From cf2bc46718b46de8105ae52a0f6c9539bef6c051 Mon Sep 17 00:00:00 2001
From: Rafael Araujo Lehmkuhl <rafael.lehmkuhl93@gmail.com>
Date: Thu, 28 Sep 2023 16:55:04 -0300
Subject: [PATCH] `Compass`: face-lift widget using canvas

---
 src/components/widgets/Compass.vue | 181 +++++++++++++++++++++++------
 1 file changed, 146 insertions(+), 35 deletions(-)

diff --git a/src/components/widgets/Compass.vue b/src/components/widgets/Compass.vue
index 708fdc397..32737e7d6 100644
--- a/src/components/widgets/Compass.vue
+++ b/src/components/widgets/Compass.vue
@@ -1,17 +1,11 @@
 <template>
-  <div class="compass">
-    <img
-      :class="{ rotated: widget.options.headingStyle === HeadingStyle.HEAD_UP }"
-      class="compass-ticks"
-      src="@/assets/nautic-compass.svg"
-      draggable="false"
-    />
-    <img
-      :class="{ rotated: widget.options.headingStyle === HeadingStyle.NORTH_UP }"
-      class="boat"
-      src="@/assets/boat.svg"
-      draggable="false"
-    />
+  <div ref="compassRoot" class="compass">
+    <canvas
+      ref="canvasRef"
+      :height="smallestDimension"
+      :width="smallestDimension"
+      class="rounded-[15%] bg-slate-950/70"
+    ></canvas>
   </div>
   <Dialog v-model:show="widget.managerVars.configMenuOpen" class="w-72">
     <div class="w-full h-full">
@@ -26,16 +20,37 @@
 </template>
 
 <script setup lang="ts">
-import { computed, onBeforeMount, toRefs } from 'vue'
+import { useElementSize } from '@vueuse/core'
+import gsap from 'gsap'
+import { computed, onBeforeMount, ref, toRefs } from 'vue'
 
 import Dialog from '@/components/Dialog.vue'
 import Dropdown from '@/components/Dropdown.vue'
+import { degrees, radians, resetCanvas, sequentialArray } from '@/libs/utils'
 import { useMainVehicleStore } from '@/stores/mainVehicle'
 import type { Widget } from '@/types/widgets'
 
 const store = useMainVehicleStore()
+const compassRoot = ref()
+const canvasRef = ref<HTMLCanvasElement | undefined>()
+const canvasContext = ref()
 
-const angleStyle = computed(() => `${store.attitude.yaw ?? 0}rad`)
+// Object used to store current render state
+const renderVariables = {
+  yawAngleDegrees: 0,
+}
+
+// Angles used for the main marks
+const mainAngles = {
+  [0]: 'N',
+  [45]: 'NE',
+  [90]: 'E',
+  [135]: 'SE',
+  [180]: 'S',
+  [225]: 'SW',
+  [270]: 'W',
+  [315]: 'NW',
+}
 
 /**
  * Possible compass configurations.
@@ -64,30 +79,126 @@ onBeforeMount(() => {
     }
   }
 })
+
+// Calculates the smallest between the widget dimensions, so we can keep the inner content always inside it, without overlays
+const { width, height } = useElementSize(compassRoot)
+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 = 0.13 * 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
+  const innerIndicatorRadius = 0.4 * halfCanvasSize
+  const outerIndicatorRadius = 0.55 * halfCanvasSize
+
+  // Start drawing from the center
+  ctx.translate(halfCanvasSize, halfCanvasSize)
+
+  // Draw central angle text
+  ctx.font = `bold ${fontSize}px Arial`
+  ctx.fillText(`${renderVariables.yawAngleDegrees.toFixed(0)}°`, 0.15 * fontSize, 0)
+
+  // Set 0 degrees on the top position
+  ctx.rotate(radians(-90))
+
+  // Draw line and identification for each cardinal and sub-cardinal angle
+  for (const [angleDegrees, angleName] of Object.entries(mainAngles)) {
+    ctx.save()
+
+    ctx.rotate(radians(Number(angleDegrees)))
+    ctx.beginPath()
+    ctx.moveTo(outerIndicatorRadius, 0)
+    ctx.lineTo(outerCircleRadius, 0)
+
+    // Draw angle text
+    ctx.textBaseline = 'bottom'
+    ctx.font = `bold ${0.7 * fontSize}px Arial`
+    ctx.translate(outerCircleRadius * 1.025, 0)
+    ctx.rotate(radians(90))
+    ctx.fillText(angleName, 0, 0)
+
+    ctx.stroke()
+    ctx.restore()
+  }
+
+  // Draw line for each smaller angle, with 9 degree steps
+  for (const angleDegrees of sequentialArray(360)) {
+    if (angleDegrees % 9 !== 0) continue
+    ctx.save()
+    ctx.lineWidth = 0.25 * baseLineWidth
+    ctx.rotate(radians(Number(angleDegrees)))
+    ctx.beginPath()
+    ctx.moveTo(1.1 * outerIndicatorRadius, 0)
+    ctx.lineTo(outerCircleRadius, 0)
+    ctx.stroke()
+    ctx.restore()
+  }
+
+  // Draw outer circle
+  ctx.beginPath()
+  ctx.arc(0, 0, outerCircleRadius, 0, radians(360))
+  ctx.stroke()
+
+  // Draw central indicator
+  ctx.rotate(radians(renderVariables.yawAngleDegrees))
+  ctx.beginPath()
+  ctx.lineWidth = 1
+  ctx.strokeStyle = 'red'
+  ctx.fillStyle = 'red'
+  const triangleBaseSize = 0.05 * halfCanvasSize
+  ctx.moveTo(innerIndicatorRadius, triangleBaseSize)
+  ctx.lineTo(outerIndicatorRadius - 0.5 * triangleBaseSize, 0)
+  ctx.lineTo(innerIndicatorRadius, -triangleBaseSize)
+  ctx.lineTo(innerIndicatorRadius, triangleBaseSize)
+  ctx.closePath()
+  ctx.fill()
+  ctx.stroke()
+}
+
+// Update canvas at 60fps
+setInterval(() => {
+  const angleDegrees = degrees(store.attitude.yaw ?? 0)
+  const fullRangeAngleDegrees = angleDegrees < 0 ? angleDegrees + 360 : angleDegrees
+
+  const fromWestToEast = renderVariables.yawAngleDegrees > 270 && fullRangeAngleDegrees < 90
+  const fromEastToWest = renderVariables.yawAngleDegrees < 90 && fullRangeAngleDegrees > 270
+  // If cruzing 0 degrees, use a chained animation, so the pointer does not turn 360 degrees to the other side (visual artifact)
+  if (fromWestToEast) {
+    gsap.to(renderVariables, 0.05, { yawAngleDegrees: 0 })
+    gsap.fromTo(renderVariables, 0.05, { yawAngleDegrees: 0 }, { yawAngleDegrees: fullRangeAngleDegrees })
+  } else if (fromEastToWest) {
+    gsap.to(renderVariables, 0.05, { yawAngleDegrees: 360 })
+    gsap.fromTo(renderVariables, 0.05, { yawAngleDegrees: 360 }, { yawAngleDegrees: fullRangeAngleDegrees })
+  } else {
+    gsap.to(renderVariables, 0.1, { yawAngleDegrees: fullRangeAngleDegrees })
+  }
+  renderCanvas()
+}, 1000 / 60)
 </script>
 
 <style scoped>
 .compass {
-  position: relative;
-}
-.compass-ticks {
-  transition: -webkit-transform 0.2s;
-  user-select: none;
-  height: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
   width: 100%;
-  opacity: 0.9;
-}
-.boat {
-  position: absolute;
-  margin: auto;
-  top: 0;
-  left: 0;
-  right: 0;
-  bottom: 0;
-  user-select: none;
-  height: 55%;
-}
-.rotated {
-  transform: rotate(v-bind('angleStyle'));
+  height: 100%;
 }
 </style>