From 6082b5a6a988352f5d48eb59f49040048abfd12f Mon Sep 17 00:00:00 2001
From: Rafael Araujo Lehmkuhl <rafael.lehmkuhl93@gmail.com>
Date: Thu, 19 Oct 2023 04:02:56 -0300
Subject: [PATCH] Add `VirtualHorizon` widget

---
 src/components/widgets/VirtualHorizon.vue | 206 ++++++++++++++++++++++
 src/types/widgets.ts                      |   1 +
 src/views/WidgetsView.vue                 |   4 +
 3 files changed, 211 insertions(+)
 create mode 100644 src/components/widgets/VirtualHorizon.vue

diff --git a/src/components/widgets/VirtualHorizon.vue b/src/components/widgets/VirtualHorizon.vue
new file mode 100644
index 000000000..09d5e3c84
--- /dev/null
+++ b/src/components/widgets/VirtualHorizon.vue
@@ -0,0 +1,206 @@
+<template>
+  <div ref="virtualHorizonRoot" class="virtualHorizon">
+    <canvas
+      ref="canvasRef"
+      :height="smallestDimension"
+      :width="smallestDimension"
+      class="rounded-[15%] bg-slate-950/70"
+    ></canvas>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { useElementSize } from '@vueuse/core'
+import gsap from 'gsap'
+import { computed, ref } from 'vue'
+
+import { degrees, radians, resetCanvas } from '@/libs/utils'
+import { useMainVehicleStore } from '@/stores/mainVehicle'
+
+const store = useMainVehicleStore()
+const virtualHorizonRoot = ref()
+const canvasRef = ref<HTMLCanvasElement | undefined>()
+const canvasContext = ref()
+
+// Object used to store current render state
+const renderVariables = {
+  pitchAngleDegrees: 0,
+  rollAngleDegrees: 0,
+}
+
+// Calculates the smallest between the widget dimensions, so we can keep the inner content always inside it, without overlays
+const { width, height } = useElementSize(virtualHorizonRoot)
+const smallestDimension = computed(() => (width.value < height.value ? width.value : height.value))
+
+// Renders the updated canvas state
+const renderCanvas = (): void => {
+  if (canvasRef.value === undefined) return
+  if (canvasContext.value === undefined) canvasContext.value = canvasRef.value.getContext('2d')
+  const ctx = canvasContext.value
+  resetCanvas(ctx)
+
+  const halfCanvasSize = 0.5 * smallestDimension.value
+
+  // Set canvas general properties
+  const fontSize = 0.06 * smallestDimension.value
+  const baseLineWidth = 0.03 * halfCanvasSize
+
+  ctx.textAlign = 'center'
+  ctx.strokeStyle = 'white'
+  ctx.font = `bold ${fontSize}px Arial`
+  ctx.fillStyle = 'white'
+  ctx.lineWidth = baseLineWidth
+  ctx.textBaseline = 'middle'
+
+  const outerCircleRadius = 0.7 * halfCanvasSize
+
+  // Start drawing from the center
+  ctx.translate(halfCanvasSize, halfCanvasSize)
+
+  // Set 0 degrees on the top position
+  ctx.rotate(radians(-90))
+
+  ctx.rotate(radians(90))
+
+  // Draw outer circle
+  ctx.save()
+  ctx.strokeStyle = 'white'
+  ctx.lineWidth = 1.5 * baseLineWidth
+  ctx.beginPath()
+  ctx.arc(0, 0, outerCircleRadius, 0, radians(360))
+  ctx.stroke()
+  ctx.restore()
+
+  ctx.save()
+
+  ctx.rotate(radians(-1 * renderVariables.rollAngleDegrees))
+
+  // Draw circular clipping mask
+  ctx.beginPath()
+  ctx.arc(0, 0, outerCircleRadius, 0, radians(360))
+  ctx.clip()
+
+  const pitchGainFactor = 4
+  const zeroPitchLineHeight = pitchGainFactor * (renderVariables.pitchAngleDegrees / 90) * outerCircleRadius
+
+  // Draw virtual horizon ground and sky
+  ctx.fillStyle = 'rgb(69, 144, 190)'
+  ctx.fillRect(-1.5 * outerCircleRadius, zeroPitchLineHeight, +3 * outerCircleRadius, -3 * outerCircleRadius)
+  ctx.fillStyle = 'rgb(152, 104, 76)'
+  ctx.fillRect(-1.5 * outerCircleRadius, zeroPitchLineHeight, +3 * outerCircleRadius, 3 * outerCircleRadius)
+
+  // Draw virtual horizon moving line
+  ctx.lineWidth = 0.6 * baseLineWidth
+  ctx.strokeStyle = 'white'
+  ctx.beginPath()
+  ctx.moveTo(-0.75 * outerCircleRadius, zeroPitchLineHeight)
+  ctx.lineTo(-0.45 * outerCircleRadius, zeroPitchLineHeight)
+  ctx.lineTo(-0.43 * outerCircleRadius, zeroPitchLineHeight + 0.07 * outerCircleRadius)
+  ctx.moveTo(0.75 * outerCircleRadius, zeroPitchLineHeight)
+  ctx.lineTo(0.45 * outerCircleRadius, zeroPitchLineHeight)
+  ctx.lineTo(0.43 * outerCircleRadius, zeroPitchLineHeight + 0.07 * outerCircleRadius)
+  ctx.stroke()
+
+  // Draw pitch lines
+  ctx.save()
+  ctx.fillStyle = 'white'
+  ctx.strokeStyle = 'white'
+  ctx.lineWidth = 0.5 * baseLineWidth
+  ctx.font = `bold ${fontSize}px Arial`
+  for (const angle of [-10, 0, 10]) {
+    const lineSizeMultiplier = pitchGainFactor * Math.abs(angle / 300) || 0.15
+    const pitchLineHeight = pitchGainFactor * (angle / 90) * outerCircleRadius
+    const smallerPitchLineHeight = pitchGainFactor * ((angle - 5 * Math.sign(angle)) / 90) * outerCircleRadius
+    ctx.beginPath()
+    ctx.moveTo(-lineSizeMultiplier * outerCircleRadius, pitchLineHeight)
+    ctx.lineTo(+lineSizeMultiplier * outerCircleRadius, pitchLineHeight)
+    ctx.moveTo(-0.5 * lineSizeMultiplier * outerCircleRadius, smallerPitchLineHeight)
+    ctx.lineTo(+0.5 * lineSizeMultiplier * outerCircleRadius, smallerPitchLineHeight)
+    ctx.stroke()
+    ctx.textAlign = 'right'
+    ctx.fillText(`${Math.abs(angle)}`, -1 * (lineSizeMultiplier * outerCircleRadius + 0.3 * fontSize), pitchLineHeight)
+    ctx.textAlign = 'left'
+    ctx.fillText(`${Math.abs(angle)}`, 1 * (lineSizeMultiplier * outerCircleRadius + 0.3 * fontSize), pitchLineHeight)
+  }
+  ctx.restore()
+
+  ctx.restore()
+
+  // Draw current horizon fixed reference lines
+  ctx.save()
+  ctx.lineWidth = 0.8 * baseLineWidth
+  ctx.rotate(radians(-1 * renderVariables.rollAngleDegrees))
+  ctx.beginPath()
+  ctx.moveTo(-1 * outerCircleRadius, 0)
+  ctx.lineTo(-0.85 * outerCircleRadius, 0)
+  ctx.moveTo(0.85 * outerCircleRadius, 0)
+  ctx.lineTo(1 * outerCircleRadius, 0)
+  ctx.stroke()
+  ctx.restore()
+
+  // Draw current roll fixed reference lines
+  for (const angle of [-60, -45, -30, -20, -10, 0, 10, 20, 30, 45, 60]) {
+    ctx.save()
+    ctx.rotate(radians(angle))
+    ctx.beginPath()
+    if ([-60, -30, 30, 60].includes(angle)) {
+      ctx.lineWidth = 0.8 * baseLineWidth
+      ctx.moveTo(0, -1.2 * outerCircleRadius)
+      ctx.lineTo(0, -1 * outerCircleRadius)
+    } else if ([-20, -10, 10, 20].includes(angle)) {
+      ctx.lineWidth = 0.6 * baseLineWidth
+      ctx.moveTo(0, -1.1 * outerCircleRadius)
+      ctx.lineTo(0, -1 * outerCircleRadius)
+    } else if ([-45, 45].includes(angle)) {
+      ctx.lineWidth = 0.01 * baseLineWidth
+      ctx.moveTo(0, -1.01 * outerCircleRadius)
+      ctx.lineTo(-0.05 * outerCircleRadius, -1.15 * outerCircleRadius)
+      ctx.lineTo(+0.05 * outerCircleRadius, -1.15 * outerCircleRadius)
+      ctx.lineTo(0, -1.01 * outerCircleRadius)
+    } else if (angle === 0) {
+      ctx.lineWidth = 0.01 * baseLineWidth
+      ctx.moveTo(0, -1.01 * outerCircleRadius)
+      ctx.lineTo(-0.07 * outerCircleRadius, -1.25 * outerCircleRadius)
+      ctx.lineTo(+0.07 * outerCircleRadius, -1.25 * outerCircleRadius)
+      ctx.lineTo(0, -1.01 * outerCircleRadius)
+    }
+    ctx.stroke()
+    ctx.fill()
+    ctx.restore()
+  }
+
+  // Draw virtual roll moving triangle
+  ctx.save()
+  ctx.beginPath()
+  ctx.rotate(radians(90))
+  ctx.rotate(radians(-1 * renderVariables.rollAngleDegrees))
+  ctx.lineWidth = 0.01 * baseLineWidth
+  ctx.fillStyle = 'rgb(221, 43, 43)'
+  ctx.moveTo(-1 * outerCircleRadius, 0)
+  ctx.lineTo(-0.8 * outerCircleRadius, -0.08 * outerCircleRadius)
+  ctx.lineTo(-0.8 * outerCircleRadius, 0.08 * outerCircleRadius)
+  ctx.lineTo(-1 * outerCircleRadius, 0)
+  ctx.stroke()
+  ctx.fill()
+  ctx.restore()
+}
+
+// Update canvas at 60fps
+setInterval(() => {
+  gsap.to(renderVariables, 0.1, {
+    pitchAngleDegrees: degrees(store.attitude.pitch ?? 0),
+    rollAngleDegrees: degrees(store.attitude.roll ?? 0),
+  })
+  renderCanvas()
+}, 1000 / 60)
+</script>
+
+<style scoped>
+.virtualHorizon {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 100%;
+  height: 100%;
+}
+</style>
diff --git a/src/types/widgets.ts b/src/types/widgets.ts
index f4403c0a2..71c619fc6 100644
--- a/src/types/widgets.ts
+++ b/src/types/widgets.ts
@@ -17,6 +17,7 @@ export enum WidgetType {
   MiniWidgetsBar = 'MiniWidgetsBar',
   URLVideoPlayer = 'URLVideoPlayer',
   VideoPlayer = 'VideoPlayer',
+  VirtualHorizon = 'VirtualHorizon',
 }
 
 export type Widget = {
diff --git a/src/views/WidgetsView.vue b/src/views/WidgetsView.vue
index 1c850b98c..3268eff98 100644
--- a/src/views/WidgetsView.vue
+++ b/src/views/WidgetsView.vue
@@ -42,6 +42,9 @@
           <template v-if="widget.component === WidgetType.VideoPlayer">
             <VideoPlayer :widget="widget" />
           </template>
+          <template v-if="widget.component === WidgetType.VirtualHorizon">
+            <VirtualHorizon :widget="widget" />
+          </template>
           <!-- TODO: Use the line below instead of the 12 lines above -->
           <!-- <component :is="componentFromType(widget.component)"></component> -->
         </WidgetHugger>
@@ -70,6 +73,7 @@ import Map from '../components/widgets/Map.vue'
 import MiniWidgetsBar from '../components/widgets/MiniWidgetsBar.vue'
 import URLVideoPlayer from '../components/widgets/URLVideoPlayer.vue'
 import VideoPlayer from '../components/widgets/VideoPlayer.vue'
+import VirtualHorizon from '../components/widgets/VirtualHorizon.vue'
 
 const store = useWidgetManagerStore()