Class: GeometryUtils

GeometryUtils()

Utility class for geometry color and index buffers. Provides static methods for: - expanding a uniform RGB color into a per-vertex buffer - choosing between 16-bit and 32-bit index buffers - generating sequential vertex indexes - extracting unique wireframe edges from triangle indexes

Constructor

new GeometryUtils()

Source:

Methods

(static) appendGridTriangleIndices(indices, columnSegments, rowSegments, vertexOffsetopt, reverseopt)

Appends triangles for a rectangular vertex grid in row order. Dimensions and offsets come from normalized geometry options.
Parameters:
Name Type Attributes Default Description
indices Array.<number> Output triangle indexes.
columnSegments number Number of cells per row.
rowSegments number Number of cell rows.
vertexOffset number <optional>
 0 First vertex in the grid.
reverse boolean <optional>
 false Whether to reverse each triangle's winding.
Source:

(static) createColorsFromSpec(vertexCount, colors, expectedPerVertexLengthopt) → {Float32Array}

Creates a per-vertex RGB buffer from a uniform color or an existing color buffer. A positive `expectedPerVertexLength` overrides the length derived from `vertexCount`.
Parameters:
Name Type Attributes Default Description
vertexCount number Total vertex count.
colors Float32Array Uniform RGB color or per-vertex colors.
expectedPerVertexLength number <optional>
 0 Optional explicit expected buffer length.
Source:
Throws:
When colors have an unsupported type or length.
Type
TypeError
Returns:
- A new uniform-color buffer or the supplied per-vertex buffer.
Type
Float32Array

(static) createIndexArray(vertexCount, indices) → {Uint16Array|Uint32Array}

Creates an index buffer using the smallest type required by the vertex count. The largest vertex index is `vertexCount - 1`.
Parameters:
Name Type Description
vertexCount number Total vertex count.
indices Array.<number> Index list.
Source:
Throws:
When indices are not an ordinary array.
Type
TypeError
Returns:
- A new typed index buffer.
Type
Uint16Array | Uint32Array

(static) createSequentialIndexArray(vertexCount) → {Uint16Array|Uint32Array}

Creates a sequential index buffer without an intermediate JavaScript array. The buffer contains every vertex index, from zero through `vertexCount - 1`.
Parameters:
Name Type Description
vertexCount number Total vertex count.
Source:
Throws:
  • When `vertexCount` is not a finite number.
    Type
    TypeError
  • When `vertexCount` is negative or non-integer.
    Type
    RangeError
Returns:
- A new sequential index buffer.
Type
Uint16Array | Uint32Array

(static) createWireframeIndicesFromSolidIndices(vertexCount, triangleIndices) → {Uint16Array|Uint32Array}

Creates a wireframe line index buffer from a solid triangle index buffer. Shared edges are included once, regardless of their direction in each triangle.
Parameters:
Name Type Description
vertexCount number Total vertex count.
triangleIndices Uint16Array | Uint32Array Solid triangle indexes.
Source:
Throws:
When triangle indices have an unsupported type.
Type
TypeError
Returns:
- Wireframe indexes, with two indexes per edge.
Type
Uint16Array | Uint32Array

(static) normalizeSegmentCount(value, optionName, minimumValue, geometryName) → {number}

Floors a finite segment count and checks the minimum required by a geometry.
Parameters:
Name Type Description
value number Requested segment count.
optionName string Option name included in errors.
minimumValue number Minimum supported count.
geometryName string Geometry class name included in errors.
Source:
Throws:
  • When the value is not a finite number.
    Type
    TypeError
  • When the rounded count is below the minimum.
    Type
    RangeError
Returns:
- Validated integer segment count.
Type
number