferView.buffer;
            var buffer = buffers[bufferId];
            var source = buffer.extras._pipeline.source;

            var componentType = accessor.componentType;
            var type = accessor.type;
            var count = accessor.count;
            var byteStride = getAccessorByteStride(gltf, accessor);
            var byteOffset = bufferView.byteOffset + accessor.byteOffset;
            var numberOfComponents = numberOfComponentsForType(type);

            matrices = new Array(count);

            if ((componentType === WebGLConstants.FLOAT) && (type === AttributeType.MAT4)) {
                for (var i = 0; i < count; ++i) {
                    var typedArrayView = ComponentDatatype.createArrayBufferView(componentType, source.buffer, source.byteOffset + byteOffset, numberOfComponents);
                    matrices[i] = Matrix4.fromArray(typedArrayView);
                    byteOffset += byteStride;
                }
            }

            cachedSkinInverseBindMatrices[key] = matrices;
        }

        return matrices;
    };
export default ModelAnimationCache;