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Fix Sphere/AABB collision

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This commit is contained in:
Stephen Seo 2024-04-26 19:48:43 +09:00
parent cc4e67ace1
commit c0e3ea82f3
2 changed files with 19 additions and 115 deletions
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132
src/sc_sacd.cpp
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@ -207,124 +207,28 @@ 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) {
std::vector<SC_SACD_Vec3> dirs{// yz-plane
{0.0F, INV_SQRT2, INV_SQRT2},
// xz-plane
{INV_SQRT2, 0.0F, INV_SQRT2},
// xy-plane
{INV_SQRT2, INV_SQRT2, 0.0F}};
SC_SACD_Vec3 pos{box->x, box->y, box->z};
SC_SACD_Vec3 sphere_pos{sphere->x, sphere->y, sphere->z};
SC_SACD_Vec3 box_min{
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,
};
for (unsigned int i = 0; i < 3; ++i) {
SC_SACD_Vec3 side_pos = pos;
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))
};
// Side 1 of 2.
SC_SACD_Vec3 diff = clamped - SC_SACD_Vec3{sphere->x, sphere->y, sphere->z};
// Get point on side.
switch (i) {
case 0: // yz-plane
side_pos.x += box->width / 2.0F;
break;
case 1: // xz-plane
side_pos.y += box->height / 2.0F;
break;
case 2: // xy-plane
side_pos.z += box->depth / 2.0F;
break;
}
float dist = std::sqrt(SC_SACD_Dot_Product(diff, diff));
// Calculate closest point to "side".
SC_SACD_Vec3 closest_point =
SC_SACD_Closest_Point_Dir_Normalized(&side_pos, &dirs[i], &sphere_pos);
// Calculate diff between closest and sphere.
SC_SACD_Vec3 point_diff = closest_point - sphere_pos;
float magnitude = std::sqrt(SC_SACD_Dot_Product(point_diff, point_diff));
if (magnitude < sphere->radius) {
// Check if point is on side.
switch (i) {
case 0: // yz-plane
if (closest_point.y > side_pos.y - box->height / 2.0F &&
closest_point.y < side_pos.y + box->height / 2.0F &&
closest_point.z > side_pos.z - box->depth / 2.0F &&
closest_point.z < side_pos.z + box->depth / 2.0F) {
return 1;
}
break;
case 1: // xz-plane
if (closest_point.x > side_pos.x - box->width / 2.0F &&
closest_point.x < side_pos.x + box->width / 2.0F &&
closest_point.z > side_pos.z - box->depth / 2.0F &&
closest_point.z < side_pos.z + box->depth / 2.0F) {
return 1;
}
break;
case 2: // xy-plane
if (closest_point.x > side_pos.x - box->width / 2.0F &&
closest_point.x < side_pos.x + box->width / 2.0F &&
closest_point.y > side_pos.y - box->height / 2.0F &&
closest_point.y < side_pos.y + box->height / 2.0F) {
return 1;
}
break;
}
}
// Side 2 of 2.
// Get point on side.
switch (i) {
case 0: // yz-plane
side_pos.x -= box->width / 2.0F;
break;
case 1: // xz-plane
side_pos.y -= box->height / 2.0F;
break;
case 2: // xy-plane
side_pos.z -= box->depth / 2.0F;
break;
}
// Calculate closest point to "side".
closest_point =
SC_SACD_Closest_Point_Dir_Normalized(&side_pos, &dirs[i], &sphere_pos);
// Calculate diff between closest and sphere.
point_diff = closest_point - sphere_pos;
magnitude = std::sqrt(SC_SACD_Dot_Product(point_diff, point_diff));
if (magnitude < sphere->radius) {
// Check if point is on side.
switch (i) {
case 0: // yz-plane
if (closest_point.y > side_pos.y - box->height / 2.0F &&
closest_point.y < side_pos.y + box->height / 2.0F &&
closest_point.z > side_pos.z - box->depth / 2.0F &&
closest_point.z < side_pos.z + box->depth / 2.0F) {
return 1;
}
break;
case 1: // xz-plane
if (closest_point.x > side_pos.x - box->width / 2.0F &&
closest_point.x < side_pos.x + box->width / 2.0F &&
closest_point.z > side_pos.z - box->depth / 2.0F &&
closest_point.z < side_pos.z + box->depth / 2.0F) {
return 1;
}
break;
case 2: // xy-plane
if (closest_point.x > side_pos.x - box->width / 2.0F &&
closest_point.x < side_pos.x + box->width / 2.0F &&
closest_point.y > side_pos.y - box->height / 2.0F &&
closest_point.y < side_pos.y + box->height / 2.0F) {
return 1;
}
break;
}
}
}
return 0;
return dist < sphere->radius;
}
int SC_SACD_Sphere_Box_Collision(const SC_SACD_Sphere *sphere,

2
src/test.cpp
View file

@ -218,7 +218,7 @@ int main() {
CHECK_TRUE(SC_SACD_Sphere_AABB_Box_Collision(&sphere, &box));
sphere.x = 1.0F;
sphere.z = 1.8F;
sphere.z = 2.0F;
CHECK_FALSE(SC_SACD_Sphere_AABB_Box_Collision(&sphere, &box));
}