using System;
namespace SpriteWave
{
public class SNESTile : Tile
{
public const int W = 8;
public const int H = 8;
public const int ByPP = 1; // bytes per pixel
public const int TileSize = 32;
public override int Width { get { return W; } }
public override int Height { get { return H; } }
public override int BytesPP { get { return ByPP; } }
public SNESTile()
{
_data = new byte[W * H];
}
public override int Import(byte[] tile, int offset)
{
if (tile.Length - offset < TileSize)
return offset;
// byte position for current row, bit to access current column
int rpos, bit;
int i, j, idx = 0;
for (i = 0, rpos = 0; i < H; i++, rpos += 2)
{
// First column is most significant bit, last column is least significant bit
for (j = 0, bit = 7; j < W; j++, bit--)
{
int c, mask = 1 << bit;
c = ((int)tile[offset + rpos] & mask) >> bit;
c |= (((int)tile[offset + rpos + 1] & mask) >> bit) << 1;
c |= (((int)tile[offset + rpos + 16] & mask) >> bit) << 2;
c |= (((int)tile[offset + rpos + 16+1] & mask) >> bit) << 3;
_data[idx] = (byte)c;
idx++;
}
}
return offset + TileSize;
}
public override void ExtractRow(byte[] line, int offset, int y, byte[] palBGRA)
{
const int cLen = 4;
int row = y % H;
int idx = row * W;
for (int i = 0, s = 0; i < W; i++, s += cLen)
{
// Copies a color from inside 'palBGRA', indexed by 'palIdx', to 'line' at 'offset + s'
int palIdx = _data[idx] * cLen;
Buffer.BlockCopy(palBGRA, palIdx, line, offset + s, cLen);
idx++;
}
}
}
}
