wolf3d-ios/wolf3d/code/env/matrix.c

158 lines
5.1 KiB
C

/*
Copyright (C) 2005 Michael Liebscher <johnnycanuck@users.sourceforge.net>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
* matrix.c: Matrix math routines.
*
* Author: Michael Liebscher <johnnycanuck@users.sourceforge.net>
*
*/
#include "../wolfiphone.h"
/*
-----------------------------------------------------------------------------
Function: Matrix3x3Multiply -Computes the product of two 3x3 matrices.
Parameters: in1, in2 -[in] 3x3 matrices.
out -[out] result.
Returns: Nothing
Notes:
Product of two 3x3 matrices
( a b c ) ( r u x ) ( ar + bs + ct au + bv + cw ax + by + cz )
( d e f ) ( s v y ) = ( dr + es + ft du + ev + fw dx + ey + fz )
( h i j ) ( t w z ) ( hr + hs + ht iu + iv + iw jx + jy + jz )
-----------------------------------------------------------------------------
*/
PUBLIC void Matrix3x3Multiply( mat3_t in1, mat3_t in2, mat3_t out )
{
out[0] = in1[0] * in2[0] + in1[1] * in2[3] + in1[2] * in2[6];
out[1] = in1[0] * in2[1] + in1[1] * in2[4] + in1[2] * in2[7];
out[2] = in1[0] * in2[2] + in1[1] * in2[5] + in1[2] * in2[8];
out[3] = in1[3] * in2[0] + in1[4] * in2[3] + in1[5] * in2[6];
out[4] = in1[3] * in2[1] + in1[4] * in2[4] + in1[5] * in2[7];
out[5] = in1[3] * in2[2] + in1[4] * in2[5] + in1[5] * in2[8];
out[6] = in1[6] * in2[0] + in1[7] * in2[3] + in1[8] * in2[6];
out[7] = in1[6] * in2[1] + in1[7] * in2[4] + in1[8] * in2[7];
out[8] = in1[6] * in2[2] + in1[7] * in2[5] + in1[8] * in2[8];
}
/*
-----------------------------------------------------------------------------
Function: MatrixIdentity -Set matrix to the identity matrix (unit matrix).
Parameters: matrix -[in/out] 4x4 matrix.
Returns: Nothing.
Notes:
-----------------------------------------------------------------------------
*/
PUBLIC void MatrixIdentity( mat4_t matrix )
{
matrix[ 0] = 1.0; matrix[ 1] = 0.0; matrix[ 2] = 0.0; matrix[ 3] = 0.0;
matrix[ 4] = 0.0; matrix[ 5] = 1.0; matrix[ 6] = 0.0; matrix[ 7] = 0.0;
matrix[ 8] = 0.0; matrix[ 9] = 0.0; matrix[10] = 1.0; matrix[11] = 0.0;
matrix[12] = 0.0; matrix[13] = 0.0; matrix[14] = 0.0; matrix[15] = 1.0;
}
/*
-----------------------------------------------------------------------------
Function: MatrixInvert -Invert a matrix.
Parameters:
in -[in] Input matrix
out -[out] Output matrix.
Returns: Nothing.
Notes: Matrix MUST be orthonormal
-----------------------------------------------------------------------------
*/
PUBLIC void MatrixInvert( mat4_t in, mat4_t out )
{
// Transpose rotation
out[ 0] = in[ 0]; out[ 1] = in[ 4]; out[ 2] = in[ 8];
out[ 4] = in[ 1]; out[ 5] = in[ 5]; out[ 6] = in[ 9];
out[ 8] = in[ 2]; out[ 9] = in[ 6]; out[10] = in[10];
// Clear shearing terms
out[3] = 0.0f; out[7] = 0.0f; out[11] = 0.0f; out[15] = 1.0f;
// Translation is minus the dot of translation and rotations
out[12] = -(in[12] * in[ 0]) - (in[13] * in[ 1]) - (in[14] * in[ 2]);
out[13] = -(in[12] * in[ 4]) - (in[13] * in[ 5]) - (in[14] * in[ 6]);
out[14] = -(in[12] * in[ 8]) - (in[13] * in[ 9]) - (in[14] * in[10]);
}
/*
-----------------------------------------------------------------------------
Function: VectorMatrixMultiply -Multiply a vector by a matrix.
Parameters:
vecIn -[in] Input vector.
m -[in] Input matrix.
vecOut -[out] Output vector.
Returns: Nothing.
Notes:
-----------------------------------------------------------------------------
*/
PUBLIC void VectorMatrixMultiply( vec3_t vecIn, mat4_t m, vec3_t vecOut )
{
vecOut[0] = (vecIn[0] * m[ 0]) + (vecIn[1] * m[ 4]) + (vecIn[2] * m[ 8]) + m[12];
vecOut[1] = (vecIn[0] * m[ 1]) + (vecIn[1] * m[ 5]) + (vecIn[2] * m[ 9]) + m[13];
vecOut[2] = (vecIn[0] * m[ 2]) + (vecIn[1] * m[ 6]) + (vecIn[2] * m[10]) + m[14];
}
/*
-----------------------------------------------------------------------------
Function: VectorMatrix3x3Multiply -Multiply a vector by just the 3x3 portion
of a matrix.
Parameters:
in -[in] Input vector.
m -[in] Input matrix.
out -[out] Output vector.
Returns: Nothing.
Notes:
-----------------------------------------------------------------------------
*/
PUBLIC void VectorMatrix3x3Multiply( vec3_t in, mat4_t m, vec3_t out )
{
out[0] = (in[0] * m[ 0]) + (in[1] * m[ 4]) + (in[2] * m[ 8]);
out[1] = (in[0] * m[ 1]) + (in[1] * m[ 5]) + (in[2] * m[ 9]);
out[2] = (in[0] * m[ 2]) + (in[1] * m[ 6]) + (in[2] * m[10]);
}