/// <summary>Sweeps all marked entries as part of mark-and-sweep garbage collection.</summary>
/// <remarks>This method should be called at the end of each frame.</remarks>
public void RemoveUnusedEntries()
{
bool unusedEntriesFound;
do
{
unusedEntriesFound = false;
foreach (KeyValuePair <string, TextCacheEntry> dictionaryEntry in entries)
{
TextCacheEntry entry = dictionaryEntry.Value;
if (entry.Unused)
{
for (int i = 0; i < entry.TexturePoolEntries.Length; ++i)
{
TexturePoolEntry poolEntry = entry.TexturePoolEntries[i];
poolEntry.StripeAllocated[entry.StripeIndexes[i]] = false;
if (!poolEntry.Used)
{
poolEntry.Texture.Dispose();
texturePool.Remove(poolEntry);
}
}
entries.Remove(dictionaryEntry.Key);
unusedEntriesFound = true;
break; // the iterator has been invalidated, so we need a new foreach loop
}
}
} while(unusedEntriesFound);
}
/// <summary>Finds a free stripe on a texture to store a text fragment.</summary>
/// <param name="texturePoolEntry">Texture pool entry that contains the allocated stripe.</param>
/// <param name="stripeIndex">Index of the stripe, from top to bottom.</param>
/// <param name="textFragment">New text fragment.</param>
private void allocateTextureFragment(out TexturePoolEntry texturePoolEntry, out int stripeIndex, out DXCachedTextFragment textFragment)
{
// look for a free stripe on an existing texture
foreach (TexturePoolEntry poolEntry in texturePool)
{
for (int i = 0; i < poolEntry.StripeAllocated.Length; ++i)
{
if (!poolEntry.StripeAllocated[i])
{
poolEntry.StripeAllocated[i] = true;
texturePoolEntry = poolEntry;
stripeIndex = i;
textFragment.Texture = poolEntry.Texture;
textFragment.TextureCoordinates = new RectangleF(0.0f, (textHeight * i) / 256.0f, 1.0f, textHeight / 256.0f);
return;
}
}
}
// no stripe available -> allocate a whole new texture
TexturePoolEntry newPoolEntry = new TexturePoolEntry(graphics, textHeight);
texturePool.Add(newPoolEntry);
newPoolEntry.StripeAllocated[0] = true;
texturePoolEntry = newPoolEntry;
stripeIndex = 0;
textFragment.Texture = newPoolEntry.Texture;
textFragment.TextureCoordinates = new RectangleF(0.0f, 0.0f, 1.0f, textHeight / 256.0f);
}
