using System;
using System.Collections.Generic;

using UnityEngine;
using UnityEngine.Serialization;
using UnityEngine.Sprites;
using UnityEngine.UI;

/// <summary>
/// Image is a textured element in the UI hierarchy.
/// </summary>

[AddComponentMenu("UI/Image Extended", 10)]
public class ImageExtended : MaskableGraphic, ISerializationCallbackReceiver, ILayoutElement, ICanvasRaycastFilter
{
	public enum Type
	{
		Simple,
		Sliced,
		Tiled,
		Filled
	}

	public enum FillMethod
	{
		Horizontal,
		Vertical,
		Radial90,
		Radial180,
		Radial360,
	}

	public enum OriginHorizontal
	{
		Left,
		Right,
	}

	public enum OriginVertical
	{
		Bottom,
		Top,
	}

	public enum Origin90
	{
		BottomLeft,
		TopLeft,
		TopRight,
		BottomRight,
	}

	public enum Origin180
	{
		Bottom,
		Left,
		Top,
		Right,
	}

	public enum Origin360
	{
		Bottom,
		Right,
		Top,
		Left,
	}

	public enum Rotate
	{
		Rotate0,
		Rotate90,
		Rotate180,
		Rotate270,
	}

	[FormerlySerializedAs("m_Frame")]
	[SerializeField] private Sprite m_Sprite;
	public Sprite sprite { get { return m_Sprite; } set { if (SetPropertyUtility.SetClass(ref m_Sprite, value)) SetAllDirty(); } }

	[NonSerialized]
	private Sprite m_OverrideSprite;
	public Sprite overrideSprite { get { return m_OverrideSprite == null ? sprite : m_OverrideSprite; } set { if (SetPropertyUtility.SetClass(ref m_OverrideSprite, value)) SetAllDirty(); } }

	/// How the Image is drawn.
	[SerializeField] private Type m_Type = Type.Simple;
	public Type type { get { return m_Type; } set { if (SetPropertyUtility.SetStruct(ref m_Type, value)) SetVerticesDirty(); } }

	[SerializeField] private bool m_PreserveAspect = false;
	public bool preserveAspect { get { return m_PreserveAspect; } set { if (SetPropertyUtility.SetStruct(ref m_PreserveAspect, value)) SetVerticesDirty(); } }

	[SerializeField] private bool m_FillCenter = true;
	public bool fillCenter { get { return m_FillCenter; } set { if (SetPropertyUtility.SetStruct(ref m_FillCenter, value)) SetVerticesDirty(); } }

	/// Filling method for filled sprites.
	[SerializeField] private FillMethod m_FillMethod = FillMethod.Radial360;
	public FillMethod fillMethod { get { return m_FillMethod; } set { if (SetPropertyUtility.SetStruct(ref m_FillMethod, value)) {SetVerticesDirty(); m_FillOrigin = 0; } } }

	/// Amount of the Image shown. 0-1 range with 0 being nothing shown, and 1 being the full Image.
	[Range(0, 1)]
	[SerializeField] private float m_FillAmount = 1.0f;
	public float fillAmount { get { return m_FillAmount; } set { if (SetPropertyUtility.SetStruct(ref m_FillAmount, Mathf.Clamp01(value))) SetVerticesDirty(); } }

	/// Whether the Image should be filled clockwise (true) or counter-clockwise (false).
	[SerializeField] private bool m_FillClockwise = true;
	public bool fillClockwise { get { return m_FillClockwise; } set { if (SetPropertyUtility.SetStruct(ref m_FillClockwise, value)) SetVerticesDirty(); } }

	/// Controls the origin point of the Fill process. Value means different things with each fill method.
	[SerializeField] private int m_FillOrigin;
	public int fillOrigin { get { return m_FillOrigin; } set { if (SetPropertyUtility.SetStruct(ref m_FillOrigin, value)) SetVerticesDirty(); } }

	[SerializeField] private Rotate m_Rotate = Rotate.Rotate0;
	public Rotate rotate { get { return m_Rotate; } set { if (SetPropertyUtility.SetStruct(ref m_Rotate, value)) SetVerticesDirty(); } }

	// Not serialized until we support read-enabled sprites better.
	private float m_EventAlphaThreshold = 1;
	public float eventAlphaThreshold { get { return m_EventAlphaThreshold; } set { m_EventAlphaThreshold = value; } }

	protected ImageExtended()
	{ }

	/// <summary>
	/// Image's texture comes from the UnityEngine.Image.
	/// </summary>
	public override Texture mainTexture
	{
		get
		{
			return overrideSprite == null ? s_WhiteTexture : overrideSprite.texture;
		}
	}

	/// <summary>
	/// Whether the Image has a border to work with.
	/// </summary>

	public bool hasBorder
	{
		get
		{
			if (overrideSprite != null)
			{
				Vector4 v = overrideSprite.border;
				return v.sqrMagnitude > 0f;
			}
			return false;
		}
	}

	public float pixelsPerUnit
	{
		get
		{
			float spritePixelsPerUnit = 100;
			if (sprite)
				spritePixelsPerUnit = sprite.pixelsPerUnit;

			float referencePixelsPerUnit = 100;
			if (canvas)
				referencePixelsPerUnit = canvas.referencePixelsPerUnit;

			return spritePixelsPerUnit / referencePixelsPerUnit;
		}
	}

	public virtual void OnBeforeSerialize() { }

	public virtual void OnAfterDeserialize()
	{
		if (m_FillOrigin < 0)
			m_FillOrigin = 0;
		else if (m_FillMethod == FillMethod.Horizontal && m_FillOrigin > 1)
			m_FillOrigin = 0;
		else if (m_FillMethod == FillMethod.Vertical && m_FillOrigin > 1)
			m_FillOrigin = 0;
		else if (m_FillOrigin > 3)
			m_FillOrigin = 0;

		m_FillAmount = Mathf.Clamp(m_FillAmount, 0f, 1f);
	}

	/// Image's dimensions used for drawing. X = left, Y = bottom, Z = right, W = top.
	private Vector4 GetDrawingDimensions(bool shouldPreserveAspect)
	{
		var padding = overrideSprite == null ? Vector4.zero : DataUtility.GetPadding(overrideSprite);
		var size = overrideSprite == null ? Vector2.zero : new Vector2(overrideSprite.rect.width, overrideSprite.rect.height);

		Rect r = GetPixelAdjustedRect();
		// Debug.Log(string.Format("r:{2}, size:{0}, padding:{1}", size, padding, r));

		int spriteW = Mathf.RoundToInt(size.x);
		int spriteH = Mathf.RoundToInt(size.y);

		var v = overrideSprite == null ? new Vector4(0, 0, 1, 1) :
			new Vector4(
				padding.x / spriteW,
				padding.y / spriteH,
				(spriteW - padding.z) / spriteW,
				(spriteH - padding.w) / spriteH);

		if (shouldPreserveAspect && size.sqrMagnitude > 0.0f)
		{
			var spriteRatio = size.x / size.y;
			var rectRatio = r.width / r.height;

			if (spriteRatio > rectRatio)
			{
				var oldHeight = r.height;
				r.height = r.width * (1.0f / spriteRatio);
				r.y += (oldHeight - r.height) * rectTransform.pivot.y;
			}
			else
			{
				var oldWidth = r.width;
				r.width = r.height * spriteRatio;
				r.x += (oldWidth - r.width) * rectTransform.pivot.x;
			}
		}

		v = new Vector4(
				r.x + r.width * v.x,
				r.y + r.height * v.y,
				r.x + r.width * v.z,
				r.y + r.height * v.w
				);

		return v;
	}

	public override void SetNativeSize()
	{
		if (overrideSprite != null)
		{
			float w = overrideSprite.rect.width / pixelsPerUnit;
			float h = overrideSprite.rect.height / pixelsPerUnit;
			rectTransform.anchorMax = rectTransform.anchorMin;
			rectTransform.sizeDelta = new Vector2(w, h);
			SetAllDirty();
		}
	}

	/// <summary>
	/// Update the UI renderer mesh.
	/// </summary>

	protected override void OnFillVBO(List<UIVertex> vbo)
	{
		switch (type)
		{
			case Type.Simple:
				GenerateSimpleSprite(vbo, m_PreserveAspect);
				break;
			case Type.Sliced:
				GenerateSlicedSprite(vbo);
				break;
			case Type.Tiled:
				GenerateTiledSprite(vbo);
				break;
			case Type.Filled:
				GenerateFilledSprite(vbo, m_PreserveAspect);
				break;
		}
	}

	#region Various fill functions
	/// <summary>
	/// Generate vertices for a simple Image.
	/// </summary>

	void GenerateSimpleSprite(List<UIVertex> vbo, bool preserveAspect)
	{
		var vert = UIVertex.simpleVert;
		vert.color = color;

		Vector4 v = GetDrawingDimensions(preserveAspect);
		var uv = (overrideSprite != null) ? DataUtility.GetOuterUV(overrideSprite) : Vector4.zero;

		AddQuad(vbo, vert,
			new Vector2(v.x, v.y), new Vector2(v.z, v.w),
			new Vector2(uv.x, uv.y), new Vector2(uv.z, uv.w));
	}

	/// <summary>
	/// Generate vertices for a 9-sliced Image.
	/// </summary>

	static readonly Vector2[] s_VertScratch = new Vector2[4];
	static readonly Vector2[] s_UVScratch = new Vector2[4];
	void GenerateSlicedSprite(List<UIVertex> vbo)
	{
		if (!hasBorder)
		{
			GenerateSimpleSprite(vbo, false);
			return;
		}

		Vector4 outer, inner, padding, border;

		if (overrideSprite != null)
		{
			outer = DataUtility.GetOuterUV(overrideSprite);
			inner = DataUtility.GetInnerUV(overrideSprite);
			padding = DataUtility.GetPadding(overrideSprite);
			border = overrideSprite.border;
		}
		else
		{
			outer = Vector4.zero;
			inner = Vector4.zero;
			padding = Vector4.zero;
			border = Vector4.zero;
		}

		Rect rect = GetPixelAdjustedRect();
		border = GetAdjustedBorders(border / pixelsPerUnit, rect);
		padding = padding / pixelsPerUnit;

		int offset = 4 - (int)rotate;
		for (int i = 0; i < 4; ++i)
		{
			s_VertScratch[(4 - i / 2) % 4][i % 2] = padding[(i + offset) % 4];
			s_VertScratch[1 + i / 2][i % 2] = border[(i + offset) % 4];
		}
		for (int i = 2; i < 4; ++i)
		{
			s_VertScratch[i].x = rect.width - s_VertScratch[i].x;
			s_VertScratch[i].y = rect.height - s_VertScratch[i].y;
		}
		for (int i = 0; i < 4; ++i)
		{
			s_VertScratch[i].x += rect.x;
			s_VertScratch[i].y += rect.y;
		}

		s_UVScratch[0] = new Vector2(outer.x, outer.y);
		s_UVScratch[1] = new Vector2(inner.x, inner.y);
		s_UVScratch[2] = new Vector2(inner.z, inner.w);
		s_UVScratch[3] = new Vector2(outer.z, outer.w);

		var uiv = UIVertex.simpleVert;
		uiv.color = color;
		for (int x = 0; x < 3; ++x)
		{
			int x2 = x + 1;

			for (int y = 0; y < 3; ++y)
			{
				if (!m_FillCenter && x == 1 && y == 1)
					continue;

				int y2 = y + 1;

				int vx1 = x, vy1 = y;
				int vx2 = x2, vy2 = y2;
				for (int i = 0; i < (int) rotate; ++i)
				{
					int t1 = 4 - vy1 - 1;
					vy1 = vx1; vx1 = t1;
					int t2 = 4 - vy2 - 1;
					vy2 = vx2; vx2 = t2;
				}
				int ux1 = x, uy1 = y;
				int ux2 = x2, uy2 = y2;
				if ((int) rotate >= 2)
				{
					ux1 = x2; ux2 = x;
				}
				if (((int)rotate + 1) % 4 >= 2)
				{
					uy1 = y2; uy2 = y;
				}
				if (Mathf.Abs(s_VertScratch[vx1].x - s_VertScratch[vx2].x) < Mathf.Epsilon)
					continue;
				if (Mathf.Abs(s_VertScratch[vy1].y - s_VertScratch[vy2].y) < Mathf.Epsilon)
					continue;
				AddQuad(vbo, uiv,
					new Vector2(s_VertScratch[vx1].x, s_VertScratch[vy1].y),
					new Vector2(s_VertScratch[vx2].x, s_VertScratch[vy2].y),
					new Vector2(s_UVScratch[ux1].x, s_UVScratch[uy1].y),
					new Vector2(s_UVScratch[ux2].x, s_UVScratch[uy2].y));
			}
		}
	}

	/// <summary>
	/// Generate vertices for a tiled Image.
	/// </summary>

	static readonly Vector2[] s_UVTiled = new Vector2[2];
	void GenerateTiledSprite(List<UIVertex> vbo)
	{
		Vector4 outer, inner, border;
		Vector2 spriteSize;

		if (overrideSprite != null)
		{
			outer = DataUtility.GetOuterUV(overrideSprite);
			inner = DataUtility.GetInnerUV(overrideSprite);
			border = overrideSprite.border;
			spriteSize = overrideSprite.rect.size;
		}
		else
		{
			outer = Vector4.zero;
			inner = Vector4.zero;
			border = Vector4.zero;
			spriteSize = Vector2.one * 100;
		}

		Rect rect = GetPixelAdjustedRect();
		float tileWidth = (spriteSize.x - border.x - border.z) / pixelsPerUnit;
		float tileHeight = (spriteSize.y - border.y - border.w) / pixelsPerUnit;
		border = GetAdjustedBorders(border / pixelsPerUnit, rect);

		int offset = 4 - (int)rotate;
		int rx = (0 + offset) % 4, ry = (1 + offset) % 4, rz = (2 + offset) % 4, rw = (3 + offset) % 4;

		var v = UIVertex.simpleVert;
		v.color = color;

		// Min to max max range for tiled region in coordinates relative to lower left corner.
		float xMin = border[rx];
		float xMax = rect.width - border[rz];
		float yMin = border[ry];
		float yMax = rect.height - border[rw];

		// Safety check. Useful so Unity doesn't run out of memory if the sprites are too small.
		// Max tiles are 100 x 100.
		if ((xMax - xMin) > tileWidth * 100 || (yMax - yMin) > tileHeight * 100)
		{
			tileWidth = (xMax - xMin) / 100;
			tileHeight = (yMax - yMin) / 100;
		}
		if ((int) rotate % 2 == 1)
		{
			float t = tileWidth;
			tileWidth = tileHeight;
			tileHeight = t;
		}

		if (m_FillCenter)
		{
			for (float y1 = yMin; y1 < yMax; y1 += tileHeight)
			{
				s_UVTiled[0] = new Vector2(inner.x, inner.y);
				s_UVTiled[1] = new Vector2(inner.z, inner.w);
				float y2 = y1 + tileHeight;
				if (y2 > yMax)
				{
					int k1 = 1 - (int) rotate / 2, k2 = 1 - (int) rotate % 2;
					s_UVTiled[k1][k2] = s_UVTiled[1 - k1][k2] + (s_UVTiled[k1][k2] - s_UVTiled[1 - k1][k2]) * (yMax - y1) / (y2 - y1);
					y2 = yMax;
				}
				for (float x1 = xMin; x1 < xMax; x1 += tileWidth)
				{
					float x2 = x1 + tileWidth;
					if (x2 > xMax)
					{
						int k1 = ((int)rotate + 3) % 4 / 2, k2 = (int)rotate % 2;
						s_UVTiled[k1][k2] = s_UVTiled[1 - k1][k2] + (s_UVTiled[k1][k2] - s_UVTiled[1 - k1][k2]) * (xMax - x1) / (x2 - x1);
						x2 = xMax;
					}
					AddQuad(vbo, v, new Vector2(x1, y1) + rect.position, new Vector2(x2, y2) + rect.position, s_UVTiled[0], s_UVTiled[1]);
				}
			}
		}

		if (!hasBorder)
			return;

		// Bottom and top tiled border
		for (int i = 0; i < 2; ++i)
		{
			float y1 = i == 0 ? 0 : yMax;
			float y2 = i == 0 ? yMin : rect.height;
			if (Mathf.Abs(y1 - y2) < Mathf.Epsilon)
				continue;

			s_UVTiled[0] = GetRotatedUV(inner, 0, i == 0 ? outer : inner, i == 0 ? 1 : 3);
			s_UVTiled[1] = GetRotatedUV(inner, 2, i == 0 ? inner : outer, i == 0 ? 1 : 3);
			RotatePairUV(s_UVTiled);
			for (float x1 = xMin; x1 < xMax; x1 += tileWidth)
			{
				float x2 = x1 + tileWidth;
				if (x2 > xMax)
				{
					int k1 = ((int)rotate + 3) % 4 / 2, k2 = (int)rotate % 2;
					s_UVTiled[k1][k2] = s_UVTiled[1 - k1][k2] + (s_UVTiled[k1][k2] - s_UVTiled[1 - k1][k2]) * (xMax - x1) / (x2 - x1);
					x2 = xMax;
				}
				AddQuad(vbo, v,
					new Vector2(x1, y1) + rect.position,
					new Vector2(x2, y2) + rect.position,
					s_UVTiled[0], s_UVTiled[1]);
			}
		}

		// Left and right tiled border
		for (int i = 0; i < 2; ++i)
		{
			float x1 = i == 0 ? 0 : xMax;
			float x2 = i == 0 ? xMin : rect.width;
			if (Mathf.Abs(x1 - x2) < Mathf.Epsilon)
				continue;

			s_UVTiled[0] = GetRotatedUV(i == 0 ? outer : inner, i == 0 ? 0 : 2, inner, 1);
			s_UVTiled[1] = GetRotatedUV(i == 0 ? inner : outer, i == 0 ? 0 : 2, inner, 3);
			RotatePairUV(s_UVTiled);
			for (float y1 = yMin; y1 < yMax; y1 += tileHeight)
			{
				float y2 = y1 + tileHeight;
				if (y2 > yMax)
				{
					int k1 = 1 - (int)rotate / 2, k2 = 1 - (int)rotate % 2;
					s_UVTiled[k1][k2] = s_UVTiled[1 - k1][k2] + (s_UVTiled[k1][k2] - s_UVTiled[1 - k1][k2]) * (yMax - y1) / (y2 - y1);
					y2 = yMax;
				}
				AddQuad(vbo, v,
					new Vector2(x1, y1) + rect.position,
					new Vector2(x2, y2) + rect.position,
					s_UVTiled[0], s_UVTiled[1]);
			}
		}

		// Corners
		if (Mathf.Abs(border[rx]) > Mathf.Epsilon &&
			Mathf.Abs(border[ry]) > Mathf.Epsilon)
		{
			s_UVTiled[0] = GetRotatedUV(outer, 0, outer, 1);
			s_UVTiled[1] = GetRotatedUV(inner, 0, inner, 1);
			RotatePairUV(s_UVTiled);
			AddQuad(vbo, v,
				new Vector2(0, 0) + rect.position,
				new Vector2(xMin, yMin) + rect.position,
					s_UVTiled[0], s_UVTiled[1]);
		}
		if (Mathf.Abs(border[rz]) > Mathf.Epsilon &&
			Mathf.Abs(border[ry]) > Mathf.Epsilon)
		{
			s_UVTiled[0] = GetRotatedUV(inner, 2, outer, 1);
			s_UVTiled[1] = GetRotatedUV(outer, 2, inner, 1);
			RotatePairUV(s_UVTiled);
			AddQuad(vbo, v,
				new Vector2(xMax, 0) + rect.position,
				new Vector2(rect.width, yMin) + rect.position,
					s_UVTiled[0], s_UVTiled[1]);
		}
		if (Mathf.Abs(border[rx]) > Mathf.Epsilon &&
			Mathf.Abs(border[rw]) > Mathf.Epsilon)
		{
			s_UVTiled[0] = GetRotatedUV(outer, 0, inner, 3);
			s_UVTiled[1] = GetRotatedUV(inner, 0, outer, 3);
			RotatePairUV(s_UVTiled);
			AddQuad(vbo, v,
				new Vector2(0, yMax) + rect.position,
				new Vector2(xMin, rect.height) + rect.position,
					s_UVTiled[0], s_UVTiled[1]);
		}
		if (Mathf.Abs(border[rz]) > Mathf.Epsilon &&
			Mathf.Abs(border[rw]) > Mathf.Epsilon)
		{
			s_UVTiled[0] = GetRotatedUV(inner, 2, inner, 3);
			s_UVTiled[1] = GetRotatedUV(outer, 2, outer, 3);
			RotatePairUV(s_UVTiled);
			AddQuad(vbo, v,
				new Vector2(xMax, yMax) + rect.position,
				new Vector2(rect.width, rect.height) + rect.position,
					s_UVTiled[0], s_UVTiled[1]);
		}
	}

	Vector2 GetRotatedUV(Vector4 sX, int iX, Vector4 sY, int iY)
	{
		for (int i = 0; i < (int)rotate; i++)
		{
			Vector4 tS = sX;
			sX = sY; sY = tS;
			int tI = (iX + 3) % 4;
			iX = iY - 1; iY = tI;
		}
		return new Vector2(sX[iX], sY[iY]);
	}

	void RotatePairUV(Vector2[] uv)
	{
		if ((int)rotate / 2 == 1)
		{
			float t = uv[0].x;
			uv[0].x = uv[1].x;
			uv[1].x = t;
		}
		if (((int)rotate + 1) / 2 == 1)
		{
			float t = uv[0].y;
			uv[0].y = uv[1].y;
			uv[1].y = t;
		}
	}

	static readonly Vector3[] s_VertQuad = new Vector3[4];
	static readonly Vector2[] s_UVQuad = new Vector2[4];
	void AddQuad(List<UIVertex> vbo, UIVertex v, Vector2 posMin, Vector2 posMax, Vector2 uvMin, Vector2 uvMax)
	{
		s_VertQuad[0] = new Vector3(posMin.x, posMin.y, 0);
		s_VertQuad[1] = new Vector3(posMin.x, posMax.y, 0);
		s_VertQuad[2] = new Vector3(posMax.x, posMax.y, 0);
		s_VertQuad[3] = new Vector3(posMax.x, posMin.y, 0);
		s_UVQuad[0] = new Vector2(uvMin.x, uvMin.y);
		s_UVQuad[1] = new Vector2(uvMin.x, uvMax.y);
		s_UVQuad[2] = new Vector2(uvMax.x, uvMax.y);
		s_UVQuad[3] = new Vector2(uvMax.x, uvMin.y);

		int offset = (int) rotate;
		for (int i = 0; i < 4; i++)
		{
			v.position = s_VertQuad[i];
			v.uv0 = s_UVQuad[(i + offset) % 4];
			vbo.Add(v);
		}
	}

	Vector4 GetAdjustedBorders(Vector4 border, Rect rect)
	{
		for (int axis = 0; axis <= 1; axis++)
		{
			// If the rect is smaller than the combined borders, then there's not room for the borders at their normal size.
			// In order to avoid artefacts with overlapping borders, we scale the borders down to fit.
			float combinedBorders = border[axis] + border[axis + 2];
			float rectSize = rect.size[(axis + (int)rotate % 2) % 2];
			if (rectSize < combinedBorders && combinedBorders != 0)
			{
				float borderScaleRatio = rectSize / combinedBorders;
				border[axis] *= borderScaleRatio;
				border[axis + 2] *= borderScaleRatio;
			}
		}
		return border;
	}

	/// <summary>
	/// Generate vertices for a filled Image.
	/// </summary>

	static readonly Vector2[] s_Xy = new Vector2[4];
	static readonly Vector2[] s_Uv = new Vector2[4];
	void GenerateFilledSprite(List<UIVertex> vbo, bool preserveAspect)
	{
		if (m_FillAmount < 0.001f)
			return;

		Vector4 v = GetDrawingDimensions(preserveAspect);
		Vector4 outer = overrideSprite != null ? DataUtility.GetOuterUV(overrideSprite) : Vector4.zero;
		UIVertex uiv = UIVertex.simpleVert;
		uiv.color = color;

		int offset = 4 - (int)rotate;
		int rx = (0 + offset) % 4, ry = (1 + offset) % 4, rz = (2 + offset) % 4, rw = (3 + offset) % 4;

		// Horizontal and vertical filled sprites are simple -- just end the Image prematurely
		if (m_FillMethod == FillMethod.Horizontal || m_FillMethod == FillMethod.Vertical)
		{
			if (fillMethod == FillMethod.Horizontal)
			{
				float fill = (outer[rz] - outer[rx]) * m_FillAmount;

				if (m_FillOrigin == 1)
				{
					v.x = v.z - (v.z - v.x) * m_FillAmount;
					outer[rx] = outer[rz] - fill;
				}
				else
				{
					v.z = v.x + (v.z - v.x) * m_FillAmount;
					outer[rz] = outer[rx] + fill;
				}
			}
			else if (fillMethod == FillMethod.Vertical)
			{
				float fill = (outer[rw] - outer[ry]) * m_FillAmount;

				if (m_FillOrigin == 1)
				{
					v.y = v.w - (v.w - v.y) * m_FillAmount;
					outer[ry] = outer[rw] - fill;
				}
				else
				{
					v.w = v.y + (v.w - v.y) * m_FillAmount;
					outer[rw] = outer[ry] + fill;
				}
			}
		}

		s_Xy[0] = new Vector2(v.x, v.y);
		s_Xy[1] = new Vector2(v.x, v.w);
		s_Xy[2] = new Vector2(v.z, v.w);
		s_Xy[3] = new Vector2(v.z, v.y);

		s_Uv[(0 + offset) % 4] = new Vector2(outer.x, outer.y);
		s_Uv[(1 + offset) % 4] = new Vector2(outer.x, outer.w);
		s_Uv[(2 + offset) % 4] = new Vector2(outer.z, outer.w);
		s_Uv[(3 + offset) % 4] = new Vector2(outer.z, outer.y);

		if (m_FillAmount < 1f)
		{
			float tx0 = outer.x;
			float ty0 = outer.y;
			float tx1 = outer.z;
			float ty1 = outer.w;
			if (fillMethod == FillMethod.Radial90)
			{
				if (RadialCut(s_Xy, s_Uv, m_FillAmount, m_FillClockwise, m_FillOrigin))
				{
					for (int i = 0; i < 4; ++i)
					{
						uiv.position = s_Xy[i];
						uiv.uv0 = s_Uv[i];
						vbo.Add(uiv);
					}
				}
				return;
			}

			if (fillMethod == FillMethod.Radial180)
			{
				for (int side = 0; side < 2; ++side)
				{
					float fx0, fx1, fy0, fy1;
					int even = m_FillOrigin > 1 ? 1 : 0;

					if (m_FillOrigin == 0 || m_FillOrigin == 2)
					{
						fy0 = 0f;
						fy1 = 1f;
						if (side == even) { fx0 = 0f; fx1 = 0.5f; }
						else { fx0 = 0.5f; fx1 = 1f; }
					}
					else
					{
						fx0 = 0f;
						fx1 = 1f;
						if (side == even) { fy0 = 0.5f; fy1 = 1f; }
						else { fy0 = 0f; fy1 = 0.5f; }
					}

					s_Xy[0].x = Mathf.Lerp(v.x, v.z, fx0);
					s_Xy[1].x = s_Xy[0].x;
					s_Xy[2].x = Mathf.Lerp(v.x, v.z, fx1);
					s_Xy[3].x = s_Xy[2].x;

					s_Xy[0].y = Mathf.Lerp(v.y, v.w, fy0);
					s_Xy[1].y = Mathf.Lerp(v.y, v.w, fy1);
					s_Xy[2].y = s_Xy[1].y;
					s_Xy[3].y = s_Xy[0].y;

					s_Uv[0].x = Mathf.Lerp(tx0, tx1, fx0);
					s_Uv[1].x = s_Uv[0].x;
					s_Uv[2].x = Mathf.Lerp(tx0, tx1, fx1);
					s_Uv[3].x = s_Uv[2].x;

					s_Uv[0].y = Mathf.Lerp(ty0, ty1, fy0);
					s_Uv[1].y = Mathf.Lerp(ty0, ty1, fy1);
					s_Uv[2].y = s_Uv[1].y;
					s_Uv[3].y = s_Uv[0].y;

					float val = m_FillClockwise ? fillAmount * 2f - side : m_FillAmount * 2f - (1 - side);

					if (RadialCut(s_Xy, s_Uv, Mathf.Clamp01(val), m_FillClockwise, ((side + m_FillOrigin + 3) % 4)))
					{
						for (int i = 0; i < 4; ++i)
						{
							uiv.position = s_Xy[i];
							uiv.uv0 = s_Uv[i];
							vbo.Add(uiv);
						}
					}
				}
				return;
			}

			if (fillMethod == FillMethod.Radial360)
			{
				for (int corner = 0; corner < 4; ++corner)
				{
					float fx0, fx1, fy0, fy1;

					if (corner < 2) { fx0 = 0f; fx1 = 0.5f; }
					else { fx0 = 0.5f; fx1 = 1f; }

					if (corner == 0 || corner == 3) { fy0 = 0f; fy1 = 0.5f; }
					else { fy0 = 0.5f; fy1 = 1f; }

					s_Xy[0].x = Mathf.Lerp(v.x, v.z, fx0);
					s_Xy[1].x = s_Xy[0].x;
					s_Xy[2].x = Mathf.Lerp(v.x, v.z, fx1);
					s_Xy[3].x = s_Xy[2].x;

					s_Xy[0].y = Mathf.Lerp(v.y, v.w, fy0);
					s_Xy[1].y = Mathf.Lerp(v.y, v.w, fy1);
					s_Xy[2].y = s_Xy[1].y;
					s_Xy[3].y = s_Xy[0].y;

					s_Uv[0].x = Mathf.Lerp(tx0, tx1, fx0);
					s_Uv[1].x = s_Uv[0].x;
					s_Uv[2].x = Mathf.Lerp(tx0, tx1, fx1);
					s_Uv[3].x = s_Uv[2].x;

					s_Uv[0].y = Mathf.Lerp(ty0, ty1, fy0);
					s_Uv[1].y = Mathf.Lerp(ty0, ty1, fy1);
					s_Uv[2].y = s_Uv[1].y;
					s_Uv[3].y = s_Uv[0].y;

					float val = m_FillClockwise ?
						m_FillAmount * 4f - ((corner + m_FillOrigin) % 4) :
						m_FillAmount * 4f - (3 - ((corner + m_FillOrigin) % 4));

					if (RadialCut(s_Xy, s_Uv, Mathf.Clamp01(val), m_FillClockwise, ((corner + 2) % 4)))
					{
						for (int i = 0; i < 4; ++i)
						{
							uiv.position = s_Xy[i];
							uiv.uv0 = s_Uv[i];
							vbo.Add(uiv);
						}
					}
				}
				return;
			}
		}

		// Fill the buffer with the quad for the Image
		for (int i = 0; i < 4; ++i)
		{
			uiv.position = s_Xy[i];
			uiv.uv0 = s_Uv[i];
			vbo.Add(uiv);
		}
	}

	/// <summary>
	/// Adjust the specified quad, making it be radially filled instead.
	/// </summary>

	static bool RadialCut(Vector2[] xy, Vector2[] uv, float fill, bool invert, int corner)
	{
		// Nothing to fill
		if (fill < 0.001f) return false;

		// Even corners invert the fill direction
		if ((corner & 1) == 1) invert = !invert;

		// Nothing to adjust
		if (!invert && fill > 0.999f) return true;

		// Convert 0-1 value into 0 to 90 degrees angle in radians
		float angle = Mathf.Clamp01(fill);
		if (invert) angle = 1f - angle;
		angle *= 90f * Mathf.Deg2Rad;

		// Calculate the effective X and Y factors
		float cos = Mathf.Cos(angle);
		float sin = Mathf.Sin(angle);

		RadialCut(xy, cos, sin, invert, corner);
		RadialCut(uv, cos, sin, invert, corner);
		return true;
	}

	/// <summary>
	/// Adjust the specified quad, making it be radially filled instead.
	/// </summary>

	static void RadialCut(Vector2[] xy, float cos, float sin, bool invert, int corner)
	{
		int i0 = corner;
		int i1 = ((corner + 1) % 4);
		int i2 = ((corner + 2) % 4);
		int i3 = ((corner + 3) % 4);

		if ((corner & 1) == 1)
		{
			if (sin > cos)
			{
				cos /= sin;
				sin = 1f;

				if (invert)
				{
					xy[i1].x = Mathf.Lerp(xy[i0].x, xy[i2].x, cos);
					xy[i2].x = xy[i1].x;
				}
			}
			else if (cos > sin)
			{
				sin /= cos;
				cos = 1f;

				if (!invert)
				{
					xy[i2].y = Mathf.Lerp(xy[i0].y, xy[i2].y, sin);
					xy[i3].y = xy[i2].y;
				}
			}
			else
			{
				cos = 1f;
				sin = 1f;
			}

			if (!invert) xy[i3].x = Mathf.Lerp(xy[i0].x, xy[i2].x, cos);
			else xy[i1].y = Mathf.Lerp(xy[i0].y, xy[i2].y, sin);
		}
		else
		{
			if (cos > sin)
			{
				sin /= cos;
				cos = 1f;

				if (!invert)
				{
					xy[i1].y = Mathf.Lerp(xy[i0].y, xy[i2].y, sin);
					xy[i2].y = xy[i1].y;
				}
			}
			else if (sin > cos)
			{
				cos /= sin;
				sin = 1f;

				if (invert)
				{
					xy[i2].x = Mathf.Lerp(xy[i0].x, xy[i2].x, cos);
					xy[i3].x = xy[i2].x;
				}
			}
			else
			{
				cos = 1f;
				sin = 1f;
			}

			if (invert) xy[i3].y = Mathf.Lerp(xy[i0].y, xy[i2].y, sin);
			else xy[i1].x = Mathf.Lerp(xy[i0].x, xy[i2].x, cos);
		}
	}

	#endregion

	public virtual void CalculateLayoutInputHorizontal() { }
	public virtual void CalculateLayoutInputVertical() { }

	public virtual float minWidth { get { return 0; } }

	public virtual float preferredWidth
	{
		get
		{
			if (overrideSprite == null)
				return 0;
			if (type == Type.Sliced || type == Type.Tiled)
				return DataUtility.GetMinSize(overrideSprite).x / pixelsPerUnit;
			return overrideSprite.rect.size.x / pixelsPerUnit;
		}
	}

	public virtual float flexibleWidth { get { return -1; } }

	public virtual float minHeight { get { return 0; } }

	public virtual float preferredHeight
	{
		get
		{
			if (overrideSprite == null)
				return 0;
			if (type == Type.Sliced || type == Type.Tiled)
				return DataUtility.GetMinSize(overrideSprite).y / pixelsPerUnit;
			return overrideSprite.rect.size.y / pixelsPerUnit;
		}
	}

	public virtual float flexibleHeight { get { return -1; } }

	public virtual int layoutPriority { get { return 0; } }

	public virtual bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera)
	{
		if (m_EventAlphaThreshold >= 1)
			return true;

		Sprite sprite = overrideSprite;
		if (sprite == null)
			return true;

		Vector2 local;
		RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, screenPoint, eventCamera, out local);

		Rect rect = GetPixelAdjustedRect();

		// Convert to have lower left corner as reference point.
		local.x += rectTransform.pivot.x * rect.width;
		local.y += rectTransform.pivot.y * rect.height;

		local = MapCoordinate(local, rect);

		// Normalize local coordinates.
		Rect spriteRect = sprite.textureRect;
		Vector2 normalized = new Vector2(local.x / spriteRect.width, local.y / spriteRect.height);

		// Convert to texture space.
		float x = Mathf.Lerp(spriteRect.x, spriteRect.xMax, normalized.x) / sprite.texture.width;
		float y = Mathf.Lerp(spriteRect.y, spriteRect.yMax, normalized.y) / sprite.texture.height;

		try
		{
			return sprite.texture.GetPixelBilinear(x, y).a >= m_EventAlphaThreshold;
		}
		catch (UnityException e)
		{
			Debug.LogError("Using clickAlphaThreshold lower than 1 on Image whose sprite texture cannot be read. " + e.Message + " Also make sure to disable sprite packing for this sprite.", this);
			return true;
		}
	}

	private Vector2 MapCoordinate(Vector2 local, Rect rect)
	{
		Rect spriteRect = sprite.rect;
		if (type == Type.Simple || type == Type.Filled)
			return new Vector2(local.x * spriteRect.width / rect.width, local.y * spriteRect.height / rect.height);

		Vector4 border = sprite.border;
		Vector4 adjustedBorder = GetAdjustedBorders(border / pixelsPerUnit, rect);

		for (int i = 0; i < 2; i++)
		{
			if (local[i] <= adjustedBorder[i])
				continue;

			if (rect.size[i] - local[i] <= adjustedBorder[i + 2])
			{
				local[i] -= (rect.size[i] - spriteRect.size[i]);
				continue;
			}

			if (type == Type.Sliced)
			{
				float lerp = Mathf.InverseLerp(adjustedBorder[i], rect.size[i] - adjustedBorder[i + 2], local[i]);
				local[i] = Mathf.Lerp(border[i], spriteRect.size[i] - border[i + 2], lerp);
				continue;
			}
			else
			{
				local[i] -= adjustedBorder[i];
				local[i] = Mathf.Repeat(local[i], spriteRect.size[i] - border[i] - border[i + 2]);
				local[i] += border[i];
				continue;
			}
		}

		return local;
	}
}