From 5386b8bee9deadbe0ed476c2213ade7ca9f972d7 Mon Sep 17 00:00:00 2001
From: Zack Buhman <zack@buhman.org>
Date: Thu, 30 Jul 2026 12:12:24 -0500
Subject: [PATCH] flat renderer

---
 flat.js   | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 flat.wgsl |  42 +++++++++++++++++++++
 index.js  |  11 ++++--
 3 files changed, 158 insertions(+), 4 deletions(-)
 create mode 100644 flat.js
 create mode 100644 flat.wgsl

diff --git a/flat.js b/flat.js
new file mode 100644
index 0000000..11f6926
--- /dev/null
+++ b/flat.js
@@ -0,0 +1,109 @@
+import { getPath } from "./common.js";
+
+class FlatRenderer {
+  constructor(device, canvasFormat, viewUniformBuffer, shaderModule)
+  {
+    const label = "flat";
+
+    //////////////////////////////////////////////////////////////////////
+    // buffer
+    //////////////////////////////////////////////////////////////////////
+
+    const array = new Uint16Array(6);
+    array[0] = 0;
+    array[1] = 1;
+    array[2] = 2;
+    array[3] = 0;
+    array[4] = 3;
+    array[5] = 1;
+
+    this.buffer = device.createBuffer({
+      label: `${label} renderer buffer`,
+      size: array.byteLength,
+      usage: GPUBufferUsage.INDEX | GPUBufferUsage.COPY_DST,
+    });
+
+    device.queue.writeBuffer(this.buffer, 0, array, 0, array.length);
+
+    //////////////////////////////////////////////////////////////////////
+    // pipeline
+    //////////////////////////////////////////////////////////////////////
+
+    const bindGroupLayouts = [
+      device.createBindGroupLayout({
+        label: `${label} view matrix bind group layout`,
+        entries: [{
+          binding: 0,
+          visibility: GPUShaderStage.VERTEX,
+          buffer: { type: "uniform" }
+        }]
+      }),
+    ];
+
+    const pipelineLayout = device.createPipelineLayout({
+      label: `${label} pipeline layout`,
+      bindGroupLayouts: bindGroupLayouts,
+    });
+
+    this.renderPipeline = device.createRenderPipeline({
+      label: `${label} pipeline`,
+      layout: pipelineLayout,
+      vertex: {
+        module: shaderModule,
+        entryPoint: "vertexMain",
+      },
+      fragment: {
+        module: shaderModule,
+        entryPoint: "fragmentMain",
+        targets: [{
+          format: canvasFormat,
+        }]
+      },
+      primitive: {
+        topology: "triangle-list",
+      },
+      depthStencil: {
+        depthWriteEnabled: true,
+        depthCompare: "less",
+        format: "depth24plus",
+      },
+    });
+
+    //////////////////////////////////////////////////////////////////////
+    // bind group
+    //////////////////////////////////////////////////////////////////////
+
+    this.bindGroups = [
+      device.createBindGroup({
+        label: `${label} bind group`,
+        layout: bindGroupLayouts[0],
+        entries: [{
+          binding: 0,
+          resource: { buffer: viewUniformBuffer },
+        }],
+      }),
+    ];
+  }
+
+  render(renderPass)
+  {
+    renderPass.setPipeline(this.renderPipeline);
+    renderPass.setIndexBuffer(this.buffer, "uint16");
+    renderPass.setBindGroup(0, this.bindGroups[0]);
+    renderPass.drawIndexed(6);
+  }
+}
+
+async function loadFlat(device, canvasFormat, viewUniformBuffer)
+{
+  const flatWgsl = await getPath("flat.wgsl");
+  const shaderModule = device.createShaderModule({
+    label: "flag shader",
+    code: flatWgsl,
+  });
+
+  const renderer = new FlatRenderer(device, canvasFormat, viewUniformBuffer, shaderModule);
+  return renderer;
+}
+
+export { loadFlat };
diff --git a/flat.wgsl b/flat.wgsl
new file mode 100644
index 0000000..a9bc02e
--- /dev/null
+++ b/flat.wgsl
@@ -0,0 +1,42 @@
+struct Configuration {
+  viewProj: mat4x4f,
+  lightViewProj: mat4x4f,
+  lightPosition: vec4f,
+  eyePosition: vec4f,
+};
+
+@group(0) @binding(0) var<uniform> config: Configuration;
+
+struct VertexInput {
+  @builtin(vertex_index) vertex_index: u32,
+};
+
+struct VertexOutput {
+  @builtin(position) position: vec4f,
+  @location(0) texture: vec2f,
+};
+
+const vertices = array(
+  vec2f(1.0, 0.0),
+  vec2f(0.0, 1.0),
+  vec2f(0.0, 0.0),
+  vec2f(1.0, 1.0),
+);
+
+@vertex
+fn vertexMain(input: VertexInput) -> VertexOutput
+{
+  let texture = vertices[input.vertex_index];
+  let position = vec4f(texture * 2.0 - 1.0, 0.0, 1.0);
+
+  var output: VertexOutput;
+  output.position = position;
+  output.texture = texture;
+  return output;
+}
+
+@fragment
+fn fragmentMain(input: VertexOutput) -> @location(0) vec4f
+{
+  return vec4(input.texture, 0.0, 1.0);
+}
diff --git a/index.js b/index.js
index 2c2a6b7..f89c2a1 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,7 @@
 import { getPath } from "./common.js";
 import { loadGltf } from "./index2.js";
 import { loadLight } from "./light.js";
+import { loadFlat } from "./flat.js";
 
 if (!navigator.gpu) {
   throw new Error("WebGPU not supported on this browser.");
@@ -95,8 +96,9 @@ const cameraStateAddress = module.instance.exports.mem_alloc(cameraStateSize);
 
 module.instance.exports.camera_init(cameraStateAddress);
 
-const gltfRenderer = await loadGltf(device, canvasFormat, viewUniformBuffer, memory, module);
-const lightRenderer = await loadLight(device, canvasFormat, viewUniformBuffer);
+//const gltfRenderer = await loadGltf(device, canvasFormat, viewUniformBuffer, memory, module);
+//const lightRenderer = await loadLight(device, canvasFormat, viewUniformBuffer);
+const flatRenderer = await loadFlat(device, canvasFormat, viewUniformBuffer);
 
 
 const KEY = {
@@ -219,8 +221,9 @@ function render2()
       },
     });
 
-    gltfRenderer.render(renderPass);
-    lightRenderer.render(renderPass);
+    //gltfRenderer.render(renderPass);
+    //lightRenderer.render(renderPass);
+    flatRenderer.render(renderPass);
 
     renderPass.end();