From af9783c838a03b54fa6a58d0ae3c739cce20aa17 Mon Sep 17 00:00:00 2001
From: Jamie Wong <jlfwong@figma.com>
Date: Wed, 22 Nov 2017 19:19:10 -0800
Subject: [PATCH] Batch rectangle renderer with regl

---
 flamechart.ts     | 76 +++++++++++++++++++++++++++++++++++++++++++++++
 index.tsx         | 51 ++++++++++++++++++++++++++++++-
 package-lock.json |  5 ++++
 package.json      |  3 ++
 regl.d.ts         | 51 +++++++++++++++++++++++++++++++
 5 files changed, 185 insertions(+), 1 deletion(-)
 create mode 100644 regl.d.ts

diff --git a/flamechart.ts b/flamechart.ts
index 93884a7..11ef3c5 100644
--- a/flamechart.ts
+++ b/flamechart.ts
@@ -1,4 +1,5 @@
 import {Profile, Frame} from './profile'
+import regl, {ReglCommandConstructor} from 'regl'
 
 interface FlamechartFrame {
   frame: Frame
@@ -49,4 +50,79 @@ export class Flamechart {
     profile.forEachSample(this.appendSample.bind(this))
     this.layers = this.layers.map(Flamechart.mergeAdjacentFrames)
   }
+}
+
+interface Rect {
+  left: number
+  top: number
+  width: number
+  height: number
+}
+
+type vec2 = [number, number]
+type vec3 = [number, number, number]
+type mat3 = [number, number, number, number, number, number, number, number, number]
+
+export const rectangleBatchRenderer = (ctx: WebGLRenderingContext, rects: Rect[], colors: vec3[]) => {
+  const gl = regl(ctx)
+
+  const positions: vec2[] = []
+  const vertexColors: vec3[] = []
+
+  const addRectangle = (r: Rect, color: [number, number, number]) => {
+    const NW: [number, number] = [r.left, r.top]
+    const NE: [number, number] = [r.left + r.width, r.top]
+    const SW: [number, number] = [r.left, r.top + r.height]
+    const SE: [number, number] = [r.left + r.width, r.top + r.height]
+
+    positions.push(NW)
+    positions.push(SW)
+    positions.push(NE)
+
+    positions.push(SW)
+    positions.push(NE)
+    positions.push(SE)
+
+    for (let i = 0; i < 6; i++) vertexColors.push(color)
+  }
+
+  for (let i = 0; i < rects.length; i++) addRectangle(rects[i], colors[i])
+
+  return gl<{
+    configSpaceToNDC: mat3
+  }>({
+    vert: `
+      uniform mat3 configSpaceToNDC;
+      attribute vec2 position;
+      attribute vec3 color;
+      varying vec3 vColor;
+      void main() {
+        vColor = color;
+        gl_Position = vec4((configSpaceToNDC * vec3(position, 1)).xy, 0, 1);
+      }
+    `,
+
+    frag: `
+      precision mediump float;
+      varying vec3 vColor;
+      void main() {
+        gl_FragColor = vec4(vColor, 1);
+      }
+    `,
+
+    attributes: {
+      position: positions,
+      color: vertexColors
+    },
+
+    uniforms: {
+      configSpaceToNDC: (context, props) => {
+        return props.configSpaceToNDC
+      }
+    },
+
+    primitive: 'triangles',
+
+    count: colors.length
+  })
 }
\ No newline at end of file
diff --git a/index.tsx b/index.tsx
index 58a3a28..26c7c49 100644
--- a/index.tsx
+++ b/index.tsx
@@ -2,6 +2,53 @@ import {h, render, Component} from 'preact'
 import {StyleSheet, css} from 'aphrodite'
 
 import {importFromStackprof} from './stackprof'
+import {Flamechart, rectangleBatchRenderer} from './flamechart'
+
+import { request } from 'https';
+
+interface Rect {
+  left: number
+  top: number
+  width: number
+  height: number
+}
+
+class Canvas extends Component<{}, void> {
+  canvasRef = (element?: Element) => {
+    if (element) {
+      const rectangles: Rect[] = []
+      const colors: [number, number, number][] = []
+
+      for (let i = 0; i < 1000; i++) {
+        rectangles.push({
+          left: 2 * Math.random() - 1,
+          top: 2 * Math.random() - 1,
+          width: 2 * Math.random(),
+          height: 2 * Math.random(),
+        })
+        colors.push([Math.random(), Math.random(), Math.random()])
+      }
+      const renderer = rectangleBatchRenderer((element as HTMLCanvasElement).getContext('webgl')!, rectangles, colors)
+
+      ;(function doit() {
+        renderer({
+          configSpaceToNDC: [
+            1, 0, 0,
+            0, 1, 0,
+            0, 0, 1,
+          ]
+        })
+        requestAnimationFrame(doit)
+      })()
+    }
+  }
+
+  render() {
+    const width = window.innerWidth
+    const height = window.innerHeight
+    return <canvas width={width} height={height} ref={this.canvasRef} className={css(style.root)}></canvas>
+  }
+}
 
 class Application extends Component<{}, void> {
   onDrop = (ev: DragEvent) => {
@@ -19,6 +66,7 @@ class Application extends Component<{}, void> {
 
   render() {
     return <div onDrop={this.onDrop} onDragOver={this.onDragOver} className={css(style.root)}>
+      <Canvas />
     </div>
   }
 }
@@ -26,7 +74,8 @@ class Application extends Component<{}, void> {
 const style = StyleSheet.create({
   root: {
     width: '100vw',
-    height: '100vw'
+    height: '100vh',
+    overflow: 'hidden'
   }
 })
 
diff --git a/package-lock.json b/package-lock.json
index f4a2d27..1821ef9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -628,6 +628,11 @@
         "is-equal-shallow": "0.1.3"
       }
     },
+    "regl": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/regl/-/regl-1.3.0.tgz",
+      "integrity": "sha1-zN6C7/iooGilWVgc6svvGv6njr0="
+    },
     "remove-trailing-separator": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/remove-trailing-separator/-/remove-trailing-separator-1.1.0.tgz",
diff --git a/package.json b/package.json
index 8ec00a1..d8e6d1e 100644
--- a/package.json
+++ b/package.json
@@ -23,5 +23,8 @@
     "rollup-plugin-replace": "^2.0.0",
     "rollup-plugin-typescript": "^0.8.1",
     "typescript": "^2.6.1"
+  },
+  "dependencies": {
+    "regl": "^1.3.0"
   }
 }
diff --git a/regl.d.ts b/regl.d.ts
new file mode 100644
index 0000000..e9e756d
--- /dev/null
+++ b/regl.d.ts
@@ -0,0 +1,51 @@
+declare module "regl" {
+  interface ReglProp {}
+
+  type ReglPrimitiveValue =
+    boolean |
+    number |
+    number[] |
+    number[][] |
+    ReglProp
+
+  type ReglValue<P> = ReglPrimitiveValue | {(context: any, props: P, batchId: number): ReglPrimitiveValue}
+
+  interface ReglCommandParameters<P> {
+    /** Source code of vertex shader */
+    vert: string
+
+    /** Source code of fragment shader */
+    frag: string
+
+    attributes: {[attributeName: string]: ReglValue<P>}
+
+    uniforms: {[uniformName: string]: ReglValue<P>}
+
+    /** Number of vertices to draw */
+    count: number
+
+    /** */
+    primitive?: 'points' | 'lines' | 'line strip' | 'triangles' | 'triangle strip' | 'triangle fan'
+
+    /** Offset of primitives to draw */
+    offset?: number
+  }
+
+  interface ReglCommand<P> {
+    (p: P): void
+  }
+
+  export interface ReglCommandConstructor {
+    <P>(params: ReglCommandParameters<P>): ReglCommand<P>
+  }
+
+  function ReglConstructor(): ReglCommandConstructor
+  function ReglConstructor(ctx: WebGLRenderingContext): ReglCommandConstructor
+  function ReglConstructor(canvas: HTMLCanvasElement): ReglCommandConstructor
+
+  namespace ReglConstructor {
+    function prop(name: string): ReglProp
+  }
+
+  export default ReglConstructor
+}