/// <summary>
/// Updates the <see cref="TerrainQuad.ZMin"/> and <see cref="TerrainQuad.ZMax"/> values.
/// Used to create a better fitting bounding box.
/// Is not essental and can be disabled if retriving the heights data from the GPU is causing performance issues.
/// </summary>
private void UpdateMinMax()
{
// If no quads need read back or if disabled return
if (NeedsReadBackDictionary.Count == 0 || !EnableReadBack)
{
return;
}
// Make a copy of all the keys of the tiles that need to be read back
var ids = new Tile.Id[NeedsReadBackDictionary.Count];
NeedsReadBackDictionary.Keys.CopyTo(ids, 0);
// Sort the keys by there level, lowest -> highest
Array.Sort(ids, new Tile.ComparerID());
var count = 0;
// Foreach key read back the tiles data until the maxReadBacksPerFrame limit is reached
foreach (var id in ids)
{
var treeZ = NeedsReadBackDictionary[id];
// If elevations container already contains key then data has been read back before so just reapply the [min, max] values to TerranQuad
if (ElevationsDicionary.ContainsKey(id))
{
var info = ElevationsDicionary.Get(id);
treeZ.TerrainQuad.ZMin = info.Min;
treeZ.TerrainQuad.ZMax = info.Max;
NeedsReadBackDictionary.Remove(id);
}
else
{
// If for some reason the tile is null remove from container and continue
if (treeZ.Tile == null)
{
NeedsReadBackDictionary.Remove(id);
continue;
}
var slot = treeZ.Tile.Slot[0] as GPUTileStorage.GPUSlot;
// If for some reason this is not a GPUSlot remove and continue
if (slot == null)
{
NeedsReadBackDictionary.Remove(id);
continue;
}
var texture = slot.Texture;
var size = texture.width * texture.height;
var elevationInfo = new ElevationInfo();
elevationInfo.Elevations = new float[size];
// Read back heights data from texture
CBUtility.ReadFromRenderTexture(texture, CBUtility.Channels.R, ElevationsBuffer, GodManager.Instance.ReadData);
// Copy into elevations info
ElevationsBuffer.GetData(elevationInfo.Elevations);
// Find the min/max values
for (int i = 0; i < size; i++)
{
if (elevationInfo.Elevations[i] < elevationInfo.Min)
{
elevationInfo.Min = elevationInfo.Elevations[i];
}
if (elevationInfo.Elevations[i] > elevationInfo.Max)
{
elevationInfo.Max = elevationInfo.Elevations[i];
}
}
// Update TerrainQuad
treeZ.TerrainQuad.ZMin = elevationInfo.Min;
treeZ.TerrainQuad.ZMax = elevationInfo.Max;
// Store elevations to prevent having to read back again soon
// Add to end of container
ElevationsDicionary.AddLast(id, elevationInfo);
NeedsReadBackDictionary.Remove(id);
count++;
// If the number of rad back to do per frame has hit the limit stop loop.
if (count >= MaxReadBacksPerFrame)
{
break;
}
}
}
// If the number of elevation info to store has exceded limit remove from start of container
while (ElevationsDicionary.Count() > MaxStoredElevations)
{
ElevationsDicionary.RemoveFirst();
}
}
/*
* Updates the terrainQuads min and max values. Used to create a better fitting bounding box.
* Is not essental and can be disabled if retriving the heights data from the GPU is causing
* performance issues.
*/
void UpdateMinMax()
{
//if no quads need read back or if disabled return
if(m_needReadBack.Count == 0 || !m_enableMinMaxReadBack) return;
//Make a copy of all the keys of the tiles that need to be read back
Tile.Id[] ids = new Tile.Id[m_needReadBack.Count];
m_needReadBack.Keys.CopyTo(ids, 0);
//Sort the keys by there level, lowest -> highest
System.Array.Sort(ids, new Tile.ComparerID());
int count = 0;
//foreach key read back the tiles data until the maxReadBacksPerFrame limit is reached
foreach(Tile.Id id in ids)
{
QuadTreeZ t = m_needReadBack[id];
//If elevations container already contains key then data has been
//read back before so just reapply the min/max values to TerranQuad
if(m_elevations.ContainsKey(id))
{
ElevationInfo info = m_elevations.Get(id);
t.quad.SetZMin(info.min);
t.quad.SetZMax(info.max);
m_needReadBack.Remove(id);
}
else
{
//if for some reason the tile is null remove from container and continue
if(t.tile == null) {
m_needReadBack.Remove(id);
continue;
}
GPUTileStorage.GPUSlot slot = t.tile.GetSlot()[0] as GPUTileStorage.GPUSlot;
//If for some reason this is not a GPUSlot remove and continue
if(slot == null) {
m_needReadBack.Remove(id);
continue;
}
RenderTexture tex = slot.GetTexture();
int size = tex.width*tex.height;
ElevationInfo info = new ElevationInfo();
info.elevations = new float[size];
//Read back heights data from texture
CBUtility.ReadFromRenderTexture(tex, 1, m_elevationsBuffer, m_manager.GetReadData());
//Copy into elevations info
m_elevationsBuffer.GetData(info.elevations);
//Find the min/max values
for(int i = 0; i < size; i++)
{
if(info.elevations[i] < info.min) info.min = info.elevations[i];
if(info.elevations[i] > info.max) info.max = info.elevations[i];
}
//Update quad
t.quad.SetZMin(info.min);
t.quad.SetZMax(info.max);
//Store elevations to prevent having to read back again soon
//Add to end of container
m_elevations.AddLast(id, info);
m_needReadBack.Remove(id);
count++;
//If the number of rad back to do per frame has hit the limit stop loop.
if(count >= m_maxReadBacksPerFrame) break;
}
}
//If the number of elevation info to store has exceded limit remove from start of container
while(m_elevations.Count() > m_maxStoredElevations)
m_elevations.RemoveFirst();
}
