3d_collision_helpers/src/sc_sacd.cpp

706 lines
18 KiB
C++
Raw Normal View History

#include "sc_sacd.h"
2024-04-26 02:43:38 +00:00
// Standard library includes.
#include <array>
#include <cmath>
#include <span>
#include <vector>
// =============================================================================
// Private Helpers BEGIN
// =============================================================================
constexpr float INV_SQRT2 = 0.70710678118654752440F;
SC_SACD_Vec3 operator+(const SC_SACD_Vec3 &a, const SC_SACD_Vec3 &b) {
return SC_SACD_Vec3{a.x + b.x, a.y + b.y, a.z + b.z};
}
SC_SACD_Vec3 operator-(const SC_SACD_Vec3 &a, const SC_SACD_Vec3 &b) {
return SC_SACD_Vec3{a.x - b.x, a.y - b.y, a.z - b.z};
}
SC_SACD_Vec3 operator*(const SC_SACD_Vec3 &a, float scalar) {
return SC_SACD_Vec3{a.x * scalar, a.y * scalar, a.z * scalar};
}
SC_SACD_Vec3 operator/(const SC_SACD_Vec3 &a, float scalar) {
return SC_SACD_Vec3{a.x / scalar, a.y / scalar, a.z / scalar};
}
2024-04-29 04:39:59 +00:00
SC_SACD_Mat4 operator*(const SC_SACD_Mat4 &a, const SC_SACD_Mat4 &b) {
SC_SACD_Mat4 mat;
2024-04-29 04:39:59 +00:00
mat.x0 = b.x0 * a.x0 + b.y0 * a.x1 + b.z0 * a.x2 + b.w0 * a.x3;
mat.y0 = b.x0 * a.y0 + b.y0 * a.y1 + b.z0 * a.y2 + b.w0 * a.y3;
mat.z0 = b.x0 * a.z0 + b.y0 * a.z1 + b.z0 * a.z2 + b.w0 * a.z3;
mat.w0 = b.x0 * a.w0 + b.y0 * a.w1 + b.z0 * a.w2 + b.w0 * a.w3;
2024-04-29 04:39:59 +00:00
mat.x1 = b.x1 * a.x0 + b.y1 * a.x1 + b.z1 * a.x2 + b.w1 * a.x3;
mat.y1 = b.x1 * a.y0 + b.y1 * a.y1 + b.z1 * a.y2 + b.w1 * a.y3;
mat.z1 = b.x1 * a.z0 + b.y1 * a.z1 + b.z1 * a.z2 + b.w1 * a.z3;
mat.w1 = b.x1 * a.w0 + b.y1 * a.w1 + b.z1 * a.w2 + b.w1 * a.w3;
2024-04-29 04:39:59 +00:00
mat.x2 = b.x2 * a.x0 + b.y2 * a.x1 + b.z2 * a.x2 + b.w2 * a.x3;
mat.y2 = b.x2 * a.y0 + b.y2 * a.y1 + b.z2 * a.y2 + b.w2 * a.y3;
mat.z2 = b.x2 * a.z0 + b.y2 * a.z1 + b.z2 * a.z2 + b.w2 * a.z3;
mat.w2 = b.x2 * a.w0 + b.y2 * a.w1 + b.z2 * a.w2 + b.w2 * a.w3;
mat.x3 = b.x3 * a.x0 + b.y3 * a.x1 + b.z3 * a.x2 + b.w3 * a.x3;
mat.y3 = b.x3 * a.y0 + b.y3 * a.y1 + b.z3 * a.y2 + b.w3 * a.y3;
mat.z3 = b.x3 * a.z0 + b.y3 * a.z1 + b.z3 * a.z2 + b.w3 * a.z3;
mat.w3 = b.x3 * a.w0 + b.y3 * a.w1 + b.z3 * a.w2 + b.w3 * a.w3;
return mat;
}
2024-04-29 04:39:59 +00:00
SC_SACD_Vec3 operator*(const SC_SACD_Mat4 &mat, const SC_SACD_Vec3 &vec) {
return SC_SACD_Vec3{
vec.x * mat.x0 + vec.y * mat.x1 + vec.z * mat.x2 + mat.x3,
vec.x * mat.y0 + vec.y * mat.y1 + vec.z * mat.y2 + mat.y3,
vec.x * mat.z0 + vec.y * mat.z1 + vec.z * mat.z2 + mat.z3};
}
std::array<SC_SACD_Vec3, 3> SC_SACD_Get_Box_Normals(SC_SACD_Generic_Box box) {
SC_SACD_Vec3 a, b, c;
// Facing positive x-axis.
a.x = 0.0F;
a.y = 0.0F;
a.z = 0.0F;
b.x = 0.0F;
b.y = 1.0F;
b.z = 0.0F;
c.x = 0.0F;
c.y = 0.0F;
c.z = 1.0F;
a = box.transform * a;
b = box.transform * b;
c = box.transform * c;
b = b - a;
c = c - a;
auto normal_x = SC_SACD_Cross_Product(b, c);
// Facing positive y-axis.
a.x = 0.0F;
a.y = 0.0F;
a.z = 0.0F;
b.x = 1.0F;
b.y = 0.0F;
b.z = 0.0F;
c.x = 0.0F;
c.y = 0.0F;
c.z = -1.0F;
a = box.transform * a;
b = box.transform * b;
c = box.transform * c;
b = b - a;
c = c - a;
auto normal_y = SC_SACD_Cross_Product(b, c);
// Facing positive z-axis.
a.x = 0.0F;
a.y = 0.0F;
a.z = 0.0F;
b.x = 0.0F;
b.y = 1.0F;
b.z = 0.0F;
c.x = -1.0F;
c.y = 0.0F;
c.z = 0.0F;
a = box.transform * a;
b = box.transform * b;
c = box.transform * c;
b = b - a;
c = c - a;
auto normal_z = SC_SACD_Cross_Product(b, c);
return {normal_x, normal_y, normal_z};
}
std::array<SC_SACD_Vec3, 3> SC_SACD_Get_Box_Normals_Normalized(
SC_SACD_Generic_Box box) {
auto normals = SC_SACD_Get_Box_Normals(box);
for (auto &normal : normals) {
normal = normal / std::sqrt(SC_SACD_Dot_Product(normal, normal));
}
return normals;
}
std::array<SC_SACD_Vec3, 8> SC_SACD_Get_Box_Corners(SC_SACD_Generic_Box box) {
SC_SACD_Vec3 corner_0 =
box.transform *
SC_SACD_Vec3{-box.width / 2.0F, -box.height / 2.0F, -box.depth / 2.0F};
corner_0.x += box.x;
corner_0.y += box.y;
corner_0.z += box.z;
SC_SACD_Vec3 corner_1 =
box.transform *
SC_SACD_Vec3{box.width / 2.0F, -box.height / 2.0F, -box.depth / 2.0F};
corner_1.x += box.x;
corner_1.y += box.y;
corner_1.z += box.z;
SC_SACD_Vec3 corner_2 =
box.transform *
SC_SACD_Vec3{-box.width / 2.0F, box.height / 2.0F, -box.depth / 2.0F};
corner_2.x += box.x;
corner_2.y += box.y;
corner_2.z += box.z;
SC_SACD_Vec3 corner_3 =
box.transform *
SC_SACD_Vec3{box.width / 2.0F, box.height / 2.0F, -box.depth / 2.0F};
corner_3.x += box.x;
corner_3.y += box.y;
corner_3.z += box.z;
SC_SACD_Vec3 corner_4 =
box.transform *
SC_SACD_Vec3{-box.width / 2.0F, -box.height / 2.0F, box.depth / 2.0F};
corner_4.x += box.x;
corner_4.y += box.y;
corner_4.z += box.z;
SC_SACD_Vec3 corner_5 =
box.transform *
SC_SACD_Vec3{box.width / 2.0F, -box.height / 2.0F, box.depth / 2.0F};
corner_5.x += box.x;
corner_5.y += box.y;
corner_5.z += box.z;
SC_SACD_Vec3 corner_6 =
box.transform *
SC_SACD_Vec3{-box.width / 2.0F, box.height / 2.0F, box.depth / 2.0F};
corner_6.x += box.x;
corner_6.y += box.y;
corner_6.z += box.z;
SC_SACD_Vec3 corner_7 =
box.transform *
SC_SACD_Vec3{box.width / 2.0F, box.height / 2.0F, box.depth / 2.0F};
corner_7.x += box.x;
corner_7.y += box.y;
corner_7.z += box.z;
return {
corner_0, corner_1, corner_2, corner_3,
corner_4, corner_5, corner_6, corner_7,
};
}
struct SC_SACD_MinMax {
float min, max;
};
std::vector<SC_SACD_MinMax> SC_SACD_Get_Box_MinMax(
SC_SACD_Generic_Box box, const std::span<SC_SACD_Vec3> normals) {
std::vector<SC_SACD_MinMax> minmaxes;
auto corners = SC_SACD_Get_Box_Corners(box);
// Assuming normals are not normalized, and will not normalize anyway.
// MinMax count should be same as normals count.
for (const auto &normal : normals) {
SC_SACD_MinMax minmax{INFINITY, -INFINITY};
for (const auto &corner : corners) {
float projected = SC_SACD_Dot_Product(corner, normal);
if (projected > minmax.max) {
minmax.max = projected;
}
if (projected < minmax.min) {
minmax.min = projected;
}
}
minmaxes.push_back(minmax);
}
return minmaxes;
}
// =============================================================================
// Private Helpers END
// =============================================================================
SC_SACD_Generic_Box SC_SACD_Generic_Box_Default() {
return {
0.0F, 0.0F, 0.0F, 2.0F, 2.0F, 2.0F, SC_SACD_Mat4_Identity(),
};
}
int SC_SACD_AABB_Box_Collision(SC_SACD_AABB_Box a, SC_SACD_AABB_Box b) {
float ax_min = a.x - a.width / 2.0F;
float ax_max = a.x + a.width / 2.0F;
float ay_min = a.y - a.height / 2.0F;
float ay_max = a.y + a.height / 2.0F;
float az_min = a.z - a.depth / 2.0F;
float az_max = a.z + a.depth / 2.0F;
float bx_min = b.x - b.width / 2.0F;
float bx_max = b.x + b.width / 2.0F;
float by_min = b.y - b.height / 2.0F;
float by_max = b.y + b.height / 2.0F;
float bz_min = b.z - b.depth / 2.0F;
float bz_max = b.z + b.depth / 2.0F;
return (ax_min < bx_max && ax_max > bx_min && ay_min < by_max &&
ay_max > by_min && az_min < bz_max && az_max > bz_min)
? 1
: 0;
2024-04-26 02:43:38 +00:00
}
int SC_SACD_Generic_Box_Collision(SC_SACD_Generic_Box a,
SC_SACD_Generic_Box b) {
// Get all normals.
std::vector<SC_SACD_Vec3> normals;
{
for (const auto &normal : SC_SACD_Get_Box_Normals(a)) {
normals.push_back(normal);
}
for (const auto &normal : SC_SACD_Get_Box_Normals(b)) {
normals.push_back(normal);
}
}
// Get all minmaxes.
std::vector<SC_SACD_MinMax> minmaxes_a = SC_SACD_Get_Box_MinMax(a, normals);
std::vector<SC_SACD_MinMax> minmaxes_b = SC_SACD_Get_Box_MinMax(b, normals);
// Check minmaxes.
for (unsigned int i = 0; i < normals.size(); ++i) {
if (minmaxes_a[i].max < minmaxes_b[i].min ||
minmaxes_b[i].max < minmaxes_a[i].min) {
return 0;
}
}
return 1;
2024-04-26 02:43:38 +00:00
}
int SC_SACD_AABB_Generic_Box_Collision(SC_SACD_AABB_Box a,
SC_SACD_Generic_Box b) {
SC_SACD_Generic_Box a_conv;
a_conv.x = a.x;
a_conv.y = a.y;
a_conv.z = a.z;
a_conv.width = a.width;
a_conv.height = a.height;
a_conv.depth = a.depth;
a_conv.transform = SC_SACD_Mat4_Identity();
return SC_SACD_Generic_Box_Collision(a_conv, b);
}
int SC_SACD_Sphere_Collision(SC_SACD_Sphere a, SC_SACD_Sphere b) {
SC_SACD_Vec3 vec{a.x - b.x, a.y - b.y, a.z - b.z};
return (a.radius + b.radius) > std::sqrt(SC_SACD_Dot_Product(vec, vec)) ? 1
: 0;
}
int SC_SACD_Sphere_AABB_Box_Collision(SC_SACD_Sphere sphere,
SC_SACD_AABB_Box box) {
2024-04-26 10:48:43 +00:00
SC_SACD_Vec3 box_min{
box.x - box.width / 2.0F,
box.y - box.height / 2.0F,
box.z - box.depth / 2.0F,
2024-04-26 10:48:43 +00:00
};
SC_SACD_Vec3 box_max{
box.x + box.width / 2.0F,
box.y + box.height / 2.0F,
box.z + box.depth / 2.0F,
2024-04-26 10:48:43 +00:00
};
SC_SACD_Vec3 clamped{std::max(box_min.x, std::min(sphere.x, box_max.x)),
std::max(box_min.y, std::min(sphere.y, box_max.y)),
std::max(box_min.z, std::min(sphere.z, box_max.z))};
2024-04-26 10:48:43 +00:00
SC_SACD_Vec3 diff = clamped - SC_SACD_Vec3{sphere.x, sphere.y, sphere.z};
2024-04-26 10:48:43 +00:00
float dist = std::sqrt(SC_SACD_Dot_Product(diff, diff));
return dist < sphere.radius;
}
int SC_SACD_Sphere_Box_Collision(SC_SACD_Sphere sphere,
SC_SACD_Generic_Box box) {
// Adapted from Generic_Box/Generic_Box collision.
// First check plane where normal = box_pos - sphere_pos.
SC_SACD_Vec3 sphere_pos{sphere.x, sphere.y, sphere.z};
std::array<SC_SACD_Vec3, 1> sphere_box_normal = {
SC_SACD_Vec3{box.x, box.y, box.z} - sphere_pos};
if (sphere_box_normal[0].x < 0.0001F && sphere_box_normal[0].x > -0.0001F &&
sphere_box_normal[0].y < 0.0001F && sphere_box_normal[0].y > -0.0001F &&
sphere_box_normal[0].z < 0.0001F && sphere_box_normal[0].z > -0.0001F) {
// Sphere center is box center.
return 1;
}
sphere_box_normal[0] =
sphere_box_normal[0] / std::sqrt(SC_SACD_Dot_Product(
sphere_box_normal[0], sphere_box_normal[0]));
std::vector<SC_SACD_MinMax> box_minmaxes =
SC_SACD_Get_Box_MinMax(box, sphere_box_normal);
float projected_0 = SC_SACD_Dot_Product(
sphere_box_normal[0], sphere_pos + sphere_box_normal[0] * sphere.radius);
float projected_1 = SC_SACD_Dot_Product(
sphere_box_normal[0], sphere_pos - sphere_box_normal[0] * sphere.radius);
if (projected_0 < projected_1) {
if (box_minmaxes[0].max < projected_0 ||
box_minmaxes[0].min > projected_1) {
return 0;
}
} else if (box_minmaxes[0].max < projected_1 ||
box_minmaxes[0].min > projected_0) {
return 0;
}
// Next check the planes for the 3 normals of the box.
auto box_normals = SC_SACD_Get_Box_Normals(box);
box_minmaxes = SC_SACD_Get_Box_MinMax(box, box_normals);
for (unsigned int i = 0; i < box_normals.size(); ++i) {
projected_0 = SC_SACD_Dot_Product(
box_normals[i], sphere_pos + box_normals[i] * sphere.radius);
projected_1 = SC_SACD_Dot_Product(
box_normals[i], sphere_pos - box_normals[i] * sphere.radius);
if (projected_0 < projected_1) {
if (box_minmaxes[i].max < projected_0 ||
box_minmaxes[i].min > projected_1) {
return 0;
}
} else if (box_minmaxes[i].max < projected_1 ||
box_minmaxes[i].min > projected_0) {
return 0;
}
}
return 1;
}
float SC_SACD_Dot_Product(SC_SACD_Vec3 a, SC_SACD_Vec3 b) {
return a.x * b.x + a.y * b.y + a.z * b.z;
}
SC_SACD_Vec3 SC_SACD_Cross_Product(SC_SACD_Vec3 a, SC_SACD_Vec3 b) {
return SC_SACD_Vec3{a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z,
a.x * b.y - a.y * b.x};
}
2024-04-29 04:39:59 +00:00
SC_SACD_Mat4 SC_SACD_Mat4_Identity(void) {
return SC_SACD_Mat4{1.0F, 0.0F, 0.0F, 0.0F, 0.0F, 1.0F, 0.0F, 0.0F,
0.0F, 0.0F, 1.0F, 0.0F, 0.0F, 0.0F, 0.0F, 1.0F};
}
SC_SACD_Mat4 SC_SACD_Mat4_Mult(SC_SACD_Mat4 a, SC_SACD_Mat4 b) { return a * b; }
SC_SACD_Vec3 SC_SACD_Mat4_Vec3_Mult(SC_SACD_Mat4 mat, SC_SACD_Vec3 vec) {
return mat * vec;
}
SC_SACD_Vec3 SC_SACD_Vec3_Rotate(SC_SACD_Vec3 vec, float x_axis, float y_axis,
float z_axis) {
/*
* z_axis counter-clockwise affects x and y.
* [ cos, -sin, 0 ]
* [ sin, cos, 0 ]
* [ 0, 0, 1 ]
*
* x_axis counter-clockwise affects y and z.
* [ 1, 0, 0 ]
* [ 0, cos, -sin ]
* [ 0, sin, cos ]
*
* y_axis counter-clockwise affects x and z.
* [ cos, 0, sin ]
* [ 0, 1, 0 ]
* [ -sin, 0, cos ]
*/
2024-04-29 04:39:59 +00:00
SC_SACD_Mat4 mat;
SC_SACD_Vec3 result;
// About x_axis.
2024-04-29 04:39:59 +00:00
mat = SC_SACD_Rotation_Mat4_XAxis(x_axis);
result = SC_SACD_Mat4_Vec3_Mult(mat, vec);
// About y_axis.
2024-04-29 04:39:59 +00:00
mat = SC_SACD_Rotation_Mat4_YAxis(y_axis);
result = SC_SACD_Mat4_Vec3_Mult(mat, result);
// About z_axis.
2024-04-29 04:39:59 +00:00
mat = SC_SACD_Rotation_Mat4_ZAxis(z_axis);
return SC_SACD_Mat4_Vec3_Mult(mat, result);
}
2024-04-29 04:39:59 +00:00
SC_SACD_Mat4 SC_SACD_Rotation_Mat4_XAxis(float x_radians) {
SC_SACD_Mat4 mat;
mat.x0 = 1.0F;
mat.x1 = 0.0F;
mat.x2 = 0.0F;
2024-04-29 04:39:59 +00:00
mat.x3 = 0.0F;
mat.y0 = 0.0F;
mat.y1 = std::cos(x_radians);
mat.y2 = -std::sin(x_radians);
2024-04-29 04:39:59 +00:00
mat.y3 = 0.0F;
mat.z0 = 0.0F;
mat.z1 = -mat.y2;
mat.z2 = mat.y1;
2024-04-29 04:39:59 +00:00
mat.z3 = 0.0F;
mat.w0 = 0.0F;
mat.w1 = 0.0F;
mat.w2 = 0.0F;
mat.w3 = 1.0F;
return mat;
}
2024-04-29 04:39:59 +00:00
SC_SACD_Mat4 SC_SACD_Rotation_Mat4_YAxis(float y_radians) {
SC_SACD_Mat4 mat;
mat.x0 = std::cos(y_radians);
mat.x1 = 0.0F;
mat.x2 = std::sin(y_radians);
2024-04-29 04:39:59 +00:00
mat.x3 = 0.0F;
mat.y0 = 0.0F;
mat.y1 = 1.0F;
mat.y2 = 0.0F;
2024-04-29 04:39:59 +00:00
mat.y3 = 0.0F;
mat.z0 = -mat.x2;
mat.z1 = 0.0F;
mat.z2 = mat.x0;
2024-04-29 04:39:59 +00:00
mat.z3 = 0.0F;
mat.w0 = 0.0F;
mat.w1 = 0.0F;
mat.w2 = 0.0F;
mat.w3 = 1.0F;
return mat;
}
2024-04-29 04:39:59 +00:00
SC_SACD_Mat4 SC_SACD_Rotation_Mat4_ZAxis(float z_radians) {
SC_SACD_Mat4 mat;
mat.x0 = std::cos(z_radians);
mat.x1 = -std::sin(z_radians);
mat.x2 = 0.0F;
2024-04-29 04:39:59 +00:00
mat.x3 = 0.0F;
mat.y0 = -mat.x1;
mat.y1 = mat.x0;
mat.y2 = 0.0F;
2024-04-29 04:39:59 +00:00
mat.y3 = 0.0F;
mat.z0 = 0.0F;
mat.z1 = 0.0F;
mat.z2 = 1.0F;
2024-04-29 04:39:59 +00:00
mat.z3 = 0.0F;
mat.w0 = 0.0F;
mat.w1 = 0.0F;
mat.w2 = 0.0F;
mat.w3 = 1.0F;
return mat;
2024-04-26 02:43:38 +00:00
}
SC_SACD_Mat4 SC_SACD_Translate_Mat4(float x, float y, float z) {
return SC_SACD_Mat4{1.0F, 0.0F, 0.0F, x, 0.0F, 1.0F, 0.0F, y,
0.0F, 0.0F, 1.0F, z, 0.0F, 0.0F, 0.0F, 1.0F};
}
SC_SACD_Mat4 SC_SACD_Scale_Mat4(float x, float y, float z) {
return SC_SACD_Mat4{x, 0.0F, 0.0F, 0.0F, 0.0F, y, 0.0F, 0.0F,
0.0F, 0.0F, z, 0.0F, 0.0F, 0.0F, 0.0F, 1.0F};
}
SC_SACD_Vec3 SC_SACD_Closest_Point_Dir_Normalized(SC_SACD_Vec3 pos,
SC_SACD_Vec3 dir,
SC_SACD_Vec3 point) {
float alpha = SC_SACD_Dot_Product(dir, point) - SC_SACD_Dot_Product(dir, pos);
return pos + dir * alpha;
}
SC_SACD_Vec3 SC_SACD_Closest_Point(SC_SACD_Vec3 pos, SC_SACD_Vec3 dir,
SC_SACD_Vec3 point) {
float alpha =
(SC_SACD_Dot_Product(dir, point) - SC_SACD_Dot_Product(dir, pos)) /
SC_SACD_Dot_Product(dir, dir);
return pos + dir * alpha;
}
float SC_SACD_Vec3_Length(SC_SACD_Vec3 vec) {
return std::sqrt(SC_SACD_Dot_Product(vec, vec));
}
2024-05-06 05:11:41 +00:00
SC_SACD_AABB_Box SC_SACD_Sphere_To_AABB(SC_SACD_Sphere s) {
2024-05-06 05:11:41 +00:00
SC_SACD_AABB_Box aabb{};
aabb.x = s.x;
aabb.y = s.y;
aabb.z = s.z;
aabb.width = s.radius * 2.0F;
aabb.height = s.radius * 2.0F;
aabb.depth = s.radius * 2.0F;
return aabb;
}
SC_SACD_AABB_Box SC_SACD_Generic_Box_To_AABB(SC_SACD_Generic_Box s) {
2024-05-06 05:11:41 +00:00
SC_SACD_AABB_Box aabb{};
auto corners = SC_SACD_Get_Box_Corners(s);
2024-05-06 05:11:41 +00:00
SC_SACD_Vec3 min{INFINITY, INFINITY, INFINITY};
SC_SACD_Vec3 max{-INFINITY, -INFINITY, -INFINITY};
for (const auto &corner : corners) {
if (corner.x < min.x) {
min.x = corner.x;
}
if (corner.y < min.y) {
min.y = corner.y;
}
if (corner.z < min.z) {
min.z = corner.z;
}
if (corner.x > max.x) {
max.x = corner.x;
}
if (corner.y > max.y) {
max.y = corner.y;
}
if (corner.z > max.z) {
max.z = corner.z;
}
}
aabb.width = max.x - min.x;
aabb.height = max.y - min.y;
aabb.depth = max.z - min.z;
aabb.x = min.x + aabb.width / 2.0F;
aabb.y = min.y + aabb.height / 2.0F;
aabb.z = min.z + aabb.depth / 2.0F;
return aabb;
}
SC_SACD_AABB_Box SC_SACD_AABB_Combine(SC_SACD_AABB_Box a, SC_SACD_AABB_Box b) {
SC_SACD_Vec3 min, max;
// Populate min values.
float temp_a = a.x - a.width / 2.0F;
float temp_b = b.x - b.width / 2.0F;
min.x = temp_a < temp_b ? temp_a : temp_b;
temp_a = a.y - a.height / 2.0F;
temp_b = b.y - b.height / 2.0F;
min.y = temp_a < temp_b ? temp_a : temp_b;
temp_a = a.z - a.depth / 2.0F;
temp_b = b.z - b.depth / 2.0F;
min.z = temp_a < temp_b ? temp_a : temp_b;
// Populate max values.
temp_a = a.x + a.width / 2.0F;
temp_b = b.x + b.width / 2.0F;
max.x = temp_a > temp_b ? temp_a : temp_b;
temp_a = a.y + a.height / 2.0F;
temp_b = b.y + b.height / 2.0F;
max.y = temp_a > temp_b ? temp_a : temp_b;
temp_a = a.z + a.depth / 2.0F;
temp_b = b.z + b.depth / 2.0F;
max.z = temp_a > temp_b ? temp_a : temp_b;
// Populate the result.
temp_a = max.x - min.x;
temp_b = max.y - min.y;
float temp_c = max.z - min.z;
return SC_SACD_AABB_Box{min.x + temp_a / 2.0F,
min.y + temp_b / 2.0F,
min.z + temp_c / 2.0F,
temp_a,
temp_b,
temp_c};
}
SC_SACD_Vec3 SC_SACD_Vec3_Sum(SC_SACD_Vec3 a, SC_SACD_Vec3 b) { return a + b; }
SC_SACD_Vec3 SC_SACD_Vec3_Difference(SC_SACD_Vec3 a, SC_SACD_Vec3 b) {
return a - b;
}
SC_SACD_Vec3 SC_SACD_Vec3_Mult(SC_SACD_Vec3 vec, float scalar) {
return vec * scalar;
}
SC_SACD_Vec3 SC_SACD_Vec3_Div(SC_SACD_Vec3 vec, float scalar) {
return vec / scalar;
}
SC_SACD_Vec3 SC_SACD_Vec3_Negate(SC_SACD_Vec3 vec) {
return SC_SACD_Vec3{-vec.x, -vec.y, -vec.z};
}
SC_SACD_Vec3 SC_SACD_Vec3_Normalize(SC_SACD_Vec3 vec) {
return vec / SC_SACD_Vec3_Length(vec);
}
SC_SACD_Vec3 SC_SACD_Vec3_Project(SC_SACD_Vec3 vec, SC_SACD_Vec3 target) {
float upper_dot_product = SC_SACD_Dot_Product(vec, target);
float lower_dot_product = SC_SACD_Dot_Product(target, target);
return target * (upper_dot_product / lower_dot_product);
}
SC_SACD_Vec3 SC_SACD_Vec3_Reflect(SC_SACD_Vec3 vec, SC_SACD_Vec3 target) {
SC_SACD_Vec3 proj = SC_SACD_Vec3_Project(vec, target);
return proj * 2.0F - vec;
}