Add viewportarray rust shaders

Author: LegNeato

shaders/rust/Cargo.lock

@@ -128,6 +128,8 @@ members = [
     "texturemipmapgen/texture",
     "triangle",
     "vertexattributes/scene",
+    "viewportarray/scene",
+    "viewportarray/multiview",
     "vulkanscene/logo",
     "vulkanscene/mesh",
     "vulkanscene/skybox",

shaders/rust/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "viewportarray-multiview"
+version = "0.1.0"
+edition.workspace = true
+
+[lib]
+crate-type = ["dylib"]
+
+[dependencies]
+spirv-std = { workspace = true }
+
+[package.metadata.rust-gpu.build]
+capabilities = ["Geometry", "ShaderViewportIndex", "MultiViewport"]

shaders/rust/viewportarray/multiview.geom.spv

@@ -0,0 +1,53 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{Mat3, Mat4, Vec3, Vec4}};
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct Ubo {
+    pub projection: [Mat4; 2],
+    pub modelview: [Mat4; 2],
+    pub light_pos: Vec4,
+}
+
+#[spirv(geometry(triangles = 3, output_triangle_strip = 3, invocations = 2))]
+pub fn main_gs(
+    #[spirv(position)] in_position: [Vec4; 3],
+    in_normal: [Vec3; 3],
+    in_color: [Vec3; 3],
+    #[spirv(invocation_id)] invocation_id: u32,
+    #[spirv(primitive_id)] primitive_id_in: u32,
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] ubo: &Ubo,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_normal: &mut Vec3,
+    out_color: &mut Vec3,
+    out_view_vec: &mut Vec3,
+    out_light_vec: &mut Vec3,
+    #[spirv(viewport_index, flat)] out_viewport_index: &mut u32,
+    #[spirv(primitive_id, flat)] out_primitive_id: &mut u32,
+) {
+    let inv_id = invocation_id as usize;
+    
+    for i in 0..3 {
+        *out_normal = Mat3::from_mat4(ubo.modelview[inv_id]) * in_normal[i];
+        *out_color = in_color[i];
+        
+        let pos = in_position[i];
+        let world_pos = ubo.modelview[inv_id] * pos;
+        
+        let l_pos = (ubo.modelview[inv_id] * ubo.light_pos).truncate();
+        *out_light_vec = l_pos - world_pos.truncate();
+        *out_view_vec = -world_pos.truncate();
+        
+        *out_position = ubo.projection[inv_id] * world_pos;
+        
+        // Set the viewport index that the vertex will be emitted to
+        *out_viewport_index = invocation_id;
+        *out_primitive_id = primitive_id_in;
+        
+        unsafe { spirv_std::arch::emit_vertex() };
+    }
+    
+    unsafe { spirv_std::arch::end_primitive() };
+}

shaders/rust/viewportarray/multiview/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "viewportarray-scene"
+version = "0.1.0"
+edition.workspace = true
+
+[lib]
+crate-type = ["dylib"]
+
+[dependencies]
+spirv-std = { workspace = true }

shaders/rust/viewportarray/multiview/src/lib.rs

@@ -0,0 +1,42 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{Vec3, Vec4}};
+use spirv_std::num_traits::Float;
+
+#[spirv(vertex)]
+pub fn main_vs(
+    in_pos: Vec3,
+    in_normal: Vec3,
+    in_color: Vec3,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_normal: &mut Vec3,
+    out_color: &mut Vec3,
+) {
+    *out_color = in_color;
+    *out_normal = in_normal;
+    *out_position = Vec4::new(in_pos.x, in_pos.y, in_pos.z, 1.0);
+}
+
+#[spirv(fragment)]
+pub fn main_fs(
+    in_normal: Vec3,
+    in_color: Vec3,
+    in_view_vec: Vec3,
+    in_light_vec: Vec3,
+    out_color: &mut Vec4,
+) {
+    let n = in_normal.normalize();
+    let l = in_light_vec.normalize();
+    let v = in_view_vec.normalize();
+    let r = (-l).reflect(n);
+    let ambient = Vec3::splat(0.1);
+    let diffuse = n.dot(l).max(0.0) * Vec3::ONE;
+    let specular = r.dot(v).max(0.0).powf(16.0) * Vec3::splat(0.75);
+    *out_color = Vec4::new(
+        ((ambient + diffuse) * in_color + specular).x,
+        ((ambient + diffuse) * in_color + specular).y,
+        ((ambient + diffuse) * in_color + specular).z,
+        1.0
+    );
+}