UnityEditor.HandleUtility.ApplyWireMaterial C# (CSharp) Method

        internal static void ApplyWireMaterial()
        {
            handleWireMaterial.SetPass(0);
            int textureIndex = (Camera.current == null) ? s_HandleWireTextureIndex2D : s_HandleWireTextureIndex;
            Internal_SetHandleWireTextureIndex(textureIndex);
        }

        public override void OnPreviewGUI(Rect r, GUIStyle background)
        {
            if (Event.current.type == EventType.Repaint)
            {
                background.Draw(r, false, false, false, false);
            }
            Texture       texture       = this.target as Texture;
            RenderTexture renderTexture = texture as RenderTexture;

            if (renderTexture != null)
            {
                if (!SystemInfo.SupportsRenderTextureFormat(renderTexture.format))
                {
                    return;
                }
                renderTexture.Create();
            }
            if (this.IsCubemap())
            {
                this.m_CubemapPreview.OnPreviewGUI(texture, r, background);
                return;
            }
            int   num  = Mathf.Max(texture.width, 1);
            int   num2 = Mathf.Max(texture.height, 1);
            float mipLevelForRendering = this.GetMipLevelForRendering();
            float num3 = Mathf.Min(Mathf.Min(r.width / (float)num, r.height / (float)num2), 1f);
            Rect  rect = new Rect(r.x, r.y, (float)num * num3, (float)num2 * num3);

            PreviewGUI.BeginScrollView(r, this.m_Pos, rect, "PreHorizontalScrollbar", "PreHorizontalScrollbarThumb");
            float mipMapBias = texture.mipMapBias;

            TextureUtil.SetMipMapBiasNoDirty(texture, mipLevelForRendering - this.Log2((float)num / rect.width));
            FilterMode filterMode = texture.filterMode;

            TextureUtil.SetFilterModeNoDirty(texture, FilterMode.Point);
            if (this.m_ShowAlpha)
            {
                EditorGUI.DrawTextureAlpha(rect, texture);
            }
            else
            {
                Texture2D texture2D = texture as Texture2D;
                if (texture2D != null && texture2D.alphaIsTransparency)
                {
                    EditorGUI.DrawTextureTransparent(rect, texture);
                }
                else
                {
                    EditorGUI.DrawPreviewTexture(rect, texture);
                }
            }
            if (rect.width > 32f && rect.height > 32f)
            {
                string           assetPath       = AssetDatabase.GetAssetPath(texture);
                TextureImporter  textureImporter = AssetImporter.GetAtPath(assetPath) as TextureImporter;
                SpriteMetaData[] array           = (!(textureImporter != null)) ? null : textureImporter.spritesheet;
                if (array != null && textureImporter.spriteImportMode == SpriteImportMode.Multiple)
                {
                    Rect rect2 = default(Rect);
                    Rect rect3 = default(Rect);
                    GUI.CalculateScaledTextureRects(rect, ScaleMode.StretchToFill, (float)texture.width / (float)texture.height, ref rect2, ref rect3);
                    int width  = texture.width;
                    int height = texture.height;
                    textureImporter.GetWidthAndHeight(ref width, ref height);
                    float num4 = (float)texture.width / (float)width;
                    HandleUtility.ApplyWireMaterial();
                    GL.PushMatrix();
                    GL.MultMatrix(Handles.matrix);
                    GL.Begin(1);
                    GL.Color(new Color(1f, 1f, 1f, 0.5f));
                    SpriteMetaData[] array2 = array;
                    for (int i = 0; i < array2.Length; i++)
                    {
                        SpriteMetaData spriteMetaData = array2[i];
                        Rect           rect4          = spriteMetaData.rect;
                        this.DrawRect(new Rect
                        {
                            xMin = rect2.xMin + rect2.width * (rect4.xMin / (float)texture.width * num4),
                            xMax = rect2.xMin + rect2.width * (rect4.xMax / (float)texture.width * num4),
                            yMin = rect2.yMin + rect2.height * (1f - rect4.yMin / (float)texture.height * num4),
                            yMax = rect2.yMin + rect2.height * (1f - rect4.yMax / (float)texture.height * num4)
                        });
                    }
                    GL.End();
                    GL.PopMatrix();
                }
            }
            TextureUtil.SetMipMapBiasNoDirty(texture, mipMapBias);
            TextureUtil.SetFilterModeNoDirty(texture, filterMode);
            this.m_Pos = PreviewGUI.EndScrollView();
            if (mipLevelForRendering != 0f)
            {
                EditorGUI.DropShadowLabel(new Rect(r.x, r.y, r.width, 20f), "Mip " + mipLevelForRendering);
            }
        }