* 5.c Closest points
* 5.d Raycast & Spherecasts
* 5.e Curves
+ * 5.f Volumes
* 6. Statistics
* 6.a Random numbers
**/
#define VG_PIf 3.14159265358979323846264338327950288f
#define VG_TAUf 6.28318530717958647692528676655900576f
+
/*
* -----------------------------------------------------------------------------
* Section 0. Misc Operations
return ((vg_ftu32(a)) & 0x7F800000U) != 0x7F800000U;
}
+static int v3_valid( v3f a ){
+ for( u32 i=0; i<3; i++ )
+ if( !vg_validf(a[i]) ) return 0;
+ return 1;
+}
+
/*
* -----------------------------------------------------------------------------
* Section 1. Scalar Operations
return deg * VG_PIf / 180.0f;
}
+/* angle to reach b from a */
+static f32 vg_angle_diff( f32 a, f32 b ){
+ f32 d = fmod(b,VG_TAUf)-fmodf(a,VG_TAUf);
+ if( fabsf(d) > VG_PIf )
+ d = -vg_signf(d) * (VG_TAUf - fabsf(d));
+
+ return d;
+}
+
+/*
+ * quantize float to bit count
+ */
+static u32 vg_quantf( f32 a, u32 bits, f32 min, f32 max ){
+ u32 mask = (0x1 << bits) - 1;
+ return vg_clampf((a - min) * ((f32)mask/(max-min)), 0.0f, mask );
+}
+
+/*
+ * un-quantize discreet to float
+ */
+static f32 vg_dequantf( u32 q, u32 bits, f32 min, f32 max ){
+ u32 mask = (0x1 << bits) - 1;
+ return min + (f32)q * ((max-min) / (f32)mask);
+}
+
/*
* -----------------------------------------------------------------------------
* Section 2.a 2D Vectors
v3_muls( a, 1.f / v3_length( a ), a );
}
-static inline f32 vg_lerpf( f32 a, f32 b, f32 t )
-{
+static inline f32 vg_lerpf( f32 a, f32 b, f32 t ){
return a + t*(b-a);
}
return a + t*(b-a);
}
+static inline void vg_slewf( f32 *a, f32 b, f32 speed ){
+ f32 d = vg_signf( b-*a ),
+ c = *a + d*speed;
+ *a = vg_minf( b*d, c*d ) * d;
+}
+
+static inline f32 vg_smoothstepf( f32 x ){
+ return x*x*(3.0f - 2.0f*x);
+}
+
+
/* correctly lerp around circular period -pi -> pi */
static f32 vg_alerpf( f32 a, f32 b, f32 t )
{
v3_add( v1, v2, d );
}
+static void v3_tangent_basis( v3f n, v3f tx, v3f ty ){
+ /* Compute tangent basis (box2d) */
+ if( fabsf( n[0] ) >= 0.57735027f ){
+ tx[0] = n[1];
+ tx[1] = -n[0];
+ tx[2] = 0.0f;
+ }
+ else{
+ tx[0] = 0.0f;
+ tx[1] = n[2];
+ tx[2] = -n[1];
+ }
+
+ v3_normalize( tx );
+ v3_cross( n, tx, ty );
+}
+
+/*
+ * Compute yaw and pitch based of a normalized vector representing forward
+ * forward: -z
+ * result -> (YAW,PITCH,0.0)
+ */
+static void v3_angles( v3f v, v3f out_angles ){
+ float yaw = atan2f( v[0], -v[2] ),
+ pitch = atan2f(
+ -v[1],
+ sqrtf(
+ v[0]*v[0] + v[2]*v[2]
+ )
+ );
+
+ out_angles[0] = yaw;
+ out_angles[1] = pitch;
+ out_angles[2] = 0.0f;
+}
+
+/*
+ * Compute the forward vector from (YAW,PITCH,ROLL)
+ * forward: -z
+ */
+static void v3_angles_vector( v3f angles, v3f out_v ){
+ out_v[0] = sinf( angles[0] ) * cosf( angles[1] );
+ out_v[1] = -sinf( angles[1] );
+ out_v[2] = -cosf( angles[0] ) * cosf( angles[1] );
+}
+
/*
* -----------------------------------------------------------------------------
* Section 2.c 4D Vectors
d[3] = q[3]*s;
}
-static inline void q_nlerp( v4f a, v4f b, f32 t, v4f d )
-{
+static inline void q_nlerp( v4f a, v4f b, f32 t, v4f d ){
if( v4_dot(a,b) < 0.0f ){
- v4_muls( b, -1.0f, d );
- v4_lerp( a, d, t, d );
+ v4f c;
+ v4_muls( b, -1.0f, c );
+ v4_lerp( a, c, t, d );
}
else
v4_lerp( a, b, t, d );
v3_add( v1, v2, d );
}
+static f32 q_dist( v4f q0, v4f q1 ){
+ return acosf( 2.0f * v4_dot(q0,q1) -1.0f );
+}
+
/*
* -----------------------------------------------------------------------------
* Section 4.a 2x2 matrices
a[1][1] = c;
}
+static inline void m2x2_mulv( m2x2f m, v2f v, v2f d )
+{
+ v2f res;
+
+ res[0] = m[0][0]*v[0] + m[1][0]*v[1];
+ res[1] = m[0][1]*v[0] + m[1][1]*v[1];
+
+ v2_copy( res, d );
+}
+
/*
* -----------------------------------------------------------------------------
* Section 4.b 3x3 matrices
m3x3_q( rot, q );
}
-static void m4x3_expand_aabb_point( m4x3f m, boxf box, v3f point )
-{
+static void m4x3_expand_aabb_point( m4x3f m, boxf box, v3f point ){
v3f v;
m4x3_mulv( m, point, v );
v3_maxv( box[1], v, box[1] );
}
-static void m4x3_transform_aabb( m4x3f m, boxf box )
-{
+static void m4x3_expand_aabb_aabb( m4x3f m, boxf boxa, boxf boxb ){
v3f a; v3f b;
-
- v3_copy( box[0], a );
- v3_copy( box[1], b );
- v3_fill( box[0], INFINITY );
- v3_fill( box[1], -INFINITY );
-
- m4x3_expand_aabb_point( m, box, (v3f){ a[0], a[1], a[2] } );
- m4x3_expand_aabb_point( m, box, (v3f){ a[0], b[1], a[2] } );
- m4x3_expand_aabb_point( m, box, (v3f){ b[0], b[1], a[2] } );
- m4x3_expand_aabb_point( m, box, (v3f){ b[0], a[1], a[2] } );
-
- m4x3_expand_aabb_point( m, box, (v3f){ a[0], a[1], b[2] } );
- m4x3_expand_aabb_point( m, box, (v3f){ a[0], b[1], b[2] } );
- m4x3_expand_aabb_point( m, box, (v3f){ b[0], b[1], b[2] } );
- m4x3_expand_aabb_point( m, box, (v3f){ b[0], a[1], b[2] } );
+ v3_copy( boxb[0], a );
+ v3_copy( boxb[1], b );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ a[0], a[1], a[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ a[0], b[1], a[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ b[0], b[1], a[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ b[0], a[1], a[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ a[0], a[1], b[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ a[0], b[1], b[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ b[0], b[1], b[2] } );
+ m4x3_expand_aabb_point( m, boxa, (v3f){ b[0], a[1], b[2] } );
}
-
static inline void m4x3_lookat( m4x3f m, v3f pos, v3f target, v3f up )
{
v3f dir;
return 0;
}
-static inline void box_init_inf( boxf box )
-{
+static inline void box_init_inf( boxf box ){
v3_fill( box[0], INFINITY );
v3_fill( box[1], -INFINITY );
}
static int plane_segment( v4f plane, v3f a, v3f b, v3f co )
{
f32 d0 = v3_dot( a, plane ) - plane[3],
- d1 = v3_dot( b, plane ) - plane[3];
+ d1 = v3_dot( b, plane ) - plane[3];
if( d0*d1 < 0.0f )
{
;
}
+static f32 ray_plane( v4f plane, v3f co, v3f dir ){
+ f32 d = v3_dot( plane, dir );
+ if( fabsf(d) > 1e-6f ){
+ v3f v0;
+ v3_muls( plane, plane[3], v0 );
+ v3_sub( v0, co, v0 );
+ return v3_dot( v0, plane ) / d;
+ }
+ else return INFINITY;
+}
+
/*
* -----------------------------------------------------------------------------
* Section 5.c Closest point functions
* These closest point tests were learned from Real-Time Collision Detection by
* Christer Ericson
*/
-VG_STATIC f32 closest_segment_segment( v3f p1, v3f q1, v3f p2, v3f q2,
+static f32 closest_segment_segment( v3f p1, v3f q1, v3f p2, v3f q2,
f32 *s, f32 *t, v3f c1, v3f c2)
{
v3f d1,d2,r;
return v3_length2( v0 );
}
-VG_STATIC int point_inside_aabb( boxf box, v3f point )
+static int point_inside_aabb( boxf box, v3f point )
{
if((point[0]<=box[1][0]) && (point[1]<=box[1][1]) && (point[2]<=box[1][2]) &&
(point[0]>=box[0][0]) && (point[1]>=box[0][1]) && (point[2]>=box[0][2]) )
return 0;
}
-VG_STATIC void closest_point_aabb( v3f p, boxf box, v3f dest )
+static void closest_point_aabb( v3f p, boxf box, v3f dest )
{
v3_maxv( p, box[0], dest );
v3_minv( dest, box[1], dest );
}
-VG_STATIC void closest_point_obb( v3f p, boxf box,
+static void closest_point_obb( v3f p, boxf box,
m4x3f mtx, m4x3f inv_mtx, v3f dest )
{
v3f local;
m4x3_mulv( mtx, local, dest );
}
-VG_STATIC f32 closest_point_segment( v3f a, v3f b, v3f point, v3f dest )
+static f32 closest_point_segment( v3f a, v3f b, v3f point, v3f dest )
{
v3f v0, v1;
v3_sub( b, a, v0 );
return t;
}
-VG_STATIC void closest_on_triangle( v3f p, v3f tri[3], v3f dest )
+static void closest_on_triangle( v3f p, v3f tri[3], v3f dest )
{
v3f ab, ac, ap;
f32 d1, d2;
k_contact_type_edge
};
-VG_STATIC enum contact_type closest_on_triangle_1( v3f p, v3f tri[3], v3f dest )
+static enum contact_type closest_on_triangle_1( v3f p, v3f tri[3], v3f dest )
{
v3f ab, ac, ap;
f32 d1, d2;
v3_muladds( p, p2, t*t, p );
}
+/*
+ * -----------------------------------------------------------------------------
+ * Section 5.f Volumes
+ * -----------------------------------------------------------------------------
+ */
+
+static float vg_sphere_volume( float radius ){
+ float r3 = radius*radius*radius;
+ return (4.0f/3.0f) * VG_PIf * r3;
+}
+
/*
* -----------------------------------------------------------------------------
* Section 6.a PSRNG and some distributions
}
static vg_rand;
-static void vg_rand_seed( unsigned long seed )
-{
+static void vg_rand_seed( unsigned long seed ) {
/* set initial seeds to mt[STATE_VECTOR_LENGTH] using the generator
* from Line 25 of Table 1 in: Donald Knuth, "The Art of Computer
* Programming," Vol. 2 (2nd Ed.) pp.102.
/*
* Generates a pseudo-randomly generated long.
*/
-static u32 vg_randu32(void)
-{
+static u32 vg_randu32(void) {
u32 y;
/* mag[x] = x * 0x9908b0df for x = 0,1 */
static u32 mag[2] = {0x0, 0x9908b0df};
/*
* Generates a pseudo-randomly generated f64 in the range [0..1].
*/
-static inline f64 vg_randf64(void)
-{
+static inline f64 vg_randf64(void){
return (f64)vg_randu32()/(f64)0xffffffff;
}
-static inline f64 vg_randf64_range( f64 min, f64 max )
-{
+static inline f64 vg_randf64_range( f64 min, f64 max ){
return vg_lerp( min, max, (f64)vg_randf64() );
}
-static inline void vg_rand_dir( v3f dir )
-{
+static inline void vg_rand_dir( v3f dir ){
dir[0] = vg_randf64();
dir[1] = vg_randf64();
dir[2] = vg_randf64();
+ /* warning: *could* be 0 length.
+ * very unlikely.. 1 in (2^32)^3. but its mathematically wrong. */
+
v3_muls( dir, 2.0f, dir );
v3_sub( dir, (v3f){1.0f,1.0f,1.0f}, dir );
v3_normalize( dir );
}
-static inline void vg_rand_sphere( v3f co )
-{
+static inline void vg_rand_sphere( v3f co ){
vg_rand_dir(co);
v3_muls( co, cbrtf( vg_randf64() ), co );
}
+static void vg_rand_disc( v2f co ){
+ f32 a = vg_randf64() * VG_TAUf;
+ co[0] = sinf(a);
+ co[1] = cosf(a);
+ v2_muls( co, sqrtf( vg_randf64() ), co );
+}
+
+static void vg_rand_cone( v3f out_dir, f32 angle ){
+ f32 r = sqrtf(vg_randf64()) * angle * 0.5f,
+ a = vg_randf64() * VG_TAUf;
+
+ out_dir[0] = sinf(a) * sinf(r);
+ out_dir[1] = cosf(a) * sinf(r);
+ out_dir[2] = cosf(r);
+}
+
#endif /* VG_M_H */
projects / vg.git / blobdiff