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Fix normalization

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This commit is contained in:
Miloslav Číž 2019-06-30 17:25:40 +02:00
parent 4d5902990c
commit f42a7b1a3a
1 changed files with 23 additions and 15 deletions
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38
small3dlib.h
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@ -320,13 +320,17 @@ static inline void S3L_vec3Add(S3L_Vec4 *result, S3L_Vec4 added);
static inline void S3L_vec3Sub(S3L_Vec4 *result, S3L_Vec4 substracted); static inline void S3L_vec3Sub(S3L_Vec4 *result, S3L_Vec4 substracted);
S3L_Unit S3L_vec3Length(S3L_Vec4 v); S3L_Unit S3L_vec3Length(S3L_Vec4 v);
/** Normalizes Vec3. Note that this function tries to normalize correctly rather /** Normalizes Vec3. Note that this function tries to normalize correctly
than quickly! If you need to normalize quickly, do it yourself in a way that rather than quickly! If you need to normalize quickly, do it yourself in a
best fits your case. */ way that best fits your case. */
void S3L_normalizeVec3(S3L_Vec4 *v); void S3L_normalizeVec3(S3L_Vec4 *v);
/** Like S3L_normalizeVec3, but doesn't perform any checks on the input vector,
which is faster, but can be very innacurate or overflowing. You are supposed
to provide a "nice" vector (not too big or small). */
static inline void S3L_normalizeVec3Fast(S3L_Vec4 *v);
S3L_Unit S3L_vec2Length(S3L_Vec4 v); S3L_Unit S3L_vec2Length(S3L_Vec4 v);
void S3L_normalizeVec2(S3L_Vec4 *v);
void S3L_crossProduct(S3L_Vec4 a, S3L_Vec4 b, S3L_Vec4 *result); void S3L_crossProduct(S3L_Vec4 a, S3L_Vec4 b, S3L_Vec4 *result);
static inline S3L_Unit S3L_dotProductVec3(S3L_Vec4 a, S3L_Vec4 b); static inline S3L_Unit S3L_dotProductVec3(S3L_Vec4 a, S3L_Vec4 b);
@ -961,17 +965,17 @@ void S3L_crossProduct(S3L_Vec4 a, S3L_Vec4 b, S3L_Vec4 *result)
void S3L_triangleNormal(S3L_Vec4 t0, S3L_Vec4 t1, S3L_Vec4 t2, S3L_Vec4 *n) void S3L_triangleNormal(S3L_Vec4 t0, S3L_Vec4 t1, S3L_Vec4 t2, S3L_Vec4 *n)
{ {
#define antiOverflow 32 #define ANTI_OVERFLOW 32
t1.x = (t1.x - t0.x) / antiOverflow; t1.x = (t1.x - t0.x) / ANTI_OVERFLOW;
t1.y = (t1.y - t0.y) / antiOverflow; t1.y = (t1.y - t0.y) / ANTI_OVERFLOW;
t1.z = (t1.z - t0.z) / antiOverflow; t1.z = (t1.z - t0.z) / ANTI_OVERFLOW;
t2.x = (t2.x - t0.x) / antiOverflow; t2.x = (t2.x - t0.x) / ANTI_OVERFLOW;
t2.y = (t2.y - t0.y) / antiOverflow; t2.y = (t2.y - t0.y) / ANTI_OVERFLOW;
t2.z = (t2.z - t0.z) / antiOverflow; t2.z = (t2.z - t0.z) / ANTI_OVERFLOW;
#undef antiOverflow #undef ANTI_OVERFLOW
S3L_crossProduct(t1,t2,n); S3L_crossProduct(t1,t2,n);
@ -1461,7 +1465,10 @@ void S3L_normalizeVec3(S3L_Vec4 *v)
it up. We can't scale up everything as big vectors overflow in length it up. We can't scale up everything as big vectors overflow in length
calculations. */ calculations. */
if (S3L_abs(v->x + v->y + v->z) < LIMIT) if (
S3L_abs(v->x) <= LIMIT &&
S3L_abs(v->y) <= LIMIT &&
S3L_abs(v->z) <= LIMIT)
{ {
v->x *= SCALE; v->x *= SCALE;
v->y *= SCALE; v->y *= SCALE;
@ -1481,15 +1488,16 @@ void S3L_normalizeVec3(S3L_Vec4 *v)
v->z = (v->z * S3L_FRACTIONS_PER_UNIT) / l; v->z = (v->z * S3L_FRACTIONS_PER_UNIT) / l;
} }
void S3L_normalizeVec2(S3L_Vec4 *v) void S3L_normalizeVec3Fast(S3L_Vec4 *v)
{ {
S3L_Unit l = S3L_vec2Length(*v); S3L_Unit l = S3L_vec3Length(*v);
if (l == 0) if (l == 0)
return; return;
v->x = (v->x * S3L_FRACTIONS_PER_UNIT) / l; v->x = (v->x * S3L_FRACTIONS_PER_UNIT) / l;
v->y = (v->y * S3L_FRACTIONS_PER_UNIT) / l; v->y = (v->y * S3L_FRACTIONS_PER_UNIT) / l;
v->z = (v->z * S3L_FRACTIONS_PER_UNIT) / l;
} }
void S3L_initTransoform3D(S3L_Transform3D *t) void S3L_initTransoform3D(S3L_Transform3D *t)