[imager.git] / rotate.im

/*
=head1 NAME

  rotate.im - implements image rotations

=head1 SYNOPSIS

  i_img *i_rotate90(i_img *src, int degrees)

=head1 DESCRIPTION

Implements basic 90 degree rotations of an image.

Other rotations will be added as tuits become available.

=cut
*/

#include "imager.h"
#include "imageri.h"
#include <math.h> /* for floor() */

#define ROT_DEBUG(x)

i_img *i_rotate90(i_img *src, int degrees) {
  i_img *targ;
  i_img_dim x, y;

  i_clear_error();

  if (degrees == 180) {
    /* essentially the same as flipxy(..., 2) except that it's not
       done in place */
    targ = i_sametype(src, src->xsize, src->ysize);
    if (src->type == i_direct_type) {
#code src->bits <= 8
      IM_COLOR *vals = mymalloc(src->xsize * sizeof(IM_COLOR));
      for (y = 0; y < src->ysize; ++y) {
	IM_COLOR tmp;
	IM_GLIN(src, 0, src->xsize, y, vals);
	for (x = 0; x < src->xsize/2; ++x) {
	  tmp = vals[x];
	  vals[x] = vals[src->xsize - x - 1];
	  vals[src->xsize - x - 1] = tmp;
	}
	IM_PLIN(targ, 0, src->xsize, src->ysize - y - 1, vals);
      }
      myfree(vals);
#/code
    }
    else {
      i_palidx *vals = mymalloc(src->xsize * sizeof(i_palidx));

      for (y = 0; y < src->ysize; ++y) {
        i_palidx tmp;
        i_gpal(src, 0, src->xsize, y, vals);
        for (x = 0; x < src->xsize/2; ++x) {
          tmp = vals[x];
          vals[x] = vals[src->xsize - x - 1];
          vals[src->xsize - x - 1] = tmp;
        }
        i_ppal(targ, 0, src->xsize, src->ysize - y - 1, vals);
      }
      
      myfree(vals);
    }

    return targ;
  }
  else if (degrees == 270 || degrees == 90) {
    i_img_dim tx, txstart, txinc;
    i_img_dim ty, tystart, tyinc;

    if (degrees == 270) {
      txstart = 0;
      txinc = 1;
      tystart = src->xsize-1;
      tyinc = -1;
    }
    else {
      txstart = src->ysize-1;
      txinc = -1;
      tystart = 0;
      tyinc = 1;
    }
    targ = i_sametype(src, src->ysize, src->xsize);
    if (src->type == i_direct_type) {
#code src->bits <= 8
      IM_COLOR *vals = mymalloc(src->xsize * sizeof(IM_COLOR));

      tx = txstart;
      for (y = 0; y < src->ysize; ++y) {
	IM_GLIN(src, 0, src->xsize, y, vals);
	ty = tystart;
	for (x = 0; x < src->xsize; ++x) {
	  IM_PPIX(targ, tx, ty, vals+x);
	  ty += tyinc;
	}
	tx += txinc;
      }
      myfree(vals);
#/code
    }
    else {
      i_palidx *vals = mymalloc(src->xsize * sizeof(i_palidx));
      
      tx = txstart;
      for (y = 0; y < src->ysize; ++y) {
        i_gpal(src, 0, src->xsize, y, vals);
        ty = tystart;
        for (x = 0; x < src->xsize; ++x) {
          i_ppal(targ, tx, tx+1, ty, vals+x);
          ty += tyinc;
        }
        tx += txinc;
      }
      myfree(vals);
    }
    return targ;
  }
  else {
    i_push_error(0, "i_rotate90() only rotates at 90, 180, or 270 degrees");
    return NULL;
  }
}

/* linear interpolation */
static i_color interp_i_color(i_color before, i_color after, double pos,
                              int channels) {
  i_color out;
  int ch;

  pos -= floor(pos);
  if (channels == 1 || channels == 3) {
    for (ch = 0; ch < channels; ++ch)
      out.channel[ch] = ((1-pos) * before.channel[ch] + pos * after.channel[ch]) + 0.5;
  }
  else {
    int total_cover = (1-pos) * before.channel[channels-1]
      + pos * after.channel[channels-1];

    total_cover = I_LIMIT_8(total_cover);
    if (total_cover) {
      double before_alpha = before.channel[channels-1] / 255.0;
      double after_alpha = after.channel[channels-1] / 255.0;
      double total_alpha = before_alpha * (1-pos) + after_alpha * pos;

      for (ch = 0; ch < channels-1; ++ch) {
	int out_level = ((1-pos) * before.channel[ch] * before_alpha + 
			 pos * after.channel[ch] * after_alpha) / total_alpha + 0.5;

	out.channel[ch] = I_LIMIT_8(out_level);
      }
    }
    else {
      for (ch = 0; ch < channels-1; ++ch)
	out.channel[ch] = 0;
    }

    out.channel[channels-1] = total_cover;
  }

  return out;
}

/* hopefully this will be inlined  (it is with -O3 with gcc 2.95.4) */
/* linear interpolation */
static i_fcolor interp_i_fcolor(i_fcolor before, i_fcolor after, double pos,
                                int channels) {
  i_fcolor out;
  int ch;

  pos -= floor(pos);
  if (channels == 1 || channels == 3) {
    for (ch = 0; ch < channels; ++ch)
      out.channel[ch] = (1-pos) * before.channel[ch] + pos * after.channel[ch];
  }
  else {
    double total_cover = (1-pos) * before.channel[channels-1]
      + pos * after.channel[channels-1];

    total_cover = I_LIMIT_DOUBLE(total_cover);
    if (total_cover) {
      double before_alpha = before.channel[channels-1];
      double after_alpha = after.channel[channels-1];
      double total_alpha = before_alpha * (1-pos) + after_alpha * pos;

      for (ch = 0; ch < channels-1; ++ch) {
	double out_level = ((1-pos) * before.channel[ch] * before_alpha + 
			 pos * after.channel[ch] * after_alpha) / total_alpha;

	out.channel[ch] = I_LIMIT_DOUBLE(out_level);
      }
    }
    else {
      for (ch = 0; ch < channels-1; ++ch)
	out.channel[ch] = 0;
    }

    out.channel[channels-1] = total_cover;
  }

  return out;
}

i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const double *matrix,
			     const i_color *backp, const i_fcolor *fbackp) {
  i_img *result = i_sametype(src, xsize, ysize);
  i_img_dim x, y;
  int ch;
  i_img_dim i, j;
  double sx, sy, sz;

  if (src->type == i_direct_type) {
#code src->bits <= 8
    IM_COLOR *vals = mymalloc(xsize * sizeof(IM_COLOR));
    IM_COLOR back;

#ifdef IM_EIGHT_BIT
    if (backp) {
      back = *backp;
    }
    else if (fbackp) {
      for (ch = 0; ch < src->channels; ++ch) {
	i_fsample_t fsamp;
	fsamp = fbackp->channel[ch];
	back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
      }
    }
#else
#define interp_i_color interp_i_fcolor
    if (fbackp) {
      back = *fbackp;
    }
    else if (backp) {
      for (ch = 0; ch < src->channels; ++ch)
	back.channel[ch] = backp->channel[ch] / 255.0;
    }
#endif
    else {
      for (ch = 0; ch < src->channels; ++ch)
	back.channel[ch] = 0;
    }

    for (y = 0; y < ysize; ++y) {
      for (x = 0; x < xsize; ++x) {
	/* dividing by sz gives us the ability to do perspective 
	   transforms */
	sz = x * matrix[6] + y * matrix[7] + matrix[8];
	if (fabs(sz) > 0.0000001) {
	  sx = (x * matrix[0] + y * matrix[1] + matrix[2]) / sz;
	  sy = (x * matrix[3] + y * matrix[4] + matrix[5]) / sz;
	}
	else {
	  sx = sy = 0;
	}
	
	/* anything outside these ranges is either a broken co-ordinate
	   or outside the source */
	if (fabs(sz) > 0.0000001 
	    && sx >= -1 && sx < src->xsize
	    && sy >= -1 && sy < src->ysize) {
	  i_img_dim bx = floor(sx);
	  i_img_dim by = floor(sy);

	  ROT_DEBUG(fprintf(stderr, "map " i_DFp " to %g,%g\n", i_DFcp(x, y), sx, sy));
	  if (sx != bx) {
	    if (sy != by) {
	      IM_COLOR c[2][2]; 
	      IM_COLOR ci2[2];
	      ROT_DEBUG(fprintf(stderr, " both non-int\n"));
	      for (i = 0; i < 2; ++i)
		for (j = 0; j < 2; ++j)
		  if (IM_GPIX(src, bx+i, by+j, &c[j][i]))
		    c[j][i] = back;
	      for (j = 0; j < 2; ++j)
		ci2[j] = interp_i_color(c[j][0], c[j][1], sx, src->channels);
	      vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
	    }
	    else {
	      IM_COLOR ci2[2];
	      ROT_DEBUG(fprintf(stderr, " y int, x non-int\n"));
	      for (i = 0; i < 2; ++i)
		if (IM_GPIX(src, bx+i, sy, ci2+i))
		  ci2[i] = back;
	      vals[x] = interp_i_color(ci2[0], ci2[1], sx, src->channels);
	    }
	  }
	  else {
	    if (sy != (i_img_dim)sy) {
	      IM_COLOR ci2[2];
	      ROT_DEBUG(fprintf(stderr, " x int, y non-int\n"));
	      for (i = 0; i < 2; ++i)
		if (IM_GPIX(src, bx, by+i, ci2+i))
		  ci2[i] = back;
	      vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
	    }
	    else {
	      ROT_DEBUG(fprintf(stderr, " both int\n"));
	      /* all the world's an integer */
	      if (IM_GPIX(src, sx, sy, vals+x))
		vals[x] = back;
	    }
	  }
	}
	else {
	  vals[x] = back;
	}
      }
      IM_PLIN(result, 0, xsize, y, vals);
    }
    myfree(vals);
#undef interp_i_color
#/code
  }
  else {
    /* don't interpolate for a palette based image */
    i_palidx *vals = mymalloc(xsize * sizeof(i_palidx));
    i_palidx back = 0;
    int minval = 256 * 4;
    i_img_dim ix, iy;
    i_color want_back;
    i_fsample_t fsamp;

    if (backp) {
      want_back = *backp;
    }
    else if (fbackp) {
      for (ch = 0; ch < src->channels; ++ch) {
	fsamp = fbackp->channel[ch];
	want_back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
      }
    }
    else {
      for (ch = 0; ch < src->channels; ++ch)
	want_back.channel[ch] = 0;
    }
    
    /* find the closest color */
    for (i = 0; i < i_colorcount(src); ++i) {
      i_color temp;
      int tempval;
      i_getcolors(src, i, &temp, 1);
      tempval = 0;
      for (ch = 0; ch < src->channels; ++ch) {
        tempval += abs(want_back.channel[ch] - temp.channel[ch]);
      }
      if (tempval < minval) {
        back = i;
        minval = tempval;
      }
    }

    for (y = 0; y < ysize; ++y) {
      for (x = 0; x < xsize; ++x) {
        /* dividing by sz gives us the ability to do perspective 
           transforms */
        sz = x * matrix[6] + y * matrix[7] + matrix[8];
        if (abs(sz) > 0.0000001) {
          sx = (x * matrix[0] + y * matrix[1] + matrix[2]) / sz;
          sy = (x * matrix[3] + y * matrix[4] + matrix[5]) / sz;
        }
        else {
          sx = sy = 0;
        }
        
        /* anything outside these ranges is either a broken co-ordinate
           or outside the source */
        if (abs(sz) > 0.0000001 
            && sx >= -0.5 && sx < src->xsize-0.5
            && sy >= -0.5 && sy < src->ysize-0.5) {
          
          /* all the world's an integer */
          ix = (i_img_dim)(sx+0.5);
          iy = (i_img_dim)(sy+0.5);
          if (!i_gpal(src, ix, ix+1, iy, vals+x))
	    vals[i] = back;
        }
        else {
          vals[x] = back;
        }
      }
      i_ppal(result, 0, xsize, y, vals);
    }
    myfree(vals);
  }

  return result;
}

i_img *i_matrix_transform(i_img *src, i_img_dim xsize, i_img_dim ysize, const double *matrix) {
  return i_matrix_transform_bg(src, xsize, ysize, matrix, NULL, NULL);
}

static void
i_matrix_mult(double *dest, const double *left, const double *right) {
  int i, j, k;
  double accum;
  
  for (i = 0; i < 3; ++i) {
    for (j = 0; j < 3; ++j) {
      accum = 0.0;
      for (k = 0; k < 3; ++k) {
        accum += left[3*i+k] * right[3*k+j];
      }
      dest[3*i+j] = accum;
    }
  }
}

#define numfmt "%23g"

ROT_DEBUG(static void dump_mat(const char *name, double *f) {
  fprintf(stderr, "%s:\n  " numfmt " " numfmt " " numfmt "\n"
	  "  " numfmt " " numfmt " " numfmt "\n"
	  "  " numfmt " " numfmt " " numfmt "\n",
	  name, f[0], f[1], f[2], f[3], f[4], f[5], f[6], f[7], f[8]);
  })

i_img *i_rotate_exact_bg(i_img *src, double amount, 
			 const i_color *backp, const i_fcolor *fbackp) {
  double xlate1[9] = { 0 };
  double rotate[9];
  double xlate2[9] = { 0 };
  double temp[9], matrix[9];
  i_img_dim x1, x2, y1, y2, newxsize, newysize;

  ROT_DEBUG(fprintf(stderr, "rotate angle %.20g\n", amount));

  /* first translate the centre of the image to (0,0) */
  xlate1[0] = 1;
  xlate1[2] = (src->xsize-1)/2.0;
  xlate1[4] = 1;
  xlate1[5] = (src->ysize-1)/2.0;
  xlate1[8] = 1;

  ROT_DEBUG(dump_mat("xlate1", xlate1));

  /* rotate around (0.0) */
  rotate[0] = cos(amount);
  rotate[1] = sin(amount);
  rotate[2] = 0;
  rotate[3] = -rotate[1];
  rotate[4] = rotate[0];
  rotate[5] = 0;
  rotate[6] = 0;
  rotate[7] = 0;
  rotate[8] = 1;

  ROT_DEBUG(dump_mat("rotate", rotate));

  ROT_DEBUG(fprintf(stderr, "cos %g sin %g\n", rotate[0], rotate[1]));

  x1 = ceil(fabs(src->xsize * rotate[0] + src->ysize * rotate[1]) - 0.0001);
  x2 = ceil(fabs(src->xsize * rotate[0] - src->ysize * rotate[1]) - 0.0001);
  y1 = ceil(fabs(src->xsize * rotate[3] + src->ysize * rotate[4]) - 0.0001);
  y2 = ceil(fabs(src->xsize * rotate[3] - src->ysize * rotate[4]) - 0.0001);
  ROT_DEBUG(fprintf(stderr, "x1 y1 " i_DFp " x2 y2 " i_DFp "\n", i_DFcp(x1, y1), i_DFcp(x2, y2)));
  newxsize = x1 > x2 ? x1 : x2;
  newysize = y1 > y2 ? y1 : y2;
  /* translate the centre back to the center of the image */
  xlate2[0] = 1;
  xlate2[2] = -(newxsize-1)/2.0;
  xlate2[4] = 1;
  xlate2[5] = -(newysize-1)/2.0;
  xlate2[8] = 1;

  ROT_DEBUG(dump_mat("xlate2", xlate2));

  i_matrix_mult(temp, xlate1, rotate);
  i_matrix_mult(matrix, temp, xlate2);

  ROT_DEBUG(dump_mat("matrxi", matrix));

  return i_matrix_transform_bg(src, newxsize, newysize, matrix, backp, fbackp);
}

i_img *i_rotate_exact(i_img *src, double amount) {
  return i_rotate_exact_bg(src, amount, NULL, NULL);
}


/*
=back

=head1 AUTHOR

Tony Cook <tony@develop-help.com>

=head1 SEE ALSO

Imager(3)

=cut
*/
Commit	Line	Data
faa9b3e7 TC	1	/*
	2	=head1 NAME
	3
999f4294	4	rotate.im - implements image rotations
faa9b3e7 TC	5
	6	=head1 SYNOPSIS
	7
	8	i_img i_rotate90(i_img src, int degrees)
	9
	10	=head1 DESCRIPTION
	11
	12	Implements basic 90 degree rotations of an image.
	13
	14	Other rotations will be added as tuits become available.
	15
	16	=cut
	17	*/
	18
92bda632	19	#include "imager.h"
13c9a303	20	#include "imageri.h"
faa9b3e7 TC	21	#include <math.h> /* for floor() */
faa9b3e7 TC	22
289d65f4 TC	23	#define ROT_DEBUG(x)
289d65f4 TC	24
faa9b3e7 TC	25	i_img i_rotate90(i_img src, int degrees) {
faa9b3e7 TC	26	i_img *targ;
8d14daab	27	i_img_dim x, y;
faa9b3e7 TC	28
	29	i_clear_error();
	30
	31	if (degrees == 180) {
	32	/* essentially the same as flipxy(..., 2) except that it's not
	33	done in place */
	34	targ = i_sametype(src, src->xsize, src->ysize);
	35	if (src->type == i_direct_type) {
999f4294 TC	36	#code src->bits <= 8
	37	IM_COLOR vals = mymalloc(src->xsize sizeof(IM_COLOR));
	38	for (y = 0; y < src->ysize; ++y) {
	39	IM_COLOR tmp;
	40	IM_GLIN(src, 0, src->xsize, y, vals);
	41	for (x = 0; x < src->xsize/2; ++x) {
	42	tmp = vals[x];
	43	vals[x] = vals[src->xsize - x - 1];
	44	vals[src->xsize - x - 1] = tmp;
	45	}
	46	IM_PLIN(targ, 0, src->xsize, src->ysize - y - 1, vals);
faa9b3e7	47	}
999f4294 TC	48	myfree(vals);
999f4294 TC	49	#/code
faa9b3e7 TC	50	}
	51	else {
	52	i_palidx vals = mymalloc(src->xsize sizeof(i_palidx));
	53
	54	for (y = 0; y < src->ysize; ++y) {
	55	i_palidx tmp;
	56	i_gpal(src, 0, src->xsize, y, vals);
	57	for (x = 0; x < src->xsize/2; ++x) {
	58	tmp = vals[x];
	59	vals[x] = vals[src->xsize - x - 1];
	60	vals[src->xsize - x - 1] = tmp;
	61	}
	62	i_ppal(targ, 0, src->xsize, src->ysize - y - 1, vals);
	63	}
	64
	65	myfree(vals);
	66	}
	67
	68	return targ;
	69	}
	70	else if (degrees == 270 \|\| degrees == 90) {
8d14daab TC	71	i_img_dim tx, txstart, txinc;
8d14daab TC	72	i_img_dim ty, tystart, tyinc;
faa9b3e7 TC	73
	74	if (degrees == 270) {
	75	txstart = 0;
	76	txinc = 1;
	77	tystart = src->xsize-1;
	78	tyinc = -1;
	79	}
	80	else {
	81	txstart = src->ysize-1;
	82	txinc = -1;
	83	tystart = 0;
	84	tyinc = 1;
	85	}
	86	targ = i_sametype(src, src->ysize, src->xsize);
	87	if (src->type == i_direct_type) {
999f4294 TC	88	#code src->bits <= 8
	89	IM_COLOR vals = mymalloc(src->xsize sizeof(IM_COLOR));
	90
	91	tx = txstart;
	92	for (y = 0; y < src->ysize; ++y) {
	93	IM_GLIN(src, 0, src->xsize, y, vals);
	94	ty = tystart;
	95	for (x = 0; x < src->xsize; ++x) {
	96	IM_PPIX(targ, tx, ty, vals+x);
	97	ty += tyinc;
	98	}
	99	tx += txinc;
faa9b3e7	100	}
999f4294 TC	101	myfree(vals);
999f4294 TC	102	#/code
faa9b3e7 TC	103	}
	104	else {
	105	i_palidx vals = mymalloc(src->xsize sizeof(i_palidx));
	106
	107	tx = txstart;
	108	for (y = 0; y < src->ysize; ++y) {
	109	i_gpal(src, 0, src->xsize, y, vals);
	110	ty = tystart;
	111	for (x = 0; x < src->xsize; ++x) {
	112	i_ppal(targ, tx, tx+1, ty, vals+x);
	113	ty += tyinc;
	114	}
	115	tx += txinc;
	116	}
	117	myfree(vals);
	118	}
	119	return targ;
	120	}
	121	else {
	122	i_push_error(0, "i_rotate90() only rotates at 90, 180, or 270 degrees");
	123	return NULL;
	124	}
	125	}
	126
faa9b3e7 TC	127	/* linear interpolation */
	128	static i_color interp_i_color(i_color before, i_color after, double pos,
	129	int channels) {
	130	i_color out;
	131	int ch;
	132
	133	pos -= floor(pos);
13c9a303 TC	134	if (channels == 1 \|\| channels == 3) {
13c9a303 TC	135	for (ch = 0; ch < channels; ++ch)
289d65f4	136	out.channel[ch] = ((1-pos) * before.channel[ch] + pos * after.channel[ch]) + 0.5;
13c9a303 TC	137	}
	138	else {
	139	int total_cover = (1-pos) * before.channel[channels-1]
	140	+ pos * after.channel[channels-1];
	141
	142	total_cover = I_LIMIT_8(total_cover);
	143	if (total_cover) {
	144	double before_alpha = before.channel[channels-1] / 255.0;
	145	double after_alpha = after.channel[channels-1] / 255.0;
	146	double total_alpha = before_alpha * (1-pos) + after_alpha * pos;
	147
	148	for (ch = 0; ch < channels-1; ++ch) {
	149	int out_level = ((1-pos) * before.channel[ch] * before_alpha +
ef74691a	150	pos * after.channel[ch] * after_alpha) / total_alpha + 0.5;
13c9a303 TC	151
	152	out.channel[ch] = I_LIMIT_8(out_level);
	153	}
	154	}
e329f022 TC	155	else {
	156	for (ch = 0; ch < channels-1; ++ch)
	157	out.channel[ch] = 0;
	158	}
13c9a303 TC	159
	160	out.channel[channels-1] = total_cover;
	161	}
faa9b3e7 TC	162
	163	return out;
	164	}
	165
	166	/* hopefully this will be inlined (it is with -O3 with gcc 2.95.4) */
	167	/* linear interpolation */
	168	static i_fcolor interp_i_fcolor(i_fcolor before, i_fcolor after, double pos,
	169	int channels) {
	170	i_fcolor out;
	171	int ch;
	172
	173	pos -= floor(pos);
13c9a303 TC	174	if (channels == 1 \|\| channels == 3) {
	175	for (ch = 0; ch < channels; ++ch)
	176	out.channel[ch] = (1-pos) * before.channel[ch] + pos * after.channel[ch];
	177	}
	178	else {
	179	double total_cover = (1-pos) * before.channel[channels-1]
	180	+ pos * after.channel[channels-1];
	181
	182	total_cover = I_LIMIT_DOUBLE(total_cover);
	183	if (total_cover) {
	184	double before_alpha = before.channel[channels-1];
	185	double after_alpha = after.channel[channels-1];
	186	double total_alpha = before_alpha * (1-pos) + after_alpha * pos;
	187
	188	for (ch = 0; ch < channels-1; ++ch) {
	189	double out_level = ((1-pos) * before.channel[ch] * before_alpha +
	190	pos * after.channel[ch] * after_alpha) / total_alpha;
	191
	192	out.channel[ch] = I_LIMIT_DOUBLE(out_level);
	193	}
	194	}
e329f022 TC	195	else {
	196	for (ch = 0; ch < channels-1; ++ch)
	197	out.channel[ch] = 0;
	198	}
13c9a303 TC	199
	200	out.channel[channels-1] = total_cover;
	201	}
faa9b3e7 TC	202
	203	return out;
	204	}
	205
8d14daab	206	i_img i_matrix_transform_bg(i_img src, i_img_dim xsize, i_img_dim ysize, const double *matrix,
97ac0a96	207	const i_color backp, const i_fcolor fbackp) {
faa9b3e7	208	i_img *result = i_sametype(src, xsize, ysize);
8d14daab	209	i_img_dim x, y;
faa9b3e7	210	int ch;
8d14daab	211	i_img_dim i, j;
faa9b3e7	212	double sx, sy, sz;
faa9b3e7 TC	213
faa9b3e7 TC	214	if (src->type == i_direct_type) {
999f4294 TC	215	#code src->bits <= 8
	216	IM_COLOR vals = mymalloc(xsize sizeof(IM_COLOR));
	217	IM_COLOR back;
faa9b3e7	218
999f4294 TC	219	#ifdef IM_EIGHT_BIT
	220	if (backp) {
	221	back = *backp;
	222	}
	223	else if (fbackp) {
	224	for (ch = 0; ch < src->channels; ++ch) {
0a53238e	225	i_fsample_t fsamp;
999f4294 TC	226	fsamp = fbackp->channel[ch];
999f4294 TC	227	back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
faa9b3e7	228	}
faa9b3e7	229	}
999f4294 TC	230	#else
	231	#define interp_i_color interp_i_fcolor
	232	if (fbackp) {
	233	back = *fbackp;
	234	}
	235	else if (backp) {
	236	for (ch = 0; ch < src->channels; ++ch)
	237	back.channel[ch] = backp->channel[ch] / 255.0;
	238	}
	239	#endif
faa9b3e7	240	else {
999f4294 TC	241	for (ch = 0; ch < src->channels; ++ch)
	242	back.channel[ch] = 0;
	243	}
faa9b3e7	244
999f4294 TC	245	for (y = 0; y < ysize; ++y) {
	246	for (x = 0; x < xsize; ++x) {
	247	/* dividing by sz gives us the ability to do perspective
	248	transforms */
	249	sz = x * matrix[6] + y * matrix[7] + matrix[8];
	250	if (fabs(sz) > 0.0000001) {
	251	sx = (x * matrix[0] + y * matrix[1] + matrix[2]) / sz;
	252	sy = (x * matrix[3] + y * matrix[4] + matrix[5]) / sz;
	253	}
	254	else {
	255	sx = sy = 0;
	256	}
	257
	258	/* anything outside these ranges is either a broken co-ordinate
	259	or outside the source */
	260	if (fabs(sz) > 0.0000001
	261	&& sx >= -1 && sx < src->xsize
	262	&& sy >= -1 && sy < src->ysize) {
1e9de315 TC	263	i_img_dim bx = floor(sx);
1e9de315 TC	264	i_img_dim by = floor(sy);
289d65f4 TC	265
289d65f4 TC	266	ROT_DEBUG(fprintf(stderr, "map " i_DFp " to %g,%g\n", i_DFcp(x, y), sx, sy));
1e9de315 TC	267	if (sx != bx) {
1e9de315 TC	268	if (sy != by) {
999f4294 TC	269	IM_COLOR c[2][2];
999f4294 TC	270	IM_COLOR ci2[2];
289d65f4	271	ROT_DEBUG(fprintf(stderr, " both non-int\n"));
999f4294 TC	272	for (i = 0; i < 2; ++i)
999f4294 TC	273	for (j = 0; j < 2; ++j)
1e9de315	274	if (IM_GPIX(src, bx+i, by+j, &c[j][i]))
999f4294 TC	275	c[j][i] = back;
	276	for (j = 0; j < 2; ++j)
	277	ci2[j] = interp_i_color(c[j][0], c[j][1], sx, src->channels);
	278	vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
	279	}
	280	else {
	281	IM_COLOR ci2[2];
289d65f4	282	ROT_DEBUG(fprintf(stderr, " y int, x non-int\n"));
999f4294	283	for (i = 0; i < 2; ++i)
1e9de315	284	if (IM_GPIX(src, bx+i, sy, ci2+i))
999f4294 TC	285	ci2[i] = back;
	286	vals[x] = interp_i_color(ci2[0], ci2[1], sx, src->channels);
	287	}
	288	}
	289	else {
	290	if (sy != (i_img_dim)sy) {
	291	IM_COLOR ci2[2];
289d65f4	292	ROT_DEBUG(fprintf(stderr, " x int, y non-int\n"));
999f4294	293	for (i = 0; i < 2; ++i)
1e9de315	294	if (IM_GPIX(src, bx, by+i, ci2+i))
999f4294 TC	295	ci2[i] = back;
	296	vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
	297	}
	298	else {
289d65f4	299	ROT_DEBUG(fprintf(stderr, " both int\n"));
999f4294 TC	300	/* all the world's an integer */
	301	if (IM_GPIX(src, sx, sy, vals+x))
	302	vals[x] = back;
	303	}
	304	}
	305	}
	306	else {
	307	vals[x] = back;
	308	}
faa9b3e7	309	}
999f4294	310	IM_PLIN(result, 0, xsize, y, vals);
faa9b3e7	311	}
999f4294 TC	312	myfree(vals);
	313	#undef interp_i_color
	314	#/code
faa9b3e7 TC	315	}
	316	else {
	317	/* don't interpolate for a palette based image */
	318	i_palidx vals = mymalloc(xsize sizeof(i_palidx));
0d3b936e	319	i_palidx back = 0;
0d3b936e	320	int minval = 256 * 4;
8d14daab	321	i_img_dim ix, iy;
0d3b936e TC	322	i_color want_back;
0d3b936e TC	323	i_fsample_t fsamp;
faa9b3e7	324
0d3b936e TC	325	if (backp) {
	326	want_back = *backp;
	327	}
	328	else if (fbackp) {
	329	for (ch = 0; ch < src->channels; ++ch) {
	330	fsamp = fbackp->channel[ch];
	331	want_back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
	332	}
	333	}
	334	else {
	335	for (ch = 0; ch < src->channels; ++ch)
	336	want_back.channel[ch] = 0;
	337	}
	338
	339	/* find the closest color */
	340	for (i = 0; i < i_colorcount(src); ++i) {
faa9b3e7 TC	341	i_color temp;
	342	int tempval;
	343	i_getcolors(src, i, &temp, 1);
	344	tempval = 0;
	345	for (ch = 0; ch < src->channels; ++ch) {
0d3b936e	346	tempval += abs(want_back.channel[ch] - temp.channel[ch]);
faa9b3e7 TC	347	}
faa9b3e7 TC	348	if (tempval < minval) {
0d3b936e	349	back = i;
faa9b3e7 TC	350	minval = tempval;
	351	}
	352	}
	353
	354	for (y = 0; y < ysize; ++y) {
	355	for (x = 0; x < xsize; ++x) {
	356	/* dividing by sz gives us the ability to do perspective
	357	transforms */
	358	sz = x * matrix[6] + y * matrix[7] + matrix[8];
	359	if (abs(sz) > 0.0000001) {
	360	sx = (x * matrix[0] + y * matrix[1] + matrix[2]) / sz;
	361	sy = (x * matrix[3] + y * matrix[4] + matrix[5]) / sz;
	362	}
e4bf9335 TC	363	else {
	364	sx = sy = 0;
	365	}
faa9b3e7 TC	366
	367	/* anything outside these ranges is either a broken co-ordinate
	368	or outside the source */
	369	if (abs(sz) > 0.0000001
	370	&& sx >= -0.5 && sx < src->xsize-0.5
	371	&& sy >= -0.5 && sy < src->ysize-0.5) {
	372
	373	/* all the world's an integer */
8d14daab TC	374	ix = (i_img_dim)(sx+0.5);
8d14daab TC	375	iy = (i_img_dim)(sy+0.5);
0d3b936e TC	376	if (!i_gpal(src, ix, ix+1, iy, vals+x))
0d3b936e TC	377	vals[i] = back;
faa9b3e7 TC	378	}
faa9b3e7 TC	379	else {
0d3b936e	380	vals[x] = back;
faa9b3e7 TC	381	}
	382	}
	383	i_ppal(result, 0, xsize, y, vals);
	384	}
	385	myfree(vals);
	386	}
	387
	388	return result;
	389	}
	390
8d14daab	391	i_img i_matrix_transform(i_img src, i_img_dim xsize, i_img_dim ysize, const double *matrix) {
0d3b936e TC	392	return i_matrix_transform_bg(src, xsize, ysize, matrix, NULL, NULL);
	393	}
	394
35891892	395	static void
97ac0a96	396	i_matrix_mult(double dest, const double left, const double *right) {
faa9b3e7 TC	397	int i, j, k;
	398	double accum;
	399
	400	for (i = 0; i < 3; ++i) {
	401	for (j = 0; j < 3; ++j) {
	402	accum = 0.0;
	403	for (k = 0; k < 3; ++k) {
	404	accum += left[3i+k] right[3*k+j];
	405	}
	406	dest[3*i+j] = accum;
	407	}
	408	}
	409	}
	410
289d65f4 TC	411	#define numfmt "%23g"
289d65f4 TC	412
1e9de315	413	ROT_DEBUG(static void dump_mat(const char name, double f) {
289d65f4 TC	414	fprintf(stderr, "%s:\n " numfmt " " numfmt " " numfmt "\n"
	415	" " numfmt " " numfmt " " numfmt "\n"
	416	" " numfmt " " numfmt " " numfmt "\n",
	417	name, f[0], f[1], f[2], f[3], f[4], f[5], f[6], f[7], f[8]);
	418	})
	419
0d3b936e	420	i_img i_rotate_exact_bg(i_img src, double amount,
97ac0a96	421	const i_color backp, const i_fcolor fbackp) {
faa9b3e7 TC	422	double xlate1[9] = { 0 };
	423	double rotate[9];
	424	double xlate2[9] = { 0 };
	425	double temp[9], matrix[9];
8d14daab	426	i_img_dim x1, x2, y1, y2, newxsize, newysize;
faa9b3e7	427
1e9de315 TC	428	ROT_DEBUG(fprintf(stderr, "rotate angle %.20g\n", amount));
1e9de315 TC	429
faa9b3e7 TC	430	/* first translate the centre of the image to (0,0) */
faa9b3e7 TC	431	xlate1[0] = 1;
289d65f4	432	xlate1[2] = (src->xsize-1)/2.0;
faa9b3e7	433	xlate1[4] = 1;
289d65f4	434	xlate1[5] = (src->ysize-1)/2.0;
faa9b3e7 TC	435	xlate1[8] = 1;
faa9b3e7 TC	436
289d65f4 TC	437	ROT_DEBUG(dump_mat("xlate1", xlate1));
289d65f4 TC	438
faa9b3e7 TC	439	/* rotate around (0.0) */
	440	rotate[0] = cos(amount);
	441	rotate[1] = sin(amount);
	442	rotate[2] = 0;
	443	rotate[3] = -rotate[1];
	444	rotate[4] = rotate[0];
	445	rotate[5] = 0;
	446	rotate[6] = 0;
	447	rotate[7] = 0;
	448	rotate[8] = 1;
	449
289d65f4 TC	450	ROT_DEBUG(dump_mat("rotate", rotate));
	451
	452	ROT_DEBUG(fprintf(stderr, "cos %g sin %g\n", rotate[0], rotate[1]));
	453
	454	x1 = ceil(fabs(src->xsize * rotate[0] + src->ysize * rotate[1]) - 0.0001);
	455	x2 = ceil(fabs(src->xsize * rotate[0] - src->ysize * rotate[1]) - 0.0001);
	456	y1 = ceil(fabs(src->xsize * rotate[3] + src->ysize * rotate[4]) - 0.0001);
	457	y2 = ceil(fabs(src->xsize * rotate[3] - src->ysize * rotate[4]) - 0.0001);
	458	ROT_DEBUG(fprintf(stderr, "x1 y1 " i_DFp " x2 y2 " i_DFp "\n", i_DFcp(x1, y1), i_DFcp(x2, y2)));
faa9b3e7 TC	459	newxsize = x1 > x2 ? x1 : x2;
	460	newysize = y1 > y2 ? y1 : y2;
	461	/* translate the centre back to the center of the image */
	462	xlate2[0] = 1;
289d65f4	463	xlate2[2] = -(newxsize-1)/2.0;
faa9b3e7	464	xlate2[4] = 1;
289d65f4	465	xlate2[5] = -(newysize-1)/2.0;
faa9b3e7	466	xlate2[8] = 1;
289d65f4 TC	467
	468	ROT_DEBUG(dump_mat("xlate2", xlate2));
	469
faa9b3e7 TC	470	i_matrix_mult(temp, xlate1, rotate);
	471	i_matrix_mult(matrix, temp, xlate2);
	472
289d65f4 TC	473	ROT_DEBUG(dump_mat("matrxi", matrix));
289d65f4 TC	474
0d3b936e	475	return i_matrix_transform_bg(src, newxsize, newysize, matrix, backp, fbackp);
faa9b3e7	476	}
b8c2033e	477
0d3b936e TC	478	i_img i_rotate_exact(i_img src, double amount) {
	479	return i_rotate_exact_bg(src, amount, NULL, NULL);
	480	}
	481
	482
b8c2033e AMH	483	/*
	484	=back
	485
	486	=head1 AUTHOR
	487
	488	Tony Cook <tony@develop-help.com>
	489
	490	=head1 SEE ALSO
	491
	492	Imager(3)
	493
	494	=cut
	495	*/