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Impl Sphere/Generic_Box collision checking

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This commit is contained in:
Stephen Seo 2024-04-27 17:12:16 +09:00
parent c0e3ea82f3
commit e71fd96e6a
2 changed files with 132 additions and 14 deletions
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76
src/sc_sacd.cpp
View file

@ -43,7 +43,8 @@ std::vector<SC_SACD_Vec3> SC_SACD_Get_Box_Normals(
normals.back() = SC_SACD_Vec3_Rotate(normals.back(), box->x_radians,
box->y_radians, box->z_radians);
// Not normalizing the normals on purpose for optimization. (No unit vectors.)
// Not normalizing the normals on purpose for optimization. It should already
// be normalized as each normal is a rotated unit vector.
return normals;
}
@ -208,21 +209,19 @@ int SC_SACD_Sphere_Collision(const SC_SACD_Sphere *a, const SC_SACD_Sphere *b) {
int SC_SACD_Sphere_AABB_Box_Collision(const SC_SACD_Sphere *sphere,
const SC_SACD_AABB_Box *box) {
SC_SACD_Vec3 box_min{
box->x - box->width / 2.0F,
box->y - box->height / 2.0F,
box->z - box->depth / 2.0F,
box->x - box->width / 2.0F,
box->y - box->height / 2.0F,
box->z - box->depth / 2.0F,
};
SC_SACD_Vec3 box_max{
box->x + box->width / 2.0F,
box->y + box->height / 2.0F,
box->z + box->depth / 2.0F,
box->x + box->width / 2.0F,
box->y + box->height / 2.0F,
box->z + box->depth / 2.0F,
};
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))
};
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))};
SC_SACD_Vec3 diff = clamped - SC_SACD_Vec3{sphere->x, sphere->y, sphere->z};
@ -233,8 +232,57 @@ int SC_SACD_Sphere_AABB_Box_Collision(const SC_SACD_Sphere *sphere,
int SC_SACD_Sphere_Box_Collision(const SC_SACD_Sphere *sphere,
const SC_SACD_Generic_Box *box) {
// TODO
return 0;
// 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};
SC_SACD_Vec3 sphere_box_normal =
SC_SACD_Vec3{box->x, box->y, box->z} - sphere_pos;
sphere_box_normal =
sphere_box_normal /
std::sqrt(SC_SACD_Dot_Product(sphere_box_normal, sphere_box_normal));
std::vector<SC_SACD_Vec3> normals{sphere_box_normal};
std::vector<SC_SACD_MinMax> box_minmaxes =
SC_SACD_Get_Box_MinMax(box, normals);
float projected_0 = SC_SACD_Dot_Product(
sphere_box_normal, sphere_pos + sphere_box_normal * sphere->radius);
float projected_1 = SC_SACD_Dot_Product(
sphere_box_normal, sphere_pos - sphere_box_normal * 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.
normals = SC_SACD_Get_Box_Normals(box);
box_minmaxes = SC_SACD_Get_Box_MinMax(box, normals);
for (unsigned int i = 0; i < normals.size(); ++i) {
projected_0 = SC_SACD_Dot_Product(normals[i],
sphere_pos + normals[i] * sphere->radius);
projected_1 = SC_SACD_Dot_Product(normals[i],
sphere_pos - 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(const SC_SACD_Vec3 a, const SC_SACD_Vec3 b) {

70
src/test.cpp
View file

@ -222,6 +222,76 @@ int main() {
CHECK_FALSE(SC_SACD_Sphere_AABB_Box_Collision(&sphere, &box));
}
// Test Sphere/Generic_Box collision check.
{
SC_SACD_Sphere sphere{0.0F, 0.0F, 0.0F, 1.0F};
SC_SACD_Generic_Box box{0.0F, 0.0F, 0.0F,
2.0F, 2.0F, 2.0F,
0.0F, 0.0F, std::numbers::pi_v<float> / 4.0F};
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 2.5F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = -2.5F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 2.3F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = -2.3F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 0.0F;
sphere.y = 2.5F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.y = -2.5F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.y = 2.3F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.y = -2.3F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.y = 0.0F;
sphere.z = 2.1F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.z = -2.1F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.z = 1.9F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.z = -1.9F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 1.5F;
sphere.y = 1.5F;
sphere.z = 0.0F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 1.4F;
sphere.y = 1.4F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 2.2F;
sphere.y = 0.7929F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = 2.1F;
sphere.y = 0.6929F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = -1.5F;
sphere.y = -1.5F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = -1.4F;
sphere.y = -1.4F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = -2.2F;
sphere.y = -0.7929F;
CHECK_FALSE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
sphere.x = -2.1F;
sphere.y = -0.6929F;
CHECK_TRUE(SC_SACD_Sphere_Box_Collision(&sphere, &box));
}
std::cout << "Checks checked: " << checks_checked << '\n'
<< "Checks passed: " << checks_passed << '\n';