The partitioning mode used by the tessellator to derive the number and spacing of segments used to subdivide a corresponding edge.

SDKs

- iOS 10.0+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 10.0+

Framework

- Metal

## Declaration

## Overview

Table 1 lists the tessellation factor range for each partitioning mode.

**Table 1**

Partitioning mode | Tessellation factor range |
---|---|

[ | |

The floating-point tessellation level is always clamped to its corresponding range before calculating the final tessellation factor. After clamping, the calculation depends on the chosen partitioning mode:

For the

`MTLTessellation`

partitioning mode, the result is rounded up to the nearest integerPartition Mode .pow2 `n`

, where`n`

is a power of two. The corresponding edge is divided into`n`

segments of equal length in (u, v) space.For the

`MTLTessellation`

partitioning mode, the result is rounded up to the nearest integerPartition Mode .integer `n`

. The corresponding edge is divided into`n`

segments of equal length in (u, v) space.For the

`MTLTessellation`

partitioning mode, the tessellation level is rounded up the the nearest odd integerPartition Mode .fractional Odd `n`

. If`n`

is`1`

, the edge is not subdivided. Otherwise, the corresponding edge is divided into`n-2`

segments of equal length, and two additional segments of equal length that are typically shorter than the other segments. The length of the two additional segments relative to the others decreases monotonically by the value of`n-f`

, where`f`

is the clamped floating-point tessellation level. If`n-f`

is`0`

the additional segments equal length to the other segments. As`n-f`

approaches`2`

, the relative length of the additional segments approaches`0`

. The two additional segments should be placed symmetrically on opposite sides of the subdivided edge. The relative location of these two segments is undefined, but must be identical for any pair of subdivided edges with identical values of`f`

.For the

`MTLTessellation`

partitioning mode, the tessellation level is rounded up the the nearest even integerPartition Mode .fractional Even `n`

.