Add some wip stub for HSV color picker

frontend/src/App.svelte

@@ -4,7 +4,7 @@
   import Importer from './sections/Importer.svelte';
   import PaletteSection from './sections/Palette.svelte'
   import FloatingPanel from './components/FloatingPanel.svelte'
-  import { Palette, PaletteEntry, defaultPalette } from './types/palette'
+  import { Palette, PaletteEntry, defaultPalette, type Color } from './types/palette'
 
   import { LoadedFile, PixelsPlaceUndoable, SelectionClearUndoable, SelectionSetUndoable } from './types/file'
 
@@ -23,6 +23,7 @@
   import Shortcuts from './components/Shortcuts.svelte'
   import { CopyPaste } from './types/copypaste'
   import type { PixelPosition } from './types/shapes.js';
+  import ColorSelector from './components/ColorSelector.svelte';
   
   let theme: 'white'|'g10'|'g80'|'g90'|'g100' = 'g90'
   
@@ -30,6 +31,12 @@
   let primaryColorIndex: number = 1
   let secondaryColorIndex: number = 0
   
+  let primaryColor: Color = {r: 0, g: 0, b: 0, a: 0}
+  let secondaryColor: Color = {r: 0, g: 0, b: 0, a: 0}
+  
+  $: primaryColor = palette?.[primaryColorIndex]
+  $: secondaryColor = palette?.[secondaryColorIndex]
+
   // Oh no, what are you doing, step palette~
   function stepPalette(step: number, primary: boolean) {
     if (primary) {
@@ -163,6 +170,7 @@
   <section class='content'>
     <section class='left'>
       <PaletteSection bind:palette bind:primaryColorIndex bind:secondaryColorIndex file={focusedFile} />
+      <ColorSelector />
     </section>
     <menu class='toolbar'>
       <Button isSelected={currentTool === toolMove} kind="ghost" size="small" icon={Move} iconDescription="move" tooltipPosition="right" on:click={()=>swapTool(toolMove)}></Button>
@@ -271,8 +279,9 @@
   }
   .left {
     display: flex;
-    flex-direction: row;
+    flex-direction: column;
-    align-items: flex-start;
+    align-items: stretch;
+    justify-content: space-between;
   }
   .toolbar {
     display: flex;

frontend/src/components/ColorSelector.svelte

@@ -0,0 +1,71 @@
+<script lang='ts'>
+  export let red: number = 255
+  export let green: number = 0
+  export let blue: number = 0
+  export let alpha: number = 0
+  
+  let hue: number = 0
+  let saturation: number = 0
+  let value: number = 0
+</script>
+
+<main>
+  <div class="hsv">
+    <div class='hsv_hue' style="background: rgb({red}, {green}, {blue})"></div>
+    <div class='hsv_saturation'></div>
+    <div class='hsv_value'></div>
+  </div>
+  <div class='sv'>
+  </div>
+  <div class='slider'>
+    <div class='hue' style='width: 100%; height: 1em;'></div>
+  </div>
+  <div class='slider'>
+    <span class="checkerboard"></span>
+    <div class='alpha' style='width: 100%; height: 1em;'></div>
+  </div>
+</main>
+
+<style>
+  .slider {
+    position: relative;
+    width: 100%;
+    display: flex;
+  }
+  .hsv {
+    min-height: 9em;
+    width: 100%;
+    border: 1px solid red;
+  }
+ .hue {
+    background-image: linear-gradient(to left,
+      #ff0000, #ff0080,
+      #ff00ff, #8000ff,
+      #0000ff, #0080ff,
+      #00ffff, #00ff80,
+      #00ff00, #80ff00,
+      #ffff00, #ff8000,
+      #ff0000
+    );
+  }
+  .alpha {
+    background-image: linear-gradient(to right,
+      transparent 0%,
+      rgba(255, 0, 0, 1) 100%
+    );
+    z-index: 0;
+  }
+  .checkerboard {
+    pointer-events: none;
+    position: absolute;
+    z-index: 0;
+    top: 0;
+    left: 0;
+    right: 0;
+    width: 100%;
+    height: 100%;
+    background-image: linear-gradient(45deg, #808080 25%, transparent 25%), linear-gradient(-45deg, #808080 25%, transparent 25%), linear-gradient(45deg, transparent 75%, #808080 75%), linear-gradient(-45deg, transparent 75%, #808080 75%);
+    background-size: 10px 10px;
+    background-position: 0 0, 0 5px, 5px -5px, -5px 0px;
+  }
+</style>

frontend/src/sections/Palette.svelte

@@ -1,4 +1,5 @@
 <script lang='ts'>
+  import type { Color } from '../types/palette'
   import type { LoadedFile } from '../types/file'
 
   export let file: LoadedFile

frontend/src/types/colors.ts

@@ -0,0 +1,122 @@
+function floatsToBytes(colors: number[]): number[] {
+  if (colors.length <= 0) return colors
+  if (colors[0] <= 1.0) {
+    colors[0] = colors[0] * 255
+    colors[1] = colors[1] * 255
+    colors[2] = colors[2] * 255
+  }
+  return colors
+}
+
+function bytesToFloats(colors: number[]): number[] {
+  if (colors.length <= 0) return colors
+  if (colors[0] > 1.0) {
+    colors[0] = colors[0] / 255
+    colors[1] = colors[1] / 255
+    colors[2] = colors[2] / 255
+  }
+  return colors
+}
+
+export function HSV2RGB(hsv: number[]): number[] {
+  let hh: number, p: number, q: number, t: number, ff: number, i: number
+  let rgb: number[] = []
+
+  if (hsv[1] <= 0.0) {
+    rgb[0] = hsv[2]
+    rgb[1] = hsv[2]
+    rgb[2] = hsv[2]
+    return floatsToBytes(rgb)
+  }
+  hh = hsv[0]
+  if (hh >= 360.0) {
+    hh = 0.0
+  }
+  hh /= 60.0
+  i = Math.floor(hh)
+  ff = hh - i
+  p = hsv[2] * (1.0 - hsv[1])
+  q = hsv[2] * (1.0 - (hsv[1] * ff))
+  t = hsv[2] * (1.0 - (hsv[1] * (1.0 - ff)))
+
+  switch (i) {
+    case 0:
+      rgb[0] = hsv[2]
+      rgb[1] = t
+      rgb[2] = p
+      break
+    case 1:
+      rgb[0] = q
+      rgb[1] = hsv[2]
+      rgb[2] = p
+      break
+    case 2:
+      rgb[0] = p
+      rgb[1] = hsv[2]
+      rgb[2] = t
+      break
+    case 3:
+      rgb[0] = p
+      rgb[1] = q
+      rgb[2] = hsv[2]
+      break
+    case 4:
+      rgb[0] = t
+      rgb[1] = p
+      rgb[2] = hsv[2]
+      break
+    case 5:
+    default:
+      rgb[0] = hsv[2]
+      rgb[1] = p
+      rgb[2] = q
+      break
+  }
+  return floatsToBytes(rgb)
+}
+
+export function RGB2HSV(rgb: number[]): number[] {
+  rgb = bytesToFloats(rgb)
+
+  let min: number, max: number, delta: number
+  let hsv: number[] = []
+
+  min = rgb[0] < rgb[1] ? rgb[0] : rgb[1]
+  min = min < rgb[2] ? min : rgb[2]
+
+  max = rgb[0] > rgb[1] ? rgb[0] : rgb[1]
+  max = max > rgb[2] ? max : rgb[2]
+
+  hsv[2] = max
+  delta  = max - min
+
+  if (delta < 0.00001) {
+    hsv[1] = 0
+    hsv[0] = 0
+    return hsv
+  }
+
+  if (max > 0.0) {
+    hsv[1] = delta / max
+  } else {
+    hsv[1] = 0.0
+    hsv[0] = NaN
+    return hsv
+  }
+
+  if (rgb[0] >= max) {
+    hsv[0] = ( rgb[1] - rgb[2] ) / delta
+  } else if (rgb[1] >= max) {
+    hsv[0] = 2.0 + ( rgb[2] - rgb[0] ) / delta
+  } else {
+    hsv[0] = 4.0 + ( rgb[0] - rgb[1] ) / delta
+  }
+
+  hsv[0] *= 60.0;
+
+  if (hsv[0] < 0.0) {
+    hsv[0] += 360.0
+  }
+  return hsv
+}
+ 

frontend/src/types/palette.ts

@@ -15,3 +15,10 @@ export const defaultPalette = (): Palette => {
     ]
   }
 }
+
+export interface Color {
+  r: number;
+  g: number;
+  b: number;
+  a: number;
+}