-/*
-=head1 NAME
-
- rotate.c - 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() */
-
-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) {
- if (src->bits == i_8_bits) {
- i_color *vals = mymalloc(src->xsize * sizeof(i_color));
- for (y = 0; y < src->ysize; ++y) {
- i_color tmp;
- i_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;
- }
- i_plin(targ, 0, src->xsize, src->ysize - y - 1, vals);
- }
- myfree(vals);
- }
- else {
- i_fcolor *vals = mymalloc(src->xsize * sizeof(i_fcolor));
- for (y = 0; y < src->ysize; ++y) {
- i_fcolor tmp;
- i_glinf(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_plinf(targ, 0, src->xsize, src->ysize - y - 1, vals);
- }
- myfree(vals);
- }
- }
- 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) {
- if (src->bits == i_8_bits) {
- i_color *vals = mymalloc(src->xsize * sizeof(i_color));
-
- tx = txstart;
- for (y = 0; y < src->ysize; ++y) {
- i_glin(src, 0, src->xsize, y, vals);
- ty = tystart;
- for (x = 0; x < src->xsize; ++x) {
- i_ppix(targ, tx, ty, vals+x);
- ty += tyinc;
- }
- tx += txinc;
- }
- myfree(vals);
- }
- else {
- i_fcolor *vals = mymalloc(src->xsize * sizeof(i_fcolor));
-
- tx = txstart;
- for (y = 0; y < src->ysize; ++y) {
- i_glinf(src, 0, src->xsize, y, vals);
- ty = tystart;
- for (x = 0; x < src->xsize; ++x) {
- i_ppixf(targ, tx, ty, vals+x);
- ty += tyinc;
- }
- tx += txinc;
- }
- myfree(vals);
- }
- }
- 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];
- }
- 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 + 0.5) / total_alpha;
-
- out.channel[ch] = I_LIMIT_8(out_level);
- }
- }
-
- 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);
- }
- }
-
- 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) {
- if (src->bits == i_8_bits) {
- i_color *vals = mymalloc(xsize * sizeof(i_color));
- i_color back;
- i_fsample_t fsamp;
-
- if (backp) {
- back = *backp;
- }
- else if (fbackp) {
- for (ch = 0; ch < src->channels; ++ch) {
- fsamp = fbackp->channel[ch];
- back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
- }
- }
- 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) {
-
- if (sx != (i_img_dim)sx) {
- if (sy != (i_img_dim)sy) {
- i_color c[2][2];
- i_color ci2[2];
- for (i = 0; i < 2; ++i)
- for (j = 0; j < 2; ++j)
- if (i_gpix(src, floor(sx)+i, floor(sy)+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 {
- i_color ci2[2];
- for (i = 0; i < 2; ++i)
- if (i_gpix(src, floor(sx)+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) {
- i_color ci2[2];
- for (i = 0; i < 2; ++i)
- if (i_gpix(src, sx, floor(sy)+i, ci2+i))
- ci2[i] = back;
- vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
- }
- else {
- /* all the world's an integer */
- if (i_gpix(src, sx, sy, vals+x))
- vals[x] = back;
- }
- }
- }
- else {
- vals[x] = back;
- }
- }
- i_plin(result, 0, xsize, y, vals);
- }
- myfree(vals);
- }
- else {
- i_fcolor *vals = mymalloc(xsize * sizeof(i_fcolor));
- i_fcolor back;
-
- if (fbackp) {
- back = *fbackp;
- }
- else if (backp) {
- for (ch = 0; ch < src->channels; ++ch)
- back.channel[ch] = backp->channel[ch] / 255.0;
- }
- 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) {
-
- if (sx != (i_img_dim)sx) {
- if (sy != (i_img_dim)sy) {
- i_fcolor c[2][2];
- i_fcolor ci2[2];
- for (i = 0; i < 2; ++i)
- for (j = 0; j < 2; ++j)
- if (i_gpixf(src, floor(sx)+i, floor(sy)+j, &c[j][i]))
- c[j][i] = back;
- for (j = 0; j < 2; ++j)
- ci2[j] = interp_i_fcolor(c[j][0], c[j][1], sx, src->channels);
- vals[x] = interp_i_fcolor(ci2[0], ci2[1], sy, src->channels);
- }
- else {
- i_fcolor ci2[2];
- for (i = 0; i < 2; ++i)
- if (i_gpixf(src, floor(sx)+i, sy, ci2+i))
- ci2[i] = back;
- vals[x] = interp_i_fcolor(ci2[0], ci2[1], sx, src->channels);
- }
- }
- else {
- if (sy != (i_img_dim)sy) {
- i_fcolor ci2[2];
- for (i = 0; i < 2; ++i)
- if (i_gpixf(src, sx, floor(sy)+i, ci2+i))
- ci2[i] = back;
- vals[x] = interp_i_fcolor(ci2[0], ci2[1], sy, src->channels);
- }
- else {
- /* all the world's an integer */
- if (i_gpixf(src, sx, sy, vals+x))
- vals[x] = back;
- }
- }
- }
- else {
- vals[x] = back;
- }
- }
- i_plinf(result, 0, xsize, y, vals);
- }
- myfree(vals);
- }
- }
- else {
- /* don't interpolate for a palette based image */
- i_palidx *vals = mymalloc(xsize * sizeof(i_palidx));
- i_palidx back = 0;
- i_color min;
- 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;
- min = temp;
- 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;
- }
- }
-}
-
-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;
-
- /* first translate the centre of the image to (0,0) */
- xlate1[0] = 1;
- xlate1[2] = src->xsize/2.0;
- xlate1[4] = 1;
- xlate1[5] = src->ysize/2.0;
- xlate1[8] = 1;
-
- /* 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;
-
- x1 = ceil(i_abs(src->xsize * rotate[0] + src->ysize * rotate[1]));
- x2 = ceil(i_abs(src->xsize * rotate[0] - src->ysize * rotate[1]));
- y1 = ceil(i_abs(src->xsize * rotate[3] + src->ysize * rotate[4]));
- y2 = ceil(i_abs(src->xsize * rotate[3] - src->ysize * rotate[4]));
- 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/2.0;
- xlate2[4] = 1;
- xlate2[5] = -newysize/2.0;
- xlate2[8] = 1;
- i_matrix_mult(temp, xlate1, rotate);
- i_matrix_mult(matrix, temp, xlate2);
-
- 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
-*/
projects / imager.git / commitdiff