Home | History | Annotate | Download | only in math
      1 /*
      2  * Mesa 3-D graphics library
      3  * Version:  6.3
      4  *
      5  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
      6  *
      7  * Permission is hereby granted, free of charge, to any person obtaining a
      8  * copy of this software and associated documentation files (the "Software"),
      9  * to deal in the Software without restriction, including without limitation
     10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     11  * and/or sell copies of the Software, and to permit persons to whom the
     12  * Software is furnished to do so, subject to the following conditions:
     13  *
     14  * The above copyright notice and this permission notice shall be included
     15  * in all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     23  */
     24 
     25 
     26 /**
     27  * \file m_matrix.c
     28  * Matrix operations.
     29  *
     30  * \note
     31  * -# 4x4 transformation matrices are stored in memory in column major order.
     32  * -# Points/vertices are to be thought of as column vectors.
     33  * -# Transformation of a point p by a matrix M is: p' = M * p
     34  */
     35 
     36 
     37 #include "main/glheader.h"
     38 #include "main/imports.h"
     39 #include "main/macros.h"
     40 
     41 #include "m_matrix.h"
     42 
     43 
     44 /**
     45  * \defgroup MatFlags MAT_FLAG_XXX-flags
     46  *
     47  * Bitmasks to indicate different kinds of 4x4 matrices in GLmatrix::flags
     48  */
     49 /*@{*/
     50 #define MAT_FLAG_IDENTITY       0     /**< is an identity matrix flag.
     51                                        *   (Not actually used - the identity
     52                                        *   matrix is identified by the absense
     53                                        *   of all other flags.)
     54                                        */
     55 #define MAT_FLAG_GENERAL        0x1   /**< is a general matrix flag */
     56 #define MAT_FLAG_ROTATION       0x2   /**< is a rotation matrix flag */
     57 #define MAT_FLAG_TRANSLATION    0x4   /**< is a translation matrix flag */
     58 #define MAT_FLAG_UNIFORM_SCALE  0x8   /**< is an uniform scaling matrix flag */
     59 #define MAT_FLAG_GENERAL_SCALE  0x10  /**< is a general scaling matrix flag */
     60 #define MAT_FLAG_GENERAL_3D     0x20  /**< general 3D matrix flag */
     61 #define MAT_FLAG_PERSPECTIVE    0x40  /**< is a perspective proj matrix flag */
     62 #define MAT_FLAG_SINGULAR       0x80  /**< is a singular matrix flag */
     63 #define MAT_DIRTY_TYPE          0x100  /**< matrix type is dirty */
     64 #define MAT_DIRTY_FLAGS         0x200  /**< matrix flags are dirty */
     65 #define MAT_DIRTY_INVERSE       0x400  /**< matrix inverse is dirty */
     66 
     67 /** angle preserving matrix flags mask */
     68 #define MAT_FLAGS_ANGLE_PRESERVING (MAT_FLAG_ROTATION | \
     69 				    MAT_FLAG_TRANSLATION | \
     70 				    MAT_FLAG_UNIFORM_SCALE)
     71 
     72 /** geometry related matrix flags mask */
     73 #define MAT_FLAGS_GEOMETRY (MAT_FLAG_GENERAL | \
     74 			    MAT_FLAG_ROTATION | \
     75 			    MAT_FLAG_TRANSLATION | \
     76 			    MAT_FLAG_UNIFORM_SCALE | \
     77 			    MAT_FLAG_GENERAL_SCALE | \
     78 			    MAT_FLAG_GENERAL_3D | \
     79 			    MAT_FLAG_PERSPECTIVE | \
     80 	                    MAT_FLAG_SINGULAR)
     81 
     82 /** length preserving matrix flags mask */
     83 #define MAT_FLAGS_LENGTH_PRESERVING (MAT_FLAG_ROTATION | \
     84 				     MAT_FLAG_TRANSLATION)
     85 
     86 
     87 /** 3D (non-perspective) matrix flags mask */
     88 #define MAT_FLAGS_3D (MAT_FLAG_ROTATION | \
     89 		      MAT_FLAG_TRANSLATION | \
     90 		      MAT_FLAG_UNIFORM_SCALE | \
     91 		      MAT_FLAG_GENERAL_SCALE | \
     92 		      MAT_FLAG_GENERAL_3D)
     93 
     94 /** dirty matrix flags mask */
     95 #define MAT_DIRTY          (MAT_DIRTY_TYPE | \
     96 			    MAT_DIRTY_FLAGS | \
     97 			    MAT_DIRTY_INVERSE)
     98 
     99 /*@}*/
    100 
    101 
    102 /**
    103  * Test geometry related matrix flags.
    104  *
    105  * \param mat a pointer to a GLmatrix structure.
    106  * \param a flags mask.
    107  *
    108  * \returns non-zero if all geometry related matrix flags are contained within
    109  * the mask, or zero otherwise.
    110  */
    111 #define TEST_MAT_FLAGS(mat, a)  \
    112     ((MAT_FLAGS_GEOMETRY & (~(a)) & ((mat)->flags) ) == 0)
    113 
    114 
    115 
    116 /**
    117  * Names of the corresponding GLmatrixtype values.
    118  */
    119 static const char *types[] = {
    120    "MATRIX_GENERAL",
    121    "MATRIX_IDENTITY",
    122    "MATRIX_3D_NO_ROT",
    123    "MATRIX_PERSPECTIVE",
    124    "MATRIX_2D",
    125    "MATRIX_2D_NO_ROT",
    126    "MATRIX_3D"
    127 };
    128 
    129 
    130 /**
    131  * Identity matrix.
    132  */
    133 static GLfloat Identity[16] = {
    134    1.0, 0.0, 0.0, 0.0,
    135    0.0, 1.0, 0.0, 0.0,
    136    0.0, 0.0, 1.0, 0.0,
    137    0.0, 0.0, 0.0, 1.0
    138 };
    139 
    140 
    141 
    142 /**********************************************************************/
    143 /** \name Matrix multiplication */
    144 /*@{*/
    145 
    146 #define A(row,col)  a[(col<<2)+row]
    147 #define B(row,col)  b[(col<<2)+row]
    148 #define P(row,col)  product[(col<<2)+row]
    149 
    150 /**
    151  * Perform a full 4x4 matrix multiplication.
    152  *
    153  * \param a matrix.
    154  * \param b matrix.
    155  * \param product will receive the product of \p a and \p b.
    156  *
    157  * \warning Is assumed that \p product != \p b. \p product == \p a is allowed.
    158  *
    159  * \note KW: 4*16 = 64 multiplications
    160  *
    161  * \author This \c matmul was contributed by Thomas Malik
    162  */
    163 static void matmul4( GLfloat *product, const GLfloat *a, const GLfloat *b )
    164 {
    165    GLint i;
    166    for (i = 0; i < 4; i++) {
    167       const GLfloat ai0=A(i,0),  ai1=A(i,1),  ai2=A(i,2),  ai3=A(i,3);
    168       P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0);
    169       P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1);
    170       P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2);
    171       P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3);
    172    }
    173 }
    174 
    175 /**
    176  * Multiply two matrices known to occupy only the top three rows, such
    177  * as typical model matrices, and orthogonal matrices.
    178  *
    179  * \param a matrix.
    180  * \param b matrix.
    181  * \param product will receive the product of \p a and \p b.
    182  */
    183 static void matmul34( GLfloat *product, const GLfloat *a, const GLfloat *b )
    184 {
    185    GLint i;
    186    for (i = 0; i < 3; i++) {
    187       const GLfloat ai0=A(i,0),  ai1=A(i,1),  ai2=A(i,2),  ai3=A(i,3);
    188       P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0);
    189       P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1);
    190       P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2);
    191       P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3;
    192    }
    193    P(3,0) = 0;
    194    P(3,1) = 0;
    195    P(3,2) = 0;
    196    P(3,3) = 1;
    197 }
    198 
    199 #undef A
    200 #undef B
    201 #undef P
    202 
    203 /**
    204  * Multiply a matrix by an array of floats with known properties.
    205  *
    206  * \param mat pointer to a GLmatrix structure containing the left multiplication
    207  * matrix, and that will receive the product result.
    208  * \param m right multiplication matrix array.
    209  * \param flags flags of the matrix \p m.
    210  *
    211  * Joins both flags and marks the type and inverse as dirty.  Calls matmul34()
    212  * if both matrices are 3D, or matmul4() otherwise.
    213  */
    214 static void matrix_multf( GLmatrix *mat, const GLfloat *m, GLuint flags )
    215 {
    216    mat->flags |= (flags | MAT_DIRTY_TYPE | MAT_DIRTY_INVERSE);
    217 
    218    if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D))
    219       matmul34( mat->m, mat->m, m );
    220    else
    221       matmul4( mat->m, mat->m, m );
    222 }
    223 
    224 /**
    225  * Matrix multiplication.
    226  *
    227  * \param dest destination matrix.
    228  * \param a left matrix.
    229  * \param b right matrix.
    230  *
    231  * Joins both flags and marks the type and inverse as dirty.  Calls matmul34()
    232  * if both matrices are 3D, or matmul4() otherwise.
    233  */
    234 void
    235 _math_matrix_mul_matrix( GLmatrix *dest, const GLmatrix *a, const GLmatrix *b )
    236 {
    237    dest->flags = (a->flags |
    238 		  b->flags |
    239 		  MAT_DIRTY_TYPE |
    240 		  MAT_DIRTY_INVERSE);
    241 
    242    if (TEST_MAT_FLAGS(dest, MAT_FLAGS_3D))
    243       matmul34( dest->m, a->m, b->m );
    244    else
    245       matmul4( dest->m, a->m, b->m );
    246 }
    247 
    248 /**
    249  * Matrix multiplication.
    250  *
    251  * \param dest left and destination matrix.
    252  * \param m right matrix array.
    253  *
    254  * Marks the matrix flags with general flag, and type and inverse dirty flags.
    255  * Calls matmul4() for the multiplication.
    256  */
    257 void
    258 _math_matrix_mul_floats( GLmatrix *dest, const GLfloat *m )
    259 {
    260    dest->flags |= (MAT_FLAG_GENERAL |
    261 		   MAT_DIRTY_TYPE |
    262 		   MAT_DIRTY_INVERSE |
    263                    MAT_DIRTY_FLAGS);
    264 
    265    matmul4( dest->m, dest->m, m );
    266 }
    267 
    268 /*@}*/
    269 
    270 
    271 /**********************************************************************/
    272 /** \name Matrix output */
    273 /*@{*/
    274 
    275 /**
    276  * Print a matrix array.
    277  *
    278  * \param m matrix array.
    279  *
    280  * Called by _math_matrix_print() to print a matrix or its inverse.
    281  */
    282 static void print_matrix_floats( const GLfloat m[16] )
    283 {
    284    int i;
    285    for (i=0;i<4;i++) {
    286       _mesa_debug(NULL,"\t%f %f %f %f\n", m[i], m[4+i], m[8+i], m[12+i] );
    287    }
    288 }
    289 
    290 /**
    291  * Dumps the contents of a GLmatrix structure.
    292  *
    293  * \param m pointer to the GLmatrix structure.
    294  */
    295 void
    296 _math_matrix_print( const GLmatrix *m )
    297 {
    298    GLfloat prod[16];
    299 
    300    _mesa_debug(NULL, "Matrix type: %s, flags: %x\n", types[m->type], m->flags);
    301    print_matrix_floats(m->m);
    302    _mesa_debug(NULL, "Inverse: \n");
    303    print_matrix_floats(m->inv);
    304    matmul4(prod, m->m, m->inv);
    305    _mesa_debug(NULL, "Mat * Inverse:\n");
    306    print_matrix_floats(prod);
    307 }
    308 
    309 /*@}*/
    310 
    311 
    312 /**
    313  * References an element of 4x4 matrix.
    314  *
    315  * \param m matrix array.
    316  * \param c column of the desired element.
    317  * \param r row of the desired element.
    318  *
    319  * \return value of the desired element.
    320  *
    321  * Calculate the linear storage index of the element and references it.
    322  */
    323 #define MAT(m,r,c) (m)[(c)*4+(r)]
    324 
    325 
    326 /**********************************************************************/
    327 /** \name Matrix inversion */
    328 /*@{*/
    329 
    330 /**
    331  * Swaps the values of two floating point variables.
    332  *
    333  * Used by invert_matrix_general() to swap the row pointers.
    334  */
    335 #define SWAP_ROWS(a, b) { GLfloat *_tmp = a; (a)=(b); (b)=_tmp; }
    336 
    337 /**
    338  * Compute inverse of 4x4 transformation matrix.
    339  *
    340  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    341  * stored in the GLmatrix::inv attribute.
    342  *
    343  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
    344  *
    345  * \author
    346  * Code contributed by Jacques Leroy jle (at) star.be
    347  *
    348  * Calculates the inverse matrix by performing the gaussian matrix reduction
    349  * with partial pivoting followed by back/substitution with the loops manually
    350  * unrolled.
    351  */
    352 static GLboolean invert_matrix_general( GLmatrix *mat )
    353 {
    354    const GLfloat *m = mat->m;
    355    GLfloat *out = mat->inv;
    356    GLfloat wtmp[4][8];
    357    GLfloat m0, m1, m2, m3, s;
    358    GLfloat *r0, *r1, *r2, *r3;
    359 
    360    r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];
    361 
    362    r0[0] = MAT(m,0,0), r0[1] = MAT(m,0,1),
    363    r0[2] = MAT(m,0,2), r0[3] = MAT(m,0,3),
    364    r0[4] = 1.0, r0[5] = r0[6] = r0[7] = 0.0,
    365 
    366    r1[0] = MAT(m,1,0), r1[1] = MAT(m,1,1),
    367    r1[2] = MAT(m,1,2), r1[3] = MAT(m,1,3),
    368    r1[5] = 1.0, r1[4] = r1[6] = r1[7] = 0.0,
    369 
    370    r2[0] = MAT(m,2,0), r2[1] = MAT(m,2,1),
    371    r2[2] = MAT(m,2,2), r2[3] = MAT(m,2,3),
    372    r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0,
    373 
    374    r3[0] = MAT(m,3,0), r3[1] = MAT(m,3,1),
    375    r3[2] = MAT(m,3,2), r3[3] = MAT(m,3,3),
    376    r3[7] = 1.0, r3[4] = r3[5] = r3[6] = 0.0;
    377 
    378    /* choose pivot - or die */
    379    if (FABSF(r3[0])>FABSF(r2[0])) SWAP_ROWS(r3, r2);
    380    if (FABSF(r2[0])>FABSF(r1[0])) SWAP_ROWS(r2, r1);
    381    if (FABSF(r1[0])>FABSF(r0[0])) SWAP_ROWS(r1, r0);
    382    if (0.0 == r0[0])  return GL_FALSE;
    383 
    384    /* eliminate first variable     */
    385    m1 = r1[0]/r0[0]; m2 = r2[0]/r0[0]; m3 = r3[0]/r0[0];
    386    s = r0[1]; r1[1] -= m1 * s; r2[1] -= m2 * s; r3[1] -= m3 * s;
    387    s = r0[2]; r1[2] -= m1 * s; r2[2] -= m2 * s; r3[2] -= m3 * s;
    388    s = r0[3]; r1[3] -= m1 * s; r2[3] -= m2 * s; r3[3] -= m3 * s;
    389    s = r0[4];
    390    if (s != 0.0) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; }
    391    s = r0[5];
    392    if (s != 0.0) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; }
    393    s = r0[6];
    394    if (s != 0.0) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; }
    395    s = r0[7];
    396    if (s != 0.0) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; }
    397 
    398    /* choose pivot - or die */
    399    if (FABSF(r3[1])>FABSF(r2[1])) SWAP_ROWS(r3, r2);
    400    if (FABSF(r2[1])>FABSF(r1[1])) SWAP_ROWS(r2, r1);
    401    if (0.0 == r1[1])  return GL_FALSE;
    402 
    403    /* eliminate second variable */
    404    m2 = r2[1]/r1[1]; m3 = r3[1]/r1[1];
    405    r2[2] -= m2 * r1[2]; r3[2] -= m3 * r1[2];
    406    r2[3] -= m2 * r1[3]; r3[3] -= m3 * r1[3];
    407    s = r1[4]; if (0.0 != s) { r2[4] -= m2 * s; r3[4] -= m3 * s; }
    408    s = r1[5]; if (0.0 != s) { r2[5] -= m2 * s; r3[5] -= m3 * s; }
    409    s = r1[6]; if (0.0 != s) { r2[6] -= m2 * s; r3[6] -= m3 * s; }
    410    s = r1[7]; if (0.0 != s) { r2[7] -= m2 * s; r3[7] -= m3 * s; }
    411 
    412    /* choose pivot - or die */
    413    if (FABSF(r3[2])>FABSF(r2[2])) SWAP_ROWS(r3, r2);
    414    if (0.0 == r2[2])  return GL_FALSE;
    415 
    416    /* eliminate third variable */
    417    m3 = r3[2]/r2[2];
    418    r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4],
    419    r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6],
    420    r3[7] -= m3 * r2[7];
    421 
    422    /* last check */
    423    if (0.0 == r3[3]) return GL_FALSE;
    424 
    425    s = 1.0F/r3[3];             /* now back substitute row 3 */
    426    r3[4] *= s; r3[5] *= s; r3[6] *= s; r3[7] *= s;
    427 
    428    m2 = r2[3];                 /* now back substitute row 2 */
    429    s  = 1.0F/r2[2];
    430    r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2),
    431    r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2);
    432    m1 = r1[3];
    433    r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1,
    434    r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1;
    435    m0 = r0[3];
    436    r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0,
    437    r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0;
    438 
    439    m1 = r1[2];                 /* now back substitute row 1 */
    440    s  = 1.0F/r1[1];
    441    r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1),
    442    r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1);
    443    m0 = r0[2];
    444    r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0,
    445    r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;
    446 
    447    m0 = r0[1];                 /* now back substitute row 0 */
    448    s  = 1.0F/r0[0];
    449    r0[4] = s * (r0[4] - r1[4] * m0), r0[5] = s * (r0[5] - r1[5] * m0),
    450    r0[6] = s * (r0[6] - r1[6] * m0), r0[7] = s * (r0[7] - r1[7] * m0);
    451 
    452    MAT(out,0,0) = r0[4]; MAT(out,0,1) = r0[5],
    453    MAT(out,0,2) = r0[6]; MAT(out,0,3) = r0[7],
    454    MAT(out,1,0) = r1[4]; MAT(out,1,1) = r1[5],
    455    MAT(out,1,2) = r1[6]; MAT(out,1,3) = r1[7],
    456    MAT(out,2,0) = r2[4]; MAT(out,2,1) = r2[5],
    457    MAT(out,2,2) = r2[6]; MAT(out,2,3) = r2[7],
    458    MAT(out,3,0) = r3[4]; MAT(out,3,1) = r3[5],
    459    MAT(out,3,2) = r3[6]; MAT(out,3,3) = r3[7];
    460 
    461    return GL_TRUE;
    462 }
    463 #undef SWAP_ROWS
    464 
    465 /**
    466  * Compute inverse of a general 3d transformation matrix.
    467  *
    468  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    469  * stored in the GLmatrix::inv attribute.
    470  *
    471  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
    472  *
    473  * \author Adapted from graphics gems II.
    474  *
    475  * Calculates the inverse of the upper left by first calculating its
    476  * determinant and multiplying it to the symmetric adjust matrix of each
    477  * element. Finally deals with the translation part by transforming the
    478  * original translation vector using by the calculated submatrix inverse.
    479  */
    480 static GLboolean invert_matrix_3d_general( GLmatrix *mat )
    481 {
    482    const GLfloat *in = mat->m;
    483    GLfloat *out = mat->inv;
    484    GLfloat pos, neg, t;
    485    GLfloat det;
    486 
    487    /* Calculate the determinant of upper left 3x3 submatrix and
    488     * determine if the matrix is singular.
    489     */
    490    pos = neg = 0.0;
    491    t =  MAT(in,0,0) * MAT(in,1,1) * MAT(in,2,2);
    492    if (t >= 0.0) pos += t; else neg += t;
    493 
    494    t =  MAT(in,1,0) * MAT(in,2,1) * MAT(in,0,2);
    495    if (t >= 0.0) pos += t; else neg += t;
    496 
    497    t =  MAT(in,2,0) * MAT(in,0,1) * MAT(in,1,2);
    498    if (t >= 0.0) pos += t; else neg += t;
    499 
    500    t = -MAT(in,2,0) * MAT(in,1,1) * MAT(in,0,2);
    501    if (t >= 0.0) pos += t; else neg += t;
    502 
    503    t = -MAT(in,1,0) * MAT(in,0,1) * MAT(in,2,2);
    504    if (t >= 0.0) pos += t; else neg += t;
    505 
    506    t = -MAT(in,0,0) * MAT(in,2,1) * MAT(in,1,2);
    507    if (t >= 0.0) pos += t; else neg += t;
    508 
    509    det = pos + neg;
    510 
    511    if (FABSF(det) < 1e-25)
    512       return GL_FALSE;
    513 
    514    det = 1.0F / det;
    515    MAT(out,0,0) = (  (MAT(in,1,1)*MAT(in,2,2) - MAT(in,2,1)*MAT(in,1,2) )*det);
    516    MAT(out,0,1) = (- (MAT(in,0,1)*MAT(in,2,2) - MAT(in,2,1)*MAT(in,0,2) )*det);
    517    MAT(out,0,2) = (  (MAT(in,0,1)*MAT(in,1,2) - MAT(in,1,1)*MAT(in,0,2) )*det);
    518    MAT(out,1,0) = (- (MAT(in,1,0)*MAT(in,2,2) - MAT(in,2,0)*MAT(in,1,2) )*det);
    519    MAT(out,1,1) = (  (MAT(in,0,0)*MAT(in,2,2) - MAT(in,2,0)*MAT(in,0,2) )*det);
    520    MAT(out,1,2) = (- (MAT(in,0,0)*MAT(in,1,2) - MAT(in,1,0)*MAT(in,0,2) )*det);
    521    MAT(out,2,0) = (  (MAT(in,1,0)*MAT(in,2,1) - MAT(in,2,0)*MAT(in,1,1) )*det);
    522    MAT(out,2,1) = (- (MAT(in,0,0)*MAT(in,2,1) - MAT(in,2,0)*MAT(in,0,1) )*det);
    523    MAT(out,2,2) = (  (MAT(in,0,0)*MAT(in,1,1) - MAT(in,1,0)*MAT(in,0,1) )*det);
    524 
    525    /* Do the translation part */
    526    MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0) +
    527 		     MAT(in,1,3) * MAT(out,0,1) +
    528 		     MAT(in,2,3) * MAT(out,0,2) );
    529    MAT(out,1,3) = - (MAT(in,0,3) * MAT(out,1,0) +
    530 		     MAT(in,1,3) * MAT(out,1,1) +
    531 		     MAT(in,2,3) * MAT(out,1,2) );
    532    MAT(out,2,3) = - (MAT(in,0,3) * MAT(out,2,0) +
    533 		     MAT(in,1,3) * MAT(out,2,1) +
    534 		     MAT(in,2,3) * MAT(out,2,2) );
    535 
    536    return GL_TRUE;
    537 }
    538 
    539 /**
    540  * Compute inverse of a 3d transformation matrix.
    541  *
    542  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    543  * stored in the GLmatrix::inv attribute.
    544  *
    545  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
    546  *
    547  * If the matrix is not an angle preserving matrix then calls
    548  * invert_matrix_3d_general for the actual calculation. Otherwise calculates
    549  * the inverse matrix analyzing and inverting each of the scaling, rotation and
    550  * translation parts.
    551  */
    552 static GLboolean invert_matrix_3d( GLmatrix *mat )
    553 {
    554    const GLfloat *in = mat->m;
    555    GLfloat *out = mat->inv;
    556 
    557    if (!TEST_MAT_FLAGS(mat, MAT_FLAGS_ANGLE_PRESERVING)) {
    558       return invert_matrix_3d_general( mat );
    559    }
    560 
    561    if (mat->flags & MAT_FLAG_UNIFORM_SCALE) {
    562       GLfloat scale = (MAT(in,0,0) * MAT(in,0,0) +
    563                        MAT(in,0,1) * MAT(in,0,1) +
    564                        MAT(in,0,2) * MAT(in,0,2));
    565 
    566       if (scale == 0.0)
    567          return GL_FALSE;
    568 
    569       scale = 1.0F / scale;
    570 
    571       /* Transpose and scale the 3 by 3 upper-left submatrix. */
    572       MAT(out,0,0) = scale * MAT(in,0,0);
    573       MAT(out,1,0) = scale * MAT(in,0,1);
    574       MAT(out,2,0) = scale * MAT(in,0,2);
    575       MAT(out,0,1) = scale * MAT(in,1,0);
    576       MAT(out,1,1) = scale * MAT(in,1,1);
    577       MAT(out,2,1) = scale * MAT(in,1,2);
    578       MAT(out,0,2) = scale * MAT(in,2,0);
    579       MAT(out,1,2) = scale * MAT(in,2,1);
    580       MAT(out,2,2) = scale * MAT(in,2,2);
    581    }
    582    else if (mat->flags & MAT_FLAG_ROTATION) {
    583       /* Transpose the 3 by 3 upper-left submatrix. */
    584       MAT(out,0,0) = MAT(in,0,0);
    585       MAT(out,1,0) = MAT(in,0,1);
    586       MAT(out,2,0) = MAT(in,0,2);
    587       MAT(out,0,1) = MAT(in,1,0);
    588       MAT(out,1,1) = MAT(in,1,1);
    589       MAT(out,2,1) = MAT(in,1,2);
    590       MAT(out,0,2) = MAT(in,2,0);
    591       MAT(out,1,2) = MAT(in,2,1);
    592       MAT(out,2,2) = MAT(in,2,2);
    593    }
    594    else {
    595       /* pure translation */
    596       memcpy( out, Identity, sizeof(Identity) );
    597       MAT(out,0,3) = - MAT(in,0,3);
    598       MAT(out,1,3) = - MAT(in,1,3);
    599       MAT(out,2,3) = - MAT(in,2,3);
    600       return GL_TRUE;
    601    }
    602 
    603    if (mat->flags & MAT_FLAG_TRANSLATION) {
    604       /* Do the translation part */
    605       MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0) +
    606 			MAT(in,1,3) * MAT(out,0,1) +
    607 			MAT(in,2,3) * MAT(out,0,2) );
    608       MAT(out,1,3) = - (MAT(in,0,3) * MAT(out,1,0) +
    609 			MAT(in,1,3) * MAT(out,1,1) +
    610 			MAT(in,2,3) * MAT(out,1,2) );
    611       MAT(out,2,3) = - (MAT(in,0,3) * MAT(out,2,0) +
    612 			MAT(in,1,3) * MAT(out,2,1) +
    613 			MAT(in,2,3) * MAT(out,2,2) );
    614    }
    615    else {
    616       MAT(out,0,3) = MAT(out,1,3) = MAT(out,2,3) = 0.0;
    617    }
    618 
    619    return GL_TRUE;
    620 }
    621 
    622 /**
    623  * Compute inverse of an identity transformation matrix.
    624  *
    625  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    626  * stored in the GLmatrix::inv attribute.
    627  *
    628  * \return always GL_TRUE.
    629  *
    630  * Simply copies Identity into GLmatrix::inv.
    631  */
    632 static GLboolean invert_matrix_identity( GLmatrix *mat )
    633 {
    634    memcpy( mat->inv, Identity, sizeof(Identity) );
    635    return GL_TRUE;
    636 }
    637 
    638 /**
    639  * Compute inverse of a no-rotation 3d transformation matrix.
    640  *
    641  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    642  * stored in the GLmatrix::inv attribute.
    643  *
    644  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
    645  *
    646  * Calculates the
    647  */
    648 static GLboolean invert_matrix_3d_no_rot( GLmatrix *mat )
    649 {
    650    const GLfloat *in = mat->m;
    651    GLfloat *out = mat->inv;
    652 
    653    if (MAT(in,0,0) == 0 || MAT(in,1,1) == 0 || MAT(in,2,2) == 0 )
    654       return GL_FALSE;
    655 
    656    memcpy( out, Identity, 16 * sizeof(GLfloat) );
    657    MAT(out,0,0) = 1.0F / MAT(in,0,0);
    658    MAT(out,1,1) = 1.0F / MAT(in,1,1);
    659    MAT(out,2,2) = 1.0F / MAT(in,2,2);
    660 
    661    if (mat->flags & MAT_FLAG_TRANSLATION) {
    662       MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0));
    663       MAT(out,1,3) = - (MAT(in,1,3) * MAT(out,1,1));
    664       MAT(out,2,3) = - (MAT(in,2,3) * MAT(out,2,2));
    665    }
    666 
    667    return GL_TRUE;
    668 }
    669 
    670 /**
    671  * Compute inverse of a no-rotation 2d transformation matrix.
    672  *
    673  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    674  * stored in the GLmatrix::inv attribute.
    675  *
    676  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
    677  *
    678  * Calculates the inverse matrix by applying the inverse scaling and
    679  * translation to the identity matrix.
    680  */
    681 static GLboolean invert_matrix_2d_no_rot( GLmatrix *mat )
    682 {
    683    const GLfloat *in = mat->m;
    684    GLfloat *out = mat->inv;
    685 
    686    if (MAT(in,0,0) == 0 || MAT(in,1,1) == 0)
    687       return GL_FALSE;
    688 
    689    memcpy( out, Identity, 16 * sizeof(GLfloat) );
    690    MAT(out,0,0) = 1.0F / MAT(in,0,0);
    691    MAT(out,1,1) = 1.0F / MAT(in,1,1);
    692 
    693    if (mat->flags & MAT_FLAG_TRANSLATION) {
    694       MAT(out,0,3) = - (MAT(in,0,3) * MAT(out,0,0));
    695       MAT(out,1,3) = - (MAT(in,1,3) * MAT(out,1,1));
    696    }
    697 
    698    return GL_TRUE;
    699 }
    700 
    701 #if 0
    702 /* broken */
    703 static GLboolean invert_matrix_perspective( GLmatrix *mat )
    704 {
    705    const GLfloat *in = mat->m;
    706    GLfloat *out = mat->inv;
    707 
    708    if (MAT(in,2,3) == 0)
    709       return GL_FALSE;
    710 
    711    memcpy( out, Identity, 16 * sizeof(GLfloat) );
    712 
    713    MAT(out,0,0) = 1.0F / MAT(in,0,0);
    714    MAT(out,1,1) = 1.0F / MAT(in,1,1);
    715 
    716    MAT(out,0,3) = MAT(in,0,2);
    717    MAT(out,1,3) = MAT(in,1,2);
    718 
    719    MAT(out,2,2) = 0;
    720    MAT(out,2,3) = -1;
    721 
    722    MAT(out,3,2) = 1.0F / MAT(in,2,3);
    723    MAT(out,3,3) = MAT(in,2,2) * MAT(out,3,2);
    724 
    725    return GL_TRUE;
    726 }
    727 #endif
    728 
    729 /**
    730  * Matrix inversion function pointer type.
    731  */
    732 typedef GLboolean (*inv_mat_func)( GLmatrix *mat );
    733 
    734 /**
    735  * Table of the matrix inversion functions according to the matrix type.
    736  */
    737 static inv_mat_func inv_mat_tab[7] = {
    738    invert_matrix_general,
    739    invert_matrix_identity,
    740    invert_matrix_3d_no_rot,
    741 #if 0
    742    /* Don't use this function for now - it fails when the projection matrix
    743     * is premultiplied by a translation (ala Chromium's tilesort SPU).
    744     */
    745    invert_matrix_perspective,
    746 #else
    747    invert_matrix_general,
    748 #endif
    749    invert_matrix_3d,		/* lazy! */
    750    invert_matrix_2d_no_rot,
    751    invert_matrix_3d
    752 };
    753 
    754 /**
    755  * Compute inverse of a transformation matrix.
    756  *
    757  * \param mat pointer to a GLmatrix structure. The matrix inverse will be
    758  * stored in the GLmatrix::inv attribute.
    759  *
    760  * \return GL_TRUE for success, GL_FALSE for failure (\p singular matrix).
    761  *
    762  * Calls the matrix inversion function in inv_mat_tab corresponding to the
    763  * given matrix type.  In case of failure, updates the MAT_FLAG_SINGULAR flag,
    764  * and copies the identity matrix into GLmatrix::inv.
    765  */
    766 static GLboolean matrix_invert( GLmatrix *mat )
    767 {
    768    if (inv_mat_tab[mat->type](mat)) {
    769       mat->flags &= ~MAT_FLAG_SINGULAR;
    770       return GL_TRUE;
    771    } else {
    772       mat->flags |= MAT_FLAG_SINGULAR;
    773       memcpy( mat->inv, Identity, sizeof(Identity) );
    774       return GL_FALSE;
    775    }
    776 }
    777 
    778 /*@}*/
    779 
    780 
    781 /**********************************************************************/
    782 /** \name Matrix generation */
    783 /*@{*/
    784 
    785 /**
    786  * Generate a 4x4 transformation matrix from glRotate parameters, and
    787  * post-multiply the input matrix by it.
    788  *
    789  * \author
    790  * This function was contributed by Erich Boleyn (erich (at) uruk.org).
    791  * Optimizations contributed by Rudolf Opalla (rudi (at) khm.de).
    792  */
    793 void
    794 _math_matrix_rotate( GLmatrix *mat,
    795 		     GLfloat angle, GLfloat x, GLfloat y, GLfloat z )
    796 {
    797    GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c, s, c;
    798    GLfloat m[16];
    799    GLboolean optimized;
    800 
    801    s = (GLfloat) sin( angle * DEG2RAD );
    802    c = (GLfloat) cos( angle * DEG2RAD );
    803 
    804    memcpy(m, Identity, sizeof(GLfloat)*16);
    805    optimized = GL_FALSE;
    806 
    807 #define M(row,col)  m[col*4+row]
    808 
    809    if (x == 0.0F) {
    810       if (y == 0.0F) {
    811          if (z != 0.0F) {
    812             optimized = GL_TRUE;
    813             /* rotate only around z-axis */
    814             M(0,0) = c;
    815             M(1,1) = c;
    816             if (z < 0.0F) {
    817                M(0,1) = s;
    818                M(1,0) = -s;
    819             }
    820             else {
    821                M(0,1) = -s;
    822                M(1,0) = s;
    823             }
    824          }
    825       }
    826       else if (z == 0.0F) {
    827          optimized = GL_TRUE;
    828          /* rotate only around y-axis */
    829          M(0,0) = c;
    830          M(2,2) = c;
    831          if (y < 0.0F) {
    832             M(0,2) = -s;
    833             M(2,0) = s;
    834          }
    835          else {
    836             M(0,2) = s;
    837             M(2,0) = -s;
    838          }
    839       }
    840    }
    841    else if (y == 0.0F) {
    842       if (z == 0.0F) {
    843          optimized = GL_TRUE;
    844          /* rotate only around x-axis */
    845          M(1,1) = c;
    846          M(2,2) = c;
    847          if (x < 0.0F) {
    848             M(1,2) = s;
    849             M(2,1) = -s;
    850          }
    851          else {
    852             M(1,2) = -s;
    853             M(2,1) = s;
    854          }
    855       }
    856    }
    857 
    858    if (!optimized) {
    859       const GLfloat mag = SQRTF(x * x + y * y + z * z);
    860 
    861       if (mag <= 1.0e-4) {
    862          /* no rotation, leave mat as-is */
    863          return;
    864       }
    865 
    866       x /= mag;
    867       y /= mag;
    868       z /= mag;
    869 
    870 
    871       /*
    872        *     Arbitrary axis rotation matrix.
    873        *
    874        *  This is composed of 5 matrices, Rz, Ry, T, Ry', Rz', multiplied
    875        *  like so:  Rz * Ry * T * Ry' * Rz'.  T is the final rotation
    876        *  (which is about the X-axis), and the two composite transforms
    877        *  Ry' * Rz' and Rz * Ry are (respectively) the rotations necessary
    878        *  from the arbitrary axis to the X-axis then back.  They are
    879        *  all elementary rotations.
    880        *
    881        *  Rz' is a rotation about the Z-axis, to bring the axis vector
    882        *  into the x-z plane.  Then Ry' is applied, rotating about the
    883        *  Y-axis to bring the axis vector parallel with the X-axis.  The
    884        *  rotation about the X-axis is then performed.  Ry and Rz are
    885        *  simply the respective inverse transforms to bring the arbitrary
    886        *  axis back to its original orientation.  The first transforms
    887        *  Rz' and Ry' are considered inverses, since the data from the
    888        *  arbitrary axis gives you info on how to get to it, not how
    889        *  to get away from it, and an inverse must be applied.
    890        *
    891        *  The basic calculation used is to recognize that the arbitrary
    892        *  axis vector (x, y, z), since it is of unit length, actually
    893        *  represents the sines and cosines of the angles to rotate the
    894        *  X-axis to the same orientation, with theta being the angle about
    895        *  Z and phi the angle about Y (in the order described above)
    896        *  as follows:
    897        *
    898        *  cos ( theta ) = x / sqrt ( 1 - z^2 )
    899        *  sin ( theta ) = y / sqrt ( 1 - z^2 )
    900        *
    901        *  cos ( phi ) = sqrt ( 1 - z^2 )
    902        *  sin ( phi ) = z
    903        *
    904        *  Note that cos ( phi ) can further be inserted to the above
    905        *  formulas:
    906        *
    907        *  cos ( theta ) = x / cos ( phi )
    908        *  sin ( theta ) = y / sin ( phi )
    909        *
    910        *  ...etc.  Because of those relations and the standard trigonometric
    911        *  relations, it is pssible to reduce the transforms down to what
    912        *  is used below.  It may be that any primary axis chosen will give the
    913        *  same results (modulo a sign convention) using thie method.
    914        *
    915        *  Particularly nice is to notice that all divisions that might
    916        *  have caused trouble when parallel to certain planes or
    917        *  axis go away with care paid to reducing the expressions.
    918        *  After checking, it does perform correctly under all cases, since
    919        *  in all the cases of division where the denominator would have
    920        *  been zero, the numerator would have been zero as well, giving
    921        *  the expected result.
    922        */
    923 
    924       xx = x * x;
    925       yy = y * y;
    926       zz = z * z;
    927       xy = x * y;
    928       yz = y * z;
    929       zx = z * x;
    930       xs = x * s;
    931       ys = y * s;
    932       zs = z * s;
    933       one_c = 1.0F - c;
    934 
    935       /* We already hold the identity-matrix so we can skip some statements */
    936       M(0,0) = (one_c * xx) + c;
    937       M(0,1) = (one_c * xy) - zs;
    938       M(0,2) = (one_c * zx) + ys;
    939 /*    M(0,3) = 0.0F; */
    940 
    941       M(1,0) = (one_c * xy) + zs;
    942       M(1,1) = (one_c * yy) + c;
    943       M(1,2) = (one_c * yz) - xs;
    944 /*    M(1,3) = 0.0F; */
    945 
    946       M(2,0) = (one_c * zx) - ys;
    947       M(2,1) = (one_c * yz) + xs;
    948       M(2,2) = (one_c * zz) + c;
    949 /*    M(2,3) = 0.0F; */
    950 
    951 /*
    952       M(3,0) = 0.0F;
    953       M(3,1) = 0.0F;
    954       M(3,2) = 0.0F;
    955       M(3,3) = 1.0F;
    956 */
    957    }
    958 #undef M
    959 
    960    matrix_multf( mat, m, MAT_FLAG_ROTATION );
    961 }
    962 
    963 /**
    964  * Apply a perspective projection matrix.
    965  *
    966  * \param mat matrix to apply the projection.
    967  * \param left left clipping plane coordinate.
    968  * \param right right clipping plane coordinate.
    969  * \param bottom bottom clipping plane coordinate.
    970  * \param top top clipping plane coordinate.
    971  * \param nearval distance to the near clipping plane.
    972  * \param farval distance to the far clipping plane.
    973  *
    974  * Creates the projection matrix and multiplies it with \p mat, marking the
    975  * MAT_FLAG_PERSPECTIVE flag.
    976  */
    977 void
    978 _math_matrix_frustum( GLmatrix *mat,
    979 		      GLfloat left, GLfloat right,
    980 		      GLfloat bottom, GLfloat top,
    981 		      GLfloat nearval, GLfloat farval )
    982 {
    983    GLfloat x, y, a, b, c, d;
    984    GLfloat m[16];
    985 
    986    x = (2.0F*nearval) / (right-left);
    987    y = (2.0F*nearval) / (top-bottom);
    988    a = (right+left) / (right-left);
    989    b = (top+bottom) / (top-bottom);
    990    c = -(farval+nearval) / ( farval-nearval);
    991    d = -(2.0F*farval*nearval) / (farval-nearval);  /* error? */
    992 
    993 #define M(row,col)  m[col*4+row]
    994    M(0,0) = x;     M(0,1) = 0.0F;  M(0,2) = a;      M(0,3) = 0.0F;
    995    M(1,0) = 0.0F;  M(1,1) = y;     M(1,2) = b;      M(1,3) = 0.0F;
    996    M(2,0) = 0.0F;  M(2,1) = 0.0F;  M(2,2) = c;      M(2,3) = d;
    997    M(3,0) = 0.0F;  M(3,1) = 0.0F;  M(3,2) = -1.0F;  M(3,3) = 0.0F;
    998 #undef M
    999 
   1000    matrix_multf( mat, m, MAT_FLAG_PERSPECTIVE );
   1001 }
   1002 
   1003 /**
   1004  * Apply an orthographic projection matrix.
   1005  *
   1006  * \param mat matrix to apply the projection.
   1007  * \param left left clipping plane coordinate.
   1008  * \param right right clipping plane coordinate.
   1009  * \param bottom bottom clipping plane coordinate.
   1010  * \param top top clipping plane coordinate.
   1011  * \param nearval distance to the near clipping plane.
   1012  * \param farval distance to the far clipping plane.
   1013  *
   1014  * Creates the projection matrix and multiplies it with \p mat, marking the
   1015  * MAT_FLAG_GENERAL_SCALE and MAT_FLAG_TRANSLATION flags.
   1016  */
   1017 void
   1018 _math_matrix_ortho( GLmatrix *mat,
   1019 		    GLfloat left, GLfloat right,
   1020 		    GLfloat bottom, GLfloat top,
   1021 		    GLfloat nearval, GLfloat farval )
   1022 {
   1023    GLfloat m[16];
   1024 
   1025 #define M(row,col)  m[col*4+row]
   1026    M(0,0) = 2.0F / (right-left);
   1027    M(0,1) = 0.0F;
   1028    M(0,2) = 0.0F;
   1029    M(0,3) = -(right+left) / (right-left);
   1030 
   1031    M(1,0) = 0.0F;
   1032    M(1,1) = 2.0F / (top-bottom);
   1033    M(1,2) = 0.0F;
   1034    M(1,3) = -(top+bottom) / (top-bottom);
   1035 
   1036    M(2,0) = 0.0F;
   1037    M(2,1) = 0.0F;
   1038    M(2,2) = -2.0F / (farval-nearval);
   1039    M(2,3) = -(farval+nearval) / (farval-nearval);
   1040 
   1041    M(3,0) = 0.0F;
   1042    M(3,1) = 0.0F;
   1043    M(3,2) = 0.0F;
   1044    M(3,3) = 1.0F;
   1045 #undef M
   1046 
   1047    matrix_multf( mat, m, (MAT_FLAG_GENERAL_SCALE|MAT_FLAG_TRANSLATION));
   1048 }
   1049 
   1050 /**
   1051  * Multiply a matrix with a general scaling matrix.
   1052  *
   1053  * \param mat matrix.
   1054  * \param x x axis scale factor.
   1055  * \param y y axis scale factor.
   1056  * \param z z axis scale factor.
   1057  *
   1058  * Multiplies in-place the elements of \p mat by the scale factors. Checks if
   1059  * the scales factors are roughly the same, marking the MAT_FLAG_UNIFORM_SCALE
   1060  * flag, or MAT_FLAG_GENERAL_SCALE. Marks the MAT_DIRTY_TYPE and
   1061  * MAT_DIRTY_INVERSE dirty flags.
   1062  */
   1063 void
   1064 _math_matrix_scale( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
   1065 {
   1066    GLfloat *m = mat->m;
   1067    m[0] *= x;   m[4] *= y;   m[8]  *= z;
   1068    m[1] *= x;   m[5] *= y;   m[9]  *= z;
   1069    m[2] *= x;   m[6] *= y;   m[10] *= z;
   1070    m[3] *= x;   m[7] *= y;   m[11] *= z;
   1071 
   1072    if (FABSF(x - y) < 1e-8 && FABSF(x - z) < 1e-8)
   1073       mat->flags |= MAT_FLAG_UNIFORM_SCALE;
   1074    else
   1075       mat->flags |= MAT_FLAG_GENERAL_SCALE;
   1076 
   1077    mat->flags |= (MAT_DIRTY_TYPE |
   1078 		  MAT_DIRTY_INVERSE);
   1079 }
   1080 
   1081 /**
   1082  * Multiply a matrix with a translation matrix.
   1083  *
   1084  * \param mat matrix.
   1085  * \param x translation vector x coordinate.
   1086  * \param y translation vector y coordinate.
   1087  * \param z translation vector z coordinate.
   1088  *
   1089  * Adds the translation coordinates to the elements of \p mat in-place.  Marks
   1090  * the MAT_FLAG_TRANSLATION flag, and the MAT_DIRTY_TYPE and MAT_DIRTY_INVERSE
   1091  * dirty flags.
   1092  */
   1093 void
   1094 _math_matrix_translate( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
   1095 {
   1096    GLfloat *m = mat->m;
   1097    m[12] = m[0] * x + m[4] * y + m[8]  * z + m[12];
   1098    m[13] = m[1] * x + m[5] * y + m[9]  * z + m[13];
   1099    m[14] = m[2] * x + m[6] * y + m[10] * z + m[14];
   1100    m[15] = m[3] * x + m[7] * y + m[11] * z + m[15];
   1101 
   1102    mat->flags |= (MAT_FLAG_TRANSLATION |
   1103 		  MAT_DIRTY_TYPE |
   1104 		  MAT_DIRTY_INVERSE);
   1105 }
   1106 
   1107 
   1108 /**
   1109  * Set matrix to do viewport and depthrange mapping.
   1110  * Transforms Normalized Device Coords to window/Z values.
   1111  */
   1112 void
   1113 _math_matrix_viewport(GLmatrix *m, GLint x, GLint y, GLint width, GLint height,
   1114                       GLfloat zNear, GLfloat zFar, GLfloat depthMax)
   1115 {
   1116    m->m[MAT_SX] = (GLfloat) width / 2.0F;
   1117    m->m[MAT_TX] = m->m[MAT_SX] + x;
   1118    m->m[MAT_SY] = (GLfloat) height / 2.0F;
   1119    m->m[MAT_TY] = m->m[MAT_SY] + y;
   1120    m->m[MAT_SZ] = depthMax * ((zFar - zNear) / 2.0F);
   1121    m->m[MAT_TZ] = depthMax * ((zFar - zNear) / 2.0F + zNear);
   1122    m->flags = MAT_FLAG_GENERAL_SCALE | MAT_FLAG_TRANSLATION;
   1123    m->type = MATRIX_3D_NO_ROT;
   1124 }
   1125 
   1126 
   1127 /**
   1128  * Set a matrix to the identity matrix.
   1129  *
   1130  * \param mat matrix.
   1131  *
   1132  * Copies ::Identity into \p GLmatrix::m, and into GLmatrix::inv if not NULL.
   1133  * Sets the matrix type to identity, and clear the dirty flags.
   1134  */
   1135 void
   1136 _math_matrix_set_identity( GLmatrix *mat )
   1137 {
   1138    memcpy( mat->m, Identity, 16*sizeof(GLfloat) );
   1139    memcpy( mat->inv, Identity, 16*sizeof(GLfloat) );
   1140 
   1141    mat->type = MATRIX_IDENTITY;
   1142    mat->flags &= ~(MAT_DIRTY_FLAGS|
   1143 		   MAT_DIRTY_TYPE|
   1144 		   MAT_DIRTY_INVERSE);
   1145 }
   1146 
   1147 /*@}*/
   1148 
   1149 
   1150 /**********************************************************************/
   1151 /** \name Matrix analysis */
   1152 /*@{*/
   1153 
   1154 #define ZERO(x) (1<<x)
   1155 #define ONE(x)  (1<<(x+16))
   1156 
   1157 #define MASK_NO_TRX      (ZERO(12) | ZERO(13) | ZERO(14))
   1158 #define MASK_NO_2D_SCALE ( ONE(0)  | ONE(5))
   1159 
   1160 #define MASK_IDENTITY    ( ONE(0)  | ZERO(4)  | ZERO(8)  | ZERO(12) |\
   1161 			  ZERO(1)  |  ONE(5)  | ZERO(9)  | ZERO(13) |\
   1162 			  ZERO(2)  | ZERO(6)  |  ONE(10) | ZERO(14) |\
   1163 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
   1164 
   1165 #define MASK_2D_NO_ROT   (           ZERO(4)  | ZERO(8)  |           \
   1166 			  ZERO(1)  |            ZERO(9)  |           \
   1167 			  ZERO(2)  | ZERO(6)  |  ONE(10) | ZERO(14) |\
   1168 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
   1169 
   1170 #define MASK_2D          (                      ZERO(8)  |           \
   1171 			                        ZERO(9)  |           \
   1172 			  ZERO(2)  | ZERO(6)  |  ONE(10) | ZERO(14) |\
   1173 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
   1174 
   1175 
   1176 #define MASK_3D_NO_ROT   (           ZERO(4)  | ZERO(8)  |           \
   1177 			  ZERO(1)  |            ZERO(9)  |           \
   1178 			  ZERO(2)  | ZERO(6)  |                      \
   1179 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
   1180 
   1181 #define MASK_3D          (                                           \
   1182 			                                             \
   1183 			                                             \
   1184 			  ZERO(3)  | ZERO(7)  | ZERO(11) |  ONE(15) )
   1185 
   1186 
   1187 #define MASK_PERSPECTIVE (           ZERO(4)  |            ZERO(12) |\
   1188 			  ZERO(1)  |                       ZERO(13) |\
   1189 			  ZERO(2)  | ZERO(6)  |                      \
   1190 			  ZERO(3)  | ZERO(7)  |            ZERO(15) )
   1191 
   1192 #define SQ(x) ((x)*(x))
   1193 
   1194 /**
   1195  * Determine type and flags from scratch.
   1196  *
   1197  * \param mat matrix.
   1198  *
   1199  * This is expensive enough to only want to do it once.
   1200  */
   1201 static void analyse_from_scratch( GLmatrix *mat )
   1202 {
   1203    const GLfloat *m = mat->m;
   1204    GLuint mask = 0;
   1205    GLuint i;
   1206 
   1207    for (i = 0 ; i < 16 ; i++) {
   1208       if (m[i] == 0.0) mask |= (1<<i);
   1209    }
   1210 
   1211    if (m[0] == 1.0F) mask |= (1<<16);
   1212    if (m[5] == 1.0F) mask |= (1<<21);
   1213    if (m[10] == 1.0F) mask |= (1<<26);
   1214    if (m[15] == 1.0F) mask |= (1<<31);
   1215 
   1216    mat->flags &= ~MAT_FLAGS_GEOMETRY;
   1217 
   1218    /* Check for translation - no-one really cares
   1219     */
   1220    if ((mask & MASK_NO_TRX) != MASK_NO_TRX)
   1221       mat->flags |= MAT_FLAG_TRANSLATION;
   1222 
   1223    /* Do the real work
   1224     */
   1225    if (mask == (GLuint) MASK_IDENTITY) {
   1226       mat->type = MATRIX_IDENTITY;
   1227    }
   1228    else if ((mask & MASK_2D_NO_ROT) == (GLuint) MASK_2D_NO_ROT) {
   1229       mat->type = MATRIX_2D_NO_ROT;
   1230 
   1231       if ((mask & MASK_NO_2D_SCALE) != MASK_NO_2D_SCALE)
   1232 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
   1233    }
   1234    else if ((mask & MASK_2D) == (GLuint) MASK_2D) {
   1235       GLfloat mm = DOT2(m, m);
   1236       GLfloat m4m4 = DOT2(m+4,m+4);
   1237       GLfloat mm4 = DOT2(m,m+4);
   1238 
   1239       mat->type = MATRIX_2D;
   1240 
   1241       /* Check for scale */
   1242       if (SQ(mm-1) > SQ(1e-6) ||
   1243 	  SQ(m4m4-1) > SQ(1e-6))
   1244 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
   1245 
   1246       /* Check for rotation */
   1247       if (SQ(mm4) > SQ(1e-6))
   1248 	 mat->flags |= MAT_FLAG_GENERAL_3D;
   1249       else
   1250 	 mat->flags |= MAT_FLAG_ROTATION;
   1251 
   1252    }
   1253    else if ((mask & MASK_3D_NO_ROT) == (GLuint) MASK_3D_NO_ROT) {
   1254       mat->type = MATRIX_3D_NO_ROT;
   1255 
   1256       /* Check for scale */
   1257       if (SQ(m[0]-m[5]) < SQ(1e-6) &&
   1258 	  SQ(m[0]-m[10]) < SQ(1e-6)) {
   1259 	 if (SQ(m[0]-1.0) > SQ(1e-6)) {
   1260 	    mat->flags |= MAT_FLAG_UNIFORM_SCALE;
   1261          }
   1262       }
   1263       else {
   1264 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
   1265       }
   1266    }
   1267    else if ((mask & MASK_3D) == (GLuint) MASK_3D) {
   1268       GLfloat c1 = DOT3(m,m);
   1269       GLfloat c2 = DOT3(m+4,m+4);
   1270       GLfloat c3 = DOT3(m+8,m+8);
   1271       GLfloat d1 = DOT3(m, m+4);
   1272       GLfloat cp[3];
   1273 
   1274       mat->type = MATRIX_3D;
   1275 
   1276       /* Check for scale */
   1277       if (SQ(c1-c2) < SQ(1e-6) && SQ(c1-c3) < SQ(1e-6)) {
   1278 	 if (SQ(c1-1.0) > SQ(1e-6))
   1279 	    mat->flags |= MAT_FLAG_UNIFORM_SCALE;
   1280 	 /* else no scale at all */
   1281       }
   1282       else {
   1283 	 mat->flags |= MAT_FLAG_GENERAL_SCALE;
   1284       }
   1285 
   1286       /* Check for rotation */
   1287       if (SQ(d1) < SQ(1e-6)) {
   1288 	 CROSS3( cp, m, m+4 );
   1289 	 SUB_3V( cp, cp, (m+8) );
   1290 	 if (LEN_SQUARED_3FV(cp) < SQ(1e-6))
   1291 	    mat->flags |= MAT_FLAG_ROTATION;
   1292 	 else
   1293 	    mat->flags |= MAT_FLAG_GENERAL_3D;
   1294       }
   1295       else {
   1296 	 mat->flags |= MAT_FLAG_GENERAL_3D; /* shear, etc */
   1297       }
   1298    }
   1299    else if ((mask & MASK_PERSPECTIVE) == MASK_PERSPECTIVE && m[11]==-1.0F) {
   1300       mat->type = MATRIX_PERSPECTIVE;
   1301       mat->flags |= MAT_FLAG_GENERAL;
   1302    }
   1303    else {
   1304       mat->type = MATRIX_GENERAL;
   1305       mat->flags |= MAT_FLAG_GENERAL;
   1306    }
   1307 }
   1308 
   1309 /**
   1310  * Analyze a matrix given that its flags are accurate.
   1311  *
   1312  * This is the more common operation, hopefully.
   1313  */
   1314 static void analyse_from_flags( GLmatrix *mat )
   1315 {
   1316    const GLfloat *m = mat->m;
   1317 
   1318    if (TEST_MAT_FLAGS(mat, 0)) {
   1319       mat->type = MATRIX_IDENTITY;
   1320    }
   1321    else if (TEST_MAT_FLAGS(mat, (MAT_FLAG_TRANSLATION |
   1322 				 MAT_FLAG_UNIFORM_SCALE |
   1323 				 MAT_FLAG_GENERAL_SCALE))) {
   1324       if ( m[10]==1.0F && m[14]==0.0F ) {
   1325 	 mat->type = MATRIX_2D_NO_ROT;
   1326       }
   1327       else {
   1328 	 mat->type = MATRIX_3D_NO_ROT;
   1329       }
   1330    }
   1331    else if (TEST_MAT_FLAGS(mat, MAT_FLAGS_3D)) {
   1332       if (                                 m[ 8]==0.0F
   1333             &&                             m[ 9]==0.0F
   1334             && m[2]==0.0F && m[6]==0.0F && m[10]==1.0F && m[14]==0.0F) {
   1335 	 mat->type = MATRIX_2D;
   1336       }
   1337       else {
   1338 	 mat->type = MATRIX_3D;
   1339       }
   1340    }
   1341    else if (                 m[4]==0.0F                 && m[12]==0.0F
   1342             && m[1]==0.0F                               && m[13]==0.0F
   1343             && m[2]==0.0F && m[6]==0.0F
   1344             && m[3]==0.0F && m[7]==0.0F && m[11]==-1.0F && m[15]==0.0F) {
   1345       mat->type = MATRIX_PERSPECTIVE;
   1346    }
   1347    else {
   1348       mat->type = MATRIX_GENERAL;
   1349    }
   1350 }
   1351 
   1352 /**
   1353  * Analyze and update a matrix.
   1354  *
   1355  * \param mat matrix.
   1356  *
   1357  * If the matrix type is dirty then calls either analyse_from_scratch() or
   1358  * analyse_from_flags() to determine its type, according to whether the flags
   1359  * are dirty or not, respectively. If the matrix has an inverse and it's dirty
   1360  * then calls matrix_invert(). Finally clears the dirty flags.
   1361  */
   1362 void
   1363 _math_matrix_analyse( GLmatrix *mat )
   1364 {
   1365    if (mat->flags & MAT_DIRTY_TYPE) {
   1366       if (mat->flags & MAT_DIRTY_FLAGS)
   1367 	 analyse_from_scratch( mat );
   1368       else
   1369 	 analyse_from_flags( mat );
   1370    }
   1371 
   1372    if (mat->inv && (mat->flags & MAT_DIRTY_INVERSE)) {
   1373       matrix_invert( mat );
   1374       mat->flags &= ~MAT_DIRTY_INVERSE;
   1375    }
   1376 
   1377    mat->flags &= ~(MAT_DIRTY_FLAGS | MAT_DIRTY_TYPE);
   1378 }
   1379 
   1380 /*@}*/
   1381 
   1382 
   1383 /**
   1384  * Test if the given matrix preserves vector lengths.
   1385  */
   1386 GLboolean
   1387 _math_matrix_is_length_preserving( const GLmatrix *m )
   1388 {
   1389    return TEST_MAT_FLAGS( m, MAT_FLAGS_LENGTH_PRESERVING);
   1390 }
   1391 
   1392 
   1393 /**
   1394  * Test if the given matrix does any rotation.
   1395  * (or perhaps if the upper-left 3x3 is non-identity)
   1396  */
   1397 GLboolean
   1398 _math_matrix_has_rotation( const GLmatrix *m )
   1399 {
   1400    if (m->flags & (MAT_FLAG_GENERAL |
   1401                    MAT_FLAG_ROTATION |
   1402                    MAT_FLAG_GENERAL_3D |
   1403                    MAT_FLAG_PERSPECTIVE))
   1404       return GL_TRUE;
   1405    else
   1406       return GL_FALSE;
   1407 }
   1408 
   1409 
   1410 GLboolean
   1411 _math_matrix_is_general_scale( const GLmatrix *m )
   1412 {
   1413    return (m->flags & MAT_FLAG_GENERAL_SCALE) ? GL_TRUE : GL_FALSE;
   1414 }
   1415 
   1416 
   1417 GLboolean
   1418 _math_matrix_is_dirty( const GLmatrix *m )
   1419 {
   1420    return (m->flags & MAT_DIRTY) ? GL_TRUE : GL_FALSE;
   1421 }
   1422 
   1423 
   1424 /**********************************************************************/
   1425 /** \name Matrix setup */
   1426 /*@{*/
   1427 
   1428 /**
   1429  * Copy a matrix.
   1430  *
   1431  * \param to destination matrix.
   1432  * \param from source matrix.
   1433  *
   1434  * Copies all fields in GLmatrix, creating an inverse array if necessary.
   1435  */
   1436 void
   1437 _math_matrix_copy( GLmatrix *to, const GLmatrix *from )
   1438 {
   1439    memcpy( to->m, from->m, sizeof(Identity) );
   1440    memcpy(to->inv, from->inv, 16 * sizeof(GLfloat));
   1441    to->flags = from->flags;
   1442    to->type = from->type;
   1443 }
   1444 
   1445 /**
   1446  * Loads a matrix array into GLmatrix.
   1447  *
   1448  * \param m matrix array.
   1449  * \param mat matrix.
   1450  *
   1451  * Copies \p m into GLmatrix::m and marks the MAT_FLAG_GENERAL and MAT_DIRTY
   1452  * flags.
   1453  */
   1454 void
   1455 _math_matrix_loadf( GLmatrix *mat, const GLfloat *m )
   1456 {
   1457    memcpy( mat->m, m, 16*sizeof(GLfloat) );
   1458    mat->flags = (MAT_FLAG_GENERAL | MAT_DIRTY);
   1459 }
   1460 
   1461 /**
   1462  * Matrix constructor.
   1463  *
   1464  * \param m matrix.
   1465  *
   1466  * Initialize the GLmatrix fields.
   1467  */
   1468 void
   1469 _math_matrix_ctr( GLmatrix *m )
   1470 {
   1471    m->m = (GLfloat *) _mesa_align_malloc( 16 * sizeof(GLfloat), 16 );
   1472    if (m->m)
   1473       memcpy( m->m, Identity, sizeof(Identity) );
   1474    m->inv = (GLfloat *) _mesa_align_malloc( 16 * sizeof(GLfloat), 16 );
   1475    if (m->inv)
   1476       memcpy( m->inv, Identity, sizeof(Identity) );
   1477    m->type = MATRIX_IDENTITY;
   1478    m->flags = 0;
   1479 }
   1480 
   1481 /**
   1482  * Matrix destructor.
   1483  *
   1484  * \param m matrix.
   1485  *
   1486  * Frees the data in a GLmatrix.
   1487  */
   1488 void
   1489 _math_matrix_dtr( GLmatrix *m )
   1490 {
   1491    if (m->m) {
   1492       _mesa_align_free( m->m );
   1493       m->m = NULL;
   1494    }
   1495    if (m->inv) {
   1496       _mesa_align_free( m->inv );
   1497       m->inv = NULL;
   1498    }
   1499 }
   1500 
   1501 /*@}*/
   1502 
   1503 
   1504 /**********************************************************************/
   1505 /** \name Matrix transpose */
   1506 /*@{*/
   1507 
   1508 /**
   1509  * Transpose a GLfloat matrix.
   1510  *
   1511  * \param to destination array.
   1512  * \param from source array.
   1513  */
   1514 void
   1515 _math_transposef( GLfloat to[16], const GLfloat from[16] )
   1516 {
   1517    to[0] = from[0];
   1518    to[1] = from[4];
   1519    to[2] = from[8];
   1520    to[3] = from[12];
   1521    to[4] = from[1];
   1522    to[5] = from[5];
   1523    to[6] = from[9];
   1524    to[7] = from[13];
   1525    to[8] = from[2];
   1526    to[9] = from[6];
   1527    to[10] = from[10];
   1528    to[11] = from[14];
   1529    to[12] = from[3];
   1530    to[13] = from[7];
   1531    to[14] = from[11];
   1532    to[15] = from[15];
   1533 }
   1534 
   1535 /**
   1536  * Transpose a GLdouble matrix.
   1537  *
   1538  * \param to destination array.
   1539  * \param from source array.
   1540  */
   1541 void
   1542 _math_transposed( GLdouble to[16], const GLdouble from[16] )
   1543 {
   1544    to[0] = from[0];
   1545    to[1] = from[4];
   1546    to[2] = from[8];
   1547    to[3] = from[12];
   1548    to[4] = from[1];
   1549    to[5] = from[5];
   1550    to[6] = from[9];
   1551    to[7] = from[13];
   1552    to[8] = from[2];
   1553    to[9] = from[6];
   1554    to[10] = from[10];
   1555    to[11] = from[14];
   1556    to[12] = from[3];
   1557    to[13] = from[7];
   1558    to[14] = from[11];
   1559    to[15] = from[15];
   1560 }
   1561 
   1562 /**
   1563  * Transpose a GLdouble matrix and convert to GLfloat.
   1564  *
   1565  * \param to destination array.
   1566  * \param from source array.
   1567  */
   1568 void
   1569 _math_transposefd( GLfloat to[16], const GLdouble from[16] )
   1570 {
   1571    to[0] = (GLfloat) from[0];
   1572    to[1] = (GLfloat) from[4];
   1573    to[2] = (GLfloat) from[8];
   1574    to[3] = (GLfloat) from[12];
   1575    to[4] = (GLfloat) from[1];
   1576    to[5] = (GLfloat) from[5];
   1577    to[6] = (GLfloat) from[9];
   1578    to[7] = (GLfloat) from[13];
   1579    to[8] = (GLfloat) from[2];
   1580    to[9] = (GLfloat) from[6];
   1581    to[10] = (GLfloat) from[10];
   1582    to[11] = (GLfloat) from[14];
   1583    to[12] = (GLfloat) from[3];
   1584    to[13] = (GLfloat) from[7];
   1585    to[14] = (GLfloat) from[11];
   1586    to[15] = (GLfloat) from[15];
   1587 }
   1588 
   1589 /*@}*/
   1590 
   1591 
   1592 /**
   1593  * Transform a 4-element row vector (1x4 matrix) by a 4x4 matrix.  This
   1594  * function is used for transforming clipping plane equations and spotlight
   1595  * directions.
   1596  * Mathematically,  u = v * m.
   1597  * Input:  v - input vector
   1598  *         m - transformation matrix
   1599  * Output:  u - transformed vector
   1600  */
   1601 void
   1602 _mesa_transform_vector( GLfloat u[4], const GLfloat v[4], const GLfloat m[16] )
   1603 {
   1604    const GLfloat v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
   1605 #define M(row,col)  m[row + col*4]
   1606    u[0] = v0 * M(0,0) + v1 * M(1,0) + v2 * M(2,0) + v3 * M(3,0);
   1607    u[1] = v0 * M(0,1) + v1 * M(1,1) + v2 * M(2,1) + v3 * M(3,1);
   1608    u[2] = v0 * M(0,2) + v1 * M(1,2) + v2 * M(2,2) + v3 * M(3,2);
   1609    u[3] = v0 * M(0,3) + v1 * M(1,3) + v2 * M(2,3) + v3 * M(3,3);
   1610 #undef M
   1611 }
   1612