Add descriptorindexing rust shader

Author: LegNeato

shaders/rust/Cargo.lock

@@ -26,6 +26,7 @@ members = [
     "deferred/deferred",
     "deferred/mrt",
     "descriptorbuffer/cube",
+    "descriptorindexing",
     "descriptorsets/cube",
     "distancefieldfonts/bitmap",
     "distancefieldfonts/sdf",

shaders/rust/Cargo.toml

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

shaders/rust/descriptorindexing/Cargo.toml

@@ -0,0 +1,42 @@
+#![no_std]
+
+use spirv_std::spirv;
+use spirv_std::{glam::{vec4, Mat4, Vec2, Vec3, Vec4}, Image, RuntimeArray};
+use spirv_std::image::SampledImage;
+
+#[repr(C)]
+pub struct Matrices {
+    pub projection: Mat4,
+    pub view: Mat4,
+    pub model: Mat4,
+}
+
+#[spirv(vertex)]
+pub fn main_vs(
+    #[spirv(vertex_index)] _vertex_index: i32,
+    in_pos: Vec3,
+    in_uv: Vec2,
+    in_texture_index: i32,
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] matrices: &Matrices,
+    #[spirv(position)] out_pos: &mut Vec4,
+    out_uv: &mut Vec2,
+    #[spirv(flat)] out_tex_index: &mut i32,
+) {
+    *out_uv = in_uv;
+    *out_tex_index = in_texture_index;
+    let pos = vec4(in_pos.x, in_pos.y, in_pos.z, 1.0);
+    *out_pos = matrices.projection * matrices.view * matrices.model * pos;
+}
+
+#[spirv(fragment)]
+pub fn main_fs(
+    in_uv: Vec2,
+    #[spirv(flat)] in_tex_index: i32,
+    #[spirv(descriptor_set = 0, binding = 1)] textures: &RuntimeArray<SampledImage<Image!(2D, type=f32, sampled)>>,
+    out_frag_color: &mut Vec4,
+) {
+    unsafe {
+        let texture = textures.index(in_tex_index as usize);
+        *out_frag_color = texture.sample(in_uv);
+    }
+}