//========= Copyright © 1996-2002, Valve LLC, All rights reserved. ============
//
// Purpose: 
//
// $NoKeywords: $
//=============================================================================

#include <memory.h>
#include "hud.h"
#include "cl_util.h"
#include "const.h"
#include "com_model.h"
#include "studio_util.h"

/*
====================
AngleMatrix

====================
*/
void AngleMatrix (const float *angles, float (*matrix)[4] )
{
	float		angle;
	float		sr, sp, sy, cr, cp, cy;
	
	angle = angles[YAW] * (M_PI*2 / 360);
	sy = sin(angle);
	cy = cos(angle);
	angle = angles[PITCH] * (M_PI*2 / 360);
	sp = sin(angle);
	cp = cos(angle);
	angle = angles[ROLL] * (M_PI*2 / 360);
	sr = sin(angle);
	cr = cos(angle);

	// matrix = (YAW * PITCH) * ROLL
	matrix[0][0] = cp*cy;
	matrix[1][0] = cp*sy;
	matrix[2][0] = -sp;
	matrix[0][1] = sr*sp*cy+cr*-sy;
	matrix[1][1] = sr*sp*sy+cr*cy;
	matrix[2][1] = sr*cp;
	matrix[0][2] = (cr*sp*cy+-sr*-sy);
	matrix[1][2] = (cr*sp*sy+-sr*cy);
	matrix[2][2] = cr*cp;
	matrix[0][3] = 0.0;
	matrix[1][3] = 0.0;
	matrix[2][3] = 0.0;
}

/*
====================
VectorCompare

====================
*/
int VectorCompare (const float *v1, const float *v2)
{
	int		i;
	
	for (i=0 ; i<3 ; i++)
		if (v1[i] != v2[i])
			return 0;
			
	return 1;
}

/*
====================
CrossProduct

====================
*/
void CrossProduct (const float *v1, const float *v2, float *cross)
{
	cross[0] = v1[1]*v2[2] - v1[2]*v2[1];
	cross[1] = v1[2]*v2[0] - v1[0]*v2[2];
	cross[2] = v1[0]*v2[1] - v1[1]*v2[0];
}

/*
====================
VectorTransform

====================
*/
void VectorTransform (const float *in1, float in2[3][4], float *out)
{
	out[0] = DotProduct(in1, in2[0]) + in2[0][3];
	out[1] = DotProduct(in1, in2[1]) + in2[1][3];
	out[2] = DotProduct(in1, in2[2]) + in2[2][3];
}

/*
================
ConcatTransforms

================
*/
void ConcatTransforms (float in1[3][4], float in2[3][4], float out[3][4])
{
	out[0][0] = in1[0][0] * in2[0][0] + in1[0][1] * in2[1][0] +
				in1[0][2] * in2[2][0];
	out[0][1] = in1[0][0] * in2[0][1] + in1[0][1] * in2[1][1] +
				in1[0][2] * in2[2][1];
	out[0][2] = in1[0][0] * in2[0][2] + in1[0][1] * in2[1][2] +
				in1[0][2] * in2[2][2];
	out[0][3] = in1[0][0] * in2[0][3] + in1[0][1] * in2[1][3] +
				in1[0][2] * in2[2][3] + in1[0][3];
	out[1][0] = in1[1][0] * in2[0][0] + in1[1][1] * in2[1][0] +
				in1[1][2] * in2[2][0];
	out[1][1] = in1[1][0] * in2[0][1] + in1[1][1] * in2[1][1] +
				in1[1][2] * in2[2][1];
	out[1][2] = in1[1][0] * in2[0][2] + in1[1][1] * in2[1][2] +
				in1[1][2] * in2[2][2];
	out[1][3] = in1[1][0] * in2[0][3] + in1[1][1] * in2[1][3] +
				in1[1][2] * in2[2][3] + in1[1][3];
	out[2][0] = in1[2][0] * in2[0][0] + in1[2][1] * in2[1][0] +
				in1[2][2] * in2[2][0];
	out[2][1] = in1[2][0] * in2[0][1] + in1[2][1] * in2[1][1] +
				in1[2][2] * in2[2][1];
	out[2][2] = in1[2][0] * in2[0][2] + in1[2][1] * in2[1][2] +
				in1[2][2] * in2[2][2];
	out[2][3] = in1[2][0] * in2[0][3] + in1[2][1] * in2[1][3] +
				in1[2][2] * in2[2][3] + in1[2][3];
}

// angles index are not the same as ROLL, PITCH, YAW

/*
====================
AngleQuaternion

====================
*/
void AngleQuaternion( float *angles, vec4_t quaternion )
{
	float		angle;
	float		sr, sp, sy, cr, cp, cy;

	// FIXME: rescale the inputs to 1/2 angle
	angle = angles[2] * 0.5;
	sy = sin(angle);
	cy = cos(angle);
	angle = angles[1] * 0.5;
	sp = sin(angle);
	cp = cos(angle);
	angle = angles[0] * 0.5;
	sr = sin(angle);
	cr = cos(angle);

	quaternion[0] = sr*cp*cy-cr*sp*sy; // X
	quaternion[1] = cr*sp*cy+sr*cp*sy; // Y
	quaternion[2] = cr*cp*sy-sr*sp*cy; // Z
	quaternion[3] = cr*cp*cy+sr*sp*sy; // W
}

/*
====================
QuaternionSlerp

====================
*/
void QuaternionSlerp( vec4_t p, vec4_t q, float t, vec4_t qt )
{
	int i;
	float	omega, cosom, sinom, sclp, sclq;

	// decide if one of the quaternions is backwards
	float a = 0;
	float b = 0;

	for (i = 0; i < 4; i++)
	{
		a += (p[i]-q[i])*(p[i]-q[i]);
		b += (p[i]+q[i])*(p[i]+q[i]);
	}
	if (a > b)
	{
		for (i = 0; i < 4; i++)
		{
			q[i] = -q[i];
		}
	}

	cosom = p[0]*q[0] + p[1]*q[1] + p[2]*q[2] + p[3]*q[3];

	if ((1.0 + cosom) > 0.000001)
	{
		if ((1.0 - cosom) > 0.000001)
		{
			omega = acos( cosom );
			sinom = sin( omega );
			sclp = sin( (1.0 - t)*omega) / sinom;
			sclq = sin( t*omega ) / sinom;
		}
		else
		{
			sclp = 1.0 - t;
			sclq = t;
		}
		for (i = 0; i < 4; i++) {
			qt[i] = sclp * p[i] + sclq * q[i];
		}
	}
	else
	{
		qt[0] = -q[1];
		qt[1] = q[0];
		qt[2] = -q[3];
		qt[3] = q[2];
		sclp = sin( (1.0 - t) * (0.5 * M_PI));
		sclq = sin( t * (0.5 * M_PI));
		for (i = 0; i < 3; i++)
		{
			qt[i] = sclp * p[i] + sclq * qt[i];
		}
	}
}

/*
====================
QuaternionMatrix

====================
*/
void QuaternionMatrix( vec4_t quaternion, float (*matrix)[4] )
{
	matrix[0][0] = 1.0 - 2.0 * quaternion[1] * quaternion[1] - 2.0 * quaternion[2] * quaternion[2];
	matrix[1][0] = 2.0 * quaternion[0] * quaternion[1] + 2.0 * quaternion[3] * quaternion[2];
	matrix[2][0] = 2.0 * quaternion[0] * quaternion[2] - 2.0 * quaternion[3] * quaternion[1];

	matrix[0][1] = 2.0 * quaternion[0] * quaternion[1] - 2.0 * quaternion[3] * quaternion[2];
	matrix[1][1] = 1.0 - 2.0 * quaternion[0] * quaternion[0] - 2.0 * quaternion[2] * quaternion[2];
	matrix[2][1] = 2.0 * quaternion[1] * quaternion[2] + 2.0 * quaternion[3] * quaternion[0];

	matrix[0][2] = 2.0 * quaternion[0] * quaternion[2] + 2.0 * quaternion[3] * quaternion[1];
	matrix[1][2] = 2.0 * quaternion[1] * quaternion[2] - 2.0 * quaternion[3] * quaternion[0];
	matrix[2][2] = 1.0 - 2.0 * quaternion[0] * quaternion[0] - 2.0 * quaternion[1] * quaternion[1];
}

/*
====================
MatrixCopy

====================
*/
void MatrixCopy( float in[3][4], float out[3][4] )
{
	memcpy( out, in, sizeof( float ) * 3 * 4 );
}