bool dxtc_pixels::VFlip() const
{
// Check that the given dimensions are 2^x, 2^y
if (! OpenGLSize())
return false;
// Check that the given format are supported
if (! SupportedFormat())
return false;
// Nothing to do if Height == 1
if (m_Height == 1)
return true;
if (DXT1())
VFlip_DXT1();
else if (DXT3())
VFlip_DXT3();
else if (DXT5())
VFlip_DXT5();
else
return false; // We should never get there
return true;
}
bool CDDS::LoadFile(std::istream & File)
{
// Verify the type of file.
char FileCode[4];
if (! File.read(FileCode, 4))
return false;
if (strncmp(FileCode, "DDS ", 4) != 0)
return false;
// Get the surface descriptor.
DDSURFACEDESC2 DDrawSD;
if (! File.read((char *) &DDrawSD, sizeof(DDrawSD)))
return false;
// Set the attributes.
switch(DDrawSD.ddpfPixelFormat.dwFourCC)
{
case FOURCC_DXT1:
m_format = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
m_alphaChannel = CFalse;
m_blockSize = 8;
break;
case FOURCC_DXT3:
m_format = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
m_alphaChannel = CTrue;
m_blockSize = 16;
break;
case FOURCC_DXT5:
m_format = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
m_alphaChannel = CTrue;
m_blockSize = 16;
break;
default:
return false;
}
m_width = DDrawSD.dwWidth;
m_height = DDrawSD.dwHeight;
m_nbMipmaps = DDrawSD.dwMipMapCount;
if (m_nbMipmaps == 0)
m_nbMipmaps = 1;
// Check that the given dimentions are 2^x, 2^y
if (! OpenGLSize())
return false;
// How big is it going to be including all mipmaps?
size_t BufSize = 0;
size_t Width = m_width;
size_t Height = m_height;
for (size_t i = 0; (i < m_nbMipmaps) && ((Width != 0) || (Height != 0)); ++i) {
BufSize += ((Width + 3) / 4) * ((Height + 3) / 4) * m_blockSize;
if ((i == 0) && (BufSize != DDrawSD.dwLinearSize))
return false;
if ((Width /= 2) == 0) Width = 1;
if ((Height /= 2) == 0) Height = 1;
}
// Allocate pixels memory.
m_pixels.resize(BufSize);
// Read pixels.
if (! File.read((char *) &m_pixels[0], std::streamsize(BufSize)))
return false;
return true;
}
