colors

// vi:set ft=cpp: -*- Mode: C++ -*-
/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU General Public License 2.
 * Please see the COPYING-GPL-2 file for details.
 *
 * As a special exception, you may use this file as part of a free software
 * library without restriction.  Specifically, if other files instantiate
 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
 * file does not by itself cause the resulting executable to be covered by
 * the GNU General Public License.  This exception does not however
 * invalidate any other reasons why the executable file might be covered by
 * the GNU General Public License.
 */
 
#pragma once
 
#include <l4/sys/compiler.h>
#include <l4/cxx/minmax>
 
namespace L4Re { namespace Video {
 
class L4_EXPORT Color_component
{
private:
  unsigned char _bits;    
  unsigned char _shift;   
 
public:
  Color_component() : _bits(0), _shift(0) {}
 
  Color_component(unsigned char bits, unsigned char shift)
  : _bits(bits), _shift(shift) {}
 
  unsigned char size() const { return _bits; }
 
  unsigned char shift() const { return _shift; }
 
  bool operator == (Color_component const &o) const
  { return _shift == o._shift && _bits == o._bits; }
 
  int get(unsigned long v) const
  {
    return ((v >> _shift) & ~(~0UL << _bits)) << (16UL - _bits);
  }
 
  long unsigned set(int v) const
  { return (static_cast<unsigned long>(v) >> (16UL - _bits)) << _shift; }
 
  template< typename OUT >
  void dump(OUT &s) const
  {
    s.printf("%d(%d)", static_cast<int>(size()), static_cast<int>(shift()));
  }
} __attribute__((packed));
 
class L4_EXPORT Pixel_info
{
private:
  Color_component _r, _g, _b, _a;  
  unsigned char _bpp;              
 
public:
  Color_component const &r() const { return _r; }
 
  Color_component const &g() const { return _g; }
 
  Color_component const &b() const { return _b; }
 
  Color_component const &a() const { return _a; }
 
  Color_component const padding() const
  {
    unsigned char top_bit = cxx::max<unsigned char>(_r.size() + _r.shift(),
                                                    _g.size() + _g.shift());
    top_bit = cxx::max<unsigned char>(top_bit, _b.size() + _b.shift());
    top_bit = cxx::max<unsigned char>(top_bit, _a.size() + _a.shift());
 
    unsigned char bits = _bpp * 8;
 
    if (top_bit < bits)
      return Color_component(bits - top_bit, top_bit);
 
    return Color_component(0, 0);
  }
 
  unsigned char bytes_per_pixel() const { return _bpp; }
 
  unsigned char bits_per_pixel() const
  { return _r.size() + _g.size() + _b.size() + _a.size(); }
 
  bool has_alpha() const { return _a.size() > 0; }
 
  void r(Color_component const &c) { _r = c; }
 
  void g(Color_component const &c) { _g = c; }
 
  void b(Color_component const &c) { _b = c; }
 
  void a(Color_component const &c) { _a = c; }
 
  void bytes_per_pixel(unsigned char bpp) { _bpp = bpp; }
 
  Pixel_info() : _bpp(0) {};
 
  Pixel_info(unsigned char bpp, char r, char rs, char g, char gs,
             char b, char bs, char a = 0, char as = 0)
  : _r(r, rs), _g(g, gs), _b(b, bs), _a(a, as), _bpp(bpp)
  {}
 
  template<typename VBI>
  explicit Pixel_info(VBI const *vbi)
  : _r(vbi->red_mask_size, vbi->red_field_position),
    _g(vbi->green_mask_size, vbi->green_field_position),
    _b(vbi->blue_mask_size, vbi->blue_field_position),
    _bpp((vbi->bits_per_pixel + 7) / 8)
  {}
 
  bool operator == (Pixel_info const &o) const
  {
    return _r == o._r && _g == o._g && _b == o._b && _a == o._a && _bpp == o._bpp;
  }
 
  template< typename OUT >
  void dump(OUT &s) const
  {
    s.printf("RGBA(%d):%d(%d):%d(%d):%d(%d):%d(%d)",
             static_cast<int>(bytes_per_pixel()),
             static_cast<int>(r().size()), static_cast<int>(r().shift()),
             static_cast<int>(g().size()), static_cast<int>(g().shift()),
             static_cast<int>(b().size()), static_cast<int>(b().shift()),
             static_cast<int>(a().size()), static_cast<int>(a().shift()));
  }
};
 
 
}}