// vi:ft=cpp
/*
 * (c) 2010 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.
 */
#pragma once

#include <l4/mag-gfx/texture>
#include <cstring>

namespace Mag_gfx {
namespace Mem {

template< typename PT >
class Texture : public Mag_gfx::Texture
{
public:
  typedef PT Pixel_traits;
  typedef typename PT::Pixel Pixel;
  typedef typename PT::Color Color;

public:
  Texture(Pixel *pixels, Area const &size, bool xalpha = false)
  : Mag_gfx::Texture(PT::type(), pixels, size, xalpha)
  {}

  bool alloc_buffer(Area const &size)
  {
    if (_pixels)
      return false;

    _size = size;

    _pixels = malloc(_size.pixels() * (sizeof(Pixel) + (extra_alpha() ? 1 :0)));
    return _pixels;
  }

  Pixel const *pixels() const
  { return (Pixel const *)Mag_gfx::Texture::pixels(); }

  Pixel *pixels()
  { return (Pixel *)Mag_gfx::Texture::pixels(); }

  unsigned char const *alpha_buffer() const
  {
    return extra_alpha()
      ? reinterpret_cast<unsigned char const *>(pixels() + size().pixels())
      : 0;
  }

  unsigned char *alpha_buffer()
  {
    return extra_alpha()
      ? reinterpret_cast<unsigned char *>(pixels() + size().pixels())
      : 0;
  }

  void blit(Mag_gfx::Texture const *o, int start_line = 0)
  {
    Pixel *dst = pixels();

    if (start_line >= size().h())
      return;

    dst += size().w() * start_line;

    int const w = std::min(size().w(), o->size().w());
    int const h = std::min(size().h() - start_line, o->size().h());

    if (o->type() == type())
      {
	int const ow = o->size().w();
        Pixel const *src = reinterpret_cast<Pixel const *>(o->pixels());
        for (int i = 0; i < h; ++i, dst += size().w(), src += ow)
	  memcpy(dst, src, size().w() * sizeof(Pixel));

	if (extra_alpha())
	  memset(alpha_buffer() + size().w() * start_line, ~0, size().w() * h);
      }
    else
      {
#if 0
	printf("texture convert: %dx%d %d(%d):%d(%d):%d(%d):%d(%d) -> %dx%d %d(%d):%d(%d):%d(%d):%d(%d)\n",
	    (int)o->size().w(), (int)o->size().h(),
	    (int)o->type()->r.si, (int)o->type()->r.sh,
	    (int)o->type()->g.si, (int)o->type()->g.sh,
	    (int)o->type()->b.si, (int)o->type()->b.sh,
	    (int)o->type()->a.si, (int)o->type()->a.sh,
	    (int)size().w(), (int)size().h(),
	    (int)type()->r.si, (int)type()->r.sh,
	    (int)type()->g.si, (int)type()->g.sh,
	    (int)type()->b.si, (int)type()->b.sh,
	    (int)type()->a.si, (int)type()->a.sh);
#endif
	int const ow = o->size().w() * o->type()->bytes_per_pixel();
	int const op = o->type()->bytes_per_pixel();
        char const *src = reinterpret_cast<char const *>(o->pixels());

	unsigned char *ab = alpha_buffer();
	bool const xa = ab;
	ab += size().w() * start_line;

	for (int i = 0; i < h; i++, dst += size().w(), src += ow)
	  {
	    for (int y = 0; y < w; y++)
	      {
		Mag_gfx::Pixel_info::Color c = o->type()->get(src + y*op);
		dst[y] = Color(c);
		if (xa)
		  ab[y] = c.a >> 8;
	      }
	    if (xa)
	      ab += size().w();
	  }
      }
  }

  void blit_line(void const *_src, Pixel_info const *st, int line, unsigned *offset_buffer)
  {
    Pixel *dst = pixels();

    if (line >= size().h())
      return;

    dst += size().w() * line;

    char const *src = (char const *)_src;

    if (st == type())
      {
	for (int i = 0; i < size().w(); ++i, ++dst)
	  *dst = *(Pixel const *)(src + offset_buffer[i]);

	if (extra_alpha())
	  memset(alpha_buffer() + size().w() * line, ~0, size().w());
      }
    else
      {
#if 0
	printf("texture convert: %dx%d %d(%d):%d(%d):%d(%d):%d(%d) -> %dx%d %d(%d):%d(%d):%d(%d):%d(%d)\n",
	    (int)o->size().w(), (int)o->size().h(),
	    (int)o->type()->r.si, (int)o->type()->r.sh,
	    (int)o->type()->g.si, (int)o->type()->g.sh,
	    (int)o->type()->b.si, (int)o->type()->b.sh,
	    (int)o->type()->a.si, (int)o->type()->a.sh,
	    (int)size().w(), (int)size().h(),
	    (int)type()->r.si, (int)type()->r.sh,
	    (int)type()->g.si, (int)type()->g.sh,
	    (int)type()->b.si, (int)type()->b.sh,
	    (int)type()->a.si, (int)type()->a.sh);
#endif
	unsigned char *ab = alpha_buffer();
	bool const xa = ab;
	ab += size().w() * line;

	for (int y = 0; y < size().w(); y++)
	  {
	    Mag_gfx::Pixel_info::Color c = st->get(src + offset_buffer[y]);
	    dst[y] = Color(c);
	    if (xa)
	      ab[y] = c.a >> 8;
	  }
      }
  }
};

}}