{ "X3D": { "encoding":"UTF-8", "@profile":"Immersive", "@version":"3.0", "@xsd:noNamespaceSchemaLocation":"https://www.web3d.org/specifications/x3d-3.0.xsd", "JSON schema":"https://www.web3d.org/specifications/x3d-4.0-JSONSchema.autogenerated.json", "head": { "meta": [ { "@name":"title", "@content":"PositionInterpolator2dPrototype.x3d" }, { "@name":"description", "@content":"PositionInterpolator2D prototype declaration to pairwise interpolate across an array of Vector2Float/SFVec2f values to produce a single Vector2Float value - click text to see example." }, { "@name":"creator", "@content":"Don Brutzman, Jeff Weekley, Jane Wu" }, { "@name":"created", "@content":"16 October 2001" }, { "@name":"modified", "@content":"20 January 2020" }, { "@name":"reference", "@content":"https://www.web3d.org/technicalinfo/specifications/vrml97/part1/concepts.html#4.6.8" }, { "@name":"reference", "@content":"https://www.web3d.org/technicalinfo/specifications/vrml97/part1/nodesRef.html#CoordinateInterpolator" }, { "@name":"subject", "@content":"PositionInterpolator2D" }, { "@name":"identifier", "@content":"https://www.web3d.org/x3d/content/examples/Basic/development/PositionInterpolator2dPrototype.x3d" }, { "@name":"generator", "@content":"X3D-Edit 3.3, https://www.web3d.org/x3d/tools/X3D-Edit" }, { "@name":"license", "@content":"../license.html" }, { "@name":"translated", "@content":"20 April 2026" }, { "@name":"generator", "@content":"X3dToJson.xslt, https://www.web3d.org/x3d/stylesheets/X3dToJson.html" }, { "@name":"reference", "@content":"X3D JSON encoding: https://www.web3d.org/wiki/index.php/X3D_JSON_Encoding" } ] }, "Scene": { "-children":[ { "WorldInfo": { "@title":"PositionInterpolator2dPrototype.x3d" } }, { "ProtoDeclare": { "@name":"PositionInterpolator2D", "@appinfo":"Provide interpolation capability for Vector2Float/SFVec2f values", "@documentation":"https://www.web3d.org/technicalinfo/specifications/vrml97/part1/concepts.html#4.6.8", "ProtoInterface": { "field": [ { "@name":"set_fraction", "@accessType":"inputOnly", "@appinfo":"The set_fraction eventIn receives an SFFloat event and causes the interpolator function to evaluate resulting in a value_changed eventOut with the same timestamp as the set_fraction event.", "@type":"SFFloat", "-children":[ { "#comment":"Regular interpolator-style input" } ] }, { "@name":"set_key", "@accessType":"inputOnly", "@type":"MFFloat" }, { "@name":"key", "@accessType":"inputOutput", "@appinfo":"keyValue holds the array of Vector2FloatArrays that match each animation key.", "@type":"MFFloat", "-children":[ { "#comment":"initial value is [] null array" } ] }, { "@name":"key_changed", "@accessType":"outputOnly", "@appinfo":"Array sequentially increasing typically [0..1]. Must have the same number of keys as keyValues.", "@type":"MFFloat" }, { "@name":"set_keyValue", "@accessType":"inputOnly", "@appinfo":"Array of integer values. Must have the same number of keys as keyValues.", "@type":"MFVec2f" }, { "@name":"keyValue", "@accessType":"inputOutput", "@appinfo":"keyValue holds the array of Vector2Float values that match each animation key.", "@type":"MFVec2f", "-children":[ { "#comment":"initial value is [] null array" } ] }, { "@name":"keyValue_changed", "@accessType":"outputOnly", "@appinfo":"Array of integer values. Must have the same number of keys as keyValues.", "@type":"MFVec2f" }, { "@name":"value_changed", "@accessType":"outputOnly", "@appinfo":"The interpolator function averages between respective keyValue Vector2Floats resulting in a Vector2Float value_changed eventOut with the same timestamp as the set_fraction event.", "@type":"SFVec2f", "-children":[ { "#comment":"Regular interpolator-style output" } ] } ] }, "ProtoBody": { "-children":[ { "Group": { "-children":[ { "Switch": { "@whichChoice":-1, "-children":[ { "ScalarInterpolator": { "@DEF":"KeyHolder", "IS": { "connect": [ { "@nodeField":"key", "@protoField":"key" } ] } } }, { "Shape": { "-geometry": { "IndexedFaceSet": { "-texCoord": { "TextureCoordinate": { "@DEF":"KeyValueHolder", "IS": { "connect": [ { "@nodeField":"point", "@protoField":"keyValue" } ] } } } } }, "-appearance": { "Appearance": { "@DEF":"SilenceWarnings" } } } } ] } }, { "Script": { "@DEF":"InterpolationScript", "@directOutput":true, "-children":[ { "#comment":"Regular interpolator-style input" }, { "#comment":"Regular interpolator-style output" } ], "field": [ { "@name":"set_fraction", "@accessType":"inputOnly", "@type":"SFFloat" }, { "@name":"fraction", "@accessType":"initializeOnly", "@appinfo":"local variable", "@type":"SFFloat", "@value":0 }, { "@name":"set_key", "@accessType":"inputOnly", "@type":"MFFloat" }, { "@name":"keyHolderNode", "@accessType":"initializeOnly", "@type":"SFNode", "-children":[ { "ScalarInterpolator": { "@USE":"KeyHolder" } } ] }, { "@name":"key_changed", "@accessType":"outputOnly", "@type":"MFFloat" }, { "@name":"set_keyValue", "@accessType":"inputOnly", "@type":"MFVec2f" }, { "@name":"keyValueHolderNode", "@accessType":"initializeOnly", "@type":"SFNode", "-children":[ { "TextureCoordinate": { "@USE":"KeyValueHolder" } } ] }, { "@name":"keyValue_changed", "@accessType":"outputOnly", "@type":"MFVec2f" }, { "@name":"value_changed", "@accessType":"outputOnly", "@type":"SFVec2f" } ], "IS": { "connect": [ { "@nodeField":"set_fraction", "@protoField":"set_fraction" }, { "@nodeField":"set_key", "@protoField":"set_key" }, { "@nodeField":"key_changed", "@protoField":"key_changed" }, { "@nodeField":"set_keyValue", "@protoField":"set_keyValue" }, { "@nodeField":"keyValue_changed", "@protoField":"keyValue_changed" }, { "@nodeField":"value_changed", "@protoField":"value_changed" } ] }, "#sourceCode":[ "", "", "ecmascript:", "", "// internal global persistent variables", "var previousFraction;", "var previousFractionIndex;", "var blockSize;", "var outputArray;", "", "var traceEnabled = false;", "", "function tracePrint (outputString)", "{", "\tif (traceEnabled) Browser.println ('[PositionInterpolator2d]' + outputString);", "}", "function alwaysPrint (outputString)", "{", "\tBrowser.println ('[PositionInterpolator2d]' + outputString);", "}", "function initialize ()", "{", "\tkey = keyHolderNode.key;", "\tkeyValue = keyValueHolderNode.point;", "\tpreviousFractionIndex = -1;", "\tpreviousFraction = 0;", "\t// check key array ranges [0..1] and is monotonically increasing", "\t// check that size of keyValue array is integer multiple of size of key array", "\ttracePrint ('key =' + key);", "\ttracePrint ('key.length=' + key.length);", "\ttracePrint ('keyValue= ' + keyValue);", "\ttracePrint ('keyValue.length=' + keyValue.length);", "\tblockSize = keyValue.length/key.length;", "\ttracePrint ('blockSize=' + blockSize);", "\tif (blockSize != 1)", "\t{", "\t alwaysPrint ('*** warning: check sizes of key and keyValue, should be identical!');", "\t}", "\tif (key[0] != 0)", "\t{", "\t alwaysPrint ('*** warning: key[0] != 0');", "\t}", "\tif (key[key.length-1] != 1)", "\t{", "\t alwaysPrint ('*** warning: key[' + (key.length - 1) + '] != 1, reset from' + key[key.length-1] + ' to 1');", "\t key[key.length-1] = 1;", "\t}", "\tfor (index = 0; index < key.length; index++)", "\t{", "\t\tif ((key[index] < 0) || (key[index] > 1))", "\t\t{", "\t\t alwaysPrint ('*** warning: key[' + index + '] =' + key[index] + ', out of range [0..1]');", "\t\t}", "\t}", "}", "", "function set_fraction (inputFloat, timestamp) {", "\tfraction = inputFloat;", "\toutputResult = new SFVec2f ();", "\ttracePrint ('previousFractionIndex=' + previousFractionIndex", "\t\t + ', fraction=' + fraction + ', previousFraction=' + previousFraction);", "", "\tif (fraction < 0)", "\t{", "\t\ttracePrint ('*** illegal fraction' + fraction + ' set to 0');", "\t\tfraction = 0;", "\t\tpreviousFractionIndex = 0; // first", "\t}", "\telse if (fraction > 1)", "\t{", "\t\talwaysPrint ('*** illegal fraction' + fraction + ' set to 1');", "\t\tfraction = 1;", "\t\tpreviousFractionIndex = key.length - 1; // last", "\t}", "\telse if (previousFractionIndex == -1)", "\t{", "\t\tpreviousFractionIndex = 0; // first", "\t\ttracePrint ('previousFractionIndex initialized for first event');", "\t}", "\telse if ((fraction >= previousFraction) && (fraction >= key[previousFractionIndex+1]))", "\t{", "\t\tpreviousFractionIndex++;", "\t}", "\telse if (fraction < previousFraction) // regress, or loop repeat without reaching one", "\t{", "\t\tpreviousFractionIndex = 0;", "\t\twhile ((fraction >= key[previousFractionIndex+1]) && (previousFractionIndex < blockSize))", "\t\t{", "\t\t\tpreviousFractionIndex++;", "\t\t}", "\t\ttracePrint ('reset/reincrement previousFractionIndex to' + previousFractionIndex);", "\t}", "", "\tif (fraction == 1) // use final block", "\t{", "\t\ttracePrint ('(fraction == 1)');", "\t\t// update outputResult with final keyValue", "\t\toutputResult = keyValue[keyValue.length];", "", "\t\tpreviousFractionIndex = -1; // setup for restart", "\t\ttracePrint ('finished final fraction==1 block');", "\t}", "\t// when fraction matches index, calculate value_changed from corresponding keyValue array", "\telse if (fraction == key[previousFractionIndex])", "\t{", "\t\ttracePrint ('(fraction == key[previousFractionIndex])');", "\t\t// update outputResult with corresponding keyValue", "\t\toutputResult = keyValue[previousFractionIndex];", "\t}", "\telse // calculate value_changed by interpolating between adjacent keyValue arrays", "\t{", "\t\tpartialFraction = fraction - key[previousFractionIndex];", "\t\tdeltaFraction = key[previousFractionIndex+1] - key[previousFractionIndex];", "\t\tpercentFraction = partialFraction / deltaFraction;", "\t//\ttracePrint ('deltaFraction =' + deltaFraction);", "\t//\ttracePrint ('partialFraction =' + partialFraction);", "\t\ttracePrint ('percentFraction =' + percentFraction);", "\t\t// no arithmetic operators provided for SFVec2f, treat element by element", "\t\tnextKeyValue = keyValue[previousFractionIndex + 1];", "\t\tpriorKeyValue = keyValue[previousFractionIndex];", "\t\ttracePrint (' nextKeyValue =' + nextKeyValue);", "\t\ttracePrint ('priorKeyValue =' + priorKeyValue);", "\t\tdeltaKeyValue = new SFVec2f (\tnextKeyValue[0] - priorKeyValue[0],", "\t\t\t\t\t\tnextKeyValue[1] - priorKeyValue[1]);", "\t\t//\ttracePrint ('deltaKeyValue =' + deltaKeyValue);", "\t\t// update outputResult", "\t\toutputResult[0] = keyValue[previousFractionIndex][0]", "\t\t\t + percentFraction * deltaKeyValue[0];", "\t\toutputResult[1] = keyValue[previousFractionIndex][1]", "\t\t\t + percentFraction * deltaKeyValue[1];", "\t}", "\tvalue_changed = outputResult;", "\tpreviousFraction = fraction;", "\ttracePrint ('value_changed=' + value_changed);", "}", "", "function set_key (inputArray, timestamp) {", "\tkey = inputArray; // update key Vector2FloatArray", "\tkeyHolderNode.key = key; // update holder", "\tinitialize (timestamp); // reverify key, keyValue sizes", "}", "", "function set_keyValue (inputArray, timestamp) {", "\tkeyValue = inputArray; // update keyValue Vector2FloatArray", "\tkeyValueHolderNode.point = keyValue; // update holder", "\tinitialize (timestamp); // reverify key, keyValue sizes", "}", "", "" ] } } ] } } ] } } }, { "#comment":"======================================" }, { "#comment":"Example use" }, { "Anchor": { "@description":"PositionInterpolator2D Example", "@url":["PositionInterpolator2dExample.x3d","https://www.web3d.org/x3d/content/examples/Basic/development/PositionInterpolator2dExample.x3d","PositionInterpolator2dExample.wrl","https://www.web3d.org/x3d/content/examples/Basic/development/PositionInterpolator2dExample.wrl"], "-children":[ { "Shape": { "-geometry": { "Text": { "@string":["PositionInterpolator2dPrototype","defines a prototype","Click text to see","PositionInterpolator2dExample"," scene"], "-fontStyle": { "FontStyle": { "@justify":["MIDDLE","MIDDLE"], "@size":0.7 } } } }, "-appearance": { "Appearance": { "-material": { "Material": { "@diffuseColor":[1,1,0.2] } } } } } } ] } } ] } } }