internal static void AddPolygon(DecalPolygon poly, Vector3 normal)
{
int ind1 = AddVertex(poly.vertices[0], normal);
for (int i = 1; i < poly.vertices.Count - 1; i++)
{
int ind2 = AddVertex(poly.vertices[i], normal);
int ind3 = AddVertex(poly.vertices[i + 1], normal);
bufIndices.Add(ind1);
bufIndices.Add(ind2);
bufIndices.Add(ind3);
}
}
internal static DecalPolygon ClipPolygon(DecalPolygon polygon, Plane plane)
{
bool[] positive = new bool[9];
int positiveCount = 0;
for (int i = 0; i < polygon.vertices.Count; i++)
{
positive[i] = !plane.GetSide(polygon.vertices[i]);
if (positive[i])
{
positiveCount++;
}
}
if (positiveCount == 0)
{
return(null);
}
if (positiveCount == polygon.vertices.Count)
{
return(polygon);
}
DecalPolygon tempPolygon = new DecalPolygon();
for (int i = 0; i < polygon.vertices.Count; i++)
{
int next = i + 1;
next %= polygon.vertices.Count;
if (positive[i])
{
tempPolygon.vertices.Add(polygon.vertices[i]);
}
if (positive[i] != positive[next])
{
Vector3 v1 = polygon.vertices[next];
Vector3 v2 = polygon.vertices[i];
Vector3 v = LineCast(plane, v1, v2);
tempPolygon.vertices.Add(v);
}
}
return(tempPolygon);
}
internal static void BuildDecalForObject(Decal decal, GameObject affectedObject)
{
var skinnedMeshRenderer = affectedObject.GetComponent<SkinnedMeshRenderer>();
var meshFilter = affectedObject.GetComponent<MeshFilter>();
Mesh affectedMesh = skinnedMeshRenderer == null ? meshFilter.sharedMesh : skinnedMeshRenderer.sharedMesh;
if (affectedMesh == null) return;
float maxAngle = decal.maxAngle;
Plane right = new Plane(Vector3.right, Vector3.right / 2f);
Plane left = new Plane(-Vector3.right, -Vector3.right / 2f);
Plane top = new Plane(Vector3.up, Vector3.up / 2f);
Plane bottom = new Plane(-Vector3.up, -Vector3.up / 2f);
Plane front = new Plane(Vector3.forward, Vector3.forward / 2f);
Plane back = new Plane(-Vector3.forward, -Vector3.forward / 2f);
Vector3[] vertices = affectedMesh.vertices;
int[] triangles = affectedMesh.triangles;
int startVertexCount = bufVertices.Count;
Matrix4x4 matrix = decal.transform.worldToLocalMatrix * affectedObject.transform.localToWorldMatrix;
for (int i = 0; i < triangles.Length; i += 3)
{
int i1 = triangles[i];
int i2 = triangles[i + 1];
int i3 = triangles[i + 2];
Vector3 v1 = matrix.MultiplyPoint(vertices[i1]);
Vector3 v2 = matrix.MultiplyPoint(vertices[i2]);
Vector3 v3 = matrix.MultiplyPoint(vertices[i3]);
Vector3 side1 = v2 - v1;
Vector3 side2 = v3 - v1;
Vector3 normal = Vector3.Cross(side1, side2).normalized;
if (Vector3.Angle(-Vector3.forward, normal) >= maxAngle) continue;
DecalPolygon poly = new DecalPolygon(v1, v2, v3);
poly = DecalPolygon.ClipPolygon(poly, right);
if (poly == null) continue;
poly = DecalPolygon.ClipPolygon(poly, left);
if (poly == null) continue;
poly = DecalPolygon.ClipPolygon(poly, top);
if (poly == null) continue;
poly = DecalPolygon.ClipPolygon(poly, bottom);
if (poly == null) continue;
poly = DecalPolygon.ClipPolygon(poly, front);
if (poly == null) continue;
poly = DecalPolygon.ClipPolygon(poly, back);
if (poly == null) continue;
AddPolygon(poly, normal);
}
GenerateTexCoords(startVertexCount, decal.sprite);
}