diff --git a/cogl/cogl/cogl-matrix.c b/cogl/cogl/cogl-matrix.c index 8a3372427..282ed48e4 100644 --- a/cogl/cogl/cogl-matrix.c +++ b/cogl/cogl/cogl-matrix.c @@ -713,52 +713,22 @@ cogl_matrix_look_at (CoglMatrix *matrix, float world_up_y, float world_up_z) { - CoglMatrix tmp; - graphene_vec3_t forward; - graphene_vec3_t side; - graphene_vec3_t up; - - /* Get a unit viewing direction vector */ - graphene_vec3_init (&forward, - object_x - eye_position_x, - object_y - eye_position_y, - object_z - eye_position_z); - graphene_vec3_normalize (&forward, &forward); + graphene_matrix_t look_at, m; + graphene_vec3_t eye, center, up; + graphene_vec3_init (&eye, eye_position_x, eye_position_y, eye_position_z); + graphene_vec3_init (¢er, object_x, object_y, object_z); graphene_vec3_init (&up, world_up_x, world_up_y, world_up_z); + graphene_matrix_init_look_at (&look_at, &eye, ¢er, &up); - /* Take the sideways direction as being perpendicular to the viewing - * direction and the word up vector. */ - graphene_vec3_cross (&forward, &up, &side); - graphene_vec3_normalize (&side, &side); + cogl_matrix_to_graphene_matrix (matrix, &m); + graphene_matrix_transpose (&m, &m); - /* Now we have unit sideways and forward-direction vectors calculate - * a new mutually perpendicular up vector. */ - graphene_vec3_cross (&side, &forward, &up); - - tmp.xx = graphene_vec3_get_x (&side); - tmp.yx = graphene_vec3_get_y (&side); - tmp.zx = graphene_vec3_get_z (&side); - tmp.wx = 0; - - tmp.xy = graphene_vec3_get_x (&up); - tmp.yy = graphene_vec3_get_y (&up); - tmp.zy = graphene_vec3_get_z (&up); - tmp.wy = 0; - - tmp.xz = -graphene_vec3_get_x (&forward); - tmp.yz = -graphene_vec3_get_y (&forward); - tmp.zz = -graphene_vec3_get_z (&forward); - tmp.wz = 0; - - tmp.xw = 0; - tmp.yw = 0; - tmp.zw = 0; - tmp.ww = 1; - - cogl_matrix_translate (&tmp, -eye_position_x, -eye_position_y, -eye_position_z); - - cogl_matrix_multiply (matrix, matrix, &tmp); + graphene_matrix_translate (&m, &GRAPHENE_POINT3D_INIT (-eye_position_x, + -eye_position_y, + -eye_position_z)); + graphene_matrix_multiply (&m, &look_at, &m); + graphene_matrix_to_cogl_matrix (&m, matrix); } void