Texture2D MakeIndexTexture16(ColorMap map, Color32[] srcPixels, int width, int height)
{
var dstWidth = (width + 1) / 2; // 切り上げで幅半分にする
var texture = new Texture2D(dstWidth, height, TextureFormat.Alpha8, false);
for (int y = 0; y < height; y++)
{
for (int x = 0; x < dstWidth; x++) // 2画素づつ処理。書き込み側の幅でループ
{
var color0 = srcPixels[(y * width) + (x * 2)];
int index0 = map.Find(color0);
int index1 = 0;
if (((x * 2) + 1) < width) // 2画素目が含まれている時だけ
{
var color1 = srcPixels[(y * width) + ((x * 2) + 1)];
index1 = map.Find(color1);
}
Debug.Assert((index0 < 16) || (index1 < 16));
var composedIndex = (index0 << 4) | index1;
var indexAsColor = new Color(0f, 0f, 0f, (float)composedIndex / 255f);
texture.SetPixel(x, y, indexAsColor);
}
}
return(texture);
}
Texture2D MakeIndexTexture256(ColorMap map, Color32[] srcPixels, int width, int height)
{
var texture = new Texture2D(width, height, TextureFormat.RGBA32, false);
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
var color = srcPixels[(y * width) + x];
int index = map.Find(color);
Debug.Assert(index < 256);
var encoded = ((float)index) / 255f;
var indexAsColor = new Color(0f, 0f, 0f, encoded);
texture.SetPixel(x, y, indexAsColor);
}
}
return(texture);
}
Texture2D MakeTableTexture(ColorMap map, int colorCount)
{
var texture = new Texture2D(colorCount, 1, TextureFormat.RGBA32, false);
// 配列化してテクスチャに書き込み
var colors = new Color32[colorCount];
foreach (var color in map.keyList)
{
var index = map.Find(color);
Debug.Assert(index < colorCount);
colors[index] = color;
}
// 確認のために残りは紫で埋める
var magenta = new Color32(255, 0, 255, 255);
for (int i = map.keyList.Count; i < colorCount; i++)
{
colors[i] = magenta;
}
texture.SetPixels32(colors);
return(texture);
}