Rerasterize SVGs when resized and refactor a bit

wgpu/src/image/raster.rs

@@ -0,0 +1,176 @@
+use iced_native::image;
+use std::{
+    collections::{HashMap, HashSet},
+    rc::Rc,
+};
+
+#[derive(Debug)]
+pub enum Memory {
+    Host(::image::ImageBuffer<::image::Bgra<u8>, Vec<u8>>),
+    Device {
+        bind_group: Rc<wgpu::BindGroup>,
+        width: u32,
+        height: u32,
+    },
+    NotFound,
+    Invalid,
+}
+
+impl Memory {
+    pub fn dimensions(&self) -> (u32, u32) {
+        match self {
+            Memory::Host(image) => image.dimensions(),
+            Memory::Device { width, height, .. } => (*width, *height),
+            Memory::NotFound => (1, 1),
+            Memory::Invalid => (1, 1),
+        }
+    }
+
+    pub fn upload(
+        &mut self,
+        device: &wgpu::Device,
+        encoder: &mut wgpu::CommandEncoder,
+        texture_layout: &wgpu::BindGroupLayout,
+    ) -> Option<Rc<wgpu::BindGroup>> {
+        match self {
+            Memory::Host(image) => {
+                let (width, height) = image.dimensions();
+
+                let extent = wgpu::Extent3d {
+                    width,
+                    height,
+                    depth: 1,
+                };
+
+                let texture = device.create_texture(&wgpu::TextureDescriptor {
+                    size: extent,
+                    array_layer_count: 1,
+                    mip_level_count: 1,
+                    sample_count: 1,
+                    dimension: wgpu::TextureDimension::D2,
+                    format: wgpu::TextureFormat::Bgra8UnormSrgb,
+                    usage: wgpu::TextureUsage::COPY_DST
+                        | wgpu::TextureUsage::SAMPLED,
+                });
+
+                let temp_buf = {
+                    let flat_samples = image.as_flat_samples();
+                    let slice = flat_samples.as_slice();
+
+                    device
+                        .create_buffer_mapped(
+                            slice.len(),
+                            wgpu::BufferUsage::COPY_SRC,
+                        )
+                        .fill_from_slice(slice)
+                };
+
+                encoder.copy_buffer_to_texture(
+                    wgpu::BufferCopyView {
+                        buffer: &temp_buf,
+                        offset: 0,
+                        row_pitch: 4 * width as u32,
+                        image_height: height as u32,
+                    },
+                    wgpu::TextureCopyView {
+                        texture: &texture,
+                        array_layer: 0,
+                        mip_level: 0,
+                        origin: wgpu::Origin3d {
+                            x: 0.0,
+                            y: 0.0,
+                            z: 0.0,
+                        },
+                    },
+                    extent,
+                );
+
+                let bind_group =
+                    device.create_bind_group(&wgpu::BindGroupDescriptor {
+                        layout: texture_layout,
+                        bindings: &[wgpu::Binding {
+                            binding: 0,
+                            resource: wgpu::BindingResource::TextureView(
+                                &texture.create_default_view(),
+                            ),
+                        }],
+                    });
+
+                let bind_group = Rc::new(bind_group);
+
+                *self = Memory::Device {
+                    bind_group: bind_group.clone(),
+                    width,
+                    height,
+                };
+
+                Some(bind_group)
+            }
+            Memory::Device { bind_group, .. } => Some(bind_group.clone()),
+            Memory::NotFound => None,
+            Memory::Invalid => None,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Cache {
+    map: HashMap<u64, Memory>,
+    hits: HashSet<u64>,
+}
+
+impl Cache {
+    pub fn new() -> Self {
+        Self {
+            map: HashMap::new(),
+            hits: HashSet::new(),
+        }
+    }
+
+    pub fn load(&mut self, handle: &image::Handle) -> &mut Memory {
+        if self.contains(handle) {
+            return self.get(handle).unwrap();
+        }
+
+        let memory = match handle.data() {
+            image::Data::Path(path) => {
+                if let Ok(image) = ::image::open(path) {
+                    Memory::Host(image.to_bgra())
+                } else {
+                    Memory::NotFound
+                }
+            }
+            image::Data::Bytes(bytes) => {
+                if let Ok(image) = ::image::load_from_memory(&bytes) {
+                    Memory::Host(image.to_bgra())
+                } else {
+                    Memory::Invalid
+                }
+            }
+        };
+
+        self.insert(handle, memory);
+        self.get(handle).unwrap()
+    }
+
+    pub fn trim(&mut self) {
+        let hits = &self.hits;
+
+        self.map.retain(|k, _| hits.contains(k));
+        self.hits.clear();
+    }
+
+    fn get(&mut self, handle: &image::Handle) -> Option<&mut Memory> {
+        let _ = self.hits.insert(handle.id());
+
+        self.map.get_mut(&handle.id())
+    }
+
+    fn insert(&mut self, handle: &image::Handle, memory: Memory) {
+        let _ = self.map.insert(handle.id(), memory);
+    }
+
+    fn contains(&self, handle: &image::Handle) -> bool {
+        self.map.contains_key(&handle.id())
+    }
+}