Method unpack

external/basisu/encoder/basisu_gpu_texture.cpp:1209–1254

	}

	bool gpu_image::unpack(image& img) const
	{
		img.resize(get_pixel_width(), get_pixel_height());
		img.set_all(g_black_color);

		if (!img.get_width() || !img.get_height())
			return true;

		if ((m_fmt == texture_format::cPVRTC1_4_RGB) || (m_fmt == texture_format::cPVRTC1_4_RGBA))
		{
			pvrtc4_image pi(m_width, m_height);
			
			if (get_total_blocks() != pi.get_total_blocks())
				return false;
			
			memcpy(&pi.get_blocks()[0], get_ptr(), get_size_in_bytes());

			pi.deswizzle();

			pi.unpack_all_pixels(img);

			return true;
		}

		assert((m_block_width <= cMaxBlockSize) && (m_block_height <= cMaxBlockSize));
		color_rgba pixels[cMaxBlockSize * cMaxBlockSize];
		for (uint32_t i = 0; i < cMaxBlockSize * cMaxBlockSize; i++)
			pixels[i] = g_black_color;

		bool success = true;

		for (uint32_t by = 0; by < m_blocks_y; by++)
		{
			for (uint32_t bx = 0; bx < m_blocks_x; bx++)
			{
				const void* pBlock = get_block_ptr(bx, by);

				if (!unpack_block(m_fmt, pBlock, pixels))
					success = false;

				img.set_block_clipped(pixels, bx * m_block_width, by * m_block_height, m_block_width, m_block_height);
			} // bx
		} // by

		return success;
	}
		
	static const uint8_t g_ktx_file_id[12] = { 0xAB, 0x4B, 0x54, 0x58, 0x20, 0x31, 0x31, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A };