/// <summary>
/// 增加面
/// </summary>
protected static void AddEdge(MeshUtilData data, int aX, int aY, DirectionEnum direction)
{
Vector2 size = new Vector2(1.0f / data.width, 1.0f / data.height);
Vector2 uv = new Vector3(aX * size.x, aY * size.y);
Vector2 P = uv - Vector2.one * 0.5f;
uv += size * 0.5f;
Vector2 P2 = P;
Vector3 normal;
if (direction == DirectionEnum.UP)
{
P += size;
P2.y += size.y;
normal = Vector3.up;
}
else if (direction == DirectionEnum.Left)
{
P.y += size.y;
normal = Vector3.left;
}
else if (direction == DirectionEnum.Down)
{
P2.x += size.x;
normal = Vector3.down;
}
else
{
P2 += size;
P.x += size.x;
normal = Vector3.right;
}
AddQuad(data, P, P2, Vector3.forward * data.depth, normal, uv, uv, false);
}
/// <summary>
/// 增加面
/// </summary>
protected static void AddQuad(
MeshUtilData data,
Vector3 aFirstEdgeP1, Vector3 aFirstEdgeP2, Vector3 aSecondRelative, Vector3 aNormal, Vector2 aUV1, Vector2 aUV2, bool aFlipUVs)
{
data.vertices.Add(aFirstEdgeP1);
data.vertices.Add(aFirstEdgeP2);
data.vertices.Add(aFirstEdgeP2 + aSecondRelative);
data.vertices.Add(aFirstEdgeP1 + aSecondRelative);
data.normals.Add(aNormal);
data.normals.Add(aNormal);
data.normals.Add(aNormal);
data.normals.Add(aNormal);
if (aFlipUVs)
{
data.texCoords.Add(new Vector2(aUV1.x, aUV1.y));
data.texCoords.Add(new Vector2(aUV2.x, aUV1.y));
data.texCoords.Add(new Vector2(aUV2.x, aUV2.y));
data.texCoords.Add(new Vector2(aUV1.x, aUV2.y));
}
else
{
data.texCoords.Add(new Vector2(aUV1.x, aUV1.y));
data.texCoords.Add(new Vector2(aUV1.x, aUV2.y));
data.texCoords.Add(new Vector2(aUV2.x, aUV2.y));
data.texCoords.Add(new Vector2(aUV2.x, aUV1.y));
}
}
/// <summary>
/// 通过图片创建 mesh
/// </summary>
/// <param name="data"></param>
/// <returns></returns>
public static Mesh GenerateMeshPicture(MeshUtilData data)
{
//添加前后
AddQuad(data,
new Vector3(-0.5f, -0.5f, 0), new Vector3(-0.5f, 0.5f, 0), Vector3.right, Vector3.back, Vector2.zero, Vector2.one, false);
AddQuad(data,
new Vector3(-0.5f, -0.5f, data.depth), new Vector3(0.5f, -0.5f, data.depth), Vector3.up, Vector3.forward, Vector2.zero, Vector2.one, true);
for (int y = 0; y < data.height; y++) // bottom to top
{
for (int x = 0; x < data.width; x++) // left to right
{
if (HasPixel(data, x, y))
{
if (x == 0 || !HasPixel(data, x - 1, y))
{
AddEdge(data, x, y, DirectionEnum.Left);
}
if (x == data.width - 1 || !HasPixel(data, x + 1, y))
{
AddEdge(data, x, y, DirectionEnum.Right);
}
if (y == 0 || !HasPixel(data, x, y - 1))
{
AddEdge(data, x, y, DirectionEnum.Down);
}
if (y == data.height - 1 || !HasPixel(data, x, y + 1))
{
AddEdge(data, x, y, DirectionEnum.UP);
}
}
}
}
var mesh = new Mesh();
mesh.vertices = data.vertices.ToArray();
mesh.normals = data.normals.ToArray();
mesh.uv = data.texCoords.ToArray();
int[] quads = new int[data.vertices.Count];
for (int i = 0; i < quads.Length; i++)
{
quads[i] = i;
}
mesh.SetIndices(quads, MeshTopology.Quads, 0);
return(mesh);
}
protected static bool HasPixel(MeshUtilData data, int aX, int aY)
{
return(data.colors[aX + aY * data.width].a > data.alphaTheshold);
}