Do a downlevel check for anisotrophy and enable it in the webgl backe…

…nd (#2616)

* Do a downlevel check for anisotrophy and enable it in the webgl backend

* Run cargo fmt

* Change to sample_parameter_i32

wgpu-hal/src/gles/adapter.rs

@@ -284,6 +284,10 @@ impl super::Adapter {
                 && (vertex_shader_storage_blocks != 0 || vertex_ssbo_false_zero),
         );
         downlevel_flags.set(wgt::DownlevelFlags::FRAGMENT_STORAGE, supports_storage);
+        downlevel_flags.set(
+            wgt::DownlevelFlags::ANISOTROPIC_FILTERING,
+            extensions.contains("EXT_texture_filter_anisotropic"),
+        );
 
         let mut features = wgt::Features::empty()
             | wgt::Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES

wgpu-hal/src/gles/device.rs

@@ -740,8 +740,9 @@ impl crate::Device<super::Api> for super::Device {
             gl.sampler_parameter_f32(raw, glow::TEXTURE_MAX_LOD, range.end);
         }
 
-        //TODO: `desc.anisotropy_clamp` depends on the downlevel flag
-        // gl.sampler_parameter_f32(rawow::TEXTURE_MAX_ANISOTROPY, aniso as f32);
+        if let Some(anisotropy) = desc.anisotropy_clamp {
+            gl.sampler_parameter_i32(raw, glow::TEXTURE_MAX_ANISOTROPY, anisotropy.get() as i32);
+        }
 
         //set_param_float(glow::TEXTURE_LOD_BIAS, info.lod_bias.0);