public void CreateMesh(Terrain terrain, Rectangle r, Device device) {
if (_vb != null) {
Util.ReleaseCom(ref _vb);
_vb = null;
}
var halfWidth = 0.5f * terrain.Width;
var halfDepth = 0.5f * terrain.Depth;
var patchWidth = terrain.Width / (terrain.Renderer.NumPatchVertCols - 1);
var patchDepth = terrain.Depth / (terrain.Renderer.NumPatchVertRows - 1);
var vertWidth = terrain.Info.CellSpacing;
var vertDepth = terrain.Info.CellSpacing;
var du = 1.0f / (terrain.Renderer.NumPatchVertCols - 1) / Terrain.CellsPerPatch;
var dv = 1.0f / (terrain.Renderer.NumPatchVertRows - 1) / Terrain.CellsPerPatch;
_verts = new List<TerrainCP>();
var min = new Vector3(float.MaxValue);
var max = new Vector3(float.MinValue);
for (int z = r.Top, z0 = 0; z <= r.Bottom; z++, z0++) {
var zp = halfDepth - r.Top / Terrain.CellsPerPatch * patchDepth - z0 * vertDepth;
for (int x = r.Left, x0 = 0; x <= r.Right; x++, x0++) {
var xp = -halfWidth + r.Left / Terrain.CellsPerPatch * patchWidth + x0 * vertWidth;
var pos = new Vector3(xp, terrain.Height(xp, zp), zp);
min = Vector3.Minimize(min, pos);
max = Vector3.Maximize(max, pos);
var uv = new Vector2(r.Left * du + x0 * du, r.Top * dv + z0 * dv);
var v = new TerrainCP(pos, uv, new Vector2());
_verts.Add(v);
}
}
Bounds = new BoundingBox(min, max);
var vbd = new BufferDescription(
TerrainCP.Stride * _verts.Count,
ResourceUsage.Immutable,
BindFlags.VertexBuffer,
CpuAccessFlags.None,
ResourceOptionFlags.None,
0
);
_vb = new Buffer(device, new DataStream(_verts.ToArray(), false, false), vbd);
}
private void BuildQuadPatchVB(Device device) {
var patchVerts = new TerrainCP[_numPatchVertices];
var halfWidth = 0.5f * _terrain.Width;
var halfDepth = 0.5f * _terrain.Depth;
var patchWidth = _terrain.Width / (NumPatchVertCols - 1);
var patchDepth = _terrain.Depth / (NumPatchVertRows - 1);
var du = 1.0f / (NumPatchVertCols - 1);
var dv = 1.0f / (NumPatchVertRows - 1);
for (var i = 0; i < NumPatchVertRows; i++) {
var z = halfDepth - i * patchDepth;
for (var j = 0; j < NumPatchVertCols; j++) {
var x = -halfWidth + j * patchWidth;
var vertId = i * NumPatchVertCols + j;
patchVerts[vertId] = new TerrainCP(
new Vector3(x, 0, z),
new Vector2(j * du, i * dv),
new Vector2()
);
}
}
for (var i = 0; i < NumPatchVertRows - 1; i++) {
for (var j = 0; j < NumPatchVertCols - 1; j++) {
var patchID = i * (NumPatchVertCols - 1) + j;
var vertID = i * NumPatchVertCols + j;
patchVerts[vertID].BoundsY = _patchBoundsY[patchID];
}
}
var vbd = new BufferDescription(
TerrainCP.Stride * patchVerts.Length,
ResourceUsage.Immutable,
BindFlags.VertexBuffer,
CpuAccessFlags.None,
ResourceOptionFlags.None, 0
);
_quadPatchVB = new Buffer(
device,
new DataStream(patchVerts, false, false),
vbd
);
}