public TerrainLayerBlendMap(Terrain parent, byte layerIdx, HardwarePixelBuffer buf)
{
this.mParent = parent;
this.mLayerIdx = layerIdx;
this.mChannel = (byte)((this.mLayerIdx - 1) % 4);
this.mDirty = false;
this.mBuffer = buf;
this.mData = new float[this.mBuffer.Width * this.mBuffer.Height * sizeof(float)];
// we know which of RGBA we need to look at, now find it in the format
// because we can't guarantee what precise format the RS gives us
PixelFormat fmt = this.mBuffer.Format;
var rgbaShift = PixelUtil.GetBitShifts(fmt);
this.mChannelOffset = (byte)(rgbaShift[this.mChannel] / 8); // /8 convert to bytes
#if AXIOM_BIG_ENDIAN
// invert (dealing bytewise)
mChannelOffset = (byte)(PixelUtil.GetNumElemBytes(fmt) - mChannelOffset - 1);
#endif
Download();
}
