Wire live serial data into matrix renderer

src/render.rs

@@ -6,10 +6,13 @@ use eframe::{
 
 use crate::matrix::{MatrixLayout, build_view_projection, glyph_world_position};
 
+pub const PRESSURE_CELL_COUNT: usize =
+    (crate::matrix::MATRIX_ROWS * crate::matrix::MATRIX_COLS) as usize;
+
 pub struct WgpuBackgroundCallback {
     pub width: f32,
     pub height: f32,
-    pub time: f32,
+    pub pressure: [f32; PRESSURE_CELL_COUNT],
 }
 
 impl egui_wgpu::CallbackTrait for WgpuBackgroundCallback {
@@ -22,7 +25,7 @@ impl egui_wgpu::CallbackTrait for WgpuBackgroundCallback {
         resources: &mut egui_wgpu::CallbackResources,
     ) -> Vec<wgpu::CommandBuffer> {
         let resources: &mut BackgroundRenderResources = resources.get_mut().unwrap();
-        resources.prepare(queue, self.width, self.height, self.time);
+        resources.prepare(queue, self.width, self.height, &self.pressure);
 
         Vec::new()
     }
@@ -123,7 +126,7 @@ impl BackgroundRenderResources {
             usage: wgpu::BufferUsages::VERTEX,
         });
 
-        let glyph_instances = build_glyph_instances(rows, cols, &layout, 0.0);
+        let glyph_instances = build_glyph_instances(rows, cols, &layout, &[]);
         let glyph_instance_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: Some("Pressure Glyph Instance Buffer"),
             contents: bytemuck::cast_slice(&glyph_instances),
@@ -145,7 +148,7 @@ impl BackgroundRenderResources {
         }
     }
 
-    fn prepare(&mut self, queue: &wgpu::Queue, width: f32, height: f32, time: f32) {
+    fn prepare(&mut self, queue: &wgpu::Queue, width: f32, height: f32, pressure: &[f32]) {
         let aspect = width / height.max(1.0);
         self.uniform =
             MatrixUniform::new(width, height, build_view_projection(aspect, &self.layout));
@@ -155,7 +158,13 @@ impl BackgroundRenderResources {
             bytemuck::cast_slice(&[self.uniform]),
         );
 
-        self.glyph_instances = build_glyph_instances(self.rows, self.cols, &self.layout, time);
+        update_glyph_instances(
+            &mut self.glyph_instances,
+            self.rows,
+            self.cols,
+            &self.layout,
+            pressure,
+        );
         queue.write_buffer(
             &self.glyph_instance_buffer,
             0,
@@ -246,14 +255,16 @@ fn build_glyph_instances(
     rows: u32,
     cols: u32,
     layout: &MatrixLayout,
-    time: f32,
+    pressure: &[f32],
 ) -> Vec<GlyphInstance> {
     let mut instances = Vec::with_capacity((rows * cols) as usize);
 
     for row in 0..rows {
         for col in 0..cols {
+            let index = (row * cols + col) as usize;
+            let normalized = pressure.get(index).copied().unwrap_or(0.0);
             let (world_position, normalized) =
-                glyph_world_position(row, col, rows, cols, layout, time);
+                glyph_world_position(row, col, rows, cols, layout, normalized);
             instances.push(GlyphInstance {
                 world_position,
                 style: [normalized, 0.0, 0.0, 0.0],
@@ -264,6 +275,27 @@ fn build_glyph_instances(
     instances
 }
 
+fn update_glyph_instances(
+    instances: &mut [GlyphInstance],
+    rows: u32,
+    cols: u32,
+    layout: &MatrixLayout,
+    pressure: &[f32],
+) {
+    for row in 0..rows {
+        for col in 0..cols {
+            let index = (row * cols + col) as usize;
+            let normalized = pressure.get(index).copied().unwrap_or(0.0);
+            let (world_position, normalized) =
+                glyph_world_position(row, col, rows, cols, layout, normalized);
+            if let Some(instance) = instances.get_mut(index) {
+                instance.world_position = world_position;
+                instance.style = [normalized, 0.0, 0.0, 0.0];
+            }
+        }
+    }
+}
+
 #[repr(C)]
 #[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
 struct MatrixUniform {