// Only use mode11 of BC6H encoding
/// <summary>
/// Encode a Cubemap in BC6H.
///
/// It will encode all faces and selected mips of the Cubemap.
///
/// It uses only mode 11 of BC6H.
/// </summary>
/// <param name="cmb">Command buffer for execution</param>
/// <param name="source">The source Cubemap</param>
/// <param name="sourceSize">The size of the source Cubemap</param>
/// <param name="target">The compressed texture.
/// It must be a BC6H Cubemap or Cubemap array with the same size as the source Cubemap</param>
/// <param name="fromMip">Starting mip to encode</param>
/// <param name="toMip">Last mip to encode</param>
/// <param name="targetArrayIndex">The index of the cubemap to store the compressed texture.
///
/// Only relevant when target is a CubemapArray</param>
public void EncodeFastCubemap(CommandBuffer cmb, RenderTargetIdentifier source, int sourceSize, RenderTargetIdentifier target, int fromMip, int toMip, int targetArrayIndex = 0)
{
var maxMip = Mathf.Max(0, (int)(Mathf.Log(sourceSize) / Mathf.Log(2)) - 2);
var actualFromMip = (int)Mathf.Clamp(fromMip, 0, maxMip);
var actualToMip = (int)Mathf.Min(maxMip, Mathf.Max(toMip, actualFromMip));
// Convert TextureCube source to Texture2DArray
var d = new RenderTextureDescriptor
{
autoGenerateMips = false,
bindMS = false,
colorFormat = RenderTextureFormat.ARGBInt,
depthBufferBits = 0,
dimension = TextureDimension.Tex2DArray,
enableRandomWrite = true,
msaaSamples = 1,
volumeDepth = 6,
sRGB = false,
useMipMap = false,
};
cmb.SetComputeTextureParam(m_Shader, m_KEncodeFastCubemapMip, _Source, source);
for (var mip = actualFromMip; mip <= actualToMip; ++mip)
{
var size = (sourceSize >> mip) >> 2;
d.width = size;
d.height = size;
cmb.GetTemporaryRT(__Tmp_RT[mip], d);
}
for (var mip = actualFromMip; mip <= actualToMip; ++mip)
{
var size = (sourceSize >> mip) >> 2;
cmb.SetComputeTextureParam(m_Shader, m_KEncodeFastCubemapMip, _Target, __Tmp_RT[mip]);
cmb.SetComputeIntParam(m_Shader, _MipIndex, mip);
cmb.DispatchCompute(m_Shader, m_KEncodeFastCubemapMip, size, size, 6);
}
var startSlice = 6 * targetArrayIndex;
for (var mip = actualFromMip; mip <= actualToMip; ++mip)
{
var rtMip = Mathf.Clamp(mip, actualFromMip, actualToMip);
for (var faceId = 0; faceId < 6; ++faceId)
{
cmb.CopyTexture(__Tmp_RT[rtMip], faceId, 0, target, startSlice + faceId, mip);
}
}
for (var mip = actualFromMip; mip <= actualToMip; ++mip)
{
cmb.ReleaseTemporaryRT(__Tmp_RT[mip]);
}
}
