void Init()
{
fixed(void *pnfo = &_varInfo)
{
if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
{
throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
}
SetBpp();
_varInfo.yoffset = 100;
if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo))
{
_varInfo.transp = new fb_bitfield();
}
if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo))
{
throw new Exception("FBIOPUT_VSCREENINFO error: " + Marshal.GetLastWin32Error());
}
if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
{
throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
}
if (_varInfo.bits_per_pixel != 32)
{
throw new Exception("Unable to set 32-bit display mode");
}
}
fixed(void *pnfo = &_fixedInfo)
if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_FSCREENINFO, pnfo))
{
throw new Exception("FBIOGET_FSCREENINFO error: " + Marshal.GetLastWin32Error());
}
_mappedLength = new IntPtr(_fixedInfo.line_length * _varInfo.yres);
_mappedAddress = NativeUnsafeMethods.mmap(IntPtr.Zero, _mappedLength, 3, 1, _fd, IntPtr.Zero);
if (_mappedAddress == new IntPtr(-1))
{
throw new Exception($"Unable to mmap {_mappedLength} bytes, error {Marshal.GetLastWin32Error()}");
fixed(fb_fix_screeninfo *pnfo = &_fixedInfo)
{
int idlen;
for (idlen = 0; idlen < 16 && pnfo->id[idlen] != 0; idlen++)
{
;
}
Id = Encoding.ASCII.GetString(pnfo->id, idlen);
}
}
void SetBpp()
{
_varInfo.bits_per_pixel = 32;
_varInfo.grayscale = 0;
_varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
{
length = 8
};
_varInfo.green.offset = 8;
_varInfo.blue.offset = 16;
_varInfo.transp.offset = 24;
}
void VSync()
{
NativeUnsafeMethods.ioctl(_fb, FbIoCtl.FBIO_WAITFORVSYNC, null);
}