Anisotropy fixes

CHANGELOG.md

@@ -82,6 +82,21 @@ The following `Features` have been renamed.
 
 By @teoxoy in [#3534](https://github.com/gfx-rs/wgpu/pull/3534)
 
+#### Anisotropic Filtering
+
+Anisotropic filtering has been brought in line with the spec. The anisotropic clamp is now a f32 which must be between 1.0 and 16.0 inclusive.
+
+If the anisotropy clamp is not 1.0, all the filters in a sampler must be `Linear`.
+
+```diff
+SamplerDescriptor {
+- anisotropic_clamp: None,
++ anisotropic_clamp: 1.0,
+}
+```
+
+By @cwfitzgerald in [#3610](https://github.com/gfx-rs/wgpu/pull/3610).
+
 #### General
 
 - Change type of `mip_level_count` and `array_layer_count` (members of `TextureViewDescriptor` and `ImageSubresourceRange`) from `Option<NonZeroU32>` to `Option<u32>`. By @teoxoy in [#3445](https://github.com/gfx-rs/wgpu/pull/3445)
@@ -99,6 +114,7 @@ By @teoxoy in [#3534](https://github.com/gfx-rs/wgpu/pull/3534)
 - Improve attachment related errors. By @cwfitzgerald in [#3549](https://github.com/gfx-rs/wgpu/pull/3549)
 - Make error descriptions all upper case. By @cwfitzgerald in [#3549](https://github.com/gfx-rs/wgpu/pull/3549)
 - Don't include ANSI terminal color escape sequences in shader module validation error messages. By @jimblandy in [#3591](https://github.com/gfx-rs/wgpu/pull/3591)
+- Bring anisotropic filtering in line with the spec. 
 
 #### WebGPU
 
@@ -115,7 +131,7 @@ By @teoxoy in [#3534](https://github.com/gfx-rs/wgpu/pull/3534)
 ### Bug Fixes
 
 #### Metal
-- Fix incorrect mipmap being sampled when using `MinLod <= 0.0` and `MaxLod >= 32.0` or when the fragment shaders in the same squad sample different Lods. By @cwfitzgerald in [#3610](https://github.com/gfx-rs/wgpu/pull/3610).
+- Fix incorrect mipmap being sampled when using `MinLod <= 0.0` and `MaxLod >= 32.0` or when the fragment shader samples different Lods in the same quad. By @cwfitzgerald in [#3610](https://github.com/gfx-rs/wgpu/pull/3610).
 
 #### DX12
 

wgpu-core/src/device/mod.rs

@@ -1310,37 +1310,53 @@ impl<A: HalApi> Device<A> {
  self.require_features(wgt::Features::ADDRESS_MODE_CLAMP_TO_ZERO)?;
  }
 
- if desc.lod_min_clamp < 0.0 || desc.lod_max_clamp < desc.lod_min_clamp {
- return Err(resource::CreateSamplerError::InvalidLodClamp(
- desc.lod_min_clamp..desc.lod_max_clamp,
+ if desc.lod_min_clamp < 0.0 {
+ return Err(resource::CreateSamplerError::InvalidLodMinClamp(
+ desc.lod_min_clamp,
  ));
  }
+ if desc.lod_max_clamp < desc.lod_min_clamp {
+ return Err(resource::CreateSamplerError::InvalidLodMaxClamp {
+ lod_min_clamp: desc.lod_min_clamp,
+ lod_max_clamp: desc.lod_max_clamp,
+ });
+ }
 
- let lod_clamp = if desc.lod_min_clamp > 0.0 || desc.lod_max_clamp < 32.0 {
- Some(desc.lod_min_clamp..desc.lod_max_clamp)
- } else {
- None
- };
+ if !(1.0..=16.0).contains(&desc.anisotropy_clamp) {
+ return Err(resource::CreateSamplerError::InvalidAnisotropy(
+  desc.anisotropy_clamp,
+ ));
+ }
 
- let anisotropy_clamp = if let Some(clamp) = desc.anisotropy_clamp {
- let clamp = clamp.get();
- let valid_clamp =
- clamp <= hal::MAX_ANISOTROPY && conv::is_power_of_two_u32(clamp as u32);
- if !valid_clamp {
- return Err(resource::CreateSamplerError::InvalidClamp(clamp));
+ if desc.anisotropy_clamp != 1.0 {
+ if !matches!(desc.min_filter, wgt::FilterMode::Linear) {
+ return Err(
+ resource::CreateSamplerError::InvalidFilterModeWithAnisotropy {
+ filter_type: resource::SamplerFilterErrorType::MinFilter,
+ filter_mode: desc.min_filter,
+ anisotropic_clamp: desc.anisotropy_clamp,
+ },
+ );
  }
- if self
- .downlevel
- .flags
- .contains(wgt::DownlevelFlags::ANISOTROPIC_FILTERING)
- {
- std::num::NonZeroU8::new(clamp)
- } else {
- None
+ if !matches!(desc.mag_filter, wgt::FilterMode::Linear) {
+ return Err(
+  resource::CreateSamplerError::InvalidFilterModeWithAnisotropy {
+  filter_type: resource::SamplerFilterErrorType::MagFilter,
+  filter_mode: desc.mag_filter,
+  anisotropic_clamp: desc.anisotropy_clamp,
+  },
+ );
  }
- } else {
- None
- };
+ if !matches!(desc.mipmap_filter, wgt::FilterMode::Linear) {
+ return Err(
+ resource::CreateSamplerError::InvalidFilterModeWithAnisotropy {
+ filter_type: resource::SamplerFilterErrorType::MipmapFilter,
+ filter_mode: desc.mipmap_filter,
+ anisotropic_clamp: desc.anisotropy_clamp,
+ },
+ );
+ }
+ }
 
  //TODO: check for wgt::DownlevelFlags::COMPARISON_SAMPLERS
 
@@ -1350,9 +1366,9 @@ impl<A: HalApi> Device<A> {
  mag_filter: desc.mag_filter,
  min_filter: desc.min_filter,
  mipmap_filter: desc.mipmap_filter,
- lod_clamp,
+ lod_clamp: desc.lod_min_clamp..desc.lod_max_clamp,
  compare: desc.compare,
- anisotropy_clamp,
+ anisotropy_clamp: desc.anisotropy_clamp,
  border_color: desc.border_color,
  };
 

wgpu-core/src/resource.rs

@@ -11,7 +11,7 @@ use crate::{
 use smallvec::SmallVec;
 use thiserror::Error;
 
-use std::{borrow::Borrow, num::NonZeroU8, ops::Range, ptr::NonNull};
+use std::{borrow::Borrow, ops::Range, ptr::NonNull};
 
 /// The status code provided to the buffer mapping callback.
 ///
@@ -689,8 +689,8 @@ pub struct SamplerDescriptor<'a> {
  pub lod_max_clamp: f32,
  /// If this is enabled, this is a comparison sampler using the given comparison function.
  pub compare: Option<wgt::CompareFunction>,
- /// Valid values: 1, 2, 4, 8, and 16.
- pub anisotropy_clamp: Option<NonZeroU8>,
+ /// Valid values between 1 and 16 inclusive. If this is not 1.0, all filter modes must be linear.
+ pub anisotropy_clamp: f32,
  /// Border color to use when address_mode is
  /// [`AddressMode::ClampToBorder`](wgt::AddressMode::ClampToBorder)
  pub border_color: Option<wgt::SamplerBorderColor>,
@@ -707,7 +707,7 @@ impl Default for SamplerDescriptor<'_> {
  lod_min_clamp: 0.0,
  lod_max_clamp: std::f32::MAX,
  compare: None,
- anisotropy_clamp: None,
+ anisotropy_clamp: 1.0,
  border_color: None,
  }
  }
@@ -724,14 +724,42 @@ pub struct Sampler<A: hal::Api> {
  pub(crate) filtering: bool,
 }
 
+#[derive(Copy, Clone)]
+pub enum SamplerFilterErrorType {
+ MagFilter,
+ MinFilter,
+ MipmapFilter,
+}
+
+impl std::fmt::Debug for SamplerFilterErrorType {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ match *self {
+ SamplerFilterErrorType::MagFilter => write!(f, "magFilter"),
+ SamplerFilterErrorType::MinFilter => write!(f, "minFilter"),
+ SamplerFilterErrorType::MipmapFilter => write!(f, "mipmapFilter"),
+ }
+ }
+}
+
 #[derive(Clone, Debug, Error)]
 pub enum CreateSamplerError {
  #[error(transparent)]
  Device(#[from] DeviceError),
- #[error("Invalid lod clamp lod_min_clamp:{} lod_max_clamp:{}, must satisfy lod_min_clamp >= 0 and lod_max_clamp >= lod_min_clamp ", .0.start, .0.end)]
- InvalidLodClamp(Range<f32>),
- #[error("Invalid anisotropic clamp {0}, must be one of 1, 2, 4, 8 or 16")]
- InvalidClamp(u8),
+ #[error("Invalid lodMinClamp: {0}. Must be greater or equal to 0.0")]
+ InvalidLodMinClamp(f32),
+ #[error("Invalid lodMaxClamp: {lod_max_clamp}. Must be greater or equal to lodMinClamp (which is {lod_min_clamp}).")]
+ InvalidLodMaxClamp {
+ lod_min_clamp: f32,
+ lod_max_clamp: f32,
+ },
+ #[error("Invalid anisotropic clamp: {0}. Must be in the range 1 to 16 inclusive.")]
+ InvalidAnisotropy(f32),
+ #[error("Invalid filter mode for {filter_type:?}: {filter_mode:?}. When anistropic clamp is not 1.0 (it is {anisotropic_clamp}), all filter modes must be linear.")]
+ InvalidFilterModeWithAnisotropy {
+ filter_type: SamplerFilterErrorType,
+ filter_mode: wgt::FilterMode,
+ anisotropic_clamp: f32,
+ },
  #[error("Cannot create any more samplers")]
  TooManyObjects,
  /// AddressMode::ClampToBorder requires feature ADDRESS_MODE_CLAMP_TO_BORDER.

wgpu-hal/examples/halmark/main.rs

@@ -355,9 +355,9 @@ impl<A: hal::Api> Example<A> {
  mag_filter: wgt::FilterMode::Linear,
  min_filter: wgt::FilterMode::Nearest,
  mipmap_filter: wgt::FilterMode::Nearest,
- lod_clamp: None,
+ lod_clamp: 0.0..32.0,
  compare: None,
- anisotropy_clamp: None,
+ anisotropy_clamp: 1.0,
  border_color: None,
  };
  let sampler = unsafe { device.create_sampler(&sampler_desc).unwrap() };

wgpu-hal/src/dx12/device.rs

@@ -602,10 +602,10 @@ impl crate::Device<super::Api> for super::Device {
  conv::map_address_mode(desc.address_modes[2]),
  ],
  0.0,
- desc.anisotropy_clamp.map_or(0, |aniso| aniso.get() as u32),
+ desc.anisotropy_clamp as u32,
  conv::map_comparison(desc.compare.unwrap_or(wgt::CompareFunction::Always)),
  border_color,
- desc.lod_clamp.clone().unwrap_or(0.0..16.0),
+ desc.lod_clamp.clone(),
  );
 
  Ok(super::Sampler { handle })

wgpu-hal/src/gles/device.rs

@@ -864,16 +864,12 @@ impl crate::Device<super::Api> for super::Device {
  unsafe { gl.sampler_parameter_f32_slice(raw, glow::TEXTURE_BORDER_COLOR, &border) };
  }
 
- if let Some(ref range) = desc.lod_clamp {
- unsafe { gl.sampler_parameter_f32(raw, glow::TEXTURE_MIN_LOD, range.start) };
- unsafe { gl.sampler_parameter_f32(raw, glow::TEXTURE_MAX_LOD, range.end) };
- }
+ unsafe { gl.sampler_parameter_f32(raw, glow::TEXTURE_MIN_LOD, desc.lod_clamp.start) };
+ unsafe { gl.sampler_parameter_f32(raw, glow::TEXTURE_MAX_LOD, desc.lod_clamp.end) };
 
- if let Some(anisotropy) = desc.anisotropy_clamp {
- unsafe {
- gl.sampler_parameter_i32(raw, glow::TEXTURE_MAX_ANISOTROPY, anisotropy.get() as i32)
- };
- }
+ unsafe {
+ gl.sampler_parameter_f32(raw, glow::TEXTURE_MAX_ANISOTROPY, desc.anisotropy_clamp)
+ };
 
  //set_param_float(glow::TEXTURE_LOD_BIAS, info.lod_bias.0);
 

wgpu-hal/src/lib.rs

@@ -87,7 +87,7 @@ pub mod api {
 use std::{
  borrow::{Borrow, Cow},
  fmt,
- num::{NonZeroU32, NonZeroU8},
+ num::NonZeroU32,
  ops::{Range, RangeInclusive},
  ptr::NonNull,
  sync::atomic::AtomicBool,
@@ -919,9 +919,9 @@ pub struct SamplerDescriptor<'a> {
  pub mag_filter: wgt::FilterMode,
  pub min_filter: wgt::FilterMode,
  pub mipmap_filter: wgt::FilterMode,
- pub lod_clamp: Option<Range<f32>>,
+ pub lod_clamp: Range<f32>,
  pub compare: Option<wgt::CompareFunction>,
- pub anisotropy_clamp: Option<NonZeroU8>,
+ pub anisotropy_clamp: f32,
  pub border_color: Option<wgt::SamplerBorderColor>,
 }
 

wgpu-hal/src/metal/device.rs

@@ -415,6 +415,9 @@ impl crate::Device<super::Api> for super::Device {
  descriptor.set_min_filter(conv::map_filter_mode(desc.min_filter));
  descriptor.set_mag_filter(conv::map_filter_mode(desc.mag_filter));
  descriptor.set_mip_filter(match desc.mipmap_filter {
+ wgt::FilterMode::Nearest if desc.lod_clamp == (0.0..0.0) => {
+ metal::MTLSamplerMipFilter::NotMipmapped
+ }
  wgt::FilterMode::Nearest => metal::MTLSamplerMipFilter::Nearest,
  wgt::FilterMode::Linear => metal::MTLSamplerMipFilter::Linear,
  });
@@ -424,14 +427,10 @@ impl crate::Device<super::Api> for super::Device {
  descriptor.set_address_mode_t(conv::map_address_mode(t));
  descriptor.set_address_mode_r(conv::map_address_mode(r));
 
- if let Some(aniso) = desc.anisotropy_clamp {
- descriptor.set_max_anisotropy(aniso.get() as _);
- }
+ descriptor.set_max_anisotropy(desc.anisotropy_clamp as _);
 
- if let Some(ref range) = desc.lod_clamp {
- descriptor.set_lod_min_clamp(range.start);
- descriptor.set_lod_max_clamp(range.end);
- }
+ descriptor.set_lod_min_clamp(desc.lod_clamp.start);
+ descriptor.set_lod_max_clamp(desc.lod_clamp.end);
 
  if let Some(fun) = desc.compare {
  descriptor.set_compare_function(conv::map_compare_function(fun));

wgpu-hal/src/vulkan/device.rs

@@ -1103,8 +1103,6 @@ impl crate::Device<super::Api> for super::Device {
  &self,
  desc: &crate::SamplerDescriptor,
  ) -> Result<super::Sampler, crate::DeviceError> {
- let lod_range = desc.lod_clamp.clone().unwrap_or(0.0..16.0);
-
  let mut vk_info = vk::SamplerCreateInfo::builder()
  .flags(vk::SamplerCreateFlags::empty())
  .mag_filter(conv::map_filter_mode(desc.mag_filter))
@@ -1113,25 +1111,23 @@ impl crate::Device<super::Api> for super::Device {
  .address_mode_u(conv::map_address_mode(desc.address_modes[0]))
  .address_mode_v(conv::map_address_mode(desc.address_modes[1]))
  .address_mode_w(conv::map_address_mode(desc.address_modes[2]))
- .min_lod(lod_range.start)
- .max_lod(lod_range.end);
+ .min_lod(desc.lod_clamp.start)
+ .max_lod(desc.lod_clamp.end);
 
  if let Some(fun) = desc.compare {
  vk_info = vk_info
  .compare_enable(true)
  .compare_op(conv::map_comparison(fun));
  }
 
- if let Some(aniso) = desc.anisotropy_clamp {
- if self
- .shared
- .downlevel_flags
- .contains(wgt::DownlevelFlags::ANISOTROPIC_FILTERING)
- {
- vk_info = vk_info
- .anisotropy_enable(true)
- .max_anisotropy(aniso.get() as f32);
- }
+ if self
+ .shared
+ .downlevel_flags
+ .contains(wgt::DownlevelFlags::ANISOTROPIC_FILTERING)
+ {
+ vk_info = vk_info
+ .anisotropy_enable(true)
+ .max_anisotropy(desc.anisotropy_clamp);
  }
 
  if let Some(color) = desc.border_color {

wgpu/src/lib.rs

@@ -19,7 +19,7 @@ use std::{
  fmt::{Debug, Display},
  future::Future,
  marker::PhantomData,
- num::{NonZeroU32, NonZeroU8},
+ num::NonZeroU32,
  ops::{Bound, Deref, DerefMut, Range, RangeBounds},
  sync::Arc,
  thread,
@@ -1008,8 +1008,8 @@ pub struct SamplerDescriptor<'a> {
  pub lod_max_clamp: f32,
  /// If this is enabled, this is a comparison sampler using the given comparison function.
  pub compare: Option<CompareFunction>,
- /// Valid values: 1, 2, 4, 8, and 16.
- pub anisotropy_clamp: Option<NonZeroU8>,
+ /// Valid values between 1 and 16 inclusive. If this is not 1.0, all filter modes must be linear.
+ pub anisotropy_clamp: f32,
  /// Border color to use when address_mode is [`AddressMode::ClampToBorder`]
  pub border_color: Option<SamplerBorderColor>,
 }
@@ -1028,7 +1028,7 @@ impl Default for SamplerDescriptor<'_> {
  lod_min_clamp: 0.0,
  lod_max_clamp: std::f32::MAX,
  compare: None,
- anisotropy_clamp: None,
+ anisotropy_clamp: 1.0,
  border_color: None,
  }
  }