raekna-ui 0.1.0

use std::iter;

use winit::window::Window;

use super::{buffers::Buffers, controls::Controls, text_painter::TextPainter};
use crate::{
    constants::BACKGROUND_COLOR,
    coordinator::{content::Content, dimensions::Dimensions},
    graphics::vertex::Vertex,
};

pub struct Renderer {
    surface: wgpu::Surface,
    pub device: wgpu::Device,
    queue: wgpu::Queue,
    config: wgpu::SurfaceConfiguration,
    pub size: winit::dpi::PhysicalSize<u32>,
    render_pipeline: wgpu::RenderPipeline,
    text_painter: TextPainter,
    buffers: Buffers,
}

impl Renderer {
    pub async fn new(window: &Window, controls: &Controls) -> Self {
        let size = window.inner_size();

        // The instance is a handle to our GPU
        // BackendBit::PRIMARY => Vulkan + Metal + DX12 + Browser WebGPU
        let instance = wgpu::Instance::new(wgpu::Backends::all());
        let surface = unsafe { instance.create_surface(window) };
        let adapter = instance
            .request_adapter(&wgpu::RequestAdapterOptions {
                power_preference: wgpu::PowerPreference::default(),
                compatible_surface: Some(&surface),
                force_fallback_adapter: false,
            })
            .await
            .unwrap();

        let (device, queue) = adapter
            .request_device(
                &wgpu::DeviceDescriptor {
                    label: None,
                    features: wgpu::Features::empty(),
                    limits: wgpu::Limits::default(),
                },
                None, // Trace path
            )
            .await
            .unwrap();

        let render_format = surface.get_preferred_format(&adapter).unwrap();
        let config = wgpu::SurfaceConfiguration {
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
            format: render_format,
            width: size.width,
            height: size.height,
            present_mode: wgpu::PresentMode::Fifo,
        };
        surface.configure(&device, &config);

        let shader = device.create_shader_module(&wgpu::ShaderModuleDescriptor {
            label: Some("Shader"),
            source: wgpu::ShaderSource::Wgsl(include_str!("shaders/shader.wgsl").into()),
        });

        let render_pipeline_layout =
            device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
                label: Some("Render Pipeline Layout"),
                bind_group_layouts: &[],
                push_constant_ranges: &[],
            });

        let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
            label: Some("Render Pipeline"),
            layout: Some(&render_pipeline_layout),
            vertex: wgpu::VertexState {
                module: &shader,
                entry_point: "vs_main",
                buffers: &[Vertex::desc()],
            },
            fragment: Some(wgpu::FragmentState {
                module: &shader,
                entry_point: "fs_main",
                targets: &[wgpu::ColorTargetState {
                    format: config.format,
                    blend: Some(wgpu::BlendState {
                        color: wgpu::BlendComponent::REPLACE,
                        alpha: wgpu::BlendComponent::REPLACE,
                    }),
                    write_mask: wgpu::ColorWrites::ALL,
                }],
            }),
            primitive: wgpu::PrimitiveState {
                topology: wgpu::PrimitiveTopology::TriangleList,
                strip_index_format: None,
                front_face: wgpu::FrontFace::Ccw,
                cull_mode: Some(wgpu::Face::Back),
                // Setting this to anything other than Fill requires Features::NON_FILL_POLYGON_MODE
                polygon_mode: wgpu::PolygonMode::Fill,
                // Requires Features::DEPTH_CLAMPING
                unclipped_depth: false,
                // Requires Features::CONSERVATIVE_RASTERIZATION
                conservative: false,
            },
            depth_stencil: None,
            multisample: wgpu::MultisampleState {
                count: 1,
                mask: !0,
                alpha_to_coverage_enabled: false,
            },
            multiview: None,
        });

        let text_painter = TextPainter::new(&size, &device, render_format);

        let buffers = controls.get_as_buffers(&device);

        Self {
            surface,
            device,
            queue,
            config,
            size,
            render_pipeline,
            text_painter,
            buffers,
        }
    }

    pub fn resize(&mut self, new_size: winit::dpi::PhysicalSize<u32>) {
        if new_size.width > 0 && new_size.height > 0 {
            self.size = new_size;
            self.config.width = new_size.width;
            self.config.height = new_size.height;
            self.surface.configure(&self.device, &self.config);
            self.text_painter.resize(&new_size);
        }
    }

    pub fn update(&mut self, controls: &Controls) {
        self.buffers = controls.get_as_buffers(&self.device);
    }

    pub fn render(
        &mut self,
        content: &Content,
        dimensions: &Dimensions,
    ) -> Result<(), wgpu::SurfaceError> {
        let output = self.surface.get_current_texture()?;
        let view = output
            .texture
            .create_view(&wgpu::TextureViewDescriptor::default());

        let mut encoder = self
            .device
            .create_command_encoder(&wgpu::CommandEncoderDescriptor {
                label: Some("Render Encoder"),
            });

        {
            let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                label: Some("Render Pass"),
                color_attachments: &[wgpu::RenderPassColorAttachment {
                    view: &view,
                    resolve_target: None,
                    ops: wgpu::Operations {
                        load: wgpu::LoadOp::Clear(BACKGROUND_COLOR),
                        store: true,
                    },
                }],
                depth_stencil_attachment: None,
            });

            render_pass.set_pipeline(&self.render_pipeline);
            let Buffers {
                ref vertex_buffer,
                ref index_buffer,
                num_indices,
            } = self.buffers;
            render_pass.set_vertex_buffer(0, vertex_buffer.slice(..));
            render_pass.set_index_buffer(index_buffer.slice(..), wgpu::IndexFormat::Uint16);
            render_pass.draw_indexed(0..num_indices, 0, 0..1);
        }

        self.text_painter
            .draw(&self.device, &view, &mut encoder, content, dimensions);

        self.queue.submit(iter::once(encoder.finish()));
        output.present();

        Ok(())
    }
}