/// <summary>
/// Modifies the mesh.
/// </summary>
public override void ModifyMesh(VertexHelper vh)
{
// Invalid.
if (!isActiveAndEnabled || vh.currentVertCount == 0 || (vh.currentVertCount % 4 != 0 && vh.currentVertCount % 6 != 0))
{
return;
}
_rect = graphic.rectTransform.rect;
var quad = UIVertexUtil.s_QuadVerts;
var inputVerts = UIVertexUtil.s_InputVerts;
var outputVerts = UIVertexUtil.s_OutputVerts;
inputVerts.Clear();
outputVerts.Clear();
vh.GetUIVertexStream(inputVerts);
for (int i = 0; i < inputVerts.Count; i += 6)
{
if (graphic is Text)
{
quad[0] = inputVerts[i + 4]; // bottom-left
quad[1] = inputVerts[i + 0]; // top-left
quad[2] = inputVerts[i + 1]; // top-right
quad[3] = inputVerts[i + 2]; // bottom-right
}
else
{
quad[0] = inputVerts[i + 0]; // bottom-left
quad[1] = inputVerts[i + 1]; // top-left
quad[2] = inputVerts[i + 2]; // top-right
quad[3] = inputVerts[i + 4]; // bottom-right
}
var originalQuad = new UIVertex[quad.Length];
Array.Copy(quad, originalQuad, quad.Length);
AddMirrorReflectedQuad(quad, outputVerts); // reflected quad
UIVertexUtil.AddQuadToStream(originalQuad, outputVerts); // origin quad
}
vh.Clear();
vh.AddUIVertexTriangleStream(outputVerts);
inputVerts.Clear();
outputVerts.Clear();
}
void AddMirrorReflectedQuad(UIVertex[] quad, List <UIVertex> result)
{
// Read the existing quad vertices
UIVertex v0 = quad[0]; // bottom-left
UIVertex v1 = quad[1]; // top-left
UIVertex v2 = quad[2]; // top-right
UIVertex v3 = quad[3]; // bottom-right
// Reflection is unnecessary.
if (m_Height < (v0.position.y - _rect.yMin) && m_Height < (v3.position.y - _rect.yMin))
{
return;
}
// Trim quad.
if (m_Height < (v1.position.y - _rect.yMin) || m_Height < (v2.position.y - _rect.yMin))
{
v1 = UIVertexUtil.Lerp(v0, v1, GetLerpFactor(v0.position.y, v1.position.y));
v2 = UIVertexUtil.Lerp(v3, v2, GetLerpFactor(v3.position.y, v2.position.y));
}
// Calculate reflected position and color.
MirrorReflectVertex(ref v0);
MirrorReflectVertex(ref v1);
MirrorReflectVertex(ref v2);
MirrorReflectVertex(ref v3);
// Reverse quad index.
quad[0] = v1;
quad[1] = v0;
quad[2] = v3;
quad[3] = v2;
// Add reflected quad.
UIVertexUtil.AddQuadToStream(quad, result);
}