static void AddQuad(UnityEngine.UI.VertexHelper vertexHelper, Vector2 posMin, Vector2 posMax, Color32 color)
{
int startIndex = vertexHelper.currentVertCount;
var v = UnityEngine.UIVertex.simpleVert;
v.position = new Vector3(posMin.x, posMin.y, 0);
v.color = color;
vertexHelper.AddVert(v);
v.position = new Vector3(posMin.x, posMax.y, 0);
v.color = color;
vertexHelper.AddVert(v);
v.position = new Vector3(posMax.x, posMax.y, 0);
v.color = color;
vertexHelper.AddVert(v);
v.position = new Vector3(posMax.x, posMin.y, 0);
v.color = color;
vertexHelper.AddVert(v);
vertexHelper.AddTriangle(startIndex, startIndex + 1, startIndex + 2);
vertexHelper.AddTriangle(startIndex + 2, startIndex + 3, startIndex);
}
