/// <summary>
/// Updates the internal quadtree to make it identical to the given terrain quadtree.
/// Collects the tasks necessary to create the missing texture tiles, corresponding to newly created quads.
/// </summary>
/// <param name="parent">Parent quadtree.</param>
/// <param name="tree">Internal quadtree.</param>
/// <param name="quad">Quad.</param>
protected virtual void GetTiles(QuadTree parent, ref QuadTree tree, TerrainQuad quad)
{
// If tree not created, create a new tree and check if its tile is needed
if (tree == null)
{
tree = new QuadTree(parent);
tree.IsNeedTile = NeedTile(quad);
}
// If this trees tile is needed get a tile and add its task to the schedular if the task is not already done
if (tree.IsNeedTile && tree.Tile == null)
{
tree.Tile = Producer.GetTile(quad.Level, quad.Tx, quad.Ty);
if (!tree.Tile.Task.IsDone)
{
// If task not done schedule task
Schedular.Instance.Add(tree.Tile.Task);
}
}
if (!quad.IsLeaf && Producer.HasChildren(quad.Level, quad.Tx, quad.Ty))
{
for (byte i = 0; i < 4; ++i)
{
GetTiles(tree, ref tree.Children[i], quad.GetChild(i));
}
}
}
/// <summary>
/// Updates the internal quadtree to make it identical to the given terrain quadtree.
/// This method releases the texture tiles corresponding to deleted quads.
/// </summary>
/// <param name="tree">Internal quadtree.</param>
/// <param name="quad">Quad.</param>
protected virtual void PutTiles(QuadTree tree, TerrainQuad quad)
{
if (tree == null)
{
return;
}
// Check if this tile is needed, if not put tile.
tree.IsNeedTile = NeedTile(quad);
if (!tree.IsNeedTile && tree.Tile != null)
{
Producer.PutTile(tree.Tile);
tree.Tile = null;
}
// If this qiad is a leaf then all children of the tree are not needed
if (quad.IsLeaf)
{
if (!tree.IsLeaf)
{
tree.RecursiveDeleteChildren(this);
}
}
else if (Producer.HasChildren(quad.Level, quad.Tx, quad.Ty))
{
for (byte i = 0; i < 4; ++i)
{
PutTiles(tree.Children[i], quad.GetChild(i));
}
}
}
private void FindDrawableQuads(TerrainQuad quad, List <TileSampler> samplers)
{
quad.Drawable = false;
if (!quad.IsVisible)
{
quad.Drawable = true;
return;
}
if (quad.IsLeaf)
{
if (FindDrawableSamplers(quad, samplers))
{
return;
}
}
else
{
byte drawableCount = 0;
for (byte i = 0; i < 4; ++i)
{
FindDrawableQuads(quad.GetChild(i), samplers);
if (quad.GetChild(i).Drawable)
{
++drawableCount;
}
}
if (drawableCount < 4)
{
if (FindDrawableSamplers(quad, samplers))
{
return;
}
}
}
quad.Drawable = true;
}
private void DrawQuad(TerrainNode node, TerrainQuad quad, List <TileSampler> samplers)
{
if (!quad.IsVisible)
{
return;
}
if (!quad.Drawable)
{
return;
}
if (quad.IsLeaf)
{
MPB.Clear();
for (int i = 0; i < samplers.Count; ++i)
{
// Set the unifroms needed to draw the texture for this sampler
samplers[i].SetTile(MPB, quad.Level, quad.Tx, quad.Ty);
}
// Set the uniforms unique to each quad
node.SetPerQuadUniforms(quad, MPB);
DrawNode(node);
}
else
{
// Draw quads in a order based on distance to camera
var order = new byte[4];
var cameraX = node.LocalCameraPosition.x;
var cameraY = node.LocalCameraPosition.y;
var quadX = quad.Oy + quad.Length / 2.0;
var quadY = quad.Oy + quad.Length / 2.0;
if (cameraY < quadY)
{
if (cameraX < quadX)
{
order[0] = 0;
order[1] = 1;
order[2] = 2;
order[3] = 3;
}
else
{
order[0] = 1;
order[1] = 0;
order[2] = 3;
order[3] = 2;
}
}
else
{
if (cameraX < quadX)
{
order[0] = 2;
order[1] = 0;
order[2] = 3;
order[3] = 1;
}
else
{
order[0] = 3;
order[1] = 1;
order[2] = 2;
order[3] = 0;
}
}
var done = 0;
for (byte i = 0; i < 4; ++i)
{
if (quad.GetChild(order[i]).Visibility == Frustum.VISIBILITY.INVISIBLE)
{
done |= (1 << order[i]);
}
else if (quad.GetChild(order[i]).Drawable)
{
DrawQuad(node, quad.GetChild(order[i]), samplers);
done |= (1 << order[i]);
}
}
if (done < 15)
{
// If the a leaf quad needs to be drawn but its tiles are not ready then this will draw the next parent tile instead that is ready.
// Because of the current set up all tiles always have there tasks run on the frame they are generated so this section of code is never reached.
MPB.Clear();
for (int i = 0; i < samplers.Count; ++i)
{
// Set the unifroms needed to draw the texture for this sampler
samplers[i].SetTile(MPB, quad.Level, quad.Tx, quad.Ty);
}
// Set the uniforms unique to each quad
node.SetPerQuadUniforms(quad, MPB);
DrawNode(node);
}
}
}