From 315c0417285dfd1e3dff0e5b0de9ec696eaee6af Mon Sep 17 00:00:00 2001
From: pkunjam <punit17100@iiitnr.edu.in>
Date: Thu, 1 Oct 2020 01:58:32 +0530
Subject: [PATCH] Get sprite color in realtime

---
 Assets/Scripts/ImageEffects/SpriteColor.cs | 78 ++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 Assets/Scripts/ImageEffects/SpriteColor.cs

diff --git a/Assets/Scripts/ImageEffects/SpriteColor.cs b/Assets/Scripts/ImageEffects/SpriteColor.cs
new file mode 100644
index 0000000..bf7cad6
--- /dev/null
+++ b/Assets/Scripts/ImageEffects/SpriteColor.cs
@@ -0,0 +1,78 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+// This script gets the color of a sprite in realtime 
+// Usage: Attach this script to any gameobject having a sprite renderer component
+
+public class SpriteColor : MonoBehaviour
+{
+    public static Color GetColor { get; set; }
+
+    public SpriteRenderer targetSprite;
+
+    Color finalColor;
+
+    void Update()
+    {
+        GetSpritePixelColorUnderMousePointer(targetSprite, out finalColor);
+    }
+
+    public bool GetSpritePixelColorUnderMousePointer(SpriteRenderer spriteRenderer, out Color color)
+    {
+        color = new Color();
+        Camera cam = Camera.main;
+        Vector2 mousePos = Input.mousePosition;
+        Vector2 viewportPos = cam.ScreenToViewportPoint(mousePos);
+        if (viewportPos.x < 0.0f || viewportPos.x > 1.0f || viewportPos.y < 0.0f || viewportPos.y > 1.0f) return false; // out of viewport bounds
+
+        // Cast a ray from viewport point into world
+        Ray ray = cam.ViewportPointToRay(viewportPos);
+
+        // Check for intersection with sprite and get the color
+        return IntersectsSprite(spriteRenderer, ray, out color);
+    }
+
+    private bool IntersectsSprite(SpriteRenderer spriteRenderer, Ray ray, out Color color)
+    {
+        color = new Color();
+        if (spriteRenderer == null) return false;
+
+        Sprite sprite = spriteRenderer.sprite;
+        if (sprite == null) return false;
+
+        Texture2D texture = sprite.texture;
+        if (texture == null) return false;
+
+
+        // Craete a plane so it has the same orientation as the sprite transform
+        Plane plane = new Plane(transform.forward, transform.position);
+
+        // Intersect the ray and the plane
+        float rayIntersectDist; // the distance from the ray origin to the intersection point
+        if (!plane.Raycast(ray, out rayIntersectDist)) return false;
+
+        // Convert world position to sprite position
+        // worldToLocalMatrix.MultiplyPoint3x4 returns a value from based on the texture dimensions (+/- half texDimension / pixelsPerUnit) )
+        // 0, 0 corresponds to the center of the TEXTURE ITSELF, not the center of the trimmed sprite textureRect
+
+        Vector3 spritePos = spriteRenderer.worldToLocalMatrix.MultiplyPoint3x4(ray.origin + (ray.direction * rayIntersectDist));
+        Rect textureRect = sprite.textureRect;
+        float pixelsPerUnit = sprite.pixelsPerUnit;
+        float halfRealTexWidth = texture.width * 0.5f; // use the real texture width here because center is based on this -- probably won't work right for atlases
+        float halfRealTexHeight = texture.height * 0.5f;
+        // Convert to pixel position, offsetting so 0,0 is in lower left instead of center
+        int texPosX = (int)(spritePos.x * pixelsPerUnit + halfRealTexWidth);
+        int texPosY = (int)(spritePos.y * pixelsPerUnit + halfRealTexHeight);
+        // Check if pixel is within texture
+        if (texPosX < 0 || texPosX < textureRect.x || texPosX >= Mathf.FloorToInt(textureRect.xMax)) return false; // out of bounds
+        if (texPosY < 0 || texPosY < textureRect.y || texPosY >= Mathf.FloorToInt(textureRect.yMax)) return false; // out of bounds
+                                                                                                                   // Get pixel color
+        color = texture.GetPixel(texPosX, texPosY);
+        GetColor = color;
+
+        return true;
+    }
+
+}