/// <summary>
///
/// </summary>
/// <param name="texelX"></param>
/// <param name="texelY"></param>
/// <param name="mipLevel"></param>
/// <returns></returns>
void SampleMegatextureQ4(TileSamplerCache cache, int texelX, int texelY, int mipLevel, ref Color a, ref Color b, ref Color c)
{
int textureSize = VTConfig.TextureSize >> mipLevel;
texelX = MathUtil.Clamp(0, texelX, textureSize);
texelY = MathUtil.Clamp(0, texelY, textureSize);
int pageX = texelX / VTConfig.PageSize;
int pageY = texelY / VTConfig.PageSize;
int x = texelX % VTConfig.PageSize;
int y = texelY % VTConfig.PageSize;
int pbw = VTConfig.PageBorderWidth;
var address = new VTAddress(pageX, pageY, mipLevel);
cache.LoadImage(address).SampleQ4(x + pbw, y + pbw, ref a, ref b, ref c);
}
/// <summary>
/// Generates mip levels for all tiles.
/// </summary>
/// <param name="buildContext"></param>
/// <param name="pageTable"></param>
/// <param name="sourceMipLevel"></param>
/// <param name="mapStorage"></param>
void GenerateMipLevels(BuildContext buildContext, VTTextureTable pageTable, int sourceMipLevel, IStorage mapStorage)
{
if (sourceMipLevel >= VTConfig.MipCount)
{
throw new ArgumentOutOfRangeException("mipLevel");
}
//int count = VTConfig.VirtualPageCount >> sourceMipLevel;
int sizeB = VTConfig.PageSizeBordered;
var cache = new TileSamplerCache(mapStorage);
foreach (var vttex in pageTable.SourceTextures)
{
if (!vttex.TilesDirty)
{
continue;
}
int startX = RoundDown2(vttex.AddressX, sourceMipLevel);
int startY = RoundDown2(vttex.AddressY, sourceMipLevel);
int wTiles = (vttex.Width / VTConfig.PageSize);
int hTiles = (vttex.Width / VTConfig.PageSize);
int endExX = RoundUp2(vttex.AddressX + wTiles, sourceMipLevel);
int endExY = RoundUp2(vttex.AddressY + hTiles, sourceMipLevel);
for (int pageX = startX; pageX < endExX; pageX += 2)
{
for (int pageY = startY; pageY < endExY; pageY += 2)
{
var address00 = new VTAddress(pageX + 0, pageY + 0, sourceMipLevel);
var address01 = new VTAddress(pageX + 0, pageY + 1, sourceMipLevel);
var address10 = new VTAddress(pageX + 1, pageY + 0, sourceMipLevel);
var address11 = new VTAddress(pageX + 1, pageY + 1, sourceMipLevel);
// there are no images touching target mip-level.
// NOTE: we can skip images that are touched by border.
//if ( !pageTable.IsAnyExists( address00, address01, address10, address11 ) ) {
// continue;
//}
var address = new VTAddress(pageX / 2, pageY / 2, sourceMipLevel + 1);
var tile = new VTTile(address);
var offsetX = (pageX) * VTConfig.PageSize;
var offsetY = (pageY) * VTConfig.PageSize;
var border = VTConfig.PageBorderWidth;
var colorValue = Color.Zero;
var normalValue = Color.Zero;
var specularValue = Color.Zero;
for (int x = 0; x < sizeB; x++)
{
for (int y = 0; y < sizeB; y++)
{
int srcX = offsetX + x * 2 - border * 2;
int srcY = offsetY + y * 2 - border * 2;
SampleMegatextureQ4(cache, srcX, srcY, sourceMipLevel, ref colorValue, ref normalValue, ref specularValue);
tile.SetValues(x, y, ref colorValue, ref normalValue, ref specularValue);
}
}
pageTable.SaveTile(address, mapStorage, tile);
}
}
}
}
