Add tessellation rust shaders

Author: LegNeato

shaders/rust/Cargo.lock

@@ -110,6 +110,9 @@ members = [
     "ssao/ssao",
     "stencilbuffer/outline",
     "stencilbuffer/toon",
+    "tessellation/base",
+    "tessellation/passthrough",
+    "tessellation/pntriangles",
     "textoverlay/mesh",
     "textoverlay/text",
     "texture",

shaders/rust/Cargo.toml

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

shaders/rust/tessellation/base.frag.spv

@@ -0,0 +1,40 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{Vec2, Vec3, Vec4}, Image, Sampler};
+
+#[spirv(vertex)]
+pub fn main_vs(
+    in_pos: Vec3,
+    in_normal: Vec3,
+    in_uv: Vec2,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_normal: &mut Vec3,
+    out_uv: &mut Vec2,
+) {
+    *out_position = Vec4::new(in_pos.x, in_pos.y, in_pos.z, 1.0);
+    *out_normal = in_normal;
+    *out_uv = in_uv;
+}
+
+#[spirv(fragment)]
+pub fn main_fs(
+    #[spirv(descriptor_set = 1, binding = 0)] color_sampler: &Sampler,
+    #[spirv(descriptor_set = 1, binding = 0)] color_texture: &Image!(2D, type=f32, sampled),
+    in_normal: Vec3,
+    in_uv: Vec2,
+    out_frag_color: &mut Vec4,
+) {
+    let n = in_normal.normalize();
+    let l = Vec3::new(-4.0, -4.0, 0.0).normalize();
+    
+    let color: Vec4 = color_texture.sample(*color_sampler, in_uv);
+    
+    let lighting = n.dot(l).max(0.0).clamp(0.2, 1.0);
+    *out_frag_color = Vec4::new(
+        lighting * color.x,
+        lighting * color.y,
+        lighting * color.z,
+        color.w
+    );
+}

shaders/rust/tessellation/base.vert.spv

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

shaders/rust/tessellation/base/Cargo.toml

@@ -0,0 +1,63 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{Mat4, Vec2, Vec3, Vec4}};
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct Ubo {
+    pub projection: Mat4,
+    pub model: Mat4,
+    pub tess_alpha: f32,
+    pub tess_level: f32,
+}
+
+#[spirv(tessellation_control(output_vertices = 3))]
+pub fn main_tcs(
+    #[spirv(invocation_id)] invocation_id: u32,
+    #[spirv(position)] in_position: [Vec4; 3],
+    in_normal: [Vec3; 3],
+    in_uv: [Vec2; 3],
+    #[spirv(position)] out_position: &mut [Vec4; 3],
+    out_normal: &mut [Vec3; 3],
+    out_uv: &mut [Vec2; 3],
+    #[spirv(tess_level_inner)] tess_level_inner: &mut [f32; 2],
+    #[spirv(tess_level_outer)] tess_level_outer: &mut [f32; 4],
+) {
+    if invocation_id == 0 {
+        tess_level_inner[0] = 1.0;
+        tess_level_outer[0] = 1.0;
+        tess_level_outer[1] = 1.0;
+        tess_level_outer[2] = 1.0;
+    }
+
+    out_position[invocation_id as usize] = in_position[invocation_id as usize];
+    out_normal[invocation_id as usize] = in_normal[invocation_id as usize];
+    out_uv[invocation_id as usize] = in_uv[invocation_id as usize];
+}
+
+#[spirv(tessellation_evaluation(triangles, spacing_equal, vertex_order_cw))]
+pub fn main_tes(
+    #[spirv(tess_coord)] tess_coord: Vec3,
+    #[spirv(position)] in_position: [Vec4; 3],
+    in_normal: [Vec3; 3],
+    in_uv: [Vec2; 3],
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] ubo: &Ubo,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_normal: &mut Vec3,
+    out_uv: &mut Vec2,
+) {
+    let pos = tess_coord.x * in_position[0] + 
+              tess_coord.y * in_position[1] + 
+              tess_coord.z * in_position[2];
+    
+    *out_position = ubo.projection * ubo.model * pos;
+    
+    *out_normal = tess_coord.x * in_normal[0] + 
+                  tess_coord.y * in_normal[1] + 
+                  tess_coord.z * in_normal[2];
+    
+    *out_uv = tess_coord.x * in_uv[0] + 
+              tess_coord.y * in_uv[1] + 
+              tess_coord.z * in_uv[2];
+}