// Return values: 0 = no intersection,
// 1 = intersection,
// 2 = box is completely inside frustum
public int Intersect(BoundingBox box) {
var totalIn = 0;
foreach (var plane in Planes) {
var intersection = Plane.Intersects(plane, box);
if (intersection == PlaneIntersectionType.Back) return 0;
if (intersection == PlaneIntersectionType.Front) {
totalIn++;
}
}
if (totalIn == 6) {
return 2;
}
return 1;
}
private void BuildSkullGeometryBuffers()
{
try {
var min = new Vector3(float.MaxValue, float.MaxValue, float.MaxValue);
var max = new Vector3(float.MinValue, float.MinValue, float.MinValue);
var vertices = new List<Basic32>();
var indices = new List<int>();
var vcount = 0;
var tcount = 0;
using (var reader = new StreamReader("Models\\skull.txt")) {
var input = reader.ReadLine();
if (input != null)
// VertexCount: X
vcount = Convert.ToInt32(input.Split(new[] { ':' })[1].Trim());
input = reader.ReadLine();
if (input != null)
//TriangleCount: X
tcount = Convert.ToInt32(input.Split(new[] { ':' })[1].Trim());
// skip ahead to the vertex data
do {
input = reader.ReadLine();
} while (input != null && !input.StartsWith("{"));
// Get the vertices
for (int i = 0; i < vcount; i++) {
input = reader.ReadLine();
if (input != null) {
var vals = input.Split(new[] { ' ' });
var position = new Vector3(Convert.ToSingle(vals[0].Trim()), Convert.ToSingle(vals[1].Trim()), Convert.ToSingle(vals[2].Trim()));
vertices.Add(
new Basic32(
position,
new Vector3(
Convert.ToSingle(vals[3].Trim()),
Convert.ToSingle(vals[4].Trim()),
Convert.ToSingle(vals[5].Trim())),
new Vector2()
)
);
min = Vector3.Minimize(min, position);
max = Vector3.Maximize(max, position);
}
}
_skullBox = new BoundingBox(min, max);
// skip ahead to the index data
do {
input = reader.ReadLine();
} while (input != null && !input.StartsWith("{"));
// Get the indices
_skullIndexCount = 3 * tcount;
for (var i = 0; i < tcount; i++) {
input = reader.ReadLine();
if (input == null) {
break;
}
var m = input.Trim().Split(new[] { ' ' });
indices.Add(Convert.ToInt32(m[0].Trim()));
indices.Add(Convert.ToInt32(m[1].Trim()));
indices.Add(Convert.ToInt32(m[2].Trim()));
}
}
var vbd = new BufferDescription(Basic32.Stride * vcount, ResourceUsage.Immutable,
BindFlags.VertexBuffer, CpuAccessFlags.None, ResourceOptionFlags.None, 0);
_skullVB = new Buffer(Device, new DataStream(vertices.ToArray(), false, false), vbd);
var ibd = new BufferDescription(sizeof(int) * _skullIndexCount, ResourceUsage.Immutable,
BindFlags.IndexBuffer, CpuAccessFlags.None, ResourceOptionFlags.None, 0);
_skullIB = new Buffer(Device, new DataStream(indices.ToArray(), false, false), ibd);
} catch (Exception ex) {
MessageBox.Show(ex.Message);
}
}
public override void UpdateScene(float dt)
{
base.UpdateScene(dt);
if (Util.IsKeyDown(Keys.Up)) {
_cam.Walk(10.0f*dt);
}
if (Util.IsKeyDown(Keys.Down)) {
_cam.Walk(-10.0f * dt);
}
if (Util.IsKeyDown(Keys.Left)) {
_cam.Strafe(-10.0f * dt);
}
if (Util.IsKeyDown(Keys.Right)) {
_cam.Strafe(10.0f * dt);
}
if (Util.IsKeyDown(Keys.D1)) {
_frustumCullingEnabled = true;
}
if (Util.IsKeyDown(Keys.D2)) {
_frustumCullingEnabled = false;
}
if (Util.IsKeyDown(Keys.U)) {
_instancing = false;
}
if (Util.IsKeyDown(Keys.I)) {
_instancing = true;
}
if (Util.IsKeyDown(Keys.B)) {
_skullsOrBoxes = false;
}
if (Util.IsKeyDown(Keys.S)) {
_skullsOrBoxes = true;
}
_cam.UpdateViewMatrix();
_visibleObjectCount = 0;
if (_frustumCullingEnabled) {
var db = ImmediateContext.MapSubresource(_instanceBuffer, MapMode.WriteDiscard, MapFlags.None);
foreach (var instancedData in _instancedData) {
var w = instancedData.World;
var box = new BoundingBox(
Vector3.TransformCoordinate(_skullBox.Minimum, w),
Vector3.TransformCoordinate(_skullBox.Maximum, w)
);
if (_cam.Visible(box)) {
db.Data.Write(instancedData);
_visibleObjectCount++;
}
}
ImmediateContext.UnmapSubresource(_instanceBuffer, 0);
} else {
var db = ImmediateContext.MapSubresource(_instanceBuffer, MapMode.WriteDiscard, MapFlags.None);
foreach (var instancedData in _instancedData) {
db.Data.Write(instancedData);
_visibleObjectCount++;
}
ImmediateContext.UnmapSubresource(_instanceBuffer, 0);
}
MainWindowCaption = String.Format("Instancing and Culling Demo {0} objects visible out of {1}", _visibleObjectCount, _instancedData.Count);
}
