public async Task <NearestInterpolatingChunk <T> > GetLazySimpleInterpolator(StandardChunkMetadata template, TraceListener log)
{
if (template == null)
{
return(null);
}
string filename = GetShortFilename(template);
string fullFileName = GetFullFileName(template, filename);
while (
!(await BlobHelper.BlobExists(cachedFileContainer, fullFileName, log)) &&
template.ZoomLevel > SourceDataZoom)
{
template = template.GetParentChunk();
return(await GetLazySimpleInterpolator(template, log));
}
byte[] buffer = new byte[Math.Max(4, pixelDataSize)];
return(new NearestInterpolatingChunk <T>(
template.LatLo.DecimalDegree, template.LonLo.DecimalDegree,
template.LatHi.DecimalDegree, template.LonHi.DecimalDegree,
template.LatSteps, template.LonSteps,
cachedFileContainer, fullFileName,
(ms, i, j) =>
{
ms.Seek(8 + pixelDataSize * (i * template.LatSteps + j), SeekOrigin.Begin);
return ReadPixel(ms, buffer);
}));
}
public async Task <ChunkHolder <T> > GetData(StandardChunkMetadata template, TraceListener log)
{
var computedChunk = await GetComputedChunk(template, log);
string fileName = computedChunk.Item1;
ChunkHolder <T> ret = computedChunk.Item2;
if (computedChunk.Item2 != null)
{
log?.WriteLine("Cached " + description + " chunk file exists: " + fileName);
return(computedChunk.Item2);
}
log?.WriteLine("Cached " + description + " chunk file does not exist: " + fileName);
if (template.ZoomLevel <= this.SourceDataZoom)
{
throw new MountainViewException("Source data is missing for chunk " + template.ToString());
//log?.WriteLine("Starting generation...");
//ret = await GenerateData(template, log);
//await WriteChunk(ret, fileName, log);
//log?.WriteLine("Finished generation of " + description + " cached chunk file: " + fileName);
//return ret;
}
log?.WriteLine("Need to interpolate from lower zoom data");
var parent = template.GetParentChunk();
var chunks = new ChunkHolder <T>[] { await GetData(parent, log) };
ret = new ChunkHolder <T>(
template.LatSteps, template.LonSteps,
template.LatLo, template.LonLo,
template.LatHi, template.LonHi,
null,
toDouble,
fromDouble);
ret.RenderChunksInto(chunks, aggregate, log);
await WriteChunk(ret, fileName, log);
log?.WriteLine("Finished generation of " + description + " cached chunk file: " + fileName);
return(ret);
}