EncodedCartesian3

Members

high :Number

The high bits for each component. Bits 0 to 22 store the whole value. Bits 23 to 31 are not used.

The default is Cartesian3.ZERO.

low :Number

The low bits for each component. Bits 7 to 22 store the whole value, and bits 0 to 6 store the fraction. Bits 23 to 31 are not used.

The default is Cartesian3.ZERO.

Methods

<static> encode

Encodes a 64-bit floating-point value as two floating-point values that, when converted to 32-bit floating-point and added, approximate the original input. The returned object has high and low properties for the high and low bits, respectively.

The fixed-point encoding follows Precisions, Precisions.

Parameters:

Name	Type	Argument	Description
value	Number		The floating-point value to encode.
result	Object	<optional>	The object onto which to store the result.

Throws:

DeveloperError : value is required.

Returns:

Object The modified result parameter or a new instance if one was not provided.

Example

var value = 1234567.1234567;
var splitValue = EncodedCartesian3.encode(value);

<static> fromCartesian

Encodes a Cartesian3 with 64-bit floating-point components as two Cartesian3 values that, when converted to 32-bit floating-point and added, approximate the original input.

The fixed-point encoding follows Precisions, Precisions.

Parameters:

Name	Type	Argument	Description
cartesian	Cartesian3		The cartesian to encode.
result	EncodedCartesian3	<optional>	The object onto which to store the result.

Throws:

DeveloperError : cartesian is required.

Returns:

EncodedCartesian3 The modified result parameter or a new EncodedCartesian3 instance if one was not provided.

Example

var cart = new Cartesian3(-10000000.0, 0.0, 10000000.0);
var encoded = EncodedCartesian3.fromCartesian(cart);

<static> writeElements

Encodes the provided cartesian, and writes it to an array with high components followed by low components, i.e. [high.x, high.y, high.z, low.x, low.y, low.z].

This is used to create interleaved high-precision position vertex attributes.

Parameters:

Name	Type	Description
cartesian	Cartesian3	The cartesian to encode.
cartesianArray	Array	The array to write to.
index	Number	The index into the array to start writing. Six elements will be written.

Throws:

• DeveloperError : cartesian is required.
• DeveloperError : cartesianArray is required.
• DeveloperError : index must be a number greater than or equal to 0.

Example

var positions = [
   new Cartesian3(),
   // ...
];
var encodedPositions = new Float32Array(2 * 3 * positions.length);
var j = 0;
for (var i = 0; i < positions.length; ++i) {
  EncodedCartesian3.writeElement(positions[i], encodedPositions, j);
  j += 6;
}