Kickstart a new rewrite of the raidillon engine

Endless refactors, refactor everyday, refactor relentlessly, refactor
every morning, every day, every hour.

raidillon_glium/src/assets.rs

@@ -0,0 +1,30 @@
+use raidillon_platform::AssetManager;
+use crate::model::Model;
+use std::path::Path;
+use raidillon_platform::assets::ModelHandle;
+use crate::gltf_loader::load_gltf;
+use glium::backend::Facade;
+use std::collections::HashMap;
+
+/// Glium platform asset manager implementation.
+pub struct GliumAssetManager {
+    models: Vec<Option<Model>>,
+    facade: Box<dyn Facade>,
+    next_model_id: usize,
+}
+
+impl AssetManager for GliumAssetManager {
+    fn load_gltf(&mut self, path: &Path) -> ModelHandle {
+        let model_id = self.next_model_id;
+        let model = load_gltf(path, self.facade.as_ref()).unwrap();
+        self.models.push(Some(model));
+        self.next_model_id += 1;
+        model_id
+    }
+
+    fn unload_model(&mut self, model_handle: ModelHandle) {
+        if model_handle < self.models.len() {
+            self.models[model_handle] = None;
+        }
+    }
+}

raidillon_glium/src/gltf_loader.rs

@@ -0,0 +1,170 @@
+use anyhow::{Context, Result};
+use glium::{backend::Facade, IndexBuffer, VertexBuffer};
+use glium::index::PrimitiveType;
+use std::{fmt::Debug, path::Path};
+use crate::model::{Vertex, Mesh, Material, Model};
+use glium::texture::{RawImage2d, Texture2d, SrgbTexture2d};
+use glium::uniforms::{SamplerWrapFunction, MinifySamplerFilter, MagnifySamplerFilter};
+use gltf::image::Format as GltfFormat;
+use glam::Vec2;
+
+/// Load a glTF 2.0 file from disk and upload the first primitive to the GPU.
+pub fn load_gltf<P>(path: P, facade: &dyn Facade) -> Result<Model>
+where
+    P: AsRef<Path> + Debug,
+{
+    // -- parse the asset & bring buffer blobs into memory --
+    let (doc, buffers, images) = gltf::import(path.as_ref()).context("failed to import glTF file")?;
+
+    // -- grab the very first mesh / primitive --
+    let mesh      = doc.meshes().next().context("glTF has no meshes")?;
+    let primitive = mesh.primitives().next().context("mesh has no primitives")?;
+
+    // ---------- MATERIAL ----------
+    let mut mat = Material::default();
+
+    let mat_idx  = primitive.material().index().context("primitive has no material")?;
+    let material = doc.materials().nth(mat_idx).unwrap();
+    let pbr      = material.pbr_metallic_roughness();
+
+    // Factors --------------------------------------------------
+    mat.base_color_factor = pbr.base_color_factor();
+    mat.metal_factor      = pbr.metallic_factor();
+    mat.roughness_factor  = pbr.roughness_factor();
+    mat.emissive_factor   = material.emissive_factor();
+
+    // Helper to update sampler settings from glTF sampler
+    fn update_sampler(mat: &mut Material, t: &gltf::texture::Texture<'_>) {
+        let sampler_info = t.sampler();
+        mat.sampler.wrap_function.0 = match sampler_info.wrap_s() {
+            gltf::texture::WrappingMode::ClampToEdge => SamplerWrapFunction::Clamp,
+            gltf::texture::WrappingMode::MirroredRepeat => SamplerWrapFunction::Mirror,
+            gltf::texture::WrappingMode::Repeat => SamplerWrapFunction::Repeat,
+        };
+        mat.sampler.wrap_function.1 = match sampler_info.wrap_t() {
+            gltf::texture::WrappingMode::ClampToEdge => SamplerWrapFunction::Clamp,
+            gltf::texture::WrappingMode::MirroredRepeat => SamplerWrapFunction::Mirror,
+            gltf::texture::WrappingMode::Repeat => SamplerWrapFunction::Repeat,
+        };
+        if let Some(f) = sampler_info.mag_filter() {
+            mat.sampler.magnify_filter = match f {
+                gltf::texture::MagFilter::Nearest => MagnifySamplerFilter::Nearest,
+                gltf::texture::MagFilter::Linear => MagnifySamplerFilter::Linear,
+            };
+        }
+        if let Some(f) = sampler_info.min_filter() {
+            mat.sampler.minify_filter = match f {
+                gltf::texture::MinFilter::Nearest => MinifySamplerFilter::Nearest,
+                gltf::texture::MinFilter::Linear => MinifySamplerFilter::Linear,
+                gltf::texture::MinFilter::NearestMipmapNearest => MinifySamplerFilter::NearestMipmapNearest,
+                gltf::texture::MinFilter::NearestMipmapLinear => MinifySamplerFilter::NearestMipmapLinear,
+                gltf::texture::MinFilter::LinearMipmapNearest => MinifySamplerFilter::LinearMipmapNearest,
+                gltf::texture::MinFilter::LinearMipmapLinear => MinifySamplerFilter::LinearMipmapLinear,
+            };
+        }
+    }
+
+    // Base-color texture (sRGB)
+    if let Some(info) = pbr.base_color_texture() {
+        update_sampler(&mut mat, &info.texture());
+        let view = info.texture().source().index();
+        mat.base_color = Some(glium_srgb_texture(facade, &images[view])?);
+    }
+
+    // Metallic-Roughness (linear)
+    if let Some(info) = pbr.metallic_roughness_texture() {
+        update_sampler(&mut mat, &info.texture());
+        let view = info.texture().source().index();
+        mat.metallic_roughness = Some(glium_linear_texture(facade, &images[view])?);
+    }
+
+    // Normal map (linear)
+    if let Some(info) = primitive.material().normal_texture() {
+        update_sampler(&mut mat, &info.texture());
+        let view = info.texture().source().index();
+        mat.normal = Some(glium_linear_texture(facade, &images[view])?);
+    }
+
+    // Occlusion (linear)
+    if let Some(info) = primitive.material().occlusion_texture() {
+        update_sampler(&mut mat, &info.texture());
+        let view = info.texture().source().index();
+        mat.occlusion = Some(glium_linear_texture(facade, &images[view])?);
+    }
+
+    // Emissive (sRGB)
+    if let Some(info) = primitive.material().emissive_texture() {
+        update_sampler(&mut mat, &info.texture());
+        let view = info.texture().source().index();
+        mat.emissive = Some(glium_srgb_texture(facade, &images[view])?);
+    }
+
+    // KHR_texture_transform
+    if let Some(tex) = pbr.base_color_texture() {
+        if let Some(xform) = tex.texture_transform() {
+            mat.uv_offset = Vec2::new(xform.offset()[0], xform.offset()[1]);
+            mat.uv_scale  = Vec2::new(xform.scale()[0],  xform.scale()[1]);
+        }
+    }
+
+    // ---- Vertex/index data ----
+    let reader = primitive.reader(|buf| Some(&buffers[buf.index()].0));
+
+    let positions: Vec<[f32; 3]> = reader.read_positions().context("missing POSITION")?.collect();
+    let normals:   Vec<[f32; 3]> = reader.read_normals().context("missing NORMAL")?.collect();
+    let tex_coords: Vec<[f32; 2]> = reader.read_tex_coords(0).map(|tc| tc.into_f32().collect()).unwrap_or_else(|| vec![[0.0, 0.0]; positions.len()]);
+    let indices:   Vec<u32> = reader.read_indices().context("missing indices")?.into_u32().collect();
+
+    // Interleave
+    let vertices: Vec<Vertex> = (0..positions.len()).map(|i| Vertex { position: positions[i], normal: normals[i], tex_coords: tex_coords[i] }).collect();
+
+    let vbuf = VertexBuffer::immutable(facade, &vertices)?;
+    let ibuf = IndexBuffer ::immutable(facade, PrimitiveType::TrianglesList, &indices)?;
+
+    Ok(Model { mesh: Mesh { vbuf, ibuf }, material: mat })
+}
+
+/// Linear-space texture (RGBA8) from glTF image data.
+fn glium_linear_texture(facade: &dyn Facade, img: &gltf::image::Data) -> Result<Texture2d>
+{
+    let rgba = to_rgba(img);
+    let raw = RawImage2d::from_raw_rgba(rgba, (img.width, img.height));
+    Ok(Texture2d::new(facade, raw)?)
+}
+
+/// sRGB texture from glTF image data.
+fn glium_srgb_texture(facade: &dyn Facade, img: &gltf::image::Data) -> Result<SrgbTexture2d>
+{
+    let rgba = to_rgba(img);
+    let raw = RawImage2d::from_raw_rgba(rgba, (img.width, img.height));
+    Ok(SrgbTexture2d::new(facade, raw)?)
+}
+
+/// Convert various glTF image formats to RGBA8 as expected by glium.
+fn to_rgba(img: &gltf::image::Data) -> Vec<u8> {
+    match img.format {
+        GltfFormat::R8G8B8A8 => img.pixels.clone(),
+        GltfFormat::R8G8B8 => {
+            // Expand RGB to RGBA with alpha=255
+            img.pixels
+                .chunks(3)
+                .flat_map(|rgb| [rgb[0], rgb[1], rgb[2], 255u8])
+                .collect()
+        }
+        GltfFormat::R8G8 => {
+            // Treat RG as luminance+alpha? For simplicity, replicate first channel into RGB, second as alpha.
+            img.pixels
+                .chunks(2)
+                .flat_map(|rg| [rg[0], rg[0], rg[0], rg[1]])
+                .collect()
+        }
+        GltfFormat::R8 => {
+            // Grayscale: replicate into RGB, alpha=255
+            img.pixels
+                .iter()
+                .flat_map(|l| [*l, *l, *l, 255u8])
+                .collect()
+        }
+        _ => img.pixels.clone(),
+    }
+}

raidillon_glium/src/lib.rs

@@ -0,0 +1,7 @@
+pub mod platform;
+pub mod assets;
+pub mod model;
+pub mod gltf_loader;
+
+pub use assets::GliumAssetManager;
+pub use platform::GliumPlatform;

raidillon_glium/src/model.rs

@@ -0,0 +1,57 @@
+use glium::{IndexBuffer, VertexBuffer, implement_vertex};
+use glium::texture::{SrgbTexture2d, Texture2d};
+use glium::uniforms::SamplerBehavior;
+use glam::{Vec2};
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+#[derive(Copy, Clone)]
+pub struct Vertex {
+    pub position:   [f32; 3],
+    pub normal:     [f32; 3],
+    pub tex_coords: [f32; 2],
+}
+implement_vertex!(Vertex, position, normal, tex_coords);
+
+pub struct Mesh {
+    pub vbuf: VertexBuffer<Vertex>,
+    pub ibuf: IndexBuffer<u32>,
+}
+
+pub struct Material {
+    pub base_color:         Option<SrgbTexture2d>,
+    pub metallic_roughness: Option<Texture2d>,
+    pub normal:             Option<Texture2d>,
+    pub occlusion:          Option<Texture2d>,
+    pub emissive:           Option<SrgbTexture2d>,
+    pub sampler: SamplerBehavior,
+    pub uv_offset: Vec2,
+    pub uv_scale:  Vec2,
+    pub base_color_factor:   [f32; 4],
+    pub emissive_factor:     [f32; 3],
+    pub metal_factor:        f32,
+    pub roughness_factor:    f32,
+}
+
+impl Default for Material {
+    fn default() -> Self {
+        Self {
+            base_color: None,
+            metallic_roughness: None,
+            normal: None,
+            occlusion: None,
+            emissive: None,
+            sampler: SamplerBehavior::default(),
+            uv_offset: Vec2::ZERO,
+            uv_scale:  Vec2::ONE,
+            base_color_factor: [1.0; 4],
+            emissive_factor:   [0.0; 3],
+            metal_factor:      1.0,
+            roughness_factor:  1.0,
+        }
+    }
+}
+
+pub struct Model {
+    pub mesh: Mesh,
+    pub material: Material,
+}

raidillon_glium/src/platform.rs

@@ -0,0 +1,31 @@
+use raidillon_platform::Platform;
+use glium::winit::event_loop::EventLoop;
+use glium::winit::window::Window;
+use glium::backend::glutin::Display;
+use glium::glutin::surface::WindowSurface;
+use glium::backend::glutin::SimpleWindowBuilder;
+
+pub struct GliumPlatform {
+    event_loop: EventLoop<()>,
+    window: Window,
+    display: Display<WindowSurface>,
+}
+
+impl Platform for GliumPlatform {
+    fn initialize(title: String, width: u32, height: u32) -> Self {
+        let event_loop = glium::winit::event_loop::EventLoop::builder()
+            .build()
+            .expect("create event-loop");
+
+        let (window, display) = SimpleWindowBuilder::new()
+            .with_title(title.as_str())
+            .with_inner_size(width, height)
+            .build(&event_loop);
+
+        Self {
+            event_loop,
+            window,
+            display
+        }
+    }
+}