Add ColorPickerUI script

Assets/Scripts/ColorPickerUI.cs

@@ -0,0 +1,193 @@
+using UnityEngine;
+using UnityEngine.UI;
+using UnityEngine.InputSystem;
+using System;
+
+public class ColorPickerUI : MonoBehaviour
+{
+    public RawImage hueImage;
+    public RawImage svImage;
+    public RectTransform svCursor;
+    public RectTransform hueCursor;
+    public event Action<Color> OnColorChanged;
+
+    private Texture2D hueTexture;
+    private Texture2D svTexture;
+
+    private const int hueHeight = 256;
+    private const int svSize = 256;
+
+    private float selectedHue = 0f;
+    private float selectedS = 1f;
+    private float selectedV = 1f;
+
+    private enum DragTarget { None, Hue, SV }
+    private DragTarget currentDrag = DragTarget.None;
+
+    private Color lastColor;
+
+    void Start()
+    {
+        GenerateHueBar();
+        GenerateSVBox(selectedHue);
+        UpdateSVCursor();
+        UpdateHueCursor();
+        lastColor = GetSelectedColor();
+        OnColorChanged?.Invoke(lastColor);
+    }
+
+    void Update()
+    {
+        if (Pointer.current == null)
+            return;
+
+        bool pressed = Pointer.current.press.isPressed;
+        Vector2 mousePos = Pointer.current.position.ReadValue();
+
+        if (pressed && currentDrag == DragTarget.None)
+        {
+            if (RectTransformUtility.RectangleContainsScreenPoint(hueImage.rectTransform, mousePos, null))
+                currentDrag = DragTarget.Hue;
+            else if (RectTransformUtility.RectangleContainsScreenPoint(svImage.rectTransform, mousePos, null))
+                currentDrag = DragTarget.SV;
+        }
+
+        if (!pressed)
+        {
+            currentDrag = DragTarget.None;
+            return;
+        }
+
+        bool colorChanged = false;
+
+        if (currentDrag == DragTarget.Hue)
+        {
+            RectTransformUtility.ScreenPointToLocalPointInRectangle(hueImage.rectTransform, mousePos, null, out Vector2 localPoint);
+            float y = Mathf.Clamp01((localPoint.y + hueImage.rectTransform.rect.height / 2f) / hueImage.rectTransform.rect.height);
+            float newHue = 1f - y;
+            if (!Mathf.Approximately(newHue, selectedHue))
+            {
+                selectedHue = newHue;
+                GenerateSVBox(selectedHue);
+                UpdateSVCursor();
+                UpdateHueCursor();
+                colorChanged = true;
+            }
+        }
+        else if (currentDrag == DragTarget.SV)
+        {
+            RectTransformUtility.ScreenPointToLocalPointInRectangle(svImage.rectTransform, mousePos, null, out Vector2 localPoint);
+            float rectWidth = svImage.rectTransform.rect.width;
+            float rectHeight = svImage.rectTransform.rect.height;
+            float x = (localPoint.x + rectWidth / 2f) / rectWidth;
+            float y = (localPoint.y + rectHeight / 2f) / rectHeight;
+            float newS = Mathf.Clamp01(x);
+            float newV = Mathf.Clamp01(y);
+            if (!Mathf.Approximately(newS, selectedS) || !Mathf.Approximately(newV, selectedV))
+            {
+                selectedS = newS;
+                selectedV = newV;
+                UpdateSVCursor();
+                colorChanged = true;
+            }
+        }
+
+        if (colorChanged)
+        {
+            Color currentColor = GetSelectedColor();
+            if (currentColor != lastColor)
+            {
+                lastColor = currentColor;
+                OnColorChanged?.Invoke(currentColor);
+            }
+        }
+    }
+
+    void UpdateSVCursor()
+    {
+        if (svCursor == null) return;
+        Rect rect = svImage.rectTransform.rect;
+        float x = selectedS * rect.width;
+        float y = selectedV * rect.height;
+        x = Mathf.Clamp(x, 0, rect.width);
+        y = Mathf.Clamp(y, 0, rect.height);
+        Vector2 clampedPos = new Vector2(x - rect.width / 2f, y - rect.height / 2f);
+        svCursor.anchoredPosition = clampedPos;
+    }
+
+    void UpdateHueCursor()
+    {
+        if (hueCursor == null) return;
+        Rect rect = hueImage.rectTransform.rect;
+        float y = (1f - selectedHue) * rect.height;
+        y = Mathf.Clamp(y, 0, rect.height);
+        Vector2 pos = new Vector2(0, y - rect.height / 2f);
+        hueCursor.anchoredPosition = pos;
+    }
+
+    void GenerateHueBar()
+    {
+        hueTexture = new Texture2D(1, hueHeight);
+        hueTexture.wrapMode = TextureWrapMode.Clamp;
+        for (int y = 0; y < hueHeight; y++)
+        {
+            float h = 1f - (float)y / (hueHeight - 1);
+            Color color = Color.HSVToRGB(h, 1f, 1f);
+            hueTexture.SetPixel(0, y, color);
+        }
+        hueTexture.Apply();
+        hueImage.texture = hueTexture;
+    }
+
+    void GenerateSVBox(float hue)
+    {
+        svTexture = new Texture2D(svSize, svSize);
+        svTexture.wrapMode = TextureWrapMode.Clamp;
+        for (int y = 0; y < svSize; y++)
+        {
+            float v = (float)y / (svSize - 1);
+            for (int x = 0; x < svSize; x++)
+            {
+                float s = (float)x / (svSize - 1);
+                Color color = Color.HSVToRGB(hue, s, v);
+                svTexture.SetPixel(x, y, color);
+            }
+        }
+        svTexture.Apply();
+        svImage.texture = svTexture;
+    }
+
+    public Color GetSelectedColor()
+    {
+        return Color.HSVToRGB(selectedHue, selectedS, selectedV);
+    }
+
+    public void SetSelectedColor(float r, float g, float b)
+    {
+        Color32 color = new((byte)r, (byte)g, (byte)b, 255);
+
+        if (color.r == 0 && color.g == 0 && color.b == 0)
+        {
+            selectedS = 0;
+            selectedV = 0;
+        }
+        else
+        {
+            Color.RGBToHSV(color, out float h, out float s, out float v);
+            selectedHue = h;
+            selectedS = s;
+            selectedV = v;
+        }
+
+        GenerateSVBox(selectedHue);
+        UpdateSVCursor();
+        UpdateHueCursor();
+
+        var current = GetSelectedColor();
+        if (current != lastColor)
+        {
+            lastColor = current;
+            OnColorChanged?.Invoke(current);
+        }
+    }
+}

Assets/Scripts/ColorPickerUI.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: f8436a018ec18f3269f65a2fd73ed10b