Implement texture filtering options

core/src/image.rs

@@ -5,11 +5,31 @@ use std::hash::{Hash, Hasher as _};
 use std::path::PathBuf;
 use std::sync::Arc;
 
+/// Image filter method
+#[derive(Default, Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum FilterMethod {
+    /// Bilinear interpolation
+    #[default]
+    Linear,
+    /// Nearest Neighbor 
+    Nearest,
+}
+
+/// Texture filter settings
+#[derive(Default, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct TextureFilter {
+    /// Filter for scaling the image down.
+    pub min: FilterMethod,
+    /// Filter for scaling the image up.
+    pub mag: FilterMethod,
+}
+
 /// A handle of some image data.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Handle {
     id: u64,
     data: Data,
+    filter: TextureFilter,
 }
 
 impl Handle {
@@ -56,6 +76,7 @@ impl Handle {
         Handle {
             id: hasher.finish(),
             data,
+            filter: TextureFilter::default(),
         }
     }
 
@@ -68,6 +89,17 @@ impl Handle {
     pub fn data(&self) -> &Data {
         &self.data
     }
+
+    /// Returns a reference to the [`TextureFilter`].
+    pub fn filter(&self) -> &TextureFilter {
+        &self.filter
+    }
+
+    /// Sets the texture filtering methods.
+    pub fn set_filter(mut self, filter: TextureFilter) -> Self {
+        self.filter = filter;
+        self
+    }
 }
 
 impl<T> From<T> for Handle

tiny_skia/src/raster.rs

@@ -39,12 +39,17 @@ impl Pipeline {
 
             let transform = transform.pre_scale(width_scale, height_scale);
 
+            let quality = match handle.filter().mag {
+                raster::FilterMethod::Linear => tiny_skia::FilterQuality::Bilinear,
+                raster::FilterMethod::Nearest => tiny_skia::FilterQuality::Nearest,
+            };
+
             pixels.draw_pixmap(
                 (bounds.x / width_scale) as i32,
                 (bounds.y / height_scale) as i32,
                 image,
                 &tiny_skia::PixmapPaint {
-                    quality: tiny_skia::FilterQuality::Bilinear,
+                    quality: quality,
                     ..Default::default()
                 },
                 transform,

wgpu/src/image.rs

@@ -7,13 +7,15 @@ mod raster;
 mod vector;
 
 use atlas::Atlas;
+use iced_graphics::core::image::{TextureFilter, FilterMethod};
 
 use crate::core::{Rectangle, Size};
 use crate::graphics::Transformation;
 use crate::layer;
 use crate::Buffer;
 
 use std::cell::RefCell;
+use std::collections::HashMap;
 use std::mem;
 
 use bytemuck::{Pod, Zeroable};
@@ -37,7 +39,7 @@ pub struct Pipeline {
     pipeline: wgpu::RenderPipeline,
     vertices: wgpu::Buffer,
     indices: wgpu::Buffer,
-    sampler: wgpu::Sampler,
+    sampler: HashMap<TextureFilter,wgpu::Sampler>,
     texture: wgpu::BindGroup,
     texture_version: usize,
     texture_atlas: Atlas,
@@ -142,15 +144,32 @@ impl Pipeline {
     pub fn new(device: &wgpu::Device, format: wgpu::TextureFormat) -> Self {
         use wgpu::util::DeviceExt;
 
-        let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
-            address_mode_u: wgpu::AddressMode::ClampToEdge,
-            address_mode_v: wgpu::AddressMode::ClampToEdge,
-            address_mode_w: wgpu::AddressMode::ClampToEdge,
-            mag_filter: wgpu::FilterMode::Linear,
-            min_filter: wgpu::FilterMode::Linear,
-            mipmap_filter: wgpu::FilterMode::Linear,
-            ..Default::default()
-        });
+        let to_wgpu = |method: FilterMethod| {
+            match method {
+                FilterMethod::Linear => wgpu::FilterMode::Linear,
+                FilterMethod::Nearest => wgpu::FilterMode::Nearest,
+            }
+        };
+
+        let mut sampler = HashMap::new();
+
+        let filter = [FilterMethod::Linear, FilterMethod::Nearest];
+        for min in 0..filter.len() {
+            for mag in 0..filter.len() {
+                let _ = sampler.insert(TextureFilter {min: filter[min], mag: filter[mag]}, 
+                    device.create_sampler(&wgpu::SamplerDescriptor {
+                        address_mode_u: wgpu::AddressMode::ClampToEdge,
+                        address_mode_v: wgpu::AddressMode::ClampToEdge,
+                        address_mode_w: wgpu::AddressMode::ClampToEdge,
+                        mag_filter: to_wgpu(filter[mag]),
+                        min_filter: to_wgpu(filter[min]),
+                        mipmap_filter: wgpu::FilterMode::Linear,
+                        ..Default::default()
+                    }
+                ));
+            }
+        }
+
 
         let constant_layout =
             device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
@@ -355,7 +374,7 @@ impl Pipeline {
         #[cfg(feature = "tracing")]
         let _ = info_span!("Wgpu::Image", "DRAW").entered();
 
-        let instances: &mut Vec<Instance> = &mut Vec::new();
+        let instances: &mut HashMap<TextureFilter,Vec<Instance>> = &mut HashMap::new();
 
         #[cfg(feature = "image")]
         let mut raster_cache = self.raster_cache.borrow_mut();
@@ -377,7 +396,7 @@ impl Pipeline {
                             [bounds.x, bounds.y],
                             [bounds.width, bounds.height],
                             atlas_entry,
-                            instances,
+                            instances.entry(handle.filter().clone()).or_insert(Vec::new()),
                         );
                     }
                 }
@@ -405,7 +424,7 @@ impl Pipeline {
                             [bounds.x, bounds.y],
                             size,
                             atlas_entry,
-                            instances,
+                            instances.entry(TextureFilter::default()).or_insert(Vec::new()),
                         );
                     }
                 }
@@ -438,18 +457,20 @@ impl Pipeline {
             self.texture_version = texture_version;
         }
 
-        if self.layers.len() <= self.prepare_layer {
-            self.layers.push(Layer::new(
-                device,
-                &self.constant_layout,
-                &self.sampler,
-            ));
+        for (filter, instances) in instances.iter_mut() {
+            if self.layers.len() <= self.prepare_layer {
+                self.layers.push(Layer::new(
+                    device,
+                    &self.constant_layout,
+                    &self.sampler.get(filter).expect("Sampler is registered"),
+                ));
+            }
+
+            let layer = &mut self.layers[self.prepare_layer];
+            layer.prepare(device, queue, &instances, transformation);
+
+            self.prepare_layer += 1;
         }
-
-        let layer = &mut self.layers[self.prepare_layer];
-        layer.prepare(device, queue, instances, transformation);
-
-        self.prepare_layer += 1;
     }
 
     pub fn render<'a>(

widget/src/image.rs

@@ -12,7 +12,7 @@ use crate::core::{
 
 use std::hash::Hash;
 
-pub use image::Handle;
+pub use image::{Handle, TextureFilter, FilterMethod};
 
 /// Creates a new [`Viewer`] with the given image `Handle`.
 pub fn viewer<Handle>(handle: Handle) -> Viewer<Handle> {