ref: f03aac3fa4e87533f0606b6d28a594504d1b0d1f
dir: /src/zmath.c/
/* Some simple mathematical functions. Don't look for some logic in the function names :-) */ #include "zmath.h" #include <math.h> #include <stdlib.h> #include <string.h> /* ******* Gestion des matrices 4x4 ****** */ void gl_M4_Id(M4* a) { GLint i, j; for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) if (i == j) a->m[i][j] = 1.0; else a->m[i][j] = 0.0; } int gl_M4_IsId(M4* a) { GLint i, j; for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) { if (i == j) { if (a->m[i][j] != 1.0) return 0; } else if (a->m[i][j] != 0.0) return 0; } return 1; } void gl_M4_Mul(M4* c, M4* a, M4* b) { GLint i, j, k; GLfloat s; for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) { s = 0.0; for (k = 0; k < 4; k++) s += a->m[i][k] * b->m[k][j]; c->m[i][j] = s; } } /* c=c*a */ void gl_M4_MulLeft(M4* c, M4* b) { GLint i, j, k; GLfloat s; M4 a; /*memcpy(&a, c, 16*sizeof(GLfloat)); */ a = *c; for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) { s = 0.0; for (k = 0; k < 4; k++) s += a.m[i][k] * b->m[k][j]; c->m[i][j] = s; } } void gl_M4_Move(M4* a, M4* b) { memcpy(a, b, sizeof(M4)); } void gl_MoveV3(V3* a, V3* b) { memcpy(a, b, sizeof(V3)); } void gl_MulM4V3(V3* a, M4* b, V3* c) { a->X = b->m[0][0] * c->X + b->m[0][1] * c->Y + b->m[0][2] * c->Z + b->m[0][3]; a->Y = b->m[1][0] * c->X + b->m[1][1] * c->Y + b->m[1][2] * c->Z + b->m[1][3]; a->Z = b->m[2][0] * c->X + b->m[2][1] * c->Y + b->m[2][2] * c->Z + b->m[2][3]; } void gl_MulM3V3(V3* a, M4* b, V3* c) { a->X = b->m[0][0] * c->X + b->m[0][1] * c->Y + b->m[0][2] * c->Z; a->Y = b->m[1][0] * c->X + b->m[1][1] * c->Y + b->m[1][2] * c->Z; a->Z = b->m[2][0] * c->X + b->m[2][1] * c->Y + b->m[2][2] * c->Z; } void gl_M4_MulV4(V4* a, M4* b, V4* c) { a->X = b->m[0][0] * c->X + b->m[0][1] * c->Y + b->m[0][2] * c->Z + b->m[0][3] * c->W; a->Y = b->m[1][0] * c->X + b->m[1][1] * c->Y + b->m[1][2] * c->Z + b->m[1][3] * c->W; a->Z = b->m[2][0] * c->X + b->m[2][1] * c->Y + b->m[2][2] * c->Z + b->m[2][3] * c->W; a->W = b->m[3][0] * c->X + b->m[3][1] * c->Y + b->m[3][2] * c->Z + b->m[3][3] * c->W; } /* transposition of a 4x4 matrix */ void gl_M4_Transpose(M4* a, M4* b) { a->m[0][0] = b->m[0][0]; a->m[0][1] = b->m[1][0]; a->m[0][2] = b->m[2][0]; a->m[0][3] = b->m[3][0]; a->m[1][0] = b->m[0][1]; a->m[1][1] = b->m[1][1]; a->m[1][2] = b->m[2][1]; a->m[1][3] = b->m[3][1]; a->m[2][0] = b->m[0][2]; a->m[2][1] = b->m[1][2]; a->m[2][2] = b->m[2][2]; a->m[2][3] = b->m[3][2]; a->m[3][0] = b->m[0][3]; a->m[3][1] = b->m[1][3]; a->m[3][2] = b->m[2][3]; a->m[3][3] = b->m[3][3]; } /* inversion of an orthogonal matrix of type Y=M.X+P */ void gl_M4_InvOrtho(M4* a, M4 b) { GLint i, j; GLfloat s; for (i = 0; i < 3; i++) for (j = 0; j < 3; j++) a->m[i][j] = b.m[j][i]; a->m[3][0] = 0.0; a->m[3][1] = 0.0; a->m[3][2] = 0.0; a->m[3][3] = 1.0; for (i = 0; i < 3; i++) { s = 0; for (j = 0; j < 3; j++) s -= b.m[j][i] * b.m[j][3]; a->m[i][3] = s; } } /* Inversion of a general nxn matrix. Note : m is destroyed */ int Matrix_Inv(GLfloat* r, GLfloat* m, GLint n) { GLint i, j, k, l; GLfloat max, tmp, t; /* identit�e dans r */ for (i = 0; i < n * n; i++) r[i] = 0; for (i = 0; i < n; i++) r[i * n + i] = 1; for (j = 0; j < n; j++) { /* recherche du nombre de plus grand module sur la colonne j */ max = m[j * n + j]; k = j; for (i = j + 1; i < n; i++) if (fabs(m[i * n + j]) > fabs(max)) { k = i; max = m[i * n + j]; } /* non GLintersible matrix */ if (max == 0) return 1; /* permutation des lignes j et k */ if (k != j) { for (i = 0; i < n; i++) { tmp = m[j * n + i]; m[j * n + i] = m[k * n + i]; m[k * n + i] = tmp; tmp = r[j * n + i]; r[j * n + i] = r[k * n + i]; r[k * n + i] = tmp; } } /* multiplication de la ligne j par 1/max */ max = 1 / max; for (i = 0; i < n; i++) { m[j * n + i] *= max; r[j * n + i] *= max; } for (l = 0; l < n; l++) if (l != j) { t = m[l * n + j]; for (i = 0; i < n; i++) { m[l * n + i] -= m[j * n + i] * t; r[l * n + i] -= r[j * n + i] * t; } } } return 0; } /* inversion of a 4x4 matrix */ void gl_M4_Inv(M4* a, M4* b) { M4 tmp; memcpy(&tmp, b, 16 * sizeof(GLfloat)); /*tmp=*b;*/ Matrix_Inv(&a->m[0][0], &tmp.m[0][0], 4); } void gl_M4_Rotate(M4* a, GLfloat t, GLint u) { GLfloat s, c; GLint v, w; if ((v = u + 1) > 2) v = 0; if ((w = v + 1) > 2) w = 0; s = sin(t); c = cos(t); gl_M4_Id(a); a->m[v][v] = c; a->m[v][w] = -s; a->m[w][v] = s; a->m[w][w] = c; } /* inverse of a 3x3 matrix */ void gl_M3_Inv(M3* a, M3* m) { GLfloat det; det = m->m[0][0] * m->m[1][1] * m->m[2][2] - m->m[0][0] * m->m[1][2] * m->m[2][1] - m->m[1][0] * m->m[0][1] * m->m[2][2] + m->m[1][0] * m->m[0][2] * m->m[2][1] + m->m[2][0] * m->m[0][1] * m->m[1][2] - m->m[2][0] * m->m[0][2] * m->m[1][1]; a->m[0][0] = (m->m[1][1] * m->m[2][2] - m->m[1][2] * m->m[2][1]) / det; a->m[0][1] = -(m->m[0][1] * m->m[2][2] - m->m[0][2] * m->m[2][1]) / det; a->m[0][2] = -(-m->m[0][1] * m->m[1][2] + m->m[0][2] * m->m[1][1]) / det; a->m[1][0] = -(m->m[1][0] * m->m[2][2] - m->m[1][2] * m->m[2][0]) / det; a->m[1][1] = (m->m[0][0] * m->m[2][2] - m->m[0][2] * m->m[2][0]) / det; a->m[1][2] = -(m->m[0][0] * m->m[1][2] - m->m[0][2] * m->m[1][0]) / det; a->m[2][0] = (m->m[1][0] * m->m[2][1] - m->m[1][1] * m->m[2][0]) / det; a->m[2][1] = -(m->m[0][0] * m->m[2][1] - m->m[0][1] * m->m[2][0]) / det; a->m[2][2] = (m->m[0][0] * m->m[1][1] - m->m[0][1] * m->m[1][0]) / det; } /* vector arithmetic */ int gl_V3_Norm(V3* a) { GLfloat n; n = sqrt(a->X * a->X + a->Y * a->Y + a->Z * a->Z); if (n == 0) return 1; a->X /= n; a->Y /= n; a->Z /= n; return 0; } V3 gl_V3_New(GLfloat x, GLfloat y, GLfloat z) { V3 a; a.X = x; a.Y = y; a.Z = z; return a; } V4 gl_V4_New(GLfloat x, GLfloat y, GLfloat z, GLfloat w) { V4 a; a.X = x; a.Y = y; a.Z = z; a.W = w; return a; }