Add distancefieldfonts rust shaders

Author: LegNeato

shaders/rust/Cargo.lock

@@ -75,6 +75,8 @@ members = [
     "descriptorbuffer/cube",
     "dynamicrendering/texture",
     "computeparticles/particle",
+    "distancefieldfonts/bitmap",
+    "distancefieldfonts/sdf",
 ]
 
 [workspace.dependencies]

shaders/rust/Cargo.toml

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

shaders/rust/distancefieldfonts/bitmap.frag.spv

@@ -0,0 +1,34 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{vec4, Mat4, Vec2, Vec3, Vec4}, Image};
+use spirv_std::image::SampledImage;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct Ubo {
+    pub projection: Mat4,
+    pub model: Mat4,
+}
+
+#[spirv(vertex)]
+pub fn main_vs(
+    in_pos: Vec3,
+    in_uv: Vec2,
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] ubo: &Ubo,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_uv: &mut Vec2,
+) {
+    *out_uv = in_uv;
+    *out_position = ubo.projection * ubo.model * vec4(in_pos.x, in_pos.y, in_pos.z, 1.0);
+}
+
+#[spirv(fragment)]
+pub fn main_fs(
+    in_uv: Vec2,
+    #[spirv(descriptor_set = 0, binding = 1)] sampler_color: &SampledImage<Image!(2D, type=f32, sampled)>,
+    out_frag_color: &mut Vec4,
+) {
+    let alpha = sampler_color.sample(in_uv).w;
+    *out_frag_color = vec4(alpha, alpha, alpha, alpha);
+}

shaders/rust/distancefieldfonts/bitmap.vert.spv

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

shaders/rust/distancefieldfonts/bitmap/Cargo.toml

@@ -0,0 +1,54 @@
+#![cfg_attr(target_arch = "spirv", no_std)]
+#![allow(clippy::missing_safety_doc)]
+
+use spirv_std::{spirv, glam::{vec3, vec4, Mat4, Vec2, Vec3, Vec4}, Image};
+use spirv_std::image::SampledImage;
+use spirv_std::arch::Derivative;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct Ubo {
+    pub projection: Mat4,
+    pub model: Mat4,
+    pub outline_color: Vec4,
+    pub outline_width: f32,
+    pub outline: f32,
+}
+
+#[spirv(vertex)]
+pub fn main_vs(
+    in_pos: Vec3,
+    in_uv: Vec2,
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] ubo: &Ubo,
+    #[spirv(position)] out_position: &mut Vec4,
+    out_uv: &mut Vec2,
+) {
+    *out_uv = in_uv;
+    *out_position = ubo.projection * ubo.model * vec4(in_pos.x, in_pos.y, in_pos.z, 1.0);
+}
+
+fn smooth_step(edge0: f32, edge1: f32, x: f32) -> f32 {
+    let t = ((x - edge0) / (edge1 - edge0)).clamp(0.0, 1.0);
+    t * t * (3.0 - 2.0 * t)
+}
+
+#[spirv(fragment)]
+pub fn main_fs(
+    in_uv: Vec2,
+    #[spirv(uniform, descriptor_set = 0, binding = 0)] ubo: &Ubo,
+    #[spirv(descriptor_set = 0, binding = 1)] sampler_color: &SampledImage<Image!(2D, type=f32, sampled)>,
+    out_frag_color: &mut Vec4,
+) {
+    let distance = sampler_color.sample(in_uv).w;
+    let smooth_width = distance.fwidth();
+    let mut alpha = smooth_step(0.5 - smooth_width, 0.5 + smooth_width, distance);
+    let mut rgb = vec3(alpha, alpha, alpha);
+    
+    if ubo.outline > 0.0 {
+        let w = 1.0 - ubo.outline_width;
+        alpha = smooth_step(w - smooth_width, w + smooth_width, distance);
+        rgb += rgb.lerp(ubo.outline_color.truncate(), alpha);
+    }
+    
+    *out_frag_color = vec4(rgb.x, rgb.y, rgb.z, alpha);
+}