[−][src]Crate crevice

Crevice creates GLSL-compatible versions of types through the power of derive macros. Generated structs implement bytemuck::Zeroable and bytemuck::Pod to ease packing data into buffers for uploading.

Crevice is similar to glsl-layout, but supports mint types and explicitly initializes padding to remove one source of undefined behavior.

Examples in this crate use cgmath, but any math crate that works with the mint crate will also work. Some other crates include nalgebra, ultraviolet, glam, and vek.

Examples

Single Value

Uploading many types can be done by deriving AsStd140 and using the bytemuck crate to turn the result into bytes.

uniform MAIN {
    mat3 orientation;
    vec3 position;
    float scale;
} main;

use crevice::std140::AsStd140;
use cgmath::prelude::*;
use cgmath::{Matrix3, Vector3};

#[derive(AsStd140)]
struct MainUniform {
    orientation: mint::ColumnMatrix3<f32>,
    position: mint::Vector3<f32>,
    scale: f32,
}

let value = MainUniform {
    orientation: Matrix3::identity().into(),
    position: Vector3::new(1.0, 2.0, 3.0).into(),
    scale: 4.0,
};

let value_std140 = value.as_std140();

upload_data_to_gpu(bytemuck::bytes_of(&value_std140));

Sequential Types

More complicated data can be uploaded using the std140 Writer type.

struct PointLight {
    vec3 position;
    vec3 color;
    float brightness;
};

buffer POINT_LIGHTS {
    uint len;
    PointLight[] lights;
} point_lights;

use crevice::std140::{self, AsStd140};

#[derive(AsStd140)]
struct PointLight {
    position: mint::Vector3<f32>,
    color: mint::Vector3<f32>,
    brightness: f32,
}

let lights = vec![
    PointLight {
        position: [0.0, 1.0, 0.0].into(),
        color: [1.0, 0.0, 0.0].into(),
        brightness: 0.6,
    },
    PointLight {
        position: [0.0, 4.0, 3.0].into(),
        color: [1.0, 1.0, 1.0].into(),
        brightness: 1.0,
    },
];

let target_buffer = map_gpu_buffer_for_write();
let mut writer = std140::Writer::new(target_buffer);

let light_count = lights.len() as u32;
writer.write(&light_count)?;

// Crevice will automatically insert the required padding to align the
// PointLight structure correctly. In this case, there will be 12 bytes of
// padding between the length field and the light list.

for light in &lights {
    writer.write(light)?;

    // Crevice will also pad between each array element.
}

unmap_gpu_buffer();

[−][src]Crate crevice

Examples

Single Value

Sequential Types

Minimum Supported Rust Version (MSRV)

Re-exports

Modules