Files
VoxelEngine/src/maths/rays.cpp
T
2023-12-10 00:38:32 +06:00

351 lines
12 KiB
C++

#include "rays.h"
#include "aabb.h"
#include "glm/glm.hpp"
std::unordered_map<rayvec3, AABBFaces> Rays::raysBoxCache_ = {};
const rayvec3 X_AXIS = rayvec3(1,0,0), Y_AXIS = rayvec3(0,1,0), Z_AXIS = rayvec3(0,0,1);
//make faces from AABB
AABBFaces::AABBFaces(const rayvec3& parentBoxPos, const AABB& parentBox){
rayvec3 pbMin = parentBox.min(), // every face is min-point and opposite corner point
pbMax = parentBox.max(),
pbRealPos = parentBoxPos + pbMin;
rayvec2 yzMax = rayvec2(parentBoxPos.y + pbMax.y, parentBoxPos.z + pbMax.z ),
xzMax = rayvec2(parentBoxPos.x + pbMax.x, parentBoxPos.z + pbMax.z ),
xyMax = rayvec2(parentBoxPos.x + pbMax.x, parentBoxPos.y + pbMax.y );
faces[0] = {pbRealPos, yzMax}; //in order of AABBFaces::KINDS_ORDER!
faces[1] = {parentBoxPos + rayvec3(pbMax.x, pbMin.y, pbMin.z), yzMax};
faces[2] = {pbRealPos, xzMax};
faces[3] = {parentBoxPos + rayvec3(pbMin.x, pbMax.y, pbMin.z), xzMax};
faces[4] = {pbRealPos, xyMax};
faces[5] = {parentBoxPos + rayvec3(pbMin.x, pbMin.y, pbMax.z), xyMax};
}
template <>
RayRelation Rays::rayIntersectAAFace<AAFaceKind::Xperp>(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& faceMin,
const rayvec2& faceOppositeCorner, //y and z global coords of opposite corner
rayvec3& intersectPoint_ret
){
if (fabs(glm::dot(rayDir, X_AXIS)) < 1.0E-8){ //precision
return RayRelation::Parallel;
}
glm::float64 rayCoef = (faceMin.x - rayOrigin.x) / (rayDir.x);
intersectPoint_ret = {faceMin.x,
rayCoef*rayDir.y + rayOrigin.y,
rayCoef*rayDir.z + rayOrigin.z};
if (rayDir.x > 0){
if (intersectPoint_ret.y >= faceMin.y
&& intersectPoint_ret.y <= faceOppositeCorner[0]
&& intersectPoint_ret.z >= faceMin.z
&& intersectPoint_ret.z <= faceOppositeCorner[1]){
return RayRelation::Intersect;
}
}
else{
if (intersectPoint_ret.y <= faceMin.y
&& intersectPoint_ret.y >= faceOppositeCorner[0]
&& intersectPoint_ret.z <= faceMin.z
&& intersectPoint_ret.z >= faceOppositeCorner[1]){
return RayRelation::Intersect;
}
}
return RayRelation::None;
}
template <>
RayRelation Rays::rayIntersectAAFace<AAFaceKind::Yperp>(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& faceMin,
const rayvec2& faceOppositeCorner, //x and z global coords of opposite corner
rayvec3& intersectPoint_ret
){
if (fabs(glm::dot(rayDir, Y_AXIS)) < 1.0E-8){ //precision
return RayRelation::Parallel;
}
glm::float64 rayCoef = (faceMin.y - rayOrigin.y) / (rayDir.y);
intersectPoint_ret = {rayCoef*rayDir.x + rayOrigin.x,
faceMin.y,
rayCoef*rayDir.z + rayOrigin.z};
if (rayDir.y > 0){
if (intersectPoint_ret.x >= faceMin.x //Face-hit check
&& intersectPoint_ret.x <= faceOppositeCorner[0]
&& intersectPoint_ret.z >= faceMin.z
&& intersectPoint_ret.z <= faceOppositeCorner[1] ){
return RayRelation::Intersect;
}
}
else{
if (intersectPoint_ret.x <= faceMin.x //Face-hit check for negative dir.
&& intersectPoint_ret.x >= faceOppositeCorner[0]
&& intersectPoint_ret.z <= faceMin.z
&& intersectPoint_ret.z >= faceOppositeCorner[1]){
return RayRelation::Intersect;
}
}
return RayRelation::None;
}
template <>
RayRelation Rays::rayIntersectAAFace<AAFaceKind::Zperp>(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& faceMin,
const rayvec2& faceOppositeCorner, //x and y global coords of opposite corner
rayvec3& intersectPoint_ret
){
if (fabs(glm::dot(rayDir, Z_AXIS)) < 1.0E-8){ //precision
return RayRelation::Parallel;
}
glm::float64 rayCoef = (faceMin.z - rayOrigin.z) / (rayDir.z);
intersectPoint_ret = {rayCoef*rayDir.x + rayOrigin.x,
rayCoef*rayDir.y + rayOrigin.y,
faceMin.z};
if (rayDir.z > 0){
if (intersectPoint_ret.x >= faceMin.x //Face-hit check
&& intersectPoint_ret.x <= faceOppositeCorner[0]
&& intersectPoint_ret.y >= faceMin.y
&& intersectPoint_ret.y <= faceOppositeCorner[1] ){
return RayRelation::Intersect;
}
}
else{
if (intersectPoint_ret.x <= faceMin.x //Face-hit check
&& intersectPoint_ret.x >= faceOppositeCorner[0]
&& intersectPoint_ret.y <= faceMin.y
&& intersectPoint_ret.y >= faceOppositeCorner[1] ){
return RayRelation::Intersect;
}
}
return RayRelation::None;
}
double Rays::updateNormal(
double newDistApprox,
const glm::ivec3& newNormal,
double currentDistApprox,
glm::ivec3& normal_ret
){
if (newDistApprox < currentDistApprox){
currentDistApprox = newDistApprox;
normal_ret = newNormal;
}
return currentDistApprox;
}
template <>
RayRelation Rays::isRayIntersectsAAFace<AAFaceKind::Xperp>(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& faceMin,
const rayvec2& faceOppositeCorner,
glm::ivec3& normal_ret,
double& currentDistApprox
){
if (fabs(glm::dot(rayDir, X_AXIS)) < 1.0E-8){ //precision of "parallelity"
return RayRelation::Parallel;
}
glm::float64 rayCoef = (faceMin.x - rayOrigin.x);
rayvec3 intersectPointMult = {faceMin.x * rayDir.x,
rayCoef*rayDir.y + rayOrigin.y * rayDir.x,
rayCoef*rayDir.z + rayOrigin.z * rayDir.x};
if (rayDir.x > 0){
if (intersectPointMult.y >= faceMin.y * rayDir.x //Face-hit check
&& intersectPointMult.y <= faceOppositeCorner[0] * rayDir.x
&& intersectPointMult.z >= faceMin.z * rayDir.x
&& intersectPointMult.z <= faceOppositeCorner[1] * rayDir.x){
currentDistApprox = updateNormal(fabs(rayCoef * rayDir.y * rayDir.z), -X_AXIS, currentDistApprox, normal_ret);
return RayRelation::Intersect;
}
}
else{
if (intersectPointMult.y <= faceMin.y * rayDir.x //Face-hit check for negative dir.
&& intersectPointMult.y >= faceOppositeCorner[0] * rayDir.x
&& intersectPointMult.z <= faceMin.z * rayDir.x
&& intersectPointMult.z >= faceOppositeCorner[1] * rayDir.x){
currentDistApprox = updateNormal(fabs(rayCoef * rayDir.y * rayDir.z), X_AXIS, currentDistApprox, normal_ret);
return RayRelation::Intersect;
}
}
return RayRelation::None;
}
template <>
RayRelation Rays::isRayIntersectsAAFace<AAFaceKind::Yperp>(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& faceMin,
const rayvec2& faceOppositeCorner,
glm::ivec3& normal_ret,
double& currentDistApprox
){
if (fabs(glm::dot(rayDir, Y_AXIS)) < 1.0E-8){ //precision of "parallelity"
return RayRelation::Parallel;
}
glm::float64 rayCoef = (faceMin.y - rayOrigin.y);
rayvec3 intersectPointMult = {rayCoef*rayDir.x + rayOrigin.x * rayDir.y,
faceMin.y * rayDir.y,
rayCoef*rayDir.z + rayOrigin.z * rayDir.y};
if (rayDir.y > 0){
if (intersectPointMult.x >= faceMin.x * rayDir.y //Face-hit check
&& intersectPointMult.x <= faceOppositeCorner[0] * rayDir.y
&& intersectPointMult.z >= faceMin.z * rayDir.y
&& intersectPointMult.z <= faceOppositeCorner[1] * rayDir.y){
currentDistApprox = updateNormal(fabs(rayCoef * rayDir.x * rayDir.z), -Y_AXIS, currentDistApprox, normal_ret);
return RayRelation::Intersect;
}
}
else{
if (intersectPointMult.x <= faceMin.x * rayDir.y //Face-hit check for negative dir.
&& intersectPointMult.x >= faceOppositeCorner[0] * rayDir.y
&& intersectPointMult.z <= faceMin.z * rayDir.y
&& intersectPointMult.z >= faceOppositeCorner[1] * rayDir.y){
currentDistApprox = updateNormal(fabs(rayCoef * rayDir.x * rayDir.z), Y_AXIS, currentDistApprox, normal_ret);
return RayRelation::Intersect;
}
}
return RayRelation::None;
}
template <>
RayRelation Rays::isRayIntersectsAAFace<AAFaceKind::Zperp>(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& faceMin,
const rayvec2& faceOppositeCorner,
glm::ivec3& normal_ret,
double& currentDistApprox
){
if (fabs(glm::dot(rayDir, Z_AXIS)) < 1.0E-8){ //precision of "parallelity"
return RayRelation::Parallel;
}
glm::float64 rayCoef = (faceMin.z - rayOrigin.z);
rayvec3 intersectPointMult = {rayCoef*rayDir.x + rayOrigin.x * rayDir.z,
rayCoef*rayDir.y + rayOrigin.y * rayDir.z,
faceMin.z * rayDir.z};
if (rayDir.z > 0){
if (intersectPointMult.x >= faceMin.x * rayDir.z //Face-hit check
&& intersectPointMult.x <= faceOppositeCorner[0] * rayDir.z
&& intersectPointMult.y >= faceMin.y * rayDir.z
&& intersectPointMult.y <= faceOppositeCorner[1] * rayDir.z){
currentDistApprox = updateNormal(fabs(rayCoef * rayDir.x * rayDir.y), -Z_AXIS, currentDistApprox, normal_ret);
return RayRelation::Intersect;
}
}
else{
if (intersectPointMult.x <= faceMin.x * rayDir.z //Face-hit check
&& intersectPointMult.x >= faceOppositeCorner[0] * rayDir.z
&& intersectPointMult.y <= faceMin.y * rayDir.z
&& intersectPointMult.y >= faceOppositeCorner[1] * rayDir.z){
currentDistApprox = updateNormal(fabs(rayCoef * rayDir.x * rayDir.y), Z_AXIS, currentDistApprox, normal_ret);
return RayRelation::Intersect;
}
}
return RayRelation::None;
}
RayRelation Rays::rayIntersectAABB(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const rayvec3& boxPos,
const AABB& box,
float maxDist,
rayvec3& pointIn_ret,
rayvec3& pointOut_ret,
glm::ivec3& normal_ret){
if constexpr (IS_RAYS_BOX_CACHE_ON){
if (raysBoxCache_.find(boxPos) != raysBoxCache_.end()){
const AABBFaces& boxFaces = raysBoxCache_[boxPos];
return rayIntersectAABBFaces(rayOrigin, rayDir, boxFaces, maxDist, pointIn_ret, pointOut_ret, normal_ret);
} else {
const AABBFaces& boxFaces = AABBFaces(boxPos, box);
raysBoxCache_[boxPos] = boxFaces;
return rayIntersectAABBFaces(rayOrigin, rayDir, boxFaces, maxDist, pointIn_ret, pointOut_ret, normal_ret);
}
} else {
const AABBFaces& boxFaces = AABBFaces(boxPos, box);
return rayIntersectAABBFaces(rayOrigin, rayDir, boxFaces, maxDist, pointIn_ret, pointOut_ret, normal_ret);
}
}
RayRelation Rays::rayIntersectAABBFaces(
const rayvec3& rayOrigin,
const rayvec3& rayDir,
const AABBFaces& boxFaces,
float maxDist,
rayvec3& pointIn_ret,
rayvec3& pointOut_ret,
glm::ivec3& normal_ret){//TODO: points returning
RayRelation rel;
double faceDistApprox = maxDist;
unsigned char intersectedCount = 0; //this code is very uncomfortable, DONT LEARN IT!
rel = isRayIntersectsAAFace<AABBFaces::KINDS_ORDER[0]>(
rayOrigin, rayDir, boxFaces.faces[0].first, boxFaces.faces[0].second, normal_ret, faceDistApprox
);
if (rel > RayRelation::None){
++intersectedCount;
}
rel = isRayIntersectsAAFace<AABBFaces::KINDS_ORDER[1]>(
rayOrigin, rayDir, boxFaces.faces[1].first, boxFaces.faces[1].second, normal_ret, faceDistApprox
);
if (rel > RayRelation::None){
++intersectedCount;
}
rel = isRayIntersectsAAFace<AABBFaces::KINDS_ORDER[2]>(
rayOrigin, rayDir, boxFaces.faces[2].first, boxFaces.faces[2].second, normal_ret, faceDistApprox
);
if (rel > RayRelation::None){
++intersectedCount;
}
rel = isRayIntersectsAAFace<AABBFaces::KINDS_ORDER[3]>(
rayOrigin, rayDir, boxFaces.faces[3].first, boxFaces.faces[3].second, normal_ret, faceDistApprox
);
if (rel > RayRelation::None){
++intersectedCount;
}
rel = isRayIntersectsAAFace<AABBFaces::KINDS_ORDER[4]>(
rayOrigin, rayDir, boxFaces.faces[4].first, boxFaces.faces[4].second, normal_ret, faceDistApprox
);
if (rel > RayRelation::None){
++intersectedCount;
}
rel = isRayIntersectsAAFace<AABBFaces::KINDS_ORDER[5]>(
rayOrigin, rayDir, boxFaces.faces[5].first, boxFaces.faces[5].second, normal_ret, faceDistApprox
);
if (rel > RayRelation::None){
++intersectedCount;
}
if (intersectedCount > 0) return RayRelation::Intersect;
return RayRelation::None;
}