diff options
Diffstat (limited to 'src/mesa/math/m_matrix.c')
| -rw-r--r-- | src/mesa/math/m_matrix.c | 252 |
1 files changed, 155 insertions, 97 deletions
diff --git a/src/mesa/math/m_matrix.c b/src/mesa/math/m_matrix.c index 2a69336b4db..95b6ebed569 100644 --- a/src/mesa/math/m_matrix.c +++ b/src/mesa/math/m_matrix.c @@ -1,8 +1,8 @@ -/* $Id: m_matrix.c,v 1.12 2002/06/29 19:48:17 brianp Exp $ */ +/* $Id: m_matrix.c,v 1.13 2002/09/12 16:26:04 brianp Exp $ */ /* * Mesa 3-D graphics library - * Version: 4.0.2 + * Version: 4.1 * * Copyright (C) 1999-2002 Brian Paul All Rights Reserved. * @@ -539,123 +539,181 @@ static GLboolean matrix_invert( GLmatrix *mat ) /* * Generate a 4x4 transformation matrix from glRotate parameters, and * postmultiply the input matrix by it. + * This function contributed by Erich Boleyn ([email protected]). + * Optimizatios contributed by Rudolf Opalla ([email protected]). */ void _math_matrix_rotate( GLmatrix *mat, GLfloat angle, GLfloat x, GLfloat y, GLfloat z ) { - /* This function contributed by Erich Boleyn ([email protected]) */ - GLfloat mag, s, c; - GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c; + GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c, s, c; GLfloat m[16]; + GLboolean optimized; s = (GLfloat) sin( angle * DEG2RAD ); c = (GLfloat) cos( angle * DEG2RAD ); - mag = (GLfloat) GL_SQRT( x*x + y*y + z*z ); + MEMCPY(m, Identity, sizeof(GLfloat)*16); + optimized = GL_FALSE; - if (mag <= 1.0e-4) { - /* generate an identity matrix and return */ - MEMCPY(m, Identity, sizeof(GLfloat)*16); - return; - } +#define M(row,col) m[col*4+row] - x /= mag; - y /= mag; - z /= mag; + if (x == 0.0F) { + if (y == 0.0F) { + if (z != 0.0F) { + optimized = GL_TRUE; + /* rotate only around z-axis */ + M(0,0) = c; + M(1,1) = c; + if (z < 0.0F) { + M(0,1) = s; + M(1,0) = -s; + } + else { + M(0,1) = -s; + M(1,0) = s; + } + } + } + else if (z == 0.0F) { + optimized = GL_TRUE; + /* rotate only around y-axis */ + M(0,0) = c; + M(2,2) = c; + if (y < 0.0F) { + M(0,2) = -s; + M(2,0) = s; + } + else { + M(0,2) = s; + M(2,0) = -s; + } + } + } + else if (y == 0.0F) { + if (z == 0.0F) { + optimized = GL_TRUE; + /* rotate only around x-axis */ + M(1,1) = c; + M(2,2) = c; + if (y < 0.0F) { + M(1,2) = s; + M(2,1) = -s; + } + else { + M(1,2) = -s; + M(2,1) = s; + } + } + } -#define M(row,col) m[col*4+row] + if (!optimized) { + const GLfloat mag = (GLfloat) GL_SQRT(x * x + y * y + z * z); - /* - * Arbitrary axis rotation matrix. - * - * This is composed of 5 matrices, Rz, Ry, T, Ry', Rz', multiplied - * like so: Rz * Ry * T * Ry' * Rz'. T is the final rotation - * (which is about the X-axis), and the two composite transforms - * Ry' * Rz' and Rz * Ry are (respectively) the rotations necessary - * from the arbitrary axis to the X-axis then back. They are - * all elementary rotations. - * - * Rz' is a rotation about the Z-axis, to bring the axis vector - * into the x-z plane. Then Ry' is applied, rotating about the - * Y-axis to bring the axis vector parallel with the X-axis. The - * rotation about the X-axis is then performed. Ry and Rz are - * simply the respective inverse transforms to bring the arbitrary - * axis back to it's original orientation. The first transforms - * Rz' and Ry' are considered inverses, since the data from the - * arbitrary axis gives you info on how to get to it, not how - * to get away from it, and an inverse must be applied. - * - * The basic calculation used is to recognize that the arbitrary - * axis vector (x, y, z), since it is of unit length, actually - * represents the sines and cosines of the angles to rotate the - * X-axis to the same orientation, with theta being the angle about - * Z and phi the angle about Y (in the order described above) - * as follows: - * - * cos ( theta ) = x / sqrt ( 1 - z^2 ) - * sin ( theta ) = y / sqrt ( 1 - z^2 ) - * - * cos ( phi ) = sqrt ( 1 - z^2 ) - * sin ( phi ) = z - * - * Note that cos ( phi ) can further be inserted to the above - * formulas: - * - * cos ( theta ) = x / cos ( phi ) - * sin ( theta ) = y / sin ( phi ) - * - * ...etc. Because of those relations and the standard trigonometric - * relations, it is pssible to reduce the transforms down to what - * is used below. It may be that any primary axis chosen will give the - * same results (modulo a sign convention) using thie method. - * - * Particularly nice is to notice that all divisions that might - * have caused trouble when parallel to certain planes or - * axis go away with care paid to reducing the expressions. - * After checking, it does perform correctly under all cases, since - * in all the cases of division where the denominator would have - * been zero, the numerator would have been zero as well, giving - * the expected result. - */ + if (mag <= 1.0e-4) { + /* no rotation, leave mat as-is */ + return; + } - xx = x * x; - yy = y * y; - zz = z * z; - xy = x * y; - yz = y * z; - zx = z * x; - xs = x * s; - ys = y * s; - zs = z * s; - one_c = 1.0F - c; - - M(0,0) = (one_c * xx) + c; - M(0,1) = (one_c * xy) - zs; - M(0,2) = (one_c * zx) + ys; - M(0,3) = 0.0F; - - M(1,0) = (one_c * xy) + zs; - M(1,1) = (one_c * yy) + c; - M(1,2) = (one_c * yz) - xs; - M(1,3) = 0.0F; - - M(2,0) = (one_c * zx) - ys; - M(2,1) = (one_c * yz) + xs; - M(2,2) = (one_c * zz) + c; - M(2,3) = 0.0F; - - M(3,0) = 0.0F; - M(3,1) = 0.0F; - M(3,2) = 0.0F; - M(3,3) = 1.0F; + x /= mag; + y /= mag; + z /= mag; + + + /* + * Arbitrary axis rotation matrix. + * + * This is composed of 5 matrices, Rz, Ry, T, Ry', Rz', multiplied + * like so: Rz * Ry * T * Ry' * Rz'. T is the final rotation + * (which is about the X-axis), and the two composite transforms + * Ry' * Rz' and Rz * Ry are (respectively) the rotations necessary + * from the arbitrary axis to the X-axis then back. They are + * all elementary rotations. + * + * Rz' is a rotation about the Z-axis, to bring the axis vector + * into the x-z plane. Then Ry' is applied, rotating about the + * Y-axis to bring the axis vector parallel with the X-axis. The + * rotation about the X-axis is then performed. Ry and Rz are + * simply the respective inverse transforms to bring the arbitrary + * axis back to it's original orientation. The first transforms + * Rz' and Ry' are considered inverses, since the data from the + * arbitrary axis gives you info on how to get to it, not how + * to get away from it, and an inverse must be applied. + * + * The basic calculation used is to recognize that the arbitrary + * axis vector (x, y, z), since it is of unit length, actually + * represents the sines and cosines of the angles to rotate the + * X-axis to the same orientation, with theta being the angle about + * Z and phi the angle about Y (in the order described above) + * as follows: + * + * cos ( theta ) = x / sqrt ( 1 - z^2 ) + * sin ( theta ) = y / sqrt ( 1 - z^2 ) + * + * cos ( phi ) = sqrt ( 1 - z^2 ) + * sin ( phi ) = z + * + * Note that cos ( phi ) can further be inserted to the above + * formulas: + * + * cos ( theta ) = x / cos ( phi ) + * sin ( theta ) = y / sin ( phi ) + * + * ...etc. Because of those relations and the standard trigonometric + * relations, it is pssible to reduce the transforms down to what + * is used below. It may be that any primary axis chosen will give the + * same results (modulo a sign convention) using thie method. + * + * Particularly nice is to notice that all divisions that might + * have caused trouble when parallel to certain planes or + * axis go away with care paid to reducing the expressions. + * After checking, it does perform correctly under all cases, since + * in all the cases of division where the denominator would have + * been zero, the numerator would have been zero as well, giving + * the expected result. + */ + + xx = x * x; + yy = y * y; + zz = z * z; + xy = x * y; + yz = y * z; + zx = z * x; + xs = x * s; + ys = y * s; + zs = z * s; + one_c = 1.0F - c; + + /* We already hold the identity-matrix so we can skip some statements */ + M(0,0) = (one_c * xx) + c; + M(0,1) = (one_c * xy) - zs; + M(0,2) = (one_c * zx) + ys; +/* M(0,3) = 0.0F; */ + + M(1,0) = (one_c * xy) + zs; + M(1,1) = (one_c * yy) + c; + M(1,2) = (one_c * yz) - xs; +/* M(1,3) = 0.0F; */ + + M(2,0) = (one_c * zx) - ys; + M(2,1) = (one_c * yz) + xs; + M(2,2) = (one_c * zz) + c; +/* M(2,3) = 0.0F; */ +/* + M(3,0) = 0.0F; + M(3,1) = 0.0F; + M(3,2) = 0.0F; + M(3,3) = 1.0F; +*/ + } #undef M matrix_multf( mat, m, MAT_FLAG_ROTATION ); } + void _math_matrix_frustum( GLmatrix *mat, GLfloat left, GLfloat right, |