m_matrix.c

winNT技术操作系统,国外开放的原代码和LIUX一样

/*
 * Mesa 3-D graphics library
 * Version:  6.3
 *
 * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


/**
 * \file m_matrix.c
 * Matrix operations.
 *
 * \note
 * -# 4x4 transformation matrices are stored in memory in column major order.
 * -# Points/vertices are to be thought of as column vectors.
 * -# Transformation of a point p by a matrix M is: p' = M * p
 */


#include "glheader.h"
#include "imports.h"
#include "macros.h"
#include "imports.h"

#include "m_matrix.h"


/**
 * \defgroup MatFlags MAT_FLAG_XXX-flags
 *
 * Bitmasks to indicate different kinds of 4x4 matrices in GLmatrix::flags
 * It would be nice to make all these flags private to m_matrix.c
 */
/*@{*/
#define MAT_FLAG_IDENTITY       0     /**< is an identity matrix flag.
                                       *   (Not actually used - the identity
                                       *   matrix is identified by the absense
                                       *   of all other flags.)
                                       */
#define MAT_FLAG_GENERAL        0x1   /**< is a general matrix flag */
#define MAT_FLAG_ROTATION       0x2   /**< is a rotation matrix flag */
#define MAT_FLAG_TRANSLATION    0x4   /**< is a translation matrix flag */
#define MAT_FLAG_UNIFORM_SCALE  0x8   /**< is an uniform scaling matrix flag */
#define MAT_FLAG_GENERAL_SCALE  0x10  /**< is a general scaling matrix flag */
#define MAT_FLAG_GENERAL_3D     0x20  /**< general 3D matrix flag */
#define MAT_FLAG_PERSPECTIVE    0x40  /**< is a perspective proj matrix flag */
#define MAT_FLAG_SINGULAR       0x80  /**< is a singular matrix flag */
#define MAT_DIRTY_TYPE          0x100  /**< matrix type is dirty */
#define MAT_DIRTY_FLAGS         0x200  /**< matrix flags are dirty */
#define MAT_DIRTY_INVERSE       0x400  /**< matrix inverse is dirty */

/** angle preserving matrix flags mask */
#define MAT_FLAGS_ANGLE_PRESERVING (MAT_FLAG_ROTATION | \
				    MAT_FLAG_TRANSLATION | \
				    MAT_FLAG_UNIFORM_SCALE)

/** geometry related matrix flags mask */
#define MAT_FLAGS_GEOMETRY (MAT_FLAG_GENERAL | \
			    MAT_FLAG_ROTATION | \
			    MAT_FLAG_TRANSLATION | \
			    MAT_FLAG_UNIFORM_SCALE | \
			    MAT_FLAG_GENERAL_SCALE | \
			    MAT_FLAG_GENERAL_3D | \
			    MAT_FLAG_PERSPECTIVE | \
	                    MAT_FLAG_SINGULAR)

/** length preserving matrix flags mask */
#define MAT_FLAGS_LENGTH_PRESERVING (MAT_FLAG_ROTATION | \
				     MAT_FLAG_TRANSLATION)


/** 3D (non-perspective) matrix flags mask */
#define MAT_FLAGS_3D (MAT_FLAG_ROTATION | \
		      MAT_FLAG_TRANSLATION | \
		      MAT_FLAG_UNIFORM_SCALE | \
		      MAT_FLAG_GENERAL_SCALE | \
		      MAT_FLAG_GENERAL_3D)

/** dirty matrix flags mask */
#define MAT_DIRTY          (MAT_DIRTY_TYPE | \
			    MAT_DIRTY_FLAGS | \
			    MAT_DIRTY_INVERSE)

/*@}*/


/** 
 * Test geometry related matrix flags.
 * 
 * \param mat a pointer to a GLmatrix structure.
 * \param a flags mask.
 *
 * \returns non-zero if all geometry related matrix flags are contained within
 * the mask, or zero otherwise.
 */ 
#define TEST_MAT_FLAGS(mat, a)  \
    ((MAT_FLAGS_GEOMETRY & (~(a)) & ((mat)->flags) ) == 0)



/**
 * Names of the corresponding GLmatrixtype values.
 */
static const char *types[] = {
   "MATRIX_GENERAL",
   "MATRIX_IDENTITY",
   "MATRIX_3D_NO_ROT",
   "MATRIX_PERSPECTIVE",
   "MATRIX_2D",
   "MATRIX_2D_NO_ROT",
   "MATRIX_3D"
};


/**
 * Identity matrix.
 */
static GLfloat Identity[16] = {
   1.0, 0.0, 0.0, 0.0,
   0.0, 1.0, 0.0, 0.0,
   0.0, 0.0, 1.0, 0.0,
   0.0, 0.0, 0.0, 1.0
};



/**********************************************************************/
/** \name Matrix multiplication */
/*@{*/

#define A(row,col)  a[(col<<2)+row]
#define B(row,col)  b[(col<<2)+row]
#define P(row,col)  product[(col<<2)+row]

/**
 * Perform a full 4x4 matrix multiplication.
 *
 * \param a matrix.
 * \param b matrix.
 * \param product will receive the product of \p a and \p b.
 *
 * \warning Is assumed that \p product != \p b. \p product == \p a is allowed.
 *
 * \note KW: 4*16 = 64 multiplications
 * 
 * \author This \c matmul was contributed by Thomas Malik
 */
static void matmul4( GLfloat *product, const GLfloat *a, const GLfloat *b )
{
   GLint i;
   for (i = 0; i < 4; i++) {
      const GLfloat ai0=A(i,0),  ai1=A(i,1),  ai2=A(i,2),  ai3=A(i,3);
      P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0);
      P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1);
      P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2);
      P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3);
   }
}

/**
 * Multiply two matrices known to occupy only the top three rows, such
 * as typical model matrices, and orthogonal matrices.
 *
 * \param a matrix.
 * \param b matrix.
 * \param product will receive the product of \p a and \p b.
 */
static void matmul34( GLfloat *product, const GLfloat *a, const GLfloat *b )
{
   GLint i;
   for (i = 0; i < 3; i++) {
      const GLfloat ai0=A(i,0),  ai1=A(i,1),  ai2=A(i,2),  ai3=A(i,3);
      P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0);
      P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1);
      P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2);
      P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3;
   }
   P(3,0) = 0;
   P(3,1) = 0;
   P(3,2) = 0;
   P(3,3) = 1;
}

#undef A
#undef B
#undef P

/**
 * Multiply a matrix by an array of floats with known properties.
 *
 * \param mat pointer to a GLmatrix structure containing the left multiplication
 * matrix, and that will receive the product result.
 * \param m right multiplication matrix array.
 * \param flags flags of the matrix \p m.
 * 
 * Joins both flags and marks the type and inverse as dirty.  Calls matmul34()
 * if both matrices are 3D, or matmul4() otherwise.
 */
static void matrix_multf( GLmatrix *mat, const GLfloat *m, GLuint flags )
{
   mat->flags |= (flags | MAT_DIRTY_TYPE | MAT_DIRTY_INVERSE);

   if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D))
      matmul34( mat->m, mat->m, m );
   else
      matmul4( mat->m, mat->m, m );
}

/**
 * Matrix multiplication.
 *
 * \param dest destination matrix.
 * \param a left matrix.
 * \param b right matrix.
 * 
 * Joins both flags and marks the type and inverse as dirty.  Calls matmul34()
 * if both matrices are 3D, or matmul4() otherwise.
 */
void
_math_matrix_mul_matrix( GLmatrix *dest, const GLmatrix *a, const GLmatrix *b )
{
   dest->flags = (a->flags |
		  b->flags |
		  MAT_DIRTY_TYPE |
		  MAT_DIRTY_INVERSE);

   if (TEST_MAT_FLAGS(dest, MAT_FLAGS_3D))
      matmul34( dest->m, a->m, b->m );
   else
      matmul4( dest->m, a->m, b->m );
}

/**
 * Matrix multiplication.
 *
 * \param dest left and destination matrix.
 * \param m right matrix array.
 * 
 * Marks the matrix flags with general flag, and type and inverse dirty flags.
 * Calls matmul4() for the multiplication.
 */
void
_math_matrix_mul_floats( GLmatrix *dest, const GLfloat *m )
{
   dest->flags |= (MAT_FLAG_GENERAL |
		   MAT_DIRTY_TYPE |
		   MAT_DIRTY_INVERSE |
                   MAT_DIRTY_FLAGS);

   matmul4( dest->m, dest->m, m );
}

/*@}*/


/**********************************************************************/
/** \name Matrix output */
/*@{*/

/**
 * Print a matrix array.
 *
 * \param m matrix array.
 *
 * Called by _math_matrix_print() to print a matrix or its inverse.
 */
static void print_matrix_floats( const GLfloat m[16] )
{
   int i;
   for (i=0;i<4;i++) {
      _mesa_debug(NULL,"\t%f %f %f %f\n", m[i], m[4+i], m[8+i], m[12+i] );
   }
}

/**
 * Dumps the contents of a GLmatrix structure.
 * 
 * \param m pointer to the GLmatrix structure.
 */
void
_math_matrix_print( const GLmatrix *m )
{
   _mesa_debug(NULL, "Matrix type: %s, flags: %x\n", types[m->type], m->flags);
   print_matrix_floats(m->m);
   _mesa_debug(NULL, "Inverse: \n");
   if (m->inv) {
      GLfloat prod[16];
      print_matrix_floats(m->inv);
      matmul4(prod, m->m, m->inv);
      _mesa_debug(NULL, "Mat * Inverse:\n");
      print_matrix_floats(prod);
   }
   else {
      _mesa_debug(NULL, "  - not available\n");
   }
}

/*@}*/


/**
 * References an element of 4x4 matrix.
 *
 * \param m matrix array.
 * \param c column of the desired element.
 * \param r row of the desired element.
 * 
 * \return value of the desired element.
 *
 * Calculate the linear storage index of the element and references it. 
 */
#define MAT(m,r,c) (m)[(c)*4+(r)]


/**********************************************************************/
/** \name Matrix inversion */
/*@{*/

/**
 * Swaps the values of two floating pointer variables.
 *
 * Used by invert_matrix_general() to swap the row pointers.
 */
#define SWAP_ROWS(a, b) { GLfloat *_tmp = a; (a)=(b); (b)=_tmp; }

/**
 * Compute inverse of 4x4 transformation matrix.
 * 
 * \param mat pointer to a GLmatrix structure. The matrix inverse will be
 * stored in the GLmatrix::inv attribute.
 * 
 * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
 * 
 * \author
 * Code contributed by Jacques Leroy [e-mail]
 *
 * Calculates the inverse matrix by performing the gaussian matrix reduction
 * with partial pivoting followed by back/substitution with the loops manually
 * unrolled.
 */
static GLboolean invert_matrix_general( GLmatrix *mat )
{
   const GLfloat *m = mat->m;
   GLfloat *out = mat->inv;
   GLfloat wtmp[4][8];
   GLfloat m0, m1, m2, m3, s;
   GLfloat *r0, *r1, *r2, *r3;

   r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];

   r0[0] = MAT(m,0,0), r0[1] = MAT(m,0,1),
   r0[2] = MAT(m,0,2), r0[3] = MAT(m,0,3),
   r0[4] = 1.0, r0[5] = r0[6] = r0[7] = 0.0,

   r1[0] = MAT(m,1,0), r1[1] = MAT(m,1,1),
   r1[2] = MAT(m,1,2), r1[3] = MAT(m,1,3),
   r1[5] = 1.0, r1[4] = r1[6] = r1[7] = 0.0,

   r2[0] = MAT(m,2,0), r2[1] = MAT(m,2,1),
   r2[2] = MAT(m,2,2), r2[3] = MAT(m,2,3),
   r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0,

   r3[0] = MAT(m,3,0), r3[1] = MAT(m,3,1),
   r3[2] = MAT(m,3,2), r3[3] = MAT(m,3,3),
   r3[7] = 1.0, r3[4] = r3[5] = r3[6] = 0.0;

   /* choose pivot - or die */
   if (fabs(r3[0])>fabs(r2[0])) SWAP_ROWS(r3, r2);
   if (fabs(r2[0])>fabs(r1[0])) SWAP_ROWS(r2, r1);
   if (fabs(r1[0])>fabs(r0[0])) SWAP_ROWS(r1, r0);
   if (0.0 == r0[0])  return GL_FALSE;

   /* eliminate first variable     */
   m1 = r1[0]/r0[0]; m2 = r2[0]/r0[0]; m3 = r3[0]/r0[0];
   s = r0[1]; r1[1] -= m1 * s; r2[1] -= m2 * s; r3[1] -= m3 * s;
   s = r0[2]; r1[2] -= m1 * s; r2[2] -= m2 * s; r3[2] -= m3 * s;
   s = r0[3]; r1[3] -= m1 * s; r2[3] -= m2 * s; r3[3] -= m3 * s;
   s = r0[4];
   if (s != 0.0) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; }
   s = r0[5];
   if (s != 0.0) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; }
   s = r0[6];
   if (s != 0.0) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; }
   s = r0[7];
   if (s != 0.0) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; }

   /* choose pivot - or die */
   if (fabs(r3[1])>fabs(r2[1])) SWAP_ROWS(r3, r2);
   if (fabs(r2[1])>fabs(r1[1])) SWAP_ROWS(r2, r1);