Image.cs

using System;
using System.Collections.Generic;
using System.Text;
using UnityEngine.Serialization;

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

    [AddComponentMenu("UI/Image", 11)]
    public class Image : 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,
        }

        [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(); } }

        // 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 Image()
        {
            useLegacyMeshGeneration = false;
        }

        /// <summary>
        /// Image's texture comes from the UnityEngine.Image.
        /// </summary>
        public override Texture mainTexture
        {
            get
            {
                if (overrideSprite == null)
                {
                    if (material != null && material.mainTexture != null)
                    {
                        return material.mainTexture;
                    }
                    return s_WhiteTexture;
                }

                return 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 : Sprites.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 = 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 OnPopulateMesh(VertexHelper toFill)
        {
            if (overrideSprite == null)
            {
                base.OnPopulateMesh(toFill);
                return;
            }

            switch (type)
            {
                case Type.Simple:
                    GenerateSimpleSprite(toFill, m_PreserveAspect);
                    break;
                case Type.Sliced:
                    GenerateSlicedSprite(toFill);
                    break;
                case Type.Tiled:
                    GenerateTiledSprite(toFill);
                    break;
                case Type.Filled:
                    GenerateFilledSprite(toFill, m_PreserveAspect);
                    break;
            }
        }

        #region Various fill functions
        /// <summary>
        /// Generate vertices for a simple Image.
        /// </summary>
        void GenerateSimpleSprite(VertexHelper vh, bool lPreserveAspect)
        {
            Vector4 v = GetDrawingDimensions(lPreserveAspect);
            var uv = (overrideSprite != null) ? Sprites.DataUtility.GetOuterUV(overrideSprite) : Vector4.zero;

            var color32 = color;
            vh.Clear();
            vh.AddVert(new Vector3(v.x, v.y), color32, new Vector2(uv.x, uv.y));
            vh.AddVert(new Vector3(v.x, v.w), color32, new Vector2(uv.x, uv.w));
            vh.AddVert(new Vector3(v.z, v.w), color32, new Vector2(uv.z, uv.w));
            vh.AddVert(new Vector3(v.z, v.y), color32, new Vector2(uv.z, uv.y));

            vh.AddTriangle(0, 1, 2);
            vh.AddTriangle(2, 3, 0);
        }

        /// <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];

        private void GenerateSlicedSprite(VertexHelper toFill)
        {
            if (!hasBorder)
            {
                GenerateSimpleSprite(toFill, false);
                return;
            }

            Vector4 outer, inner, padding, border;

            if (overrideSprite != null)
            {
                outer = Sprites.DataUtility.GetOuterUV(overrideSprite);
                inner = Sprites.DataUtility.GetInnerUV(overrideSprite);
                padding = Sprites.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;

            s_VertScratch[0] = new Vector2(padding.x, padding.y);
            s_VertScratch[3] = new Vector2(rect.width - padding.z, rect.height - padding.w);

            s_VertScratch[1].x = border.x;
            s_VertScratch[1].y = border.y;
            s_VertScratch[2].x = rect.width - border.z;
            s_VertScratch[2].y = rect.height - border.w;

            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);

            toFill.Clear();

            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;

                    AddQuad(toFill,
                        new Vector2(s_VertScratch[x].x, s_VertScratch[y].y),
                        new Vector2(s_VertScratch[x2].x, s_VertScratch[y2].y),
                        color,
                        new Vector2(s_UVScratch[x].x, s_UVScratch[y].y),
                        new Vector2(s_UVScratch[x2].x, s_UVScratch[y2].y));
                }
            }
        }

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

        void GenerateTiledSprite(VertexHelper toFill)
        {
            Vector4 outer, inner, border;
            Vector2 spriteSize;

            if (overrideSprite != null)
            {
                outer = Sprites.DataUtility.GetOuterUV(overrideSprite);
                inner = Sprites.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);

            var uvMin = new Vector2(inner.x, inner.y);
            var uvMax = new Vector2(inner.z, inner.w);

            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.x;
            float xMax = rect.width - border.z;
            float yMin = border.y;
            float yMax = rect.height - border.w;

            toFill.Clear();
            var clipped = uvMax;

            // if either with is zero we cant tile so just assume it was the full width.
            if (tileWidth == 0)
                tileWidth = xMax - xMin;

            if (tileHeight == 0)
                tileHeight = yMax - yMin;

            if (m_FillCenter)
            {
                for (float y1 = yMin; y1 < yMax; y1 += tileHeight)
                {
                    float y2 = y1 + tileHeight;
                    if (y2 > yMax)
                    {
                        clipped.y = uvMin.y + (uvMax.y - uvMin.y) * (yMax - y1) / (y2 - y1);
                        y2 = yMax;
                    }

                    clipped.x = uvMax.x;
                    for (float x1 = xMin; x1 < xMax; x1 += tileWidth)
                    {
                        float x2 = x1 + tileWidth;
                        if (x2 > xMax)
                        {
                            clipped.x = uvMin.x + (uvMax.x - uvMin.x) * (xMax - x1) / (x2 - x1);
                            x2 = xMax;
                        }
                        AddQuad(toFill, new Vector2(x1, y1) + rect.position, new Vector2(x2, y2) + rect.position, color, uvMin, clipped);
                    }
                }
            }

            if (hasBorder)
            {
                clipped = uvMax;
                for (float y1 = yMin; y1 < yMax; y1 += tileHeight)
                {
                    float y2 = y1 + tileHeight;
                    if (y2 > yMax)
                    {
                        clipped.y = uvMin.y + (uvMax.y - uvMin.y) * (yMax - y1) / (y2 - y1);
                        y2 = yMax;
                    }
                    AddQuad(toFill,
                        new Vector2(0, y1) + rect.position,
                        new Vector2(xMin, y2) + rect.position,
                        color,
                        new Vector2(outer.x, uvMin.y),
                        new Vector2(uvMin.x, clipped.y));
                    AddQuad(toFill,
                        new Vector2(xMax, y1) + rect.position,
                        new Vector2(rect.width, y2) + rect.position,
                        color,
                        new Vector2(uvMax.x, uvMin.y),
                        new Vector2(outer.z, clipped.y));
                }

                // Bottom and top tiled border
                clipped = uvMax;
                for (float x1 = xMin; x1 < xMax; x1 += tileWidth)
                {
                    float x2 = x1 + tileWidth;
                    if (x2 > xMax)
                    {
                        clipped.x = uvMin.x + (uvMax.x - uvMin.x) * (xMax - x1) / (x2 - x1);
                        x2 = xMax;
                    }
                    AddQuad(toFill,
                        new Vector2(x1, 0) + rect.position,
                        new Vector2(x2, yMin) + rect.position,
                        color,
                        new Vector2(uvMin.x, outer.y),
                        new Vector2(clipped.x, uvMin.y));
                    AddQuad(toFill,
                        new Vector2(x1, yMax) + rect.position,
                        new Vector2(x2, rect.height) + rect.position,
                        color,
                        new Vector2(uvMin.x, uvMax.y),
                        new Vector2(clipped.x, outer.w));
                }

                // Corners
                AddQuad(toFill,
                    new Vector2(0, 0) + rect.position,
                    new Vector2(xMin, yMin) + rect.position,
                    color,
                    new Vector2(outer.x, outer.y),
                    new Vector2(uvMin.x, uvMin.y));
                AddQuad(toFill,
                    new Vector2(xMax, 0) + rect.position,
                    new Vector2(rect.width, yMin) + rect.position,
                    color,
                    new Vector2(uvMax.x, outer.y),
                    new Vector2(outer.z, uvMin.y));
                AddQuad(toFill,
                    new Vector2(0, yMax) + rect.position,
                    new Vector2(xMin, rect.height) + rect.position,
                    color,
                    new Vector2(outer.x, uvMax.y),
                    new Vector2(uvMin.x, outer.w));
                AddQuad(toFill,
                    new Vector2(xMax, yMax) + rect.position,
                    new Vector2(rect.width, rect.height) + rect.position,
                    color,
                    new Vector2(uvMax.x, uvMax.y),
                    new Vector2(outer.z, outer.w));
            }
        }

        static void AddQuad(VertexHelper vertexHelper, Vector3[] quadPositions, Color32 color, Vector3[] quadUVs)
        {
            int startIndex = vertexHelper.currentVertCount;

            for (int i = 0; i < 4; ++i)
                vertexHelper.AddVert(quadPositions[i], color, quadUVs[i]);

            vertexHelper.AddTriangle(startIndex, startIndex + 1, startIndex + 2);
            vertexHelper.AddTriangle(startIndex + 2, startIndex + 3, startIndex);
        }

        static void AddQuad(VertexHelper vertexHelper, Vector2 posMin, Vector2 posMax, Color32 color, Vector2 uvMin, Vector2 uvMax)
        {
            int startIndex = vertexHelper.currentVertCount;

            vertexHelper.AddVert(new Vector3(posMin.x, posMin.y, 0), color, new Vector2(uvMin.x, uvMin.y));
            vertexHelper.AddVert(new Vector3(posMin.x, posMax.y, 0), color, new Vector2(uvMin.x, uvMax.y));
            vertexHelper.AddVert(new Vector3(posMax.x, posMax.y, 0), color, new Vector2(uvMax.x, uvMax.y));
            vertexHelper.AddVert(new Vector3(posMax.x, posMin.y, 0), color, new Vector2(uvMax.x, uvMin.y));

            vertexHelper.AddTriangle(startIndex, startIndex + 1, startIndex + 2);
            vertexHelper.AddTriangle(startIndex + 2, startIndex + 3, startIndex);
        }

        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];
                if (rect.size[axis] < combinedBorders && combinedBorders != 0)
                {
                    float borderScaleRatio = rect.size[axis] / combinedBorders;
                    border[axis] *= borderScaleRatio;
                    border[axis + 2] *= borderScaleRatio;
                }
            }
            return border;
        }

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

        static readonly Vector3[] s_Xy = new Vector3[4];
        static readonly Vector3[] s_Uv = new Vector3[4];
        void GenerateFilledSprite(VertexHelper toFill, bool preserveAspect)
        {
            toFill.Clear();

            if (m_FillAmount < 0.001f)
                return;

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

            float tx0 = outer.x;
            float ty0 = outer.y;
            float tx1 = outer.z;
            float ty1 = outer.w;

            // 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 = (tx1 - tx0) * m_FillAmount;

                    if (m_FillOrigin == 1)
                    {
                        v.x = v.z - (v.z - v.x) * m_FillAmount;
                        tx0 = tx1 - fill;
                    }
                    else
                    {
                        v.z = v.x + (v.z - v.x) * m_FillAmount;
                        tx1 = tx0 + fill;
                    }
                }
                else if (fillMethod == FillMethod.Vertical)
                {
                    float fill = (ty1 - ty0) * m_FillAmount;

                    if (m_FillOrigin == 1)
                    {
                        v.y = v.w - (v.w - v.y) * m_FillAmount;
                        ty0 = ty1 - fill;
                    }
                    else
                    {
                        v.w = v.y + (v.w - v.y) * m_FillAmount;
                        ty1 = ty0 + 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] = new Vector2(tx0, ty0);
            s_Uv[1] = new Vector2(tx0, ty1);
            s_Uv[2] = new Vector2(tx1, ty1);
            s_Uv[3] = new Vector2(tx1, ty0);

            {
                if (m_FillAmount < 1f && m_FillMethod != FillMethod.Horizontal && m_FillMethod != FillMethod.Vertical)
                {
                    if (fillMethod == FillMethod.Radial90)
                    {
                        if (RadialCut(s_Xy, s_Uv, m_FillAmount, m_FillClockwise, m_FillOrigin))
                            AddQuad(toFill, s_Xy, color, s_Uv);
                    }
                    else 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)))
                            {
                                AddQuad(toFill, s_Xy, color, s_Uv);
                            }
                        }
                    }
                    else 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)))
                                AddQuad(toFill, s_Xy, color, s_Uv);
                        }
                    }
                }
                else
                {
                    AddQuad(toFill, s_Xy, color, s_Uv);
                }
            }
        }

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

        static bool RadialCut(Vector3[] xy, Vector3[] 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(Vector3[] 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 Sprites.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 Sprites.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;
        }
    }
}