diff options
Diffstat (limited to 'libdimension/sphere.c')
| -rw-r--r-- | libdimension/sphere.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/libdimension/sphere.c b/libdimension/sphere.c index 09b6767..94ae44e 100644 --- a/libdimension/sphere.c +++ b/libdimension/sphere.c @@ -19,7 +19,7 @@ *************************************************************************/ #include "dimension.h" -#include <math.h> /* For sqrt */ +#include <math.h> /* For sqrt */ /* * Sphere @@ -50,13 +50,13 @@ static bool dmnsn_sphere_intersection_fn(const dmnsn_object *sphere, dmnsn_line line, dmnsn_intersection *intersection) { - double a, b, c, t; - + dmnsn_line l = dmnsn_matrix_line_mul(sphere->trans_inv, line); + /* Solve (x0 + nx*t)^2 + (y0 + ny*t)^2 + (z0 + nz*t)^2 == 1 */ - - a = line.n.x*line.n.x + line.n.y*line.n.y + line.n.z*line.n.z; - b = 2.0*(line.n.x*line.x0.x + line.n.y*line.x0.y + line.n.z*line.x0.z); - c = line.x0.x*line.x0.x + line.x0.y*line.x0.y + line.x0.z*line.x0.z - 1.0; + double a, b, c, t; + a = l.n.x*l.n.x + l.n.y*l.n.y + l.n.z*l.n.z; + b = 2.0*(l.n.x*l.x0.x + l.n.y*l.x0.y + l.n.z*l.x0.z); + c = l.x0.x*l.x0.x + l.x0.y*l.x0.y + l.x0.z*l.x0.z - 1.0; if (b*b - 4.0*a*c >= 0) { t = (-b - sqrt(b*b - 4.0*a*c))/(2*a); @@ -67,7 +67,8 @@ dmnsn_sphere_intersection_fn(const dmnsn_object *sphere, dmnsn_line line, if (t >= 0.0) { intersection->ray = line; intersection->t = t; - intersection->normal = dmnsn_line_point(line, t); + intersection->normal = dmnsn_matrix_normal_mul(sphere->trans, + dmnsn_line_point(l, t)); intersection->texture = sphere->texture; intersection->interior = sphere->interior; return true; @@ -81,5 +82,6 @@ dmnsn_sphere_intersection_fn(const dmnsn_object *sphere, dmnsn_line line, static bool dmnsn_sphere_inside_fn(const dmnsn_object *sphere, dmnsn_vector point) { + point = dmnsn_matrix_vector_mul(sphere->trans_inv, point); return point.x*point.x + point.y*point.y + point.z*point.z < 1.0; } |