@edsilv/ami.js
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209 lines (186 loc) • 6.05 kB
JavaScript
;
THREE.FreeSurferLoader = function() {};
Object.assign(THREE.FreeSurferLoader.prototype, THREE.EventDispatcher.prototype, {
constructor: THREE.FreeSurferLoader,
load: function(url, onLoad, onProgress, onError) {
let scope = this;
let xhr = new XMLHttpRequest();
function onloaded(event) {
if (event.target.status === 200 || event.target.status === 0) {
let geometry = scope.parse(event.target.response || event.target.responseText);
scope.dispatchEvent({
type: 'load',
content: geometry,
});
if (onLoad) {
onLoad(geometry);
}
} else {
scope.dispatchEvent({
type: 'error',
message: "Couldn't load URL [" + url + ']',
response: event.target.statusText,
});
}
}
xhr.addEventListener('load', onloaded, false);
xhr.addEventListener(
'progress',
function(event) {
scope.dispatchEvent({
type: 'progress',
loaded: event.loaded,
total: event.total,
});
},
false
);
xhr.addEventListener(
'error',
function() {
scope.dispatchEvent({
type: 'error',
message: "Couldn't load URL [" + url + ']',
});
},
false
);
if (xhr.overrideMimeType) {
xhr.overrideMimeType('text/plain; charset=x-user-defined');
}
xhr.open('GET', url, true);
xhr.responseType = 'arraybuffer';
xhr.send(null);
},
littleEndian: function() {
let buffer = new ArrayBuffer(2);
new DataView(buffer).setInt16(0, 256, true);
return new Int16Array(buffer)[0] === 256;
},
parse: function(data) {
let littleEndian = this.littleEndian();
let reader = new DataView(data);
let offset = 0;
let surfDesc = undefined;
let geometry = undefined;
function readInt24(offset, littleEndian = false) {
let v = 0;
let b1 = reader.getUint8(offset);
let b2 = reader.getUint8(offset + 1);
let b3 = reader.getUint8(offset + 2);
if (littleEndian) {
v += b3 << 16;
v += b2 << 8;
v += b1;
} else {
v += b1 << 16;
v += b2 << 8;
v += b3;
}
return v;
}
// check magic bytes
let surfType = readInt24(0);
if (surfType > 0xffff00) {
littleEndian = false;
} else {
littleEndian = true;
surfType = readInt24(0, littleEndian);
}
offset += 3;
let vertCount = 0;
let faceCount = 0;
switch (surfType) {
case THREE.FreeSurferLoader.QUAD_FILE_MAGIC_NUMBER: {
vertCount = readInt24(offset, littleEndian);
offset += 3;
faceCount = readInt24(offset, littleEndian);
offset += 3;
// Sanity check from FreeSurfer: utils/mrisurf.c
if (faceCount > 4 * vertCount) {
throw Error(
'file has many more faces than vertices! Probably trying to use a scalar data file as a surface!'
);
}
geometry = new THREE.Geometry();
for (let v = 0; v < vertCount; v++) {
geometry.vertices.push(
new THREE.Vector3(
reader.getInt16(offset + 0, littleEndian) / 100,
reader.getInt16(offset + 2, littleEndian) / 100,
reader.getInt16(offset + 4, littleEndian) / 100
)
);
offset += 6;
}
for (let f = 0; f < faceCount; f++) {
// THREE.Face4 doesn't exist anymore
// using recommendation from
// https://stackoverflow.com/questions/46132689/how-to-fix-face4-to-face3
let v1 = readInt24(offset + 0, littleEndian);
let v2 = readInt24(offset + 3, littleEndian);
let v3 = readInt24(offset + 6, littleEndian);
let v4 = readInt24(offset + 9, littleEndian);
offset += 12;
geometry.faces.push(new THREE.Face3(v1, v2, v3));
geometry.faces.push(new THREE.Face3(v1, v3, v4));
}
geometry.computeBoundingBox();
break;
}
case THREE.FreeSurferLoader.TRIANGLE_FILE_MAGIC_NUMBER: {
// the "created by text"
let b1 = 0;
let b2 = 0;
while (b1 != 10 && b2 != 10) {
b1 = b2;
b2 = reader.getUint8(offset);
offset++;
}
let enc = new TextDecoder();
surfDesc = enc.decode(data.slice(3, offset - 1));
offset++;
vertCount = reader.getInt32(offset, littleEndian);
offset += 4;
faceCount = reader.getInt32(offset, littleEndian);
offset += 4;
geometry = new THREE.Geometry();
for (let v = 0; v < vertCount; v++) {
geometry.vertices.push(
new THREE.Vector3(
reader.getFloat32(offset + 0, littleEndian),
reader.getFloat32(offset + 4, littleEndian),
reader.getFloat32(offset + 8, littleEndian)
)
);
offset += 12;
}
for (let f = 0; f < faceCount; f++) {
geometry.faces.push(
new THREE.Face3(
reader.getInt32(offset + 0, littleEndian),
reader.getInt32(offset + 4, littleEndian),
reader.getInt32(offset + 8, littleEndian)
)
);
offset += 12;
}
geometry.computeBoundingBox();
break;
}
case THREE.FreeSurferLoader.NEW_QUAD_FILE_MAGIC_NUMBER: {
throw Error('Parser not defined for NEW_QUAD_FILE_MAGIC_NUMBER');
}
default: {
throw Error('Unknown FreeSurfer MAGICNUMBER: ' + surfType.toString(16));
}
}
return geometry;
},
});
// From: https://github.com/freesurfer/freesurfer
// utils/mrisurf.c
// the magic number is 3 bytes although this has it listed as 4.
THREE.FreeSurferLoader.QUAD_FILE_MAGIC_NUMBER = -1 & 0x00ffffff;
THREE.FreeSurferLoader.TRIANGLE_FILE_MAGIC_NUMBER = -2 & 0x00ffffff;
THREE.FreeSurferLoader.NEW_QUAD_FILE_MAGIC_NUMBER = -3 & 0x00ffffff;