William Moberg
445 lines
15 KiB
C++
445 lines
15 KiB
C++
#include <algorithm>
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#include "Collision/Collision.h"
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#include "Engine/GLM.h"
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#include "Core/World.h"
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#include "Rendering/Model.h"
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#include "imgui/imgui.h"
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namespace Collision
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{
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//note: this one hasnt been delta adjusted like RayVsAABB has
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bool RayAABBIntr(const Ray& ray, const AABB& box)
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{
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glm::vec3 w = 75.0f * ray.Direction();
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glm::vec3 v = glm::abs(w);
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glm::vec3 c = ray.Origin() - box.Origin() + w;
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glm::vec3 half = box.HalfSize();
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if (abs(c.x) > v.x + half.x) {
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return false;
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}
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if (abs(c.y) > v.y + half.y) {
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return false;
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}
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if (abs(c.z) > v.z + half.z) {
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return false;
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}
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if (abs(c.y*w.z - c.z*w.y) > half.y*v.z + half.z*v.y) {
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return false;
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}
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if (abs(c.x*w.z - c.z*w.x) > half.x*v.z + half.z*v.x) {
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return false;
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}
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return !(abs(c.x*w.y - c.y*w.x) > half.x*v.y + half.y*v.x);
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}
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bool RayVsAABB(const Ray& ray, const AABB& box)
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{
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float dummy;
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return RayVsAABB(ray, box, dummy);
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}
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bool RayVsAABB(const Ray& ray, const AABB& box, float& outDistance)
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{
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glm::vec3 invdir = 1.0f / ray.Direction();
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glm::vec3 origin = ray.Origin();
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float t1 = (box.MinCorner().x - origin.x)*invdir.x;
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float t2 = (box.MaxCorner().x - origin.x)*invdir.x;
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float t3 = (box.MinCorner().y - origin.y)*invdir.y;
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float t4 = (box.MaxCorner().y - origin.y)*invdir.y;
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float t5 = (box.MinCorner().z - origin.z)*invdir.z;
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float t6 = (box.MaxCorner().z - origin.z)*invdir.z;
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float tmin = std::max(std::max(std::min(t1, t2), std::min(t3, t4)), std::min(t5, t6));
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float tmax = std::min(std::min(std::max(t1, t2), std::max(t3, t4)), std::max(t5, t6));
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//if (tmax < 0 || tmin > tmax)
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//if tmin,tmax are almost the same (i.e. hitting exactly in the corner) then tmin might be slightly
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//greater than tmax becuase of floating-precision problems. fixed by adding a small delta to tmax
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if (tmax < 0 || tmin>(tmax + 0.0001f))
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return false;
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outDistance = (tmin > 0) ? tmin : tmax;
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return true;
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}
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bool AABBVsAABB(const AABB& a, const AABB& b)
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{
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const glm::vec3& aCenter = a.Origin();
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const glm::vec3& bCenter = b.Origin();
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const glm::vec3& aHSize = a.HalfSize();
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const glm::vec3& bHSize = b.HalfSize();
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//Test will probably exit because of the X and Z axes more often, so test them first.
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if (abs(aCenter[0] - bCenter[0]) > (aHSize[0] + bHSize[0])) {
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return false;
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}
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if (abs(aCenter[2] - bCenter[2]) > (aHSize[2] + bHSize[2])) {
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return false;
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}
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return (abs(aCenter[1] - bCenter[1]) <= (aHSize[1] + bHSize[1]));
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}
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bool AABBVsAABB(const AABB& a, const AABB& b, glm::vec3& minimumTranslation)
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{
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minimumTranslation = glm::vec3(0, 0, 0);
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const glm::vec3& aMax = a.MaxCorner();
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const glm::vec3& bMax = b.MaxCorner();
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const glm::vec3& aMin = a.MinCorner();
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const glm::vec3& bMin = b.MinCorner();
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const glm::vec3& bSize = b.Size();
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const glm::vec3& aSize = a.Size();
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float minOffset = INFINITY;
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float off;
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auto axisesIntersecting = glm::tvec3<bool, glm::highp>(false, false, false);
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for (int i = 0; i < 3; ++i) {
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off = bMax[i] - aMin[i];
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if (off > 0 && off < bSize[i] + aSize[i]) {
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if (off < minOffset) {
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minimumTranslation = glm::vec3();
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minimumTranslation[i] = minOffset = off;
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}
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axisesIntersecting[i] = true;
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}
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off = aMax[i] - bMin[i];
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if (off > 0 && off < bSize[i] + aSize[i]) {
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if (off < minOffset) {
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minOffset = off;
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minimumTranslation = glm::vec3();
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minimumTranslation[i] = -off;
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}
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axisesIntersecting[i] = true;
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}
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}
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return glm::all(axisesIntersecting);
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}
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bool RayVsTriangle(const Ray& ray,
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const glm::vec3& v0,
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const glm::vec3& v1,
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const glm::vec3& v2,
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bool trueOnNegativeDistance)
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{
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glm::vec3 e1 = v1 - v0; //v1 - v0
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glm::vec3 e2 = v2 - v0; //v2 - v0
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glm::vec3 m = ray.Origin() - v0;
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glm::vec3 MxE1 = glm::cross(m, e1);
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glm::vec3 DxE2 = glm::cross(ray.Direction(), e2);
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float DetInv = glm::dot(e1, DxE2);
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if (std::abs(DetInv) < FLT_EPSILON) {
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return false;
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}
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DetInv = 1.0f / DetInv;
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float u = glm::dot(m, DxE2) * DetInv;
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float v = glm::dot(ray.Direction(), MxE1) * DetInv;
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//u,v can be very close to 0 but still negative sometimes. added a deltafactor to compensate for that problem
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if ((u + 0.001f) < 0 || (v + 0.001f) < 0 || 1 < u + v) {
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return false;
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}
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//Here, u and v are positive, u+v <= 1, and if distance is positive - triangle is hit.
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return trueOnNegativeDistance || 0 <= glm::dot(e2, MxE1) * DetInv;
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}
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bool RayVsModel(const Ray& ray,
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const std::vector<RawModel::Vertex>& modelVertices,
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const std::vector<unsigned int>& modelIndices)
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{
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for (int i = 0; i < modelIndices.size(); ++i) {
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glm::vec3 v0 = modelVertices[modelIndices[i]].Position;
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glm::vec3 v1 = modelVertices[modelIndices[++i]].Position;
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glm::vec3 v2 = modelVertices[modelIndices[++i]].Position;
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if (RayVsTriangle(ray, v0, v1, v2)) {
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return true;
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}
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}
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return false;
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}
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bool RayVsTriangle(const Ray& ray,
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const glm::vec3& v0,
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const glm::vec3& v1,
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const glm::vec3& v2,
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float& outDistance,
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float& outUCoord,
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float& outVCoord,
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bool trueOnNegativeDistance)
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{
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glm::vec3 e1 = v1 - v0; //v1 - v0
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glm::vec3 e2 = v2 - v0; //v2 - v0
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glm::vec3 m = ray.Origin() - v0;
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glm::vec3 MxE1 = glm::cross(m, e1);
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glm::vec3 DxE2 = glm::cross(ray.Direction(), e2);//pVec
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float DetInv = glm::dot(e1, DxE2);
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if (std::abs(DetInv) < FLT_EPSILON) {
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return false;
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}
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DetInv = 1.0f / DetInv;
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float dist = glm::dot(e2, MxE1) * DetInv;
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if (dist >= outDistance) {
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return false;
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}
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outDistance = dist;
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outUCoord = glm::dot(m, DxE2) * DetInv;
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outVCoord = glm::dot(ray.Direction(), MxE1) * DetInv;
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//u,v can be very close to 0 but still negative sometimes. added a deltafactor to compensate for that problem
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//If u and v are positive, u+v <= 1, dist is positive, and less than closest.
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return (0 <= (outUCoord + 0.001f) && 0 <= (outVCoord + 0.001f) && outUCoord + outVCoord <= 1 && (trueOnNegativeDistance || 0 <= dist));
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}
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bool RayVsModel(const Ray& ray,
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const std::vector<RawModel::Vertex>& modelVertices,
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const std::vector<unsigned int>& modelIndices,
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float& outDistance,
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float& outUCoord,
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float& outVCoord)
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{
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outDistance = INFINITY;
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bool hit = false;
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for (int i = 0; i < modelIndices.size(); ++i) {
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glm::vec3 v0 = modelVertices[modelIndices[i]].Position;
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glm::vec3 v1 = modelVertices[modelIndices[++i]].Position;
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glm::vec3 v2 = modelVertices[modelIndices[++i]].Position;
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float dist;
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float u;
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float v;
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if (RayVsTriangle(ray, v0, v1, v2, dist, u, v)) {
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outDistance = dist;
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outUCoord = u;
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outVCoord = v;
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hit = true;
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}
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}
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return hit;
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}
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bool RayVsModel(const Ray& ray,
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const std::vector<RawModel::Vertex>& modelVertices,
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const std::vector<unsigned int>& modelIndices,
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glm::vec3& outHitPosition)
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{
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float u;
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float v;
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float dist;
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bool hit = RayVsModel(ray, modelVertices, modelIndices, dist, u, v);
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outHitPosition = ray.Origin() + dist * ray.Direction();
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return hit;
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}
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constexpr inline int signNonZero(float x)
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{
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return x < 0 ? -1 : 1;
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}
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inline glm::vec3 signNonZero(const glm::vec3& x)
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{
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glm::vec3 r;
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for (int i = 0; i < 3; ++i) {
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r[i] = signNonZero(x[i]);
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}
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return r;
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}
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bool vectorHasLength(const glm::vec3& vec)
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{
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return glm::any(glm::greaterThan(glm::abs(vec), glm::vec3(0.0001f, 0.0001f, 0.0001f)));
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}
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enum BoxTriHit
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{
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Line0 = 0,
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Line1,
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Line2,
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Ground,
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Corner
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};
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bool AABBvsTriangle(const AABB& box,
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const glm::vec3& v0,
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const glm::vec3& v1,
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const glm::vec3& v2,
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glm::vec3& outVector,
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BoxTriHit& outHit)
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{
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//Check so we don't have a zero area triangle when calculating the normal.
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glm::vec3 triNormal = glm::cross(v1 - v0, v2 - v0);
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if (!vectorHasLength(triNormal)) {
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return false;
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}
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const glm::vec3& origin = box.Origin();
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const glm::vec3& half = box.HalfSize();
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const glm::vec3& min = box.MinCorner();
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const glm::vec3& max = box.MaxCorner();
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const glm::vec3 triPos[] = {
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v0, v1, v2
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};
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for (int axis : {1, 0, 2}) {
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//2D Triangle.
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//for axis=0,1,2: 2d point takes from xy,xz,yx.
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int dim1 = axis == 2 ? 0 : 1; //0,0,1
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int dim2 = axis == 0 ? 1 : 2; //1,2,2
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glm::vec2 t0(triPos[0][dim1], triPos[0][dim2]);
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glm::vec2 t1(triPos[1][dim1], triPos[1][dim2]);
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glm::vec2 t2(triPos[2][dim1], triPos[2][dim2]);
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//Project tri,
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//Project box,
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//if projections don't overlap, return false.
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}
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//If the polygon does intersect any of the cube diagonals, it will
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//intersect the cube diagonal that comes
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//closest to being perpendicular to the plane of the polygon.
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triNormal = glm::normalize(triNormal);
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glm::vec3 diagonal = -signNonZero(triNormal) * half;
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//The triangle plane contains all points P in dot(triNormal, P) == dot(triNormal, v0)
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//The diagonal line contains all points P in P = origin + diagonal * t.
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float t = glm::dot(triNormal, v0 - origin) / glm::dot(triNormal, diagonal);
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//If intersection point between plane and diagonal is within the box.
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if (glm::abs(t) > 1) {
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return false;
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}
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//TODO: Resolve it.
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return true;
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}
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bool AABBvsTriangles(const AABB& box, const std::vector<RawModel::Vertex>& modelVertices, const std::vector<unsigned int>& modelIndices, const glm::mat4& modelMatrix, glm::vec3& outResolutionVector)
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{
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AABB newBox = box;
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struct Triangle
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{
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glm::vec3 v0, v1, v2;
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};
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bool hit = false;
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bool cornerHitTODO = false;
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outResolutionVector = glm::vec3(0.f);
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std::vector<Triangle> hitTriangles;
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std::vector<glm::vec3> hitNormals;
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for (int i = 0; i < modelIndices.size(); ) {
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glm::vec3 outVec;
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glm::vec3 v0 = Transform::TransformPoint(modelVertices[modelIndices[i++]].Position, modelMatrix);
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glm::vec3 v1 = Transform::TransformPoint(modelVertices[modelIndices[i++]].Position, modelMatrix);
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glm::vec3 v2 = Transform::TransformPoint(modelVertices[modelIndices[i++]].Position, modelMatrix);
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BoxTriHit hitCase;
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if (AABBvsTriangle(newBox, v0, v1, v2, outVec, hitCase)) {
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hit = true;
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switch (hitCase) {
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case Collision::Line0:
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case Collision::Line1:
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case Collision::Line2:
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//TODO: Resolve.
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//const glm::vec3 triPos[] = {
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// v0, v1, v2
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//};
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//glm::vec3 edge = triPos[(hitCase + 1) % 3] - triPos[hitCase];
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hitTriangles.push_back({ v0, v1, v2 });
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hitNormals.push_back(outVec);
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ImGui::Text("triangle edge collision.");
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break;
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case Collision::Corner:
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//TODO: We might be able to return here instead, having only convex geometry.
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cornerHitTODO = true;
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//outResolutionVector += outVec;
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//return true;
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ImGui::Text("triangle corner collision.");
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outResolutionVector += outVec;
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newBox = AABB::FromOriginSize(newBox.Origin() + outVec, newBox.Size());
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break;
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case Collision::Ground:
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default:
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outResolutionVector += outVec;
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newBox = AABB::FromOriginSize(newBox.Origin() + outVec, newBox.Size());
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ImGui::Text("triangle ground collision.");
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break;
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}
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}
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}
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if (hitTriangles.size() > 0) {
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if (cornerHitTODO) {
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ImGui::Text("Both edges and corners was hit on the same model.");
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return true;
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}
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glm::vec3 lineResolve(0.f);
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for (const glm::vec3& norm : hitNormals) {
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lineResolve += norm;
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}
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//Normalize.
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lineResolve /= hitNormals.size();
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const glm::vec3& origin = newBox.Origin();
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const glm::vec3& half = newBox.HalfSize();
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float maxDist = -10;
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for (const Triangle& tri : hitTriangles) {
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float d = glm::dot(lineResolve, 0.333f * (tri.v0 + tri.v1 + tri.v2) - origin);
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maxDist = std::max(maxDist, d);
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}
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glm::vec3 tmp = glm::clamp(2.0f * lineResolve, glm::vec3(-1, -1, -1), glm::vec3(1, 1, 1));
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outResolutionVector += lineResolve * (maxDist + glm::length(tmp * half));
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}
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return hit;
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}
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bool IsSameBoxProbably(const AABB& first, const AABB& second, const float epsilon)
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{
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const glm::vec3& ma1 = first.MaxCorner();
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const glm::vec3& ma2 = second.MaxCorner();
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const glm::vec3& mi1 = first.MinCorner();
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const glm::vec3& mi2 = second.MinCorner();
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return (std::abs(ma1.x - ma2.x) < epsilon) &&
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(std::abs(mi1.x - mi2.x) < epsilon) &&
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(std::abs(ma1.z - ma2.z) < epsilon) &&
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(std::abs(mi1.z - mi2.z) < epsilon) &&
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(std::abs(ma1.y - ma2.y) < epsilon) &&
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(std::abs(mi1.y - mi2.y) < epsilon);
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}
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bool attachAABBComponentFromModel(World* world, EntityID id)
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{
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if (!world->HasComponent(id, "Model")) {
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return false;
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}
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ComponentWrapper model = world->GetComponent(id, "Model");
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ComponentWrapper collision = world->AttachComponent(id, "AABB");
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Model* modelRes = ResourceManager::Load<Model>(model["Resource"]);
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if (modelRes == nullptr) {
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return false;
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}
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glm::mat4 modelMatrix = modelRes->Matrix();
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glm::vec3 mini = glm::vec3(INFINITY, INFINITY, INFINITY);
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glm::vec3 maxi = glm::vec3(-INFINITY, -INFINITY, -INFINITY);
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for (const auto& v : modelRes->Vertices()) {
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const auto& wPos = modelMatrix * glm::vec4(v.Position.x, v.Position.y, v.Position.z, 1);
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maxi.x = std::max(wPos.x, maxi.x);
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maxi.y = std::max(wPos.y, maxi.y);
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maxi.z = std::max(wPos.z, maxi.z);
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mini.x = std::min(wPos.x, mini.x);
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mini.y = std::min(wPos.y, mini.y);
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mini.z = std::min(wPos.z, mini.z);
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}
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collision["Origin"] = 0.5f * (maxi + mini);
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collision["Size"] = maxi - mini;
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return true;
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}
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boost::optional<AABB> EntityAbsoluteAABB(EntityWrapper& entity)
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{
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if (!entity.HasComponent("AABB")) {
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return boost::none;
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}
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ComponentWrapper& cAABB = entity["AABB"];
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glm::vec3 absPosition = Transform::AbsolutePosition(entity.World, entity.ID);
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glm::vec3 absScale = Transform::AbsoluteScale(entity.World, entity.ID);
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glm::vec3 origin = absPosition + (glm::vec3)cAABB["Origin"];
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glm::vec3 size = (glm::vec3)cAABB["Size"] * absScale;
|
|
return AABB::FromOriginSize(origin, size);
|
|
}
|
|
|
|
}
|