internal static void *Realloc(void *a, long newSize)
{
Pointer pointer;
if (!_pointers.TryGetValue((long)a, out pointer))
{
// Allocate new
return(Malloc(newSize));
}
if (newSize <= pointer.Size)
{
// Realloc not required
return(a);
}
var result = Malloc(newSize);
CRuntime.memcpy(result, a, pointer.Size);
_pointers.TryRemove((long)pointer.Ptr, out pointer);
pointer.Dispose();
return(result);
}
internal static void MemMove(void *a, void *b, long size)
{
using (var temp = new PinnedArray <byte>(size))
{
CRuntime.memcpy(temp.Ptr, b, size);
CRuntime.memcpy(a, temp.Ptr, size);
}
}
public static byte[] stb_compress_dxt(Image image, bool hasAlpha = true, int mode = 10)
{
if (image.Comp != 4)
{
throw new Exception("This method supports only rgba images");
}
var osize = hasAlpha ? 16 : 8;
var result = new byte[(image.Width + 3) * (image.Height + 3) / 16 * osize];
fixed(byte *rgba = image.Data)
{
fixed(byte *resultPtr = result)
{
var p = resultPtr;
byte *block = stackalloc byte[16 * 4];
for (var j = 0; j < image.Width; j += 4)
{
var x = 4;
for (var i = 0; i < image.Height; i += 4)
{
if (j + 3 >= image.Width)
{
x = image.Width - j;
}
int y;
for (y = 0; y < 4; ++y)
{
if (j + y >= image.Height)
{
break;
}
CRuntime.memcpy(block + y * 16, rgba + image.Width * 4 * (j + y) + i * 4, x * 4);
}
int y2;
if (x < 4)
{
switch (x)
{
case 0:
throw new Exception("Unknown error");
case 1:
for (y2 = 0; y2 < y; ++y2)
{
CRuntime.memcpy(block + y2 * 16 + 1 * 4, block + y2 * 16 + 0 * 4, 4);
CRuntime.memcpy(block + y2 * 16 + 2 * 4, block + y2 * 16 + 0 * 4, 8);
}
break;
case 2:
for (y2 = 0; y2 < y; ++y2)
{
CRuntime.memcpy(block + y2 * 16 + 2 * 4, block + y2 * 16 + 0 * 4, 8);
}
break;
case 3:
for (y2 = 0; y2 < y; ++y2)
{
CRuntime.memcpy(block + y2 * 16 + 3 * 4, block + y2 * 16 + 1 * 4, 4);
}
break;
}
}
y2 = 0;
for (; y < 4; ++y, ++y2)
{
CRuntime.memcpy(block + y * 16, block + y2 * 16, 4 * 4);
}
stb_compress_dxt_block(p, block, hasAlpha ? 1 : 0, mode);
p += hasAlpha ? 16 : 8;
}
}
}
}
return(result);
}