public void BuildMapMesh(TileMapData mapData,
int colOffset, int rowOffset, int width, int height, float tileSize)
{
// purge existing
ClearMeshes();
// count number of actual tiles
int numTiles = 0;
for (int r = rowOffset; r < (rowOffset + height); r++)
{
for (int c = colOffset; c < (colOffset + width); c++)
{
if (mapData.GetTile(r, c) != null)
{
numTiles++;
}
}
}
// sizing
int numVertices = numTiles * 4;
int numTriangles = numTiles * 2 * 3;
float halfSize = tileSize / 2f;
// warn if we hit the Unity vert limit
if (numVertices > 65000)
{
throw new TileMapException("Number of required vertices (" + numVertices + ") exceeds Unity max of 65000!");
}
// vert offsets
Vector3 v0Offset = new Vector3(-halfSize, halfSize, 0f);
Vector3 v1Offset = new Vector3(halfSize, halfSize, 0f);
Vector3 v2Offset = new Vector3(halfSize, -halfSize, 0f);
Vector3 v3Offset = new Vector3(-halfSize, -halfSize, 0f);
// create vertices and triangles for each tile
Vector3[] vertices = new Vector3[numVertices];
Vector3[] normals = new Vector3[numVertices];
Vector2[] uvs = new Vector2[numVertices];
int[] triangles = new int[numTriangles];
/* Tile mesh setup per tile:
*
* v0 v1
* +-----------+
* | \ |
* | \ T0 |
* | X |
* | T1 \ |
* | \ |
* +-----------+
* v3 v2
*
* X = tile world position (centered)
* Triangle 0 = [v0, v1, v2]
* Triangle 1 = [v0, v2, v3]
*/
int curVertIdx = 0;
int curTriIdx = 0;
// start at 0,0 building up rows and columns of tiles from our current
// transform origin
for (int r = 0; r < height; r++)
{
for (int c = 0; c < width; c++)
{
// get tile index
int tileIdx = mapData.TileIndex(r + rowOffset, c + colOffset);
// get tile
Tile t = mapData.GetTile(tileIdx);
// only render mesh and texture here if there's actually a tile
if (t != null)
{
// calc tile world position
Vector3 tilePos = new Vector3(c * tileSize, r * tileSize, 0f);
// set tile vertices
vertices[curVertIdx] = tilePos + v0Offset;
vertices[curVertIdx + 1] = tilePos + v1Offset;
vertices[curVertIdx + 2] = tilePos + v2Offset;
vertices[curVertIdx + 3] = tilePos + v3Offset;
// set tile uvs
uvs[curVertIdx] = t.UV(0);
uvs[curVertIdx + 1] = t.UV(1);
uvs[curVertIdx + 2] = t.UV(2);
uvs[curVertIdx + 3] = t.UV(3);
// set tile triangles
// t0
triangles[curTriIdx] = (curVertIdx);
triangles[curTriIdx + 1] = (curVertIdx + 1);
triangles[curTriIdx + 2] = (curVertIdx + 2);
// t1
triangles[curTriIdx + 3] = (curVertIdx);
triangles[curTriIdx + 4] = (curVertIdx + 2);
triangles[curTriIdx + 5] = (curVertIdx + 3);
curVertIdx += 4;
curTriIdx += 6;
}
}
}
// all normals are the same
for (int i = 0; i < numVertices; i++)
{
normals[i] = Vector3.back;
}
// create the Mesh
Mesh tileMesh = new Mesh();
tileMesh.vertices = vertices;
tileMesh.triangles = triangles;
tileMesh.uv = uvs;
tileMesh.normals = normals;
// assign the mesh
meshFilter.mesh = tileMesh;
UpdateCollider();
}