bool Texture2D::createStorage(Size2i size, unsigned int channels, bool compressed, int levels) {
if (created) {
return false;
}
// levels = -1 means max mipmap level according to texture dimensions
const int maxLevels = ilogb(size.max()) + 1;
if (levels == 0) levels = 1;
if (levels < 0 || levels > maxLevels) levels = maxLevels;
this->channels = std::min(std::max(1u, channels), 4u);
this->size = size;
this->levels = levels;
if (glTexStorage2D) {
// try to allocate immutable storage (ogl 4.3)
glTexStorage2D(target, levels, glInternalFormat(compressed), size.width(), size.height());
}
else {
// ensure texture completeness despite mutable storage
for (int i=0; i<levels; ++i) {
glTexImage2D(target, i, glInternalFormat(compressed), size.width(), size.height(), 0, GL_BGRA, GL_UNSIGNED_BYTE, nullptr);
size = Size2i(std::max(1, size.width()>>1),
std::max(1, size.height()>>1));
}
glTexParameteri(target, GL_TEXTURE_MAX_LEVEL, levels-1);
}
return created = true;
}
// TODO: support mip maps
GLTextureCubeMap::GLTextureCubeMap( int sideLength, GLImageInternalFormat internalFormat ) :
GLTexture( GLTexture::Target::TEXTURE_CUBE_MAP, internalFormat, 1 ),
m_sideLength( sideLength )
{
assert( sideLength > 0 );
assert( sideLength <= GLTexture::maxSizeCubeMap() );
glTextureStorage2D( id(), 1, glInternalFormat(), sideLength, sideLength );
}
GLTexture3D::GLTexture3D( const Vector3i& size, GLImageInternalFormat internalFormat,
GLsizei nMipMapLevels ) :
GLTexture( GLTexture::Target::TEXTURE_3D, internalFormat, nMipMapLevels ),
m_size( size )
{
assert( size.x > 0 );
assert( size.y > 0 );
assert( size.z > 0 );
assert( size.x <= GLTexture::maxSize3D() );
assert( size.y <= GLTexture::maxSize3D() );
assert( size.z <= GLTexture::maxSize3D() );
glTexStorage3D( glTarget(), numMipMapLevels(),
glInternalFormat(), size.x, size.y, size.z );
}
Texture &Texture::create(int w, int h, Type type, int filter, int wrap, Type dataType, void *data) {
return create(w, h, 1, glInternalFormat(type), glFormat(type), glType(dataType), filter, wrap, data);
}
Texture &Texture::create(int w, int h, Type type, int filter, int wrap) {
return create(w, h, 1, glInternalFormat(type), glFormat(type), glType(type), filter, wrap, nullptr);
}
