	US 12,190,413 B2
	Anisotropic texture filtering for sampling points in screen space
Rostam King, Hertfordshire (GB)
Assigned to Imagination Technologies Limited, Kings Langley (GB)
Filed by Imagination Technologies Limited, Kings Langley (GB)
Filed on Jul. 31, 2023, as Appl. No. 18/228,495.
Application 18/228,495 is a continuation of application No. 17/534,749, filed on Nov. 24, 2021, granted, now 11,715,243, issued on Aug. 1, 2023.
Application 17/534,749 is a continuation of application No. 17/073,522, filed on Oct. 19, 2020, granted, now 11,216,990, issued on Jan. 4, 2022.
Claims priority of application No. 1915044 (GB), filed on Oct. 17, 2019.
Prior Publication US 2023/0377217 A1, Nov. 23, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06T 11/00 (2006.01); G06T 3/00 (2024.01); G06T 5/00 (2024.01); G06T 15/04 (2011.01)

CPC G06T 11/001 (2013.01) [G06T 2210/36 (2013.01)]

20 Claims

1. A method of performing texture filtering, comprising:

calculating first and second pairs of texture-space basis vectors that correspond to first and second pairs of screen-space basis vectors transformed to texture space under a local approximation of a mapping between screen space and texture space;

based on differences in magnitudes of the vectors of at least one of the pairs of texture-space basis vectors, determining an angular displacement between a selected pair of the first and second pairs of screen-space basis vectors and screen-space principal axes of the local approximation of the mapping that indicate maximum and minimum scale factors of the mapping;

using the determined angular displacement and the selected pair of screen-space basis vectors to generate texture-space principal axes, the texture-space principal axes comprising a major axis associated with the maximum scale factor of the mapping and a minor axis associated with the minimum scale factor of the mapping;

filtering a texture using the major and minor axes.