Move all crates into a crates directory (#1940)

crates/epaint/src/texture_handle.rs

@@ -0,0 +1,122 @@
+use std::sync::Arc;
+
+use crate::{
+    emath::NumExt, mutex::RwLock, textures::TextureFilter, ImageData, ImageDelta, TextureId,
+    TextureManager,
+};
+
+/// Used to paint images.
+///
+/// An _image_ is pixels stored in RAM, and represented using [`ImageData`].
+/// Before you can paint it however, you need to convert it to a _texture_.
+///
+/// If you are using egui, use `egui::Context::load_texture`.
+///
+/// The [`TextureHandle`] can be cloned cheaply.
+/// When the last [`TextureHandle`] for specific texture is dropped, the texture is freed.
+///
+/// See also [`TextureManager`].
+#[must_use]
+pub struct TextureHandle {
+    tex_mngr: Arc<RwLock<TextureManager>>,
+    id: TextureId,
+}
+
+impl Drop for TextureHandle {
+    fn drop(&mut self) {
+        self.tex_mngr.write().free(self.id);
+    }
+}
+
+impl Clone for TextureHandle {
+    fn clone(&self) -> Self {
+        self.tex_mngr.write().retain(self.id);
+        Self {
+            tex_mngr: self.tex_mngr.clone(),
+            id: self.id,
+        }
+    }
+}
+
+impl PartialEq for TextureHandle {
+    #[inline]
+    fn eq(&self, other: &Self) -> bool {
+        self.id == other.id
+    }
+}
+
+impl Eq for TextureHandle {}
+
+impl std::hash::Hash for TextureHandle {
+    #[inline]
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.id.hash(state);
+    }
+}
+
+impl TextureHandle {
+    /// If you are using egui, use `egui::Context::load_texture` instead.
+    pub fn new(tex_mngr: Arc<RwLock<TextureManager>>, id: TextureId) -> Self {
+        Self { tex_mngr, id }
+    }
+
+    #[inline]
+    pub fn id(&self) -> TextureId {
+        self.id
+    }
+
+    /// Assign a new image to an existing texture.
+    pub fn set(&mut self, image: impl Into<ImageData>, filter: TextureFilter) {
+        self.tex_mngr
+            .write()
+            .set(self.id, ImageDelta::full(image.into(), filter));
+    }
+
+    /// Assign a new image to a subregion of the whole texture.
+    pub fn set_partial(
+        &mut self,
+        pos: [usize; 2],
+        image: impl Into<ImageData>,
+        filter: TextureFilter,
+    ) {
+        self.tex_mngr
+            .write()
+            .set(self.id, ImageDelta::partial(pos, image.into(), filter));
+    }
+
+    /// width x height
+    pub fn size(&self) -> [usize; 2] {
+        self.tex_mngr.read().meta(self.id).unwrap().size
+    }
+
+    /// width x height
+    pub fn size_vec2(&self) -> crate::Vec2 {
+        let [w, h] = self.size();
+        crate::Vec2::new(w as f32, h as f32)
+    }
+
+    /// width / height
+    pub fn aspect_ratio(&self) -> f32 {
+        let [w, h] = self.size();
+        w as f32 / h.at_least(1) as f32
+    }
+
+    /// Debug-name.
+    pub fn name(&self) -> String {
+        self.tex_mngr.read().meta(self.id).unwrap().name.clone()
+    }
+}
+
+impl From<&TextureHandle> for TextureId {
+    #[inline(always)]
+    fn from(handle: &TextureHandle) -> Self {
+        handle.id()
+    }
+}
+
+impl From<&mut TextureHandle> for TextureId {
+    #[inline(always)]
+    fn from(handle: &mut TextureHandle) -> Self {
+        handle.id()
+    }
+}