anglestransform.qc

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#include "anglestransform.qh"

// angles transforms
// angles in fixedmakevectors/fixedvectoangles space
vector AnglesTransform_Apply(vector transform, vector v)
{
    vector forward, right, up;
    FIXED_MAKE_VECTORS(transform, forward, right, up);
    return forward * v.x + right * (-v.y) + up * v.z;
}

vector AnglesTransform_Multiply(vector t1, vector t2)
{
    vector forward, right, up;
    FIXED_MAKE_VECTORS(t2, forward, right, up);
    forward = AnglesTransform_Apply(t1, forward);
    up = AnglesTransform_Apply(t1, up);
    return fixedvectoangles2(forward, up);
}

vector AnglesTransform_Invert(vector transform)
{
    vector i_forward, i_up;
    vector forward, right, up;
    FIXED_MAKE_VECTORS(transform, forward, right, up);
    // we want angles that turn forward into '1 0 0', right into '0 1 0' and up into '0 0 1'
    // but these are orthogonal unit vectors!
    // so to invert, we can simply fixedvectoangles the TRANSPOSED matrix
    // TODO is this always -transform?
    i_forward.x = forward.x;
    i_forward.y = -right.x;
    i_forward.z = up.x;
    i_up.x = forward.z;
    i_up.y = -right.z;
    i_up.z = up.z;
    return fixedvectoangles2(i_forward, i_up);
}

vector AnglesTransform_TurnDirectionFR(vector transform)
{
    // turn 180 degrees around v_up
    // changes in-direction to out-direction
    //fixedmakevectors(transform);
    //return fixedvectoangles2(-1 * v_forward, 1 * v_up);
    transform.x = -transform.x;
    transform.y = 180 + transform.y;
    transform.z = -transform.z;
    // pitch: -s +c
    // yaw:   -s -c
    // roll:  -s +c
    return transform;
}

vector AnglesTransform_TurnDirectionFU(vector transform)
{
    // turn 180 degrees around v_up
    // changes in-direction to out-direction
    //fixedmakevectors(transform);
    //return fixedvectoangles2(-1 * v_forward, 1 * v_up);
    transform.x = -transform.x;
    transform.y = 180 + transform.y;
    transform.z = 180 - transform.z;
    return transform;
}

vector AnglesTransform_RightDivide(vector to_transform, vector from_transform)
{
    return AnglesTransform_Multiply(to_transform, AnglesTransform_Invert(from_transform));
}

vector AnglesTransform_LeftDivide(vector from_transform, vector to_transform)
{
    return AnglesTransform_Multiply(AnglesTransform_Invert(from_transform), to_transform);
}

vector AnglesTransform_Normalize(vector t, float minimize_roll)
{
    float need_flip;
    // first, bring all angles in their range...
    t.x = t.x - 360 * rint(t.x / 360);
    t.y = t.y - 360 * rint(t.y / 360);
    t.z = t.z - 360 * rint(t.z / 360);
    if(minimize_roll)
        need_flip = (t.z > 90 || t.z <= -90);
    else
        need_flip = (t.x > 90 || t.x < -90); // for pitch we prefer to allow exactly -90 degrees for looking straight down
    if(need_flip)
    {
        if(t.x >= 0) t.x = 180 - t.x; else t.x = -180 - t.x;
        if(t.y > 0) t.y -= 180; else t.y += 180;
        if(t.z > 0) t.z -= 180; else t.z += 180;
    }
    return t;
}

vector AnglesTransform_CancelRoll(vector t)
{
    const float epsilon = 30;
    float f;

    // constraints:
    // forward vector (NOT SO important)
    // right vector, up vector: screen rotation (MORE important)
    // choose best match among all pitch-yaw only rotations

    // FIXME find a better method

    f = fabs(t.x - (-90)) / epsilon;
    if(f < 1)
    {
        //t_x = -90;
        t.y += t.z;
        t.z = 0;
    }
    else
    {
        f = fabs(t.x - 90) / epsilon;
        if(f < 1)
        {
            //t_x = 90;
            t.y -= t.z;
            t.z = 0;
        }
    }
    return t;
}

#if POSITIVE_PITCH_IS_DOWN
vector AnglesTransform_ApplyToAngles(vector transform, vector v)
{
    v.x = -v.x;
    v = AnglesTransform_Multiply(transform, v);
    v.x = -v.x;
    return v;
}
vector AnglesTransform_ApplyToVAngles(vector transform, vector v)
{
    v = AnglesTransform_Multiply(transform, v);
    return v;
}
vector AnglesTransform_FromAngles(vector v)
{
    v.x = -v.x;
    return v;
}
vector AnglesTransform_ToAngles(vector v)
{
    v.x = -v.x;
    return v;
}
vector AnglesTransform_FromVAngles(vector v)
{
    return v;
}
vector AnglesTransform_ToVAngles(vector v)
{
    return v;
}
#else
vector AnglesTransform_ApplyToAngles(vector transform, vector v)
{
    v = AnglesTransform_Multiply(transform, v);
    return v;
}
vector AnglesTransform_ApplyToVAngles(vector transform, vector v)
{
    v.x = -v.x;
    v = AnglesTransform_Multiply(transform, v);
    v.x = -v.x;
    return v;
}
vector AnglesTransform_FromAngles(vector v)
{
    return v;
}
vector AnglesTransform_ToAngles(vector v)
{
    return v;
}
vector AnglesTransform_FromVAngles(vector v)
{
    v.x = -v.x;
    return v;
}
vector AnglesTransform_ToVAngles(vector v)
{
    v.x = -v.x;
    return v;
}
#endif

vector AnglesTransform_Multiply_GetPostShift(vector t0, vector st0, vector t1, vector st1)
{
    // we want the result of:
    //   t0 * (t1 * p + st1) + st0
    //   t0 * t1 * p + t0 * st1 + st0
    return st0 + AnglesTransform_Apply(t0, st1);
}
vector AnglesTransform_PrePostShift_GetPostShift(vector sf, vector t, vector st)
{
    return st - AnglesTransform_Apply(t, sf);
}