Pool/src/render/eye.rs

use crate::render::{MaterialProperties, SimpleTexture};
use bytemuck::{Pod, Zeroable};
use glam::camera::lh::proj::directx::perspective;
use glam::{Affine3A, EulerRot, Mat3A, Mat4, Vec3, Vec4};
use wgpu::util::DeviceExt;
use wgpu::{Device, Queue};

pub(crate) struct Eye {
    pub(crate) frame: Affine3A,
    pub(crate) environment: Environment,
    aspect_ratio: f32,
    z_near: f32,
    z_far: f32,
    fov_y: f32,
    pub(crate) environment_buffer: wgpu::Buffer,
    pub(crate) camera_buffer: wgpu::Buffer,
    pub(crate) layout: wgpu::BindGroupLayout,
    pub(crate) group: wgpu::BindGroup,
}

#[repr(C)]
#[derive(Pod, Copy, Clone, Zeroable)]
pub struct Environment {
    ambient: Vec4,
    light: Vec4,
    dir: Vec4,
}

impl Eye {
    pub(crate) fn write(&mut self, queue: &Queue) {
        let camera = Mat4::from_mat3_translation(
            self.frame.matrix3.into(),
            Vec3::from(self.frame.translation),
        );
        let projection = perspective(self.fov_y, self.aspect_ratio, self.z_near, self.z_far);
        queue.write_buffer(
            &self.camera_buffer,
            0,
            bytemuck::cast_slice(&[
                projection,
                camera * projection.inverse(),
                camera.inverse(),
                camera,
            ]),
        );
        queue.write_buffer(
            &self.environment_buffer,
            0,
            bytemuck::cast_slice(&[self.environment]),
        );
    }
    pub(crate) fn new(device: &Device, width: u32, height: u32, skybox: SimpleTexture) -> Eye {
        let camera_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: Some("Camera Buffer"),
            contents: bytemuck::cast_slice(&[
                Mat4::from_translation(Vec3::new(0.0, 2.0, -8.0)),
                Mat4::IDENTITY,
                Mat4::IDENTITY,
                Mat4::IDENTITY,
            ]),
            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
        });

        let dir = Vec3::new(1.0, 0.5, 1.0).normalize();
        let environment = Environment {
            ambient: Vec4::new(0.15, 0.15, 0.15, 0.0),
            light: Vec4::new(1.0, 1.0, 1.0, 0.0),
            dir: Vec4::new(dir.x, dir.y, dir.z, 0.0),
        };

        let environment_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: Some(""),
            contents: bytemuck::cast_slice(&[environment]),
            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
        });

        let layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
            entries: &[
                wgpu::BindGroupLayoutEntry {
                    binding: 0,
                    visibility: wgpu::ShaderStages::VERTEX_FRAGMENT,
                    ty: wgpu::BindingType::Buffer {
                        ty: wgpu::BufferBindingType::Uniform,
                        has_dynamic_offset: false,
                        min_binding_size: None,
                    },
                    count: None,
                },
                wgpu::BindGroupLayoutEntry {
                    binding: 1,
                    visibility: wgpu::ShaderStages::FRAGMENT,
                    ty: wgpu::BindingType::Buffer {
                        ty: wgpu::BufferBindingType::Uniform,
                        has_dynamic_offset: false,
                        min_binding_size: None,
                    },
                    count: None,
                },
                wgpu::BindGroupLayoutEntry {
                    binding: 2,
                    visibility: wgpu::ShaderStages::FRAGMENT,
                    ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
                    count: None,
                },
                wgpu::BindGroupLayoutEntry {
                    binding: 3,
                    visibility: wgpu::ShaderStages::FRAGMENT,
                    ty: wgpu::BindingType::Texture {
                        multisampled: false,
                        view_dimension: wgpu::TextureViewDimension::D2,
                        sample_type: wgpu::TextureSampleType::Float { filterable: true },
                    },
                    count: None,
                },
            ],
            label: Some("eye_bind_group_layout"),
        });

        let group = Eye::bind_group(&layout, device, &camera_buffer, &environment_buffer, skybox);

        Eye {
            aspect_ratio: width as f32 / height as f32,
            frame: Affine3A::IDENTITY,
            fov_y: 90.0,
            z_near: 0.1,
            z_far: 1000.0,
            camera_buffer,
            group,
            layout,
            environment,
            environment_buffer,
        }
    }
    fn bind_group(
        layout: &wgpu::BindGroupLayout,
        device: &wgpu::Device,
        camera: &wgpu::Buffer,
        environment: &wgpu::Buffer,
        skybox: SimpleTexture,
    ) -> wgpu::BindGroup {
        device.create_bind_group(&wgpu::BindGroupDescriptor {
            layout: &layout,
            entries: &[
                wgpu::BindGroupEntry {
                    binding: 0,
                    resource: camera.as_entire_binding(),
                },
                wgpu::BindGroupEntry {
                    binding: 1,
                    resource: environment.as_entire_binding(),
                },
                wgpu::BindGroupEntry {
                    binding: 2,
                    resource: wgpu::BindingResource::Sampler(
                        &MaterialProperties::default().sampler(device),
                    ),
                },
                wgpu::BindGroupEntry {
                    binding: 3,
                    resource: wgpu::BindingResource::TextureView(&skybox.view),
                },
            ],
            label: Some("eye_bind_group"),
        })
    }
    pub fn skybox(&mut self, device: &wgpu::Device, texture: SimpleTexture) {
        self.group = Eye::bind_group(
            &self.layout,
            device,
            &self.camera_buffer,
            &self.environment_buffer,
            texture,
        )
    }
    pub(crate) fn resize(&mut self, width: u32, height: u32) {
        self.aspect_ratio = width as f32 / height as f32
    }
    pub(crate) fn control(&mut self, delta: Vec3) {
        self.frame *= Affine3A::from_translation(delta);
    }
    pub(crate) fn rotate(&mut self, yaw: f32, pitch: f32) {
        let (mut y, mut x, z) = self.frame.matrix3.to_euler(EulerRot::YXZ);
        x = (x + pitch * 0.005).clamp(-1.4, 1.4);
        y += yaw * 0.005;
        self.frame.matrix3 = Mat3A::from_euler(EulerRot::YXZ, y, x, z);
    }
}