Started the alligator_resources project

1 files changed, 92 insertions, 0 deletions

diff --git a/alligator_resources/src/texture.rs b/alligator_resources/src/texture.rs
new file mode 100644
index 0000000..ba0ff47
--- /dev/null
+++ b/alligator_resources/src/texture.rs
@@ -0,0 +1,92 @@
+use std::collections::HashMap;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use exun::{Expect, Expected, Unexpected};
+use thiserror::Error;
+
+static NEXT_TEXTURE_ID: AtomicUsize = AtomicUsize::new(0);
+
+type Rgba16Texture = image::ImageBuffer<image::Rgba<u16>, Box<[u16]>>;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct TextureId(usize);
+
+impl TextureId {
+	fn new() -> Self {
+		Self(NEXT_TEXTURE_ID.fetch_add(1, Ordering::Relaxed))
+	}
+}
+
+/// These are the formats supported by the renderer.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[non_exhaustive]
+pub enum ImageFormat {
+	Bmp,
+	Ico,
+	Farbfeld,
+}
+
+impl From<ImageFormat> for image::ImageFormat {
+	fn from(format: ImageFormat) -> Self {
+		match format {
+			ImageFormat::Bmp => Self::Bmp,
+			ImageFormat::Ico => Self::Ico,
+			ImageFormat::Farbfeld => Self::Farbfeld,
+		}
+	}
+}
+
+#[derive(Debug, Error)]
+#[error("{}", .0)]
+pub struct DecodingError(#[from] image::error::DecodingError);
+
+type LoadError = Expect<DecodingError>;
+
+pub struct TextureManager {
+	textures: HashMap<TextureId, Rgba16Texture>,
+}
+
+#[allow(clippy::missing_const_for_fn)]
+fn convert_image_decoding(e: image::ImageError) -> Expect<DecodingError> {
+	if let image::ImageError::Decoding(de) = e {
+		Expected(de.into())
+	} else {
+		Unexpected(e.into())
+	}
+}
+
+impl TextureManager {
+	#[must_use]
+	pub fn new() -> Self {
+		Self {
+			textures: HashMap::new(),
+		}
+	}
+
+	/// Loads a texture from memory in the given format.
+	///
+	/// # Errors
+	///
+	/// This returns `Expected(DecodingError)` if the given buffer was invalid
+	/// for the given format.
+	#[allow(clippy::missing_panics_doc)]
+	pub fn load_from_memory(
+		&mut self,
+		buf: &[u8],
+		format: ImageFormat,
+	) -> Result<TextureId, LoadError> {
+		let id = TextureId::new();
+		let texture = image::load_from_memory_with_format(buf, format.into())
+			.map_err(convert_image_decoding)?;
+
+		let texture = texture.into_rgb16();
+
+		let width = texture.width();
+		let height = texture.height();
+		let buf = texture.into_raw().into_boxed_slice();
+		let texture = image::ImageBuffer::from_raw(width, height, buf).unwrap();
+		self.textures.insert(id, texture);
+
+		Ok(id)
+	}
+}