X-Git-Url: https://de.git.xonotic.org/?a=blobdiff_plain;ds=sidebyside;f=mathlib.c;h=a58d76e8cdfd97e4f9fd5f612bc5a03aa431bf50;hb=81804fa83299b491dc24dd5f058527165faa38da;hp=d6170d28977c27645f71b9987887854670d34916;hpb=fde75b49095458f8c405fef8c5550675f7e65761;p=xonotic%2Fdarkplaces.git

diff --git a/mathlib.c b/mathlib.c
index d6170d28..a58d76e8 100644
--- a/mathlib.c
+++ b/mathlib.c
@@ -198,30 +198,61 @@ void PerpendicularVector( vec3_t dst, const vec3_t src )
 // LordHavoc: like AngleVectors, but taking a forward vector instead of angles, useful!
 void VectorVectors(const vec3_t forward, vec3_t right, vec3_t up)
 {
-	float d;
-
-	right[0] = forward[2];
-	right[1] = -forward[0];
-	right[2] = forward[1];
-
-	d = DotProduct(forward, right);
-	VectorMA(right, -d, forward, right);
-	VectorNormalize(right);
-	CrossProduct(right, forward, up);
+	// NOTE: this is consistent to AngleVectors applied to AnglesFromVectors
+	if (forward[0] == 0 && forward[1] == 0)
+	{
+		if(forward[2] > 0)
+		{
+			VectorSet(right, 0, -1, 0);
+			VectorSet(up, -1, 0, 0);
+		}
+		else
+		{
+			VectorSet(right, 0, -1, 0);
+			VectorSet(up, 1, 0, 0);
+		}
+	}
+	else
+	{
+		right[0] = forward[1];
+		right[1] = -forward[0];
+		right[2] = 0;
+		VectorNormalize(right);
+
+		up[0] = (-forward[2]*forward[0]);
+		up[1] = (-forward[2]*forward[1]);
+		up[2] = (forward[0]*forward[0] + forward[1]*forward[1]);
+		VectorNormalize(up);
+	}
 }
 
 void VectorVectorsDouble(const double *forward, double *right, double *up)
 {
-	double d;
-
-	right[0] = forward[2];
-	right[1] = -forward[0];
-	right[2] = forward[1];
-
-	d = DotProduct(forward, right);
-	VectorMA(right, -d, forward, right);
-	VectorNormalize(right);
-	CrossProduct(right, forward, up);
+	if (forward[0] == 0 && forward[1] == 0)
+	{
+		if(forward[2] > 0)
+		{
+			VectorSet(right, 0, -1, 0);
+			VectorSet(up, -1, 0, 0);
+		}
+		else
+		{
+			VectorSet(right, 0, -1, 0);
+			VectorSet(up, 1, 0, 0);
+		}
+	}
+	else
+	{
+		right[0] = forward[1];
+		right[1] = -forward[0];
+		right[2] = 0;
+		VectorNormalize(right);
+
+		up[0] = (-forward[2]*forward[0]);
+		up[1] = (-forward[2]*forward[1]);
+		up[2] = (forward[0]*forward[0] + forward[1]*forward[1]);
+		VectorNormalize(up);
+	}
 }
 
 void RotatePointAroundVector( vec3_t dst, const vec3_t dir, const vec3_t point, float degrees )
@@ -518,6 +549,103 @@ void AngleVectorsFLU (const vec3_t angles, vec3_t forward, vec3_t left, vec3_t u
 	}
 }
 
+void AngleVectorsDuke3DFLU (const vec3_t angles, vec3_t forward, vec3_t left, vec3_t up, double maxShearAngle)
+{
+	double angle, sr, sy, cr, cy;
+	double sxx, sxz, szx, szz;
+	double cosMaxShearAngle = cos(maxShearAngle * (M_PI*2 / 360));
+	double tanMaxShearAngle = tan(maxShearAngle * (M_PI*2 / 360));
+
+	angle = angles[YAW] * (M_PI*2 / 360);
+	sy = sin(angle);
+	cy = cos(angle);
+	angle = angles[PITCH] * (M_PI*2 / 360);
+
+	// We will calculate a shear matrix pitch = [[sxx sxz][szx szz]].
+
+	if (fabs(cos(angle)) > cosMaxShearAngle)
+	{
+		// Pure shear. Keep the original sign of the coefficients.
+		sxx = 1;
+		sxz = 0;
+		szx = -tan(angle);
+		szz = 1;
+		// Covering angle per screen coordinate:
+		// d/dt arctan((sxz + t*szz) / (sxx + t*szx)) @ t=0
+		// d_angle = det(S) / (sxx*sxx + szx*szx)
+		//         = 1 / (1 + tan^2 angle)
+		//         = cos^2 angle.
+	}
+	else
+	{
+		// A mix of shear and rotation. Implementation-wise, we're
+		// looking at a capsule, and making the screen surface
+		// tangential to it... and if we get here, we're looking at the
+		// two half-spheres of the capsule (and the cylinder part is
+		// handled above).
+		double x, y, h, t, d, f;
+		h = tanMaxShearAngle;
+		x = cos(angle);
+		y = sin(angle);
+		t = h * fabs(y) + sqrt(1 - (h * x) * (h * x));
+		sxx =  x * t;
+		sxz =  y * t - h * (y > 0 ? 1.0 : -1.0);
+		szx = -y * t;
+		szz =  x * t;
+		// BUT: keep the amount of a sphere we see in pitch direction
+		// invariant.
+		// Covering angle per screen coordinate:
+		// d_angle = det(S) / (sxx*sxx + szx*szx)
+		d = (sxx * szz - sxz * szx) / (sxx * sxx + szx * szx);
+		f = cosMaxShearAngle * cosMaxShearAngle / d;
+		sxz *= f;
+		szz *= f;
+	}
+
+	if (forward)
+	{
+		forward[0] = sxx*cy;
+		forward[1] = sxx*sy;
+		forward[2] = szx;
+	}
+	if (left || up)
+	{
+		if (angles[ROLL])
+		{
+			angle = angles[ROLL] * (M_PI*2 / 360);
+			sr = sin(angle);
+			cr = cos(angle);
+			if (left)
+			{
+				left[0] = sr*sxz*cy+cr*-sy;
+				left[1] = sr*sxz*sy+cr*cy;
+				left[2] = sr*szz;
+			}
+			if (up)
+			{
+				up[0] = cr*sxz*cy+-sr*-sy;
+				up[1] = cr*sxz*sy+-sr*cy;
+				up[2] = cr*szz;
+			}
+		}
+		else
+		{
+			if (left)
+			{
+				left[0] = -sy;
+				left[1] = cy;
+				left[2] = 0;
+			}
+			if (up)
+			{
+				up[0] = sxz*cy;
+				up[1] = sxz*sy;
+				up[2] = szz;
+			}
+		}
+	}
+}
+
 // LordHavoc: calculates pitch/yaw/roll angles from forward and up vectors
 void AnglesFromVectors (vec3_t angles, const vec3_t forward, const vec3_t up, qboolean flippitch)
 {
@@ -539,9 +667,11 @@ void AnglesFromVectors (vec3_t angles, const vec3_t forward, const vec3_t up, qb
 	{
 		angles[YAW] = atan2(forward[1], forward[0]);
 		angles[PITCH] = -atan2(forward[2], sqrt(forward[0]*forward[0] + forward[1]*forward[1]));
+		// note: we know that angles[PITCH] is in ]-pi/2..pi/2[ due to atan2(anything, positive)
 		if (up)
 		{
 			vec_t cp = cos(angles[PITCH]), sp = sin(angles[PITCH]);
+			// note: we know cp > 0, due to the range angles[pitch] is in
 			vec_t cy = cos(angles[YAW]), sy = sin(angles[YAW]);
 			vec3_t tleft, tup;
 			tleft[0] = -sy;
@@ -551,9 +681,14 @@ void AnglesFromVectors (vec3_t angles, const vec3_t forward, const vec3_t up, qb
 			tup[1] = sp*sy;
 			tup[2] = cp;
 			angles[ROLL] = -atan2(DotProduct(up, tleft), DotProduct(up, tup));
+			// for up == '0 0 1', this is
+			// angles[ROLL] = -atan2(0, cp);
+			// which is 0
 		}
 		else
 			angles[ROLL] = 0;
+
+		// so no up vector is equivalent to '1 0 0'!
 	}
 
 	// now convert radians to degrees, and make all values positive
@@ -722,7 +857,7 @@ void Matrix4x4_Print(const matrix4x4_t *in)
 	, in->m[3][0], in->m[3][1], in->m[3][2], in->m[3][3]);
 }
 
-int Math_atov(const char *s, vec3_t out)
+int Math_atov(const char *s, prvm_vec3_t out)
 {
 	int i;
 	VectorClear(out);
@@ -756,3 +891,12 @@ void BoxFromPoints(vec3_t mins, vec3_t maxs, int numpoints, vec_t *point3f)
 	}
 }
 
+// LordHavoc: this has to be done right or you get severe precision breakdown
+int LoopingFrameNumberFromDouble(double t, int loopframes)
+{
+	if (loopframes)
+		return (int)(t - floor(t/loopframes)*loopframes);
+	else
+		return (int)t;
+}
+