librashader/librashader-runtime/src/image.rs
2023-01-13 18:23:31 -05:00

83 lines
2.1 KiB
Rust

pub use image::ImageError;
use librashader_common::Size;
use std::marker::PhantomData;
use std::path::Path;
/// An uncompressed raw image ready to upload to GPU buffers.
pub struct Image<P: PixelFormat = RGBA8> {
/// The raw bytes of the image.
pub bytes: Vec<u8>,
/// The size dimensions of the image.
pub size: Size<u32>,
/// The byte pitch of the image.
pub pitch: usize,
_pd: PhantomData<P>,
}
/// R8G8B8A8 pixel format.
///
/// Every RGB with alpha pixel is represented with 32 bits.
pub struct RGBA8;
/// B8G8R8A8 pixel format.
///
/// Every BGR with alpha pixel is represented with 32 bits.
pub struct BGRA8;
/// Represents an image pixel format to convert images into.
pub trait PixelFormat {
#[doc(hidden)]
fn convert(pixels: &mut Vec<u8>);
}
impl PixelFormat for RGBA8 {
fn convert(_pixels: &mut Vec<u8>) {}
}
impl PixelFormat for BGRA8 {
fn convert(pixels: &mut Vec<u8>) {
for [r, _g, b, _a] in pixels.array_chunks_mut::<4>() {
std::mem::swap(b, r)
}
}
}
/// The direction of UV coordinates to load the image for.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum UVDirection {
/// Origin is at the top left (Direct3D, Vulkan)
TopLeft,
/// Origin is at the bottom left (OpenGL)
BottomLeft,
}
impl<P: PixelFormat> Image<P> {
/// Load the image from the path as RGBA8.
pub fn load(path: impl AsRef<Path>, direction: UVDirection) -> Result<Self, ImageError> {
let mut image = image::open(path.as_ref())?;
if direction == UVDirection::BottomLeft {
image = image.flipv();
}
let image = image.to_rgba8();
let height = image.height();
let width = image.width();
let pitch = image
.sample_layout()
.height_stride
.max(image.sample_layout().width_stride);
let mut bytes = image.into_raw();
P::convert(&mut bytes);
Ok(Image {
bytes,
pitch,
size: Size { height, width },
_pd: Default::default(),
})
}
}