Add multiview rust shaders

Author: LegNeato

shaders/rust/Cargo.lock

@@ -88,6 +88,8 @@ members = [
     "debugutils/postprocess",
     "debugutils/toon",
     "vertexattributes/scene",
+    "multiview/multiview",
+    "multiview/viewdisplay",
 ]
 
 [workspace.dependencies]

shaders/rust/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "multiview-multiview"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["dylib"]
+
+[dependencies]
+spirv-std = { workspace = true }
+
+[package.metadata.rust-gpu.build]
+capabilities = ["MultiView"]

shaders/rust/multiview/multiview.frag.spv

@@ -0,0 +1,61 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{vec3, vec4, Mat3, Mat4, Vec3, Vec4}, num_traits::Float};
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct Ubo {
+    pub projection: [Mat4; 2],
+    pub modelview: [Mat4; 2],
+    pub light_pos: Vec4,
+}
+
+#[spirv(vertex)]
+pub fn main_vs(
+    in_pos: Vec3,
+    in_normal: Vec3,
+    in_color: Vec3,
+    #[spirv(view_index)] view_index: 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,
+) {
+    *out_color = in_color;
+    *out_normal = Mat3::from_mat4(ubo.modelview[view_index as usize]) * in_normal;
+
+    let pos = vec4(in_pos.x, in_pos.y, in_pos.z, 1.0);
+    let world_pos = ubo.modelview[view_index as usize] * pos;
+    
+    let l_pos = ubo.modelview[view_index as usize] * ubo.light_pos;
+    *out_light_vec = vec3(l_pos.x, l_pos.y, l_pos.z) - vec3(world_pos.x, world_pos.y, world_pos.z);
+    *out_view_vec = -vec3(world_pos.x, world_pos.y, world_pos.z);
+
+    *out_position = ubo.projection[view_index as usize] * world_pos;
+}
+
+#[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(0.1, 0.1, 0.1);
+    let diffuse = n.dot(l).max(0.0) * vec3(1.0, 1.0, 1.0);
+    let specular = r.dot(v).max(0.0).powf(16.0) * vec3(0.75, 0.75, 0.75);
+    *out_color = vec4(
+        (ambient.x + diffuse.x) * in_color.x + specular.x,
+        (ambient.y + diffuse.y) * in_color.y + specular.y,
+        (ambient.z + diffuse.z) * in_color.z + specular.z,
+        1.0
+    );
+}

shaders/rust/multiview/multiview.vert.spv

@@ -0,0 +1,10 @@
+[package]
+name = "multiview-viewdisplay"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["dylib"]
+
+[dependencies]
+spirv-std = { workspace = true }

shaders/rust/multiview/multiview/Cargo.toml

@@ -0,0 +1,49 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{vec2, vec3, vec4, Vec2, Vec4}, Image, image::SampledImage};
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct Ubo {
+    _padding: [Vec4; 17], // offset = 272 bytes = 17 vec4s
+    pub distortion_alpha: f32,
+}
+
+
+#[spirv(vertex)]
+pub fn main_vs(
+    #[spirv(vertex_index)] vertex_index: i32,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_uv: &mut Vec2,
+) {
+    *out_uv = vec2(
+        ((vertex_index << 1) & 2) as f32,
+        (vertex_index & 2) as f32,
+    );
+    let pos_xy = *out_uv * 2.0 - vec2(1.0, 1.0);
+    *out_position = vec4(pos_xy.x, pos_xy.y, 0.0, 1.0);
+}
+
+#[spirv(fragment)]
+pub fn main_fs(
+    in_uv: Vec2,
+    #[spirv(descriptor_set = 0, binding = 1)] sampler_view: &SampledImage<Image!(2D, type=f32, sampled, arrayed)>,
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] ubo: &Ubo,
+    #[spirv(spec_constant(id = 0, default = 0))] view_layer: u32,
+    out_color: &mut Vec4,
+) {
+    let alpha = ubo.distortion_alpha;
+
+    let p1 = 2.0 * in_uv - vec2(1.0, 1.0);
+    let p2 = p1 / (1.0 - alpha * p1.length());
+    let p2 = (p2 + vec2(1.0, 1.0)) * 0.5;
+
+    let inside = p2.x >= 0.0 && p2.x <= 1.0 && p2.y >= 0.0 && p2.y <= 1.0;
+    *out_color = if inside {
+        let layer = if view_layer == 0 { 0.0 } else { 1.0 };
+        sampler_view.sample(vec3(p2.x, p2.y, layer))
+    } else {
+        vec4(0.0, 0.0, 0.0, 0.0)
+    };
+}