From c4151344549ce3a238e6b0dd4ac78022a3aefccb Mon Sep 17 00:00:00 2001 From: Eric Guo Date: Mon, 13 Apr 2026 13:33:16 +0800 Subject: [PATCH] panfrost: disable round_to_nearest_even for NEAREST samplers When round_to_nearest_even is enabled with NEAREST filtering, texture coordinates near texel boundaries (e.g. 0.9999999404) can be incorrectly rounded up to the next texel instead of being floor()'d. According to OpenCL spec section 8.2, for CLK_FILTER_NEAREST: i = address_mode((int)floor(u)) Backport-to: * Signed-off-by: Eric Guo Reviewed-by: Erik Faye-Lund Part-of: --- src/gallium/drivers/panfrost/pan_cmdstream.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/gallium/drivers/panfrost/pan_cmdstream.c b/src/gallium/drivers/panfrost/pan_cmdstream.c index 74806aba446..6e2a36c5b27 100644 --- a/src/gallium/drivers/panfrost/pan_cmdstream.c +++ b/src/gallium/drivers/panfrost/pan_cmdstream.c @@ -230,6 +230,14 @@ panfrost_create_sampler_state(struct pipe_context *pctx, cfg.border_color_a = so->base.border_color.ui[3]; #if PAN_ARCH >= 6 + /* + * Disabling round_to_nearest_even for NEAREST filters ensures proper + * floor() behavior as required by OpenCL_C spec section 8.2. + */ + if (cso->mag_img_filter == PIPE_TEX_FILTER_NEAREST && + cso->min_img_filter == PIPE_TEX_FILTER_NEAREST) + cfg.round_to_nearest_even = false; + if (cso->max_anisotropy > 1) { cfg.maximum_anisotropy = cso->max_anisotropy; cfg.lod_algorithm = MALI_LOD_ALGORITHM_ANISOTROPIC;