ugui源码阅读 - Image九宫格绘制

public static readonly Vector2[] s_VertScratch = new Vector2[4];
public 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 (activeSprite != null)
    {
        outer = Sprites.DataUtility.GetOuterUV(activeSprite);
        inner = Sprites.DataUtility.GetInnerUV(activeSprite);
        padding = Sprites.DataUtility.GetPadding(activeSprite);
        border = activeSprite.border;
    }
    else
    {
        outer = Vector4.zero;
        inner = Vector4.zero;
        padding = Vector4.zero;
        border = Vector4.zero;
    }

    Rect rect = GetPixelAdjustedRect();
    Vector4 adjustedBorders = 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 = adjustedBorders.x;
    s_VertScratch[1].y = adjustedBorders.y;

    s_VertScratch[2].x = rect.width - adjustedBorders.z;
    s_VertScratch[2].y = rect.height - adjustedBorders.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));
        }
    }
}