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cogl/matrix: Euler-rotate with graphene matrices

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https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
This commit is contained in:
Georges Basile Stavracas Neto 2020-09-10 14:04:34 -03:00
parent 1f0e8fb23c
commit dd3c15a8a8
1 changed files with 4 additions and 71 deletions
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75
cogl/cogl/cogl-matrix.c
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@ -1491,78 +1491,11 @@ void
cogl_matrix_init_from_euler (CoglMatrix *matrix, cogl_matrix_init_from_euler (CoglMatrix *matrix,
const graphene_euler_t *euler) const graphene_euler_t *euler)
{ {
/* Convert angles to radians */ graphene_matrix_t m;
float heading_rad = graphene_euler_get_y (euler) / 180.0f * G_PI;
float pitch_rad = graphene_euler_get_x (euler) / 180.0f * G_PI;
float roll_rad = graphene_euler_get_z (euler) / 180.0f * G_PI;
/* Pre-calculate the sin and cos */
float sin_heading = sinf (heading_rad);
float cos_heading = cosf (heading_rad);
float sin_pitch = sinf (pitch_rad);
float cos_pitch = cosf (pitch_rad);
float sin_roll = sinf (roll_rad);
float cos_roll = cosf (roll_rad);
/* These calculations are based on the following website but they graphene_matrix_init_identity (&m);
* use a different order for the rotations so it has been modified graphene_matrix_rotate_euler (&m, euler);
* slightly. graphene_matrix_to_cogl_matrix (&m, matrix);
* http://www.euclideanspace.com/maths/geometry/
* rotations/conversions/eulerToMatrix/index.htm
*/
/* Heading rotation x=0, y=1, z=0 gives:
*
* [ ch 0 sh 0 ]
* [ 0 1 0 0 ]
* [ -sh 0 ch 0 ]
* [ 0 0 0 1 ]
*
* Pitch rotation x=1, y=0, z=0 gives:
* [ 1 0 0 0 ]
* [ 0 cp -sp 0 ]
* [ 0 sp cp 0 ]
* [ 0 0 0 1 ]
*
* Roll rotation x=0, y=0, z=1 gives:
* [ cr -sr 0 0 ]
* [ sr cr 0 0 ]
* [ 0 0 1 0 ]
* [ 0 0 0 1 ]
*
* Heading matrix * pitch matrix =
* [ ch sh*sp cp*sh 0 ]
* [ 0 cp -sp 0 ]
* [ -sh ch*sp ch*cp 0 ]
* [ 0 0 0 1 ]
*
* That matrix * roll matrix =
* [ ch*cr + sh*sp*sr sh*sp*cr - ch*sr sh*cp 0 ]
* [ cp*sr cp*cr -sp 0 ]
* [ ch*sp*sr - sh*cr sh*sr + ch*sp*cr ch*cp 0 ]
* [ 0 0 0 1 ]
*/
matrix->xx = cos_heading * cos_roll + sin_heading * sin_pitch * sin_roll;
matrix->yx = cos_pitch * sin_roll;
matrix->zx = cos_heading * sin_pitch * sin_roll - sin_heading * cos_roll;
matrix->wx = 0.0f;
matrix->xy = sin_heading * sin_pitch * cos_roll - cos_heading * sin_roll;
matrix->yy = cos_pitch * cos_roll;
matrix->zy = sin_heading * sin_roll + cos_heading * sin_pitch * cos_roll;
matrix->wy = 0.0f;
matrix->xz = sin_heading * cos_pitch;
matrix->yz = -sin_pitch;
matrix->zz = cos_heading * cos_pitch;
matrix->wz = 0;
matrix->xw = 0;
matrix->yw = 0;
matrix->zw = 0;
matrix->ww = 1;
matrix->flags = (MAT_FLAG_GENERAL | MAT_DIRTY_ALL);
} }
void void