1 files changed, 119 insertions, 0 deletions
diff --git a/wgpu/src/image/raster.rs b/wgpu/src/image/raster.rs
new file mode 100644
index 00000000..a6cba76a
--- /dev/null
+++ b/wgpu/src/image/raster.rs
@@ -0,0 +1,119 @@
+use crate::core::image;
+use crate::core::Size;
+use crate::graphics;
+use crate::graphics::image::image_rs;
+use crate::image::atlas::{self, Atlas};
+
+use std::collections::{HashMap, HashSet};
+
+/// Entry in cache corresponding to an image handle
+#[derive(Debug)]
+pub enum Memory {
+    /// Image data on host
+    Host(image_rs::ImageBuffer<image_rs::Rgba<u8>, Vec<u8>>),
+    /// Storage entry
+    Device(atlas::Entry),
+    /// Image not found
+    NotFound,
+    /// Invalid image data
+    Invalid,
+}
+
+impl Memory {
+    /// Width and height of image
+    pub fn dimensions(&self) -> Size<u32> {
+        match self {
+            Memory::Host(image) => {
+                let (width, height) = image.dimensions();
+
+                Size::new(width, height)
+            }
+            Memory::Device(entry) => entry.size(),
+            Memory::NotFound => Size::new(1, 1),
+            Memory::Invalid => Size::new(1, 1),
+        }
+    }
+}
+
+/// Caches image raster data
+#[derive(Debug, Default)]
+pub struct Cache {
+    map: HashMap<u64, Memory>,
+    hits: HashSet<u64>,
+}
+
+impl Cache {
+    /// Load image
+    pub fn load(&mut self, handle: &image::Handle) -> &mut Memory {
+        if self.contains(handle) {
+            return self.get(handle).unwrap();
+        }
+
+        let memory = match graphics::image::load(handle) {
+            Ok(image) => Memory::Host(image.to_rgba8()),
+            Err(image_rs::error::ImageError::IoError(_)) => Memory::NotFound,
+            Err(_) => Memory::Invalid,
+        };
+
+        self.insert(handle, memory);
+        self.get(handle).unwrap()
+    }
+
+    /// Load image and upload raster data
+    pub fn upload(
+        &mut self,
+        device: &wgpu::Device,
+        encoder: &mut wgpu::CommandEncoder,
+        handle: &image::Handle,
+        atlas: &mut Atlas,
+    ) -> Option<&atlas::Entry> {
+        let memory = self.load(handle);
+
+        if let Memory::Host(image) = memory {
+            let (width, height) = image.dimensions();
+
+            let entry = atlas.upload(device, encoder, width, height, image)?;
+
+            *memory = Memory::Device(entry);
+        }
+
+        if let Memory::Device(allocation) = memory {
+            Some(allocation)
+        } else {
+            None
+        }
+    }
+
+    /// Trim cache misses from cache
+    pub fn trim(&mut self, atlas: &mut Atlas) {
+        let hits = &self.hits;
+
+        self.map.retain(|k, memory| {
+            let retain = hits.contains(k);
+
+            if !retain {
+                if let Memory::Device(entry) = memory {
+                    atlas.remove(entry);
+                }
+            }
+
+            retain
+        });
+
+        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())
+    }
+}