public static bool DetectTextureType(byte[] data, Vector2I size, PixelFormat format, out bool hasAlpha, out bool normalMap)
{
hasAlpha = false;
normalMap = size.X > 64 && size.Y > 64;
int normalMapCount = 0;
int totalCount = 0;
for (int y = 0; y < size.Y; y++)
{
for (int x = 0; x < size.X; x++)
{
byte r;
byte g;
byte b;
byte a = 255;
int offset;
switch (format)
{
case PixelFormat.R8G8B8A8:
offset = (y * size.X + x) * 4;
r = data[offset + 3];
g = data[offset + 2];
b = data[offset + 1];
a = data[offset + 0];
break;
case PixelFormat.R8G8B8:
offset = (y * size.X + x) * 3;
r = data[offset + 2];
g = data[offset + 1];
b = data[offset + 0];
break;
case PixelFormat.X8R8G8B8:
offset = (y * size.X + x) * 4;
r = data[offset + 2];
g = data[offset + 1];
b = data[offset + 0];
break;
case PixelFormat.A8R8G8B8:
offset = (y * size.X + x) * 4;
a = data[offset + 3];
r = data[offset + 2];
g = data[offset + 1];
b = data[offset + 0];
break;
default:
hasAlpha = false;
normalMap = false;
return(false);
}
if (a != 255)
{
hasAlpha = true;
}
if (normalMap)
{
var v = new Vector3F(r, g, b) / 255.0f;
v *= 2;
v -= new Vector3F(1, 1, 1);
var l = v.Length();
if (l > 0.75f && l < 1.25f)
{
normalMapCount++;
}
else
{
if (totalCount > 10000)
{
float p = (float)normalMapCount / totalCount;
if (p < .95f)
{
normalMap = false;
}
}
}
}
totalCount++;
}
}
if (normalMap)
{
float p = (float)normalMapCount / totalCount;
if (p < .95f)
normalMap = false; }
}