src/vs/editor/common/viewLayout/viewLineRenderer.ts/CharacterMapping/setColumnInfo
class CharacterMapping:	public setColumnInfo(column: number, partIndex: number, charIndex: number, horizontalOffset: number): void {
		const partData = (
			(partIndex << CharacterMappingConstants.PART_INDEX_OFFSET)
			| (charIndex << CharacterMappingConstants.CHAR_INDEX_OFFSET)
		) >>> 0;
		this._data[column - 1] = partData;
		this._horizontalOffset[column - 1] = horizontalOffset;
	}