diff options
author | Clment Foucault <fclem> | 2022-01-12 14:46:52 +0300 |
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committer | Clément Foucault <foucault.clem@gmail.com> | 2022-01-12 14:47:43 +0300 |
commit | 46e049d0ce2bce2f53ddc41a0dbbea2969d00a5d (patch) | |
tree | 2b814f1b737ebe17364de1a5938deb9a7066d2a9 /source/blender/blenlib/BLI_math_vector.hh | |
parent | e5766752d04794c2693dedad75baeb8c7d68f4cf (diff) |
BLI: Refactor vector types & functions to use templates
This patch implements the vector types (i.e:`float2`) by making heavy
usage of templating. All vector functions are now outside of the vector
classes (inside the `blender::math` namespace) and are not vector size
dependent for the most part.
In the ongoing effort to make shaders less GL centric, we are aiming
to share more code between GLSL and C++ to avoid code duplication.
####Motivations:
- We are aiming to share UBO and SSBO structures between GLSL and C++.
This means we will use many of the existing vector types and others
we currently don't have (uintX, intX). All these variations were
asking for many more code duplication.
- Deduplicate existing code which is duplicated for each vector size.
- We also want to share small functions. Which means that vector
functions should be static and not in the class namespace.
- Reduce friction to use these types in new projects due to their
incompleteness.
- The current state of the `BLI_(float|double|mpq)(2|3|4).hh` is a
bit of a let down. Most clases are incomplete, out of sync with each
others with different codestyles, and some functions that should be
static are not (i.e: `float3::reflect()`).
####Upsides:
- Still support `.x, .y, .z, .w` for readability.
- Compact, readable and easilly extendable.
- All of the vector functions are available for all the vectors types
and can be restricted to certain types. Also template specialization
let us define exception for special class (like mpq).
- With optimization ON, the compiler unroll the loops and performance
is the same.
####Downsides:
- Might impact debugability. Though I would arge that the bugs are
rarelly caused by the vector class itself (since the operations are
quite trivial) but by the type conversions.
- Might impact compile time. I did not saw a significant impact since
the usage is not really widespread.
- Functions needs to be rewritten to support arbitrary vector length.
For instance, one can't call `len_squared_v3v3` in
`math::length_squared()` and call it a day.
- Type cast does not work with the template version of the `math::`
vector functions. Meaning you need to manually cast `float *` and
`(float *)[3]` to `float3` for the function calls.
i.e: `math::distance_squared(float3(nearest.co), positions[i]);`
- Some parts might loose in readability:
`float3::dot(v1.normalized(), v2.normalized())`
becoming
`math::dot(math::normalize(v1), math::normalize(v2))`
But I propose, when appropriate, to use
`using namespace blender::math;` on function local or file scope to
increase readability.
`dot(normalize(v1), normalize(v2))`
####Consideration:
- Include back `.length()` method. It is quite handy and is more C++
oriented.
- I considered the GLM library as a candidate for replacement. It felt
like too much for what we need and would be difficult to extend / modify
to our needs.
- I used Macros to reduce code in operators declaration and potential
copy paste bugs. This could reduce debugability and could be reverted.
- This touches `delaunay_2d.cc` and the intersection code. I would like
to know @howardt opinion on the matter.
- The `noexcept` on the copy constructor of `mpq(2|3)` is being removed.
But according to @JacquesLucke it is not a real problem for now.
I would like to give a huge thanks to @JacquesLucke who helped during this
and pushed me to reduce the duplication further.
Reviewed By: brecht, sergey, JacquesLucke
Differential Revision: https://developer.blender.org/D13791
Diffstat (limited to 'source/blender/blenlib/BLI_math_vector.hh')
-rw-r--r-- | source/blender/blenlib/BLI_math_vector.hh | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_math_vector.hh b/source/blender/blenlib/BLI_math_vector.hh new file mode 100644 index 00000000000..e7d765df842 --- /dev/null +++ b/source/blender/blenlib/BLI_math_vector.hh @@ -0,0 +1,399 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright 2022, Blender Foundation. + */ + +#pragma once + +/** \file + * \ingroup bli + */ + +#include <cmath> +#include <type_traits> + +#include "BLI_math_base_safe.h" +#include "BLI_math_vector.h" +#include "BLI_span.hh" +#include "BLI_utildefines.h" + +#ifdef WITH_GMP +# include "BLI_math_mpq.hh" +#endif + +namespace blender::math { + +#ifndef NDEBUG +# define BLI_ASSERT_UNIT(v) \ + { \ + const float _test_unit = length_squared(v); \ + BLI_assert(!(std::abs(_test_unit - 1.0f) >= BLI_ASSERT_UNIT_EPSILON) || \ + !(std::abs(_test_unit) >= BLI_ASSERT_UNIT_EPSILON)); \ + } \ + (void)0 +#else +# define BLI_ASSERT_UNIT(v) (void)(v) +#endif + +#define bT typename T::base_type + +#ifdef WITH_GMP +# define BLI_ENABLE_IF_FLT_VEC(T) \ + BLI_ENABLE_IF((std::is_floating_point_v<typename T::base_type> || \ + std::is_same_v<typename T::base_type, mpq_class>)) +#else +# define BLI_ENABLE_IF_FLT_VEC(T) BLI_ENABLE_IF((std::is_floating_point_v<typename T::base_type>)) +#endif + +#define BLI_ENABLE_IF_INT_VEC(T) BLI_ENABLE_IF((std::is_integral_v<typename T::base_type>)) + +template<typename T> inline bool is_zero(const T &a) +{ + for (int i = 0; i < T::type_length; i++) { + if (a[i] != bT(0)) { + return false; + } + } + return true; +} + +template<typename T> inline bool is_any_zero(const T &a) +{ + for (int i = 0; i < T::type_length; i++) { + if (a[i] == bT(0)) { + return true; + } + } + return false; +} + +template<typename T> inline T abs(const T &a) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = a[i] >= 0 ? a[i] : -a[i]; + } + return result; +} + +template<typename T> inline T min(const T &a, const T &b) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = a[i] < b[i] ? a[i] : b[i]; + } + return result; +} + +template<typename T> inline T max(const T &a, const T &b) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = a[i] > b[i] ? a[i] : b[i]; + } + return result; +} + +template<typename T> inline T clamp(const T &a, const T &min_v, const T &max_v) +{ + T result = a; + for (int i = 0; i < T::type_length; i++) { + CLAMP(result[i], min_v[i], max_v[i]); + } + return result; +} + +template<typename T> inline T clamp(const T &a, const bT &min_v, const bT &max_v) +{ + T result = a; + for (int i = 0; i < T::type_length; i++) { + CLAMP(result[i], min_v, max_v); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T mod(const T &a, const T &b) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + BLI_assert(b[i] != 0); + result[i] = std::fmod(a[i], b[i]); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T mod(const T &a, bT b) +{ + BLI_assert(b != 0); + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = std::fmod(a[i], b); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T safe_mod(const T &a, const T &b) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = (b[i] != 0) ? std::fmod(a[i], b[i]) : 0; + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T safe_mod(const T &a, bT b) +{ + if (b == 0) { + return T(0.0f); + } + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = std::fmod(a[i], b); + } + return result; +} + +template<typename T> inline void min_max(const T &vector, T &min_vec, T &max_vec) +{ + min_vec = min(vector, min_vec); + max_vec = max(vector, max_vec); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T safe_divide(const T &a, const T &b) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = (b[i] == 0) ? 0 : a[i] / b[i]; + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T safe_divide(const T &a, const bT b) +{ + return (b != 0) ? a / b : T(0.0f); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T floor(const T &a) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = std::floor(a[i]); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T ceil(const T &a) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = std::ceil(a[i]); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T fract(const T &a) +{ + T result; + for (int i = 0; i < T::type_length; i++) { + result[i] = a[i] - std::floor(a[i]); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline bT dot(const T &a, const T &b) +{ + bT result = a[0] * b[0]; + for (int i = 1; i < T::type_length; i++) { + result += a[i] * b[i]; + } + return result; +} + +template<typename T> inline bT length_manhattan(const T &a) +{ + bT result = std::abs(a[0]); + for (int i = 1; i < T::type_length; i++) { + result += std::abs(a[i]); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline bT length_squared(const T &a) +{ + return dot(a, a); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline bT length(const T &a) +{ + return std::sqrt(length_squared(a)); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline bT distance_manhattan(const T &a, const T &b) +{ + return length_manhattan(a - b); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline bT distance_squared(const T &a, const T &b) +{ + return length_squared(a - b); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline bT distance(const T &a, const T &b) +{ + return length(a - b); +} + +template<typename T> uint64_t vector_hash(const T &vec) +{ + BLI_STATIC_ASSERT(T::type_length <= 4, "Longer types need to implement vector_hash themself."); + const typename T::uint_type &uvec = *reinterpret_cast<const typename T::uint_type *>(&vec); + uint64_t result; + result = uvec[0] * uint64_t(435109); + if constexpr (T::type_length > 1) { + result ^= uvec[1] * uint64_t(380867); + } + if constexpr (T::type_length > 2) { + result ^= uvec[2] * uint64_t(1059217); + } + if constexpr (T::type_length > 3) { + result ^= uvec[3] * uint64_t(2002613); + } + return result; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T reflect(const T &incident, const T &normal) +{ + BLI_ASSERT_UNIT(normal); + return incident - 2.0 * dot(normal, incident) * normal; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> +inline T refract(const T &incident, const T &normal, const bT eta) +{ + float dot_ni = dot(normal, incident); + float k = 1.0f - eta * eta * (1.0f - dot_ni * dot_ni); + if (k < 0.0f) { + return T(0.0f); + } + return eta * incident - (eta * dot_ni + sqrt(k)) * normal; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T project(const T &p, const T &v_proj) +{ + if (UNLIKELY(is_zero(v_proj))) { + return T(0.0f); + } + return v_proj * (dot(p, v_proj) / dot(v_proj, v_proj)); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> +inline T normalize_and_get_length(const T &v, bT &out_length) +{ + out_length = length_squared(v); + /* A larger value causes normalize errors in a scaled down models with camera extreme close. */ + constexpr bT threshold = std::is_same_v<bT, double> ? 1.0e-70 : 1.0e-35f; + if (out_length > threshold) { + out_length = sqrt(out_length); + return v / out_length; + } + /* Either the vector is small or one of it's values contained `nan`. */ + out_length = 0.0; + return T(0.0); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T normalize(const T &v) +{ + bT len; + return normalize_and_get_length(v, len); +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T), BLI_ENABLE_IF((T::type_length == 3))> +inline T cross(const T &a, const T &b) +{ + return {a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x}; +} + +template<typename T, + BLI_ENABLE_IF((std::is_same_v<bT, float>)), + BLI_ENABLE_IF((T::type_length == 3))> +inline T cross_high_precision(const T &a, const T &b) +{ + return {(float)((double)a.y * b.z - (double)a.z * b.y), + (float)((double)a.z * b.x - (double)a.x * b.z), + (float)((double)a.x * b.y - (double)a.y * b.x)}; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T), BLI_ENABLE_IF((T::type_length == 3))> +inline T cross_poly(Span<T> poly) +{ + /* Newell's Method. */ + int nv = static_cast<int>(poly.size()); + if (nv < 3) { + return T(0, 0, 0); + } + const T *v_prev = &poly[nv - 1]; + const T *v_curr = &poly[0]; + T n(0, 0, 0); + for (int i = 0; i < nv;) { + n[0] = n[0] + ((*v_prev)[1] - (*v_curr)[1]) * ((*v_prev)[2] + (*v_curr)[2]); + n[1] = n[1] + ((*v_prev)[2] - (*v_curr)[2]) * ((*v_prev)[0] + (*v_curr)[0]); + n[2] = n[2] + ((*v_prev)[0] - (*v_curr)[0]) * ((*v_prev)[1] + (*v_curr)[1]); + v_prev = v_curr; + ++i; + if (i < nv) { + v_curr = &poly[i]; + } + } + return n; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> inline T interpolate(const T &a, const T &b, bT t) +{ + return a * (1 - t) + b * t; +} + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> +inline T faceforward(const T &vector, const T &incident, const T &reference) +{ + return (dot(reference, incident) < 0) ? vector : -vector; +} + +template<typename T> inline int dominant_axis(const T &a) +{ + T b = abs(a); + return ((b.x > b.y) ? ((b.x > b.z) ? 0 : 2) : ((b.y > b.z) ? 1 : 2)); +} + +/** Intersections. */ + +template<typename T> struct isect_result { + enum { + LINE_LINE_COLINEAR = -1, + LINE_LINE_NONE = 0, + LINE_LINE_EXACT = 1, + LINE_LINE_CROSS = 2, + } kind; + bT lambda; +}; + +template<typename T, BLI_ENABLE_IF_FLT_VEC(T)> +isect_result<T> isect_seg_seg(const T &v1, const T &v2, const T &v3, const T &v4); + +#undef BLI_ENABLE_IF_FLT_VEC +#undef BLI_ENABLE_IF_INT_VEC +#undef bT + +} // namespace blender::math |