gimp/app/core/gimp-transform-3d-utils.c

360 lines
10 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimp-3d-transform-utils.c
* Copyright (C) 2019 Ell
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib-object.h>
#include "libgimpmath/gimpmath.h"
#include "core-types.h"
#include "gimp-transform-3d-utils.h"
#define MIN_FOCAL_LENGTH 0.01
gdouble
gimp_transform_3d_angle_of_view_to_focal_length (gdouble angle_of_view,
gdouble width,
gdouble height)
{
return MAX (width, height) / (2.0 * tan (angle_of_view / 2.0));
}
gdouble
gimp_transform_3d_focal_length_to_angle_of_view (gdouble focal_length,
gdouble width,
gdouble height)
{
return 2.0 * atan (MAX (width, height) / (2.0 * focal_length));
}
gint
gimp_transform_3d_permutation_to_rotation_order (const gint permutation[3])
{
if (permutation[1] == (permutation[0] + 1) % 3)
return permutation[0] << 1;
else
return (permutation[2] << 1) + 1;
}
void
gimp_transform_3d_rotation_order_to_permutation (gint rotation_order,
gint permutation[3])
{
gboolean reverse = rotation_order & 1;
gint shift = rotation_order >> 1;
gint i;
for (i = 0; i < 3; i++)
permutation[reverse ? 2 - i : i] = (i + shift) % 3;
}
gint
gimp_transform_3d_rotation_order_reverse (gint rotation_order)
{
return rotation_order ^ 1;
}
void
gimp_transform_3d_vector3_rotate (GimpVector3 *vector,
const GimpVector3 *axis)
{
GimpVector3 normal;
GimpVector3 proj;
GimpVector3 u, v;
gdouble angle;
angle = gimp_vector3_length (axis);
if (angle == 0.0)
return;
normal = gimp_vector3_mul_val (*axis, 1.0 / angle);
proj = gimp_vector3_mul_val (normal,
gimp_vector3_inner_product_val (*vector,
normal));
u = gimp_vector3_sub_val (*vector, proj);
v = gimp_vector3_cross_product_val (u, normal);
gimp_vector3_mul (&u, cos (angle));
gimp_vector3_mul (&v, sin (angle));
*vector = proj;
gimp_vector3_add (vector, vector, &u);
gimp_vector3_add (vector, vector, &v);
}
GimpVector3
gimp_transform_3d_vector3_rotate_val (GimpVector3 vector,
GimpVector3 axis)
{
gimp_transform_3d_vector3_rotate (&vector, &axis);
return vector;
}
void
gimp_transform_3d_matrix3_to_matrix4 (const GimpMatrix3 *matrix3,
GimpMatrix4 *matrix4,
gint axis)
{
gint i, j;
gint k, l;
for (i = 0; i < 4; i++)
{
if (i == axis)
{
matrix4->coeff[i][i] = 1.0;
}
else
{
matrix4->coeff[axis][i] = 0.0;
matrix4->coeff[i][axis] = 0.0;
}
}
for (i = 0; i < 3; i++)
{
k = i + (i >= axis);
for (j = 0; j < 3; j++)
{
l = j + (j >= axis);
matrix4->coeff[k][l] = matrix3->coeff[i][j];
}
}
}
void
gimp_transform_3d_matrix4_to_matrix3 (const GimpMatrix4 *matrix4,
GimpMatrix3 *matrix3,
gint axis)
{
gint i, j;
gint k, l;
for (i = 0; i < 3; i++)
{
k = i + (i >= axis);
for (j = 0; j < 3; j++)
{
l = j + (j >= axis);
matrix3->coeff[i][j] = matrix4->coeff[k][l];
}
}
}
void
gimp_transform_3d_matrix4_translate (GimpMatrix4 *matrix,
gdouble x,
gdouble y,
gdouble z)
{
gint i;
for (i = 0; i < 4; i++)
matrix->coeff[0][i] += x * matrix->coeff[3][i];
for (i = 0; i < 4; i++)
matrix->coeff[1][i] += y * matrix->coeff[3][i];
for (i = 0; i < 4; i++)
matrix->coeff[2][i] += z * matrix->coeff[3][i];
}
void
gimp_transform_3d_matrix4_rotate (GimpMatrix4 *matrix,
const GimpVector3 *axis)
{
GimpMatrix4 rotation;
GimpVector3 v;
v = gimp_transform_3d_vector3_rotate_val ((GimpVector3) {1.0, 0.0, 0.0},
*axis);
rotation.coeff[0][0] = v.x;
rotation.coeff[1][0] = v.y;
rotation.coeff[2][0] = v.z;
rotation.coeff[3][0] = 0.0;
v = gimp_transform_3d_vector3_rotate_val ((GimpVector3) {0.0, 1.0, 0.0},
*axis);
rotation.coeff[0][1] = v.x;
rotation.coeff[1][1] = v.y;
rotation.coeff[2][1] = v.z;
rotation.coeff[3][1] = 0.0;
v = gimp_transform_3d_vector3_rotate_val ((GimpVector3) {0.0, 0.0, 1.0},
*axis);
rotation.coeff[0][2] = v.x;
rotation.coeff[1][2] = v.y;
rotation.coeff[2][2] = v.z;
rotation.coeff[3][2] = 0.0;
rotation.coeff[0][3] = 0.0;
rotation.coeff[1][3] = 0.0;
rotation.coeff[2][3] = 0.0;
rotation.coeff[3][3] = 1.0;
gimp_matrix4_mult (&rotation, matrix);
}
void
gimp_transform_3d_matrix4_rotate_standard (GimpMatrix4 *matrix,
gint axis,
gdouble angle)
{
gdouble v[3] = {};
v[axis] = angle;
gimp_transform_3d_matrix4_rotate (matrix, &(GimpVector3) {v[0], v[1], v[2]});
}
void
gimp_transform_3d_matrix4_rotate_euler (GimpMatrix4 *matrix,
gint rotation_order,
gdouble angle_x,
gdouble angle_y,
gdouble angle_z,
gdouble pivot_x,
gdouble pivot_y,
gdouble pivot_z)
{
const gdouble angles[3] = {angle_x, angle_y, angle_z};
gint permutation[3];
gint i;
gimp_transform_3d_rotation_order_to_permutation (rotation_order, permutation);
gimp_transform_3d_matrix4_translate (matrix, -pivot_x, -pivot_y, -pivot_z);
for (i = 0; i < 3; i++)
{
gimp_transform_3d_matrix4_rotate_standard (matrix,
permutation[i],
angles[permutation[i]]);
}
gimp_transform_3d_matrix4_translate (matrix, +pivot_x, +pivot_y, +pivot_z);
}
void
gimp_transform_3d_matrix4_rotate_euler_decompose (GimpMatrix4 *matrix,
gint rotation_order,
gdouble *angle_x,
gdouble *angle_y,
gdouble *angle_z)
{
GimpMatrix4 m = *matrix;
gdouble * const angles[3] = {angle_x, angle_y, angle_z};
gint permutation[3];
gboolean forward;
gimp_transform_3d_rotation_order_to_permutation (rotation_order, permutation);
forward = permutation[1] == (permutation[0] + 1) % 3;
*angles[permutation[2]] = atan2 (m.coeff[permutation[1]][permutation[0]],
m.coeff[permutation[0]][permutation[0]]);
if (forward)
*angles[permutation[2]] *= -1.0;
gimp_transform_3d_matrix4_rotate_standard (&m,
permutation[2],
-*angles[permutation[2]]);
*angles[permutation[1]] = atan2 (m.coeff[permutation[2]][permutation[0]],
m.coeff[permutation[0]][permutation[0]]);
if (! forward)
*angles[permutation[1]] *= -1.0;
gimp_transform_3d_matrix4_rotate_standard (&m,
permutation[1],
-*angles[permutation[1]]);
*angles[permutation[0]] = atan2 (m.coeff[permutation[2]][permutation[1]],
m.coeff[permutation[1]][permutation[1]]);
if (forward)
*angles[permutation[0]] *= -1.0;
}
void
gimp_transform_3d_matrix4_perspective (GimpMatrix4 *matrix,
gdouble camera_x,
gdouble camera_y,
gdouble camera_z)
{
gint i;
camera_z = MIN (camera_z, -MIN_FOCAL_LENGTH);
gimp_transform_3d_matrix4_translate (matrix, -camera_x, -camera_y, 0.0);
for (i = 0; i < 4; i++)
matrix->coeff[3][i] += matrix->coeff[2][i] / -camera_z;
gimp_transform_3d_matrix4_translate (matrix, +camera_x, +camera_y, 0.0);
}
void
gimp_transform_3d_matrix (GimpMatrix3 *matrix,
gdouble camera_x,
gdouble camera_y,
gdouble camera_z,
gdouble offset_x,
gdouble offset_y,
gdouble offset_z,
gint rotation_order,
gdouble angle_x,
gdouble angle_y,
gdouble angle_z,
gdouble pivot_x,
gdouble pivot_y,
gdouble pivot_z)
{
GimpMatrix4 m;
gimp_matrix4_identity (&m);
gimp_transform_3d_matrix4_rotate_euler (&m,
rotation_order,
angle_x, angle_y, angle_z,
pivot_x, pivot_y, pivot_z);
gimp_transform_3d_matrix4_translate (&m, offset_x, offset_y, offset_z);
gimp_transform_3d_matrix4_perspective (&m, camera_x, camera_y, camera_z);
gimp_transform_3d_matrix4_to_matrix3 (&m, matrix, 2);
}