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Cleanup of angle math functions #2027

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Cleanup of angle math functions #2027

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6392dac
Comment dangers of MakeNormalVectors()
slipher May 9, 2025
662f10e
Remove 'static to help MS compiler fp bugs'
slipher May 20, 2025
814d6e3
NUKE MatrixToAngles function
slipher Jun 6, 2025
b24fb54
Remove some unused calculations in renderer
slipher Jun 6, 2025
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118 changes: 24 additions & 94 deletions src/engine/qcommon/q_math.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -530,14 +530,17 @@ void ProjectPointOnPlane( vec3_t dst, const vec3_t point, const vec3_t normal )
*
* Given a normalized forward vector, create two
* other perpendicular vectors
* This function seems to aim to be continuous (unlike the similar vectoangles
* or PerpendicularVector), but that is impossible to fully realize per the
* Hairy Ball Theorem. At least it can work for stuff that doesn't use the
* roll angle.
* ================
*/
void MakeNormalVectors( const vec3_t forward, vec3_t right, vec3_t up )
{
float d;

// this rotate and negate guarantees a vector
// not colinear with the original
// this fails at {-1/sqrt(3), -1/sqrt(3), 1/sqrt(3)}
right[ 1 ] = -forward[ 0 ];
right[ 2 ] = forward[ 1 ];
right[ 0 ] = forward[ 2 ];
Expand Down Expand Up @@ -1006,22 +1009,17 @@ void AxisMultiply( const float in1[ 3 ][ 3 ], const float in2[ 3 ][ 3 ], float o

void AngleVectors( const vec3_t angles, vec3_t forward, vec3_t right, vec3_t up )
{
float angle;
static float sr, sp, sy, cr, cp, cy;

// static to help MS compiler fp bugs

angle = DEG2RAD( angles[ YAW ] );
sy = sinf( angle );
cy = cosf( angle );
float angle = DEG2RAD( angles[ YAW ] );
float sy = sinf( angle );
float cy = cosf( angle );

angle = DEG2RAD( angles[ PITCH ] );
sp = sinf( angle );
cp = cosf( angle );
float sp = sinf( angle );
float cp = cosf( angle );

angle = DEG2RAD( angles[ ROLL ] );
sr = sinf( angle );
cr = cosf( angle );
float sr = sinf( angle );
float cr = cosf( angle );

if ( forward )
{
Expand Down Expand Up @@ -1832,82 +1830,17 @@ void MatrixMultiplyShear( matrix_t m, vec_t x, vec_t y )
m[ 7 ] += tmp[ 3 ] * x;
}

void MatrixToAngles( const matrix_t m, vec3_t angles )
{
#if 1
float theta;
float cp;
float sp;

sp = m[ 2 ];

// cap off our sin value so that we don't get any NANs
if ( sp > 1.0f )
{
sp = 1.0f;
}

else if ( sp < -1.0f )
{
sp = -1.0f;
}

theta = -asinf( sp );
cp = cosf( theta );

if ( cp > 8192 * FLT_EPSILON )
{
angles[ PITCH ] = RAD2DEG( theta );
angles[ YAW ] = RAD2DEG( atan2f( m[ 1 ], m[ 0 ] ) );
angles[ ROLL ] = RAD2DEG( atan2f( m[ 6 ], m[ 10 ] ) );
}

else
{
angles[ PITCH ] = RAD2DEG( theta );
angles[ YAW ] = RAD2DEG( -atan2f( m[ 4 ], m[ 5 ] ) );
angles[ ROLL ] = 0;
}

#else
float a;
float ca;

a = asinf( -m[ 2 ] );
ca = cosf( a );

if ( fabsf( ca ) > 0.005f ) // Gimbal lock?
{
angles[ PITCH ] = RAD2DEG( atan2f( m[ 6 ] / ca, m[ 10 ] / ca ) );
angles[ YAW ] = RAD2DEG( a );
angles[ ROLL ] = RAD2DEG( atan2f( m[ 1 ] / ca, m[ 0 ] / ca ) );
}

else
{
// Gimbal lock has occurred
angles[ PITCH ] = RAD2DEG( atan2f( -m[ 9 ], m[ 5 ] ) );
angles[ YAW ] = RAD2DEG( a );
angles[ ROLL ] = 0;
}

#endif
}

// Tait-Bryan angles z-y-x
void MatrixFromAngles( matrix_t m, vec_t pitch, vec_t yaw, vec_t roll )
{
static float sr, sp, sy, cr, cp, cy;
float sp = sinf( DEG2RAD( pitch ) );
float cp = cosf( DEG2RAD( pitch ) );

// static to help MS compiler fp bugs
sp = sinf( DEG2RAD( pitch ) );
cp = cosf( DEG2RAD( pitch ) );
float sy = sinf( DEG2RAD( yaw ) );
float cy = cosf( DEG2RAD( yaw ) );

sy = sinf( DEG2RAD( yaw ) );
cy = cosf( DEG2RAD( yaw ) );

sr = sinf( DEG2RAD( roll ) );
cr = cosf( DEG2RAD( roll ) );
float sr = sinf( DEG2RAD( roll ) );
float cr = cosf( DEG2RAD( roll ) );

m[ 0 ] = cp * cy;
m[ 4 ] = ( sr * sp * cy + cr * -sy );
Expand Down Expand Up @@ -2836,17 +2769,14 @@ void QuatFromAngles( quat_t q, vec_t pitch, vec_t yaw, vec_t roll )
MatrixFromAngles( tmp, pitch, yaw, roll );
QuatFromMatrix( q, tmp );
#else
static float sr, sp, sy, cr, cp, cy;

// static to help MS compiler fp bugs
sp = sinf(DEG2RAD(pitch) * 0.5);
cp = cosf(DEG2RAD(pitch) * 0.5);
float sp = sinf(DEG2RAD(pitch) * 0.5);
float cp = cosf(DEG2RAD(pitch) * 0.5);

sy = sinf(DEG2RAD(yaw) * 0.5);
cy = cosf(DEG2RAD(yaw) * 0.5);
float sy = sinf(DEG2RAD(yaw) * 0.5);
float cy = cosf(DEG2RAD(yaw) * 0.5);

sr = sinf(DEG2RAD(roll) * 0.5);
cr = cosf(DEG2RAD(roll) * 0.5);
float sr = sinf(DEG2RAD(roll) * 0.5);
float cr = cosf(DEG2RAD(roll) * 0.5);

q[0] = sr * cp * cy - cr * sp * sy; // x
q[1] = cr * sp * cy + sr * cp * sy; // y
Expand Down
1 change: 0 additions & 1 deletion src/engine/qcommon/q_shared.h
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Expand Up @@ -838,7 +838,6 @@ inline vec_t VectorNormalize2( const vec3_t v, vec3_t out )
void MatrixMultiplyTranslation( matrix_t m, vec_t x, vec_t y, vec_t z );
void MatrixMultiplyScale( matrix_t m, vec_t x, vec_t y, vec_t z );
void MatrixMultiplyShear( matrix_t m, vec_t x, vec_t y );
void MatrixToAngles( const matrix_t m, vec3_t angles );
void MatrixFromAngles( matrix_t m, vec_t pitch, vec_t yaw, vec_t roll );
void MatrixFromVectorsFLU( matrix_t m, const vec3_t forward, const vec3_t left, const vec3_t up );
void MatrixFromVectorsFRU( matrix_t m, const vec3_t forward, const vec3_t right, const vec3_t up );
Expand Down
3 changes: 0 additions & 3 deletions src/engine/renderer/tr_backend.cpp
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Expand Up @@ -1950,15 +1950,12 @@ static void RB_RenderDebugUtils()
}

VectorCopy( skel->bones[ j ].t.trans, offset );
vec3_t forward, right, up;
QuatToVectorsFRU( skel->bones[ j ].t.rot, forward, right, up );

VectorSubtract( offset, origin, diff );

if ( ( length = VectorNormalize( diff ) ) )
{
PerpendicularVector( tmp, diff );
//VectorCopy(up, tmp);

VectorScale( tmp, length * 0.1, tmp2 );
VectorMA( tmp2, length * 0.2, diff, tmp2 );
Expand Down
2 changes: 0 additions & 2 deletions src/engine/renderer/tr_model_md5.cpp
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Expand Up @@ -100,7 +100,6 @@ bool R_LoadMD5( model_t *mod, const char *buffer, const char *modName )
const char *token;
vec3_t boneOrigin;
quat_t boneQuat;
matrix_t boneMat;

int numBoneReferences;

Expand Down Expand Up @@ -238,7 +237,6 @@ bool R_LoadMD5( model_t *mod, const char *buffer, const char *modName )
}

QuatCalcW( boneQuat );
MatrixFromQuat( boneMat, boneQuat );

VectorCopy( boneOrigin, bone->origin );
QuatCopy( boneQuat, bone->rotation );
Expand Down
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