docs: added more docs

Author: pemattern

examples/tutorial/main.rs

@@ -1,13 +1,29 @@
+use ratatui::style::Style;
 use tui_shader::{ShaderCanvas, ShaderCanvasState, WgslShader};
 
 fn main() {
     let mut terminal = ratatui::init();
-    let shader = WgslShader::Path("shaders/tutorial.wgsl");
-    let mut state = ShaderCanvasState::new(shader);
-    while state.get_instant().elapsed().as_secs() < 7 {
+
+    let balloon_shader = WgslShader::Path("shaders/tutorial.wgsl");
+    let mut balloon_state = ShaderCanvasState::new(balloon_shader);
+    let balloon_canvas = ShaderCanvas::new().style_rule(tui_shader::StyleRule::Map(|sample| {
+        let brightness = (sample.r() as f32 + sample.g() as f32 + sample.b() as f32) / 3.0;
+        if brightness > 127.0 {
+            Style::new().bg(sample.color())
+        } else {
+            Style::default()
+        }
+    }));
+
+    let bg_shader = WgslShader::Path("shaders/gradient.wgsl");
+    let mut bg_state = ShaderCanvasState::new(bg_shader);
+    let bg_canvas = ShaderCanvas::new();
+
+    while balloon_state.get_instant().elapsed().as_secs() < 7 {
         terminal
             .draw(|frame| {
-                frame.render_stateful_widget(ShaderCanvas::new(), frame.area(), &mut state);
+                frame.render_stateful_widget(&bg_canvas, frame.area(), &mut bg_state);
+                frame.render_stateful_widget(&balloon_canvas, frame.area(), &mut balloon_state);
             })
             .unwrap();
     }

shaders/tutorial.wgsl

@@ -2,11 +2,16 @@
 
 @fragment
 fn main(@location(0) uv: vec2<f32>) -> @location(0) vec4<f32> {
-    let r = sin(1.0 - uv.x + time.x);
-    let g = cos(1.0 - uv.y + time.x);
+    let r = sin(1.0 - uv.x + time.x) * 0.5 + 1;
+    let g = -sin(1.0 - uv.y + time.x) * 0.5 + 1;
     let b = 0.5;
+
+    let position = vec2<f32>(
+        0.5 * (sin(time.x * 2.1) * 0.5 + 1),
+        0.5 * (cos(time.x * 1.2) * 0.5 + 1)
+    );
 
-    let d = 1.0 - distance(vec2<f32>(0.5), uv);
+    let d = 1.0 - distance(position, uv);
     let color = vec4<f32>(r, g, b, 1.0) * d;
     return color;
 }

src/lib.rs

@@ -111,6 +111,8 @@ pub use crate::state::*;
 pub use crate::style::*;
 pub use crate::util::*;
 
+pub use wgpu::include_wgsl;
+
 #[cfg(test)]
 mod tests {
     use ratatui::{backend::TestBackend, layout::Position};

src/util.rs

@@ -1,5 +1,11 @@
+/// Utility `enum` to pass in a shader into [`ShaderCanvasState`](crate::ShaderCanvasState). Another option is to use the re-exported
+/// [`include_wgsl!`](wgpu::include_wgsl!) macro, which checks at runtime if the path to the file is valid and returns a
+/// [`ShaderModuleDescriptor`](wgpu::ShaderModuleDescriptor).
 pub enum WgslShader<'a> {
+    /// Use wgsl source code in a `&str`.
     Source(&'a str),
+
+    /// Use a path to a wgsl shader.
     Path(&'a str),
 }
 
@@ -21,7 +27,7 @@ impl<'a> From<WgslShader<'a>> for wgpu::ShaderModuleDescriptor<'a> {
     }
 }
 
-pub type Pixel = [u8; 4];
+pub(crate) type Pixel = [u8; 4];
 
 pub(crate) fn bytes_per_row(width: u32) -> u32 {
     let row_size = width * 4;