Merge pull request #20 from LykenSol/llXSzX

Ported "Moving Square" (https://www.shadertoy.com/view/llXSzX).

Author: eddyb

shaders/src/lib.rs

@@ -18,6 +18,7 @@ pub mod heart;
 pub mod mandelbrot_smooth;
 pub mod miracle_snowflakes;
 pub mod morphing;
+pub mod moving_square;
 pub mod phantom_star;
 pub mod playing_marble;
 pub mod protean_clouds;
@@ -169,6 +170,7 @@ pub fn fs(constants: &ShaderConstants, mut frag_coord: Vec2) -> Vec4 {
             mouse,
         }
         .main_image(&mut color, frag_coord),
+        19 => moving_square::Inputs { resolution, time }.main_image(&mut color, frag_coord),
         _ => {}
     }
     pow(color.truncate(), 2.2).extend(color.w)

shaders/src/moving_square.rs

@@ -0,0 +1,40 @@
+//! Ported to Rust from <https://www.shadertoy.com/view/llXSzX>
+
+use shared::*;
+use spirv_std::glam::{vec3, Mat2, Vec2, Vec3, Vec3Swizzles, Vec4};
+
+// Note: This cfg is incorrect on its surface, it really should be "are we compiling with std", but
+// we tie #[no_std] above to the same condition, so it's fine.
+#[cfg(target_arch = "spirv")]
+use spirv_std::num_traits::Float;
+
+pub struct Inputs {
+    pub resolution: Vec3,
+    pub time: f32,
+}
+
+fn rect(uv: Vec2, pos: Vec2, r: f32) -> Vec4 {
+    let re_c: Vec2 = (uv - pos).abs();
+    let dif1: Vec2 = re_c - Vec2::splat(r / 2.);
+    let dif2: Vec2 = (re_c - Vec2::splat(r / 2.)).clamp(Vec2::zero(), Vec2::one());
+    let d1: f32 = (dif1.x + dif1.y).clamp(0.0, 1.0);
+    let _d2: f32 = (dif2.x + dif2.y).clamp(0.0, 1.0);
+
+    Vec4::splat(d1)
+}
+
+impl Inputs {
+    pub fn main_image(&self, frag_color: &mut Vec4, frag_coord: Vec2) {
+        let mut uv: Vec2 = frag_coord;
+        let t: f32 = self.time.sin();
+
+        let c: Vec2 = self.resolution.xy() * 0.5; // + sin(iTime) * 50.;
+
+        uv = Mat2::from_cols_array(&[t.cos(), -t.sin(), t.sin(), t.cos()]) * (uv - c) + c;
+
+        *frag_color = rect(uv, c, (self.time * 10.).sin() * 50. + 50.);
+        *frag_color *= vec3(0.5, 0.2, 1.).extend(1.);
+        *frag_color += rect(uv, c, self.time.sin() * 50. + 50.);
+        *frag_color *= vec3(0.5, 0.8, 1.).extend(1.);
+    }
+}

shared/src/lib.rs

@@ -81,6 +81,12 @@ impl Clamp for f32 {
     }
 }
 
+impl Clamp for Vec2 {
+    fn clamp(self, min: Self, max: Self) -> Self {
+        self.max(min).min(max)
+    }
+}
+
 impl Clamp for Vec3 {
     fn clamp(self, min: Self, max: Self) -> Self {
         self.max(min).min(max)