private void ReadRgbe(System.IO.Stream src, Vector3Half[] ret)
{
for (int i = 0; i < ret.Length; i++)
{
var item = new Rgbe(src);
ret[i] = item.ToVector3Half();
}
}
/*
* Retrieved from the source code written by Greg Ward for reading Radiance HDR images.
*/
private void ReadRgbeRle(System.IO.Stream src, Vector3Half[] ret, int width, int height)
{
byte[] rgbe = new byte[4]; byte[] scanline_buffer; int ptr, ptr_end;
int i, count, index = 0;
byte[] buf = new byte[2];
if ((width < 8) || (width > 0x7fff))
{
/* run length encoding is not allowed so read flat*/
ReadRgbe(src, ret);
return;
}
scanline_buffer = null;
int num_scanlines = height;
/* read in each successive scanline */
long start = src.Position;
while (num_scanlines > 0)
{
if (src.Read(rgbe, 0, 4) < 1)
{
throw new FormatException();
}
if ((rgbe[0] != 2) || (rgbe[1] != 2) || ((rgbe[2] & 0x80) == 0x80))
{
/* this file is not run length encoded */
//rgbe2float(&data[0],&data[1],&data[2],rgbe);
//data += RGBE_DATA_SIZE;
//free(scanline_buffer);
//return RGBE_ReadPixels(fp,data,scanline_width*num_scanlines-1);
//src.Position = start;
//ReadRgbe(src, ret);
//return;
}
//if ((((int)rgbe[2]) << 8 | rgbe[3]) != width)
//{
// throw new FormatException();
//}
if (scanline_buffer == null)
{
scanline_buffer = new byte[4 * width];
}
ptr = 0;
/* read each of the four channels for the scanline into the buffer */
for (i = 0; i < 4; i++)
{
ptr_end = (i + 1) * width;
while (ptr < ptr_end)
{
if (src.Read(buf, 0, 2) < 1)
{
throw new EndOfStreamException();
}
if (buf[0] > 128)
{
/* a run of the same value */
count = buf[0] - 128;
if ((count == 0) || (count > ptr_end - ptr))
{
throw new FormatException();
}
while (count-- > 0)
{
scanline_buffer[ptr++] = buf[1];
}
}
else
{
/* a non-run */
count = buf[0];
if ((count == 0) || (count > ptr_end - ptr))
{
throw new FormatException();
}
scanline_buffer[ptr++] = buf[1];
if (--count > 0)
{
if (src.Read(scanline_buffer, ptr, count) < 1)
{
throw new EndOfStreamException();
}
ptr += count;
}
}
}
}
/* now convert data from buffer into floats */
for (i = 0; i < width; i++)
{
Rgbe r = new Rgbe()
{
red = scanline_buffer[i],
green = scanline_buffer[i + width],
blue = scanline_buffer[i + 2 * width],
exp = scanline_buffer[i + 3 * width]
};
ret[index] = r.ToVector3Half();
}
num_scanlines--;
}
}
