#include "imager.h"
#include "imageri.h"

/*
=item i_copyto(C<dest>, C<src>, C<x1>, C<y1>, C<x2>, C<y2>, C<tx>, C<ty>)

=category Image

Copies image data from the area (C<x1>,C<y1>)-[C<x2>,C<y2>] in the
source image to a rectangle the same size with it's top-left corner at
(C<tx>,C<ty>) in the destination image.

If C<x1> > C<x2> or C<y1> > C<y2> then the corresponding co-ordinates
are swapped.

=cut
*/

void
i_copyto(i_img *im, i_img *src, i_img_dim x1, i_img_dim y1, i_img_dim x2, i_img_dim y2, i_img_dim tx, i_img_dim ty) {
  i_img_dim y, t, tty;
  
  if (x2<x1) { t=x1; x1=x2; x2=t; }
  if (y2<y1) { t=y1; y1=y2; y2=t; }
  if (tx < 0) {
    /* adjust everything equally */
    x1 += -tx;
    x2 += -tx;
    tx = 0;
  }
  if (ty < 0) {
    y1 += -ty;
    y2 += -ty;
    ty = 0;
  }
  if (x1 >= src->xsize || y1 >= src->ysize)
    return; /* nothing to do */
  if (x2 > src->xsize)
    x2 = src->xsize;
  if (y2 > src->ysize)
    y2 = src->ysize;
  if (x1 == x2 || y1 == y2)
    return; /* nothing to do */

  mm_log((1,"i_copyto(im* %p, src %p, p1(" i_DFp "), p2(" i_DFp "), t("
	  i_DFp "))\n",
	  im, src, i_DFcp(x1, y1), i_DFcp(x2, y2), i_DFcp(tx, ty)));

#code im->bits == i_8_bits
  IM_COLOR *row = mymalloc(sizeof(IM_COLOR) * (x2-x1));
  tty = ty;
  for(y=y1; y<y2; y++) {
    IM_GLIN(src, x1, x2, y, row);
    if (src->channels != im->channels)
      IM_ADAPT_COLORS(im->channels, src->channels, row, x2-x1);
    IM_PLIN(im, tx, tx+x2-x1, tty, row);
    tty++;
  }
  myfree(row);
#/code
}

#code
void
#ifdef IM_EIGHT_BIT
i_adapt_colors
#else
i_adapt_fcolors
#endif
(int out_channels, int in_channels, IM_COLOR *colors, 
	       size_t count) {
  if (out_channels == in_channels)
    return;
  if (count == 0)
    return;

  switch (out_channels) {
  case 1:
    {
      switch (in_channels) {
      case 2:
	/* apply alpha against a black background */
	while (count) {
	  colors->channel[0] = colors->channel[0] * colors->channel[1] / IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
	return;

      case 3:
	/* convert to grey */
	while (count) {
	  colors->channel[0] = IM_ROUND(color_to_grey(colors));
	  ++colors;
	  --count;
	}
	return;
	    
      case 4:
	while (count) {
	  colors->channel[0] = IM_ROUND(color_to_grey(colors) * colors->channel[3] / IM_SAMPLE_MAX);
	  ++colors;
	  --count;
	}
	return;

      default:
	i_fatal(3, "i_adapt_colors: in_channels of %d invalid\n", in_channels);
	return; /* avoid warnings */
      }
    }

  case 2:
    {
      switch (in_channels) {
      case 1:
	while (count) {
	  colors->channel[1] = IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
	return;

      case 3:
	while (count) {
	  colors->channel[0] = IM_ROUND(color_to_grey(colors));
	  colors->channel[1] = IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
	return;

      case 4:
	while (count) {
	  colors->channel[0] = IM_ROUND(color_to_grey(colors));
	  colors->channel[1] = colors->channel[3];
	  ++colors;
	  --count;
	}
	return;

      default:
	i_fatal(3, "i_adapt_colors: in_channels of %d invalid\n", in_channels);
	return; /* avoid warnings */
      }
    }

  case 3:
    {
      switch (in_channels) {
      case 1:
	while (count) {
	  colors->channel[1] = colors->channel[2] = colors->channel[0];
	  ++colors;
	  --count;
	}
	return;

      case 2:
	while (count) {
	  int alpha = colors->channel[1];
	  colors->channel[0] = colors->channel[1] = colors->channel[2] =
	    IM_ROUND(colors->channel[0] * alpha / IM_SAMPLE_MAX);
	  ++colors;
	  --count;
	}
	return;

      case 4:
	while (count) {
	  int alpha = colors->channel[3];
	  colors->channel[0] = 
	    IM_ROUND(colors->channel[0] * alpha / IM_SAMPLE_MAX);
	  colors->channel[1] = 
	    IM_ROUND(colors->channel[1] * alpha / IM_SAMPLE_MAX);
	  colors->channel[2] = 
	    IM_ROUND(colors->channel[2] * alpha / IM_SAMPLE_MAX);
	  ++colors;
	  --count;
	}
	return;

      default:
	i_fatal(3, "i_adapt_colors: in_channels of %d invalid\n", in_channels);
	return; /* avoid warnings */
      }
    }

  case 4:
    {
      switch (in_channels) {
      case 1:
	while (count) {
	  colors->channel[1] = colors->channel[2] = colors->channel[0];
	  colors->channel[3] = IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
	return;

      case 2:
	while (count) {
	  colors->channel[3] = colors->channel[1];
	  colors->channel[1] = colors->channel[2] = colors->channel[0];
	  ++colors;
	  --count;
	}
	return;

      case 3:
	while (count) {
	  colors->channel[3] = IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
	return;

      default:
	i_fatal(3, "i_adapt_colors: in_channels of %d invalid\n", in_channels);
	return; /* avoid warnings */
      }
    }

  default:
    i_fatal(3, "i_adapt_colors: out_channels of %d invalid\n", out_channels);
    return; /* avoid warnings */
  }
}

void
#ifdef IM_EIGHT_BIT
i_adapt_colors_bg
#else
i_adapt_fcolors_bg
#endif
(int out_channels, int in_channels, IM_COLOR *colors, 
	       size_t count, IM_COLOR const *bg) {
  if (out_channels == in_channels)
    return;
  if (count == 0)
    return;

  switch (out_channels) {
  case 2:
  case 4:
    IM_ADAPT_COLORS(out_channels, in_channels, colors, count);
    return;

  case 1:
    switch (in_channels) {
    case 3:
      IM_ADAPT_COLORS(out_channels, in_channels, colors, count);
      return;

    case 2:
      {
	/* apply alpha against our given background */
	IM_WORK_T grey_bg = IM_ROUND(color_to_grey(bg));
	while (count) {
	  colors->channel[0] = 
	    (colors->channel[0] * colors->channel[1] +
	     grey_bg * (IM_SAMPLE_MAX - colors->channel[1])) / IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
      }
      break;

    case 4:
      {
	IM_WORK_T grey_bg = IM_ROUND(color_to_grey(bg));
	while (count) {
	  IM_WORK_T src_grey = IM_ROUND(color_to_grey(colors));
	  colors->channel[0] =
	    (src_grey * colors->channel[3]
	     + grey_bg * (IM_SAMPLE_MAX - colors->channel[3])) / IM_SAMPLE_MAX;
	  ++colors;
	  --count;
	}
      }
      break;
    }
    break;
      
  case 3:
    switch (in_channels) {
    case 1:
      IM_ADAPT_COLORS(out_channels, in_channels, colors, count);
      return;

    case 2:
      {
	while (count) {
	  int ch;
	  IM_WORK_T src_grey = colors->channel[0];
	  IM_WORK_T src_alpha = colors->channel[1];
	  for (ch = 0; ch < 3; ++ch) {
	    colors->channel[ch] =
	      (src_grey * src_alpha
	       + bg->channel[ch] * (IM_SAMPLE_MAX - src_alpha)) 
	      / IM_SAMPLE_MAX;
	  }
	  ++colors;
	  --count;
	}
      }
      break;

    case 4:
      {
	while (count) {
	  int ch;
	  IM_WORK_T src_alpha = colors->channel[3];
	  for (ch = 0; ch < 3; ++ch) {
	    colors->channel[ch] =
	      (colors->channel[ch] * src_alpha
	       + bg->channel[ch] * (IM_SAMPLE_MAX - src_alpha)) 
	      / IM_SAMPLE_MAX;
	  }
	  ++colors;
	  --count;
	}
      }
      break;
    }
    break;
  }
}

/*
=item i_gsamp_bg(im, l, r, y, samples, out_channels, background)

=category Drawing

Like C<i_gsampf()> but applies the source image color over a supplied
background color.

This is intended for output to image formats that don't support alpha
channels.

=cut

=item i_gsampf_bg(im, l, r, y, samples, out_channels, background)

=category Drawing

Like C<i_gsampf()> but applies the source image color over a supplied
background color.

This is intended for output to image formats that don't support alpha
channels.

=cut
*/
int
#ifdef IM_EIGHT_BIT
i_gsamp_bg
#else
i_gsampf_bg
#endif
(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, IM_SAMPLE_T *samples, 
 int out_channels, IM_COLOR const *bg) {
  if (out_channels == im->channels)
    return IM_GSAMP(im, l, r, y, samples, NULL, im->channels);
  
  switch (out_channels) {
  case 1:
    switch (im->channels) {
    case 2:
      {
	i_img_dim x;
	IM_SAMPLE_T *inp = samples, *outp = samples;
	IM_WORK_T grey_bg = IM_ROUND(color_to_grey(bg));
	i_img_dim count;

	count = IM_GSAMP(im, l, r, y, samples, NULL, im->channels);
	if (!count)
	  return 0;
	
	for (x = l; x < r; ++x) {
	  *outp++ = ( inp[0] * inp[1] +
		      grey_bg * (IM_SAMPLE_MAX - inp[1])) / IM_SAMPLE_MAX;
	  inp += 2;
	}

	return count;
      }
      break;

    default:
      i_fatal(0, "i_gsamp_bg() can only remove alpha channels");
      break;
    }
    break;
  case 3:
    switch (im->channels) {
    case 1:
      {
	int channels[3] = { 0, 0, 0 };
	return IM_GSAMP(im, l, r, y, samples, channels, out_channels);
      }
    case 2:
      {
	i_img_dim x;
	int ch;
	IM_SAMPLE_T *inp = samples, *outp = samples;
	i_img_dim count;
	int channels[4] = { 0, 0, 0, 1 };

	count = IM_GSAMP(im, l, r, y, samples, channels, im->channels);
	if (!count)
	  return 0;
	
	for (x = l; x < r; ++x) {
	  IM_WORK_T alpha = inp[3];
	  for (ch = 0; ch < 3; ++ch) {
	    *outp++ = ( *inp++ * alpha +
			bg->channel[ch] * (IM_SAMPLE_MAX - alpha)) / IM_SAMPLE_MAX;
	  }
	  ++inp;
	}

	return count;
      }

    case 4:
      {
	i_img_dim x;
	int ch;
	IM_SAMPLE_T *inp = samples, *outp = samples;
	i_img_dim count;

	count = IM_GSAMP(im, l, r, y, samples, NULL, im->channels);
	if (!count)
	  return 0;
	
	for (x = l; x < r; ++x) {
	  IM_WORK_T alpha = inp[3];
	  for (ch = 0; ch < 3; ++ch) {
	    *outp++ = ( *inp++ * alpha +
			bg->channel[ch] * (IM_SAMPLE_MAX - alpha)) / IM_SAMPLE_MAX;
	  }
	  ++inp;
	}

	return count;
      }
      break;
    default:
      i_fatal(0, "i_gsamp_bg() can only remove alpha channels");
      break;
    }
    break;

  default:
    i_fatal(0, "i_gsamp_bg() can only remove alpha channels");
  }

  return 0;
}

#/code