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author | Mattes D <github@xoft.cz> | 2020-04-03 14:50:08 +0200 |
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committer | GitHub <noreply@github.com> | 2020-04-03 14:50:08 +0200 |
commit | a765e71325c640ab47c60a41b950b446c5901d37 (patch) | |
tree | b245017dea46da13e5646a7a34dcde90d4b2680c /src/Tracer.cpp | |
parent | Pulled the BlockID and BlockInfo headers from Globals.h. (#4591) (diff) | |
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Diffstat (limited to 'src/Tracer.cpp')
-rw-r--r-- | src/Tracer.cpp | 452 |
1 files changed, 0 insertions, 452 deletions
diff --git a/src/Tracer.cpp b/src/Tracer.cpp deleted file mode 100644 index dd4cde479..000000000 --- a/src/Tracer.cpp +++ /dev/null @@ -1,452 +0,0 @@ - -#include "Globals.h" // NOTE: MSVC stupidness requires this to be the same across all modules - -#include "Tracer.h" -#include "BlockInfo.h" -#include "World.h" - -#include "Entities/Entity.h" - -#ifndef _WIN32 - #include <stdlib.h> -#endif - - - -const float FLOAT_EPSILON = 0.0001f; // TODO: Stash this in some header where it can be reused - - -const std::array<const Vector3f, 6>& cTracer::m_NormalTable(void) -{ - static std::array<const Vector3f, 6>* table = - new std::array<const Vector3f, 6> - { - { - Vector3f(-1, 0, 0), // 1: -x - Vector3f( 0, 0, -1), // 2: -z - Vector3f( 1, 0, 0), // 3: +x - Vector3f( 0, 0, 1), // 4: +z - Vector3f( 0, 1, 0), // 5: +y - Vector3f( 0, -1, 0) // 6: -y - } - }; - - return *table; -}; - - - -cTracer::cTracer(cWorld * a_World): - m_World(a_World) -{ -} - - - - - -cTracer::~cTracer() -{ -} - - - - - -int cTracer::SigNum(float a_Num) -{ - if (a_Num < 0.f) - { - return -1; - } - if (a_Num > 0.f) - { - return 1; - } - return 0; -} - - - - - -void cTracer::SetValues(const Vector3f & a_Start, const Vector3f & a_Direction) -{ - // Since this method should only be called by Trace, zero length vectors should already have been taken care of - ASSERT(a_Direction.HasNonZeroLength()); - - // calculate the direction of the ray (linear algebra) - m_Dir = a_Direction; - - // decide which direction to start walking in - m_Step.x = SigNum(m_Dir.x); - m_Step.y = SigNum(m_Dir.y); - m_Step.z = SigNum(m_Dir.z); - - - // normalize the direction vector - m_Dir.Normalize(); - - - // how far we must move in the ray direction before - // we encounter a new voxel in x-direction - // same but y-direction - if (m_Dir.x != 0.f) - { - m_tDelta.x = 1 / std::abs(m_Dir.x); - } - else - { - m_tDelta.x = 0; - } - if (m_Dir.y != 0.f) - { - m_tDelta.y = 1 / std::abs(m_Dir.y); - } - else - { - m_tDelta.y = 0; - } - if (m_Dir.z != 0.f) - { - m_tDelta.z = 1 / std::abs(m_Dir.z); - } - else - { - m_tDelta.z = 0; - } - - - // start voxel coordinates - m_Pos.x = static_cast<int>(floorf(a_Start.x)); - m_Pos.y = static_cast<int>(floorf(a_Start.y)); - m_Pos.z = static_cast<int>(floorf(a_Start.z)); - - // calculate distance to first intersection in the voxel we start from - if (m_Dir.x < 0) - { - m_tMax.x = (static_cast<float>(m_Pos.x) - a_Start.x) / m_Dir.x; - } - else - { - m_tMax.x = (static_cast<float>(m_Pos.x + 1) - a_Start.x) / m_Dir.x; // TODO: Possible division by zero - } - - if (m_Dir.y < 0) - { - m_tMax.y = (static_cast<float>(m_Pos.y) - a_Start.y) / m_Dir.y; - } - else - { - m_tMax.y = (static_cast<float>(m_Pos.y + 1) - a_Start.y) / m_Dir.y; // TODO: Possible division by zero - } - - if (m_Dir.z < 0) - { - m_tMax.z = (static_cast<float>(m_Pos.z) - a_Start.z) / m_Dir.z; - } - else - { - m_tMax.z = (static_cast<float>(m_Pos.z + 1) - a_Start.z) / m_Dir.z; // TODO: Possible division by zero - } -} - - - - - -bool cTracer::Trace(const Vector3f & a_Start, const Vector3f & a_Direction, int a_Distance, bool a_LineOfSight) -{ - if (!a_Direction.HasNonZeroLength()) - { - return false; - } - - if ((a_Start.y < 0) || (a_Start.y >= cChunkDef::Height)) - { - LOGD("%s: Start Y is outside the world (%.2f), not tracing.", __FUNCTION__, a_Start.y); - return false; - } - - SetValues(a_Start, a_Direction); - - Vector3f End = a_Start + (m_Dir * static_cast<float>(a_Distance)); - - if (End.y < 0) - { - float dist = -a_Start.y / m_Dir.y; // No division by 0 possible - End = a_Start + (m_Dir * dist); - } - - // end voxel coordinates - m_End1.x = static_cast<int>(floorf(End.x)); - m_End1.y = static_cast<int>(floorf(End.y)); - m_End1.z = static_cast<int>(floorf(End.z)); - - // check if first is occupied - if (m_Pos.Equals(m_End1)) - { - return false; - } - - bool reachedX = false, reachedY = false, reachedZ = false; - - int Iterations = 0; - while (Iterations < a_Distance) - { - Iterations++; - if ((m_tMax.x < m_tMax.y) && (m_tMax.x < m_tMax.z)) - { - m_tMax.x += m_tDelta.x; - m_Pos.x += m_Step.x; - } - else if (m_tMax.y < m_tMax.z) - { - m_tMax.y += m_tDelta.y; - m_Pos.y += m_Step.y; - } - else - { - m_tMax.z += m_tDelta.z; - m_Pos.z += m_Step.z; - } - - if (m_Step.x > 0.0f) - { - if (m_Pos.x >= m_End1.x) - { - reachedX = true; - } - } - else if (m_Pos.x <= m_End1.x) - { - reachedX = true; - } - - if (m_Step.y > 0.0f) - { - if (m_Pos.y >= m_End1.y) - { - reachedY = true; - } - } - else if (m_Pos.y <= m_End1.y) - { - reachedY = true; - } - - if (m_Step.z > 0.0f) - { - if (m_Pos.z >= m_End1.z) - { - reachedZ = true; - } - } - else if (m_Pos.z <= m_End1.z) - { - reachedZ = true; - } - - if (reachedX && reachedY && reachedZ) - { - return false; - } - - if ((m_Pos.y < 0) || (m_Pos.y >= cChunkDef::Height)) - { - return false; - } - BLOCKTYPE BlockID = m_World->GetBlock(m_Pos); - // Block is counted as a collision if we are not doing a line of sight and it is solid, - // or if the block is not air and not water. That way mobs can still see underwater. - if ((!a_LineOfSight && cBlockInfo::IsSolid(BlockID)) || (a_LineOfSight && (BlockID != E_BLOCK_AIR) && !IsBlockWater(BlockID))) - { - BlockHitPosition = m_Pos; - int Normal = GetHitNormal(a_Start, End, m_Pos); - if (Normal > 0) - { - HitNormal = m_NormalTable()[static_cast<size_t>(Normal - 1)]; - } - return true; - } - } - return false; -} - - - - - -// return 1 = hit, other is not hit -static int LinesCross(float x0, float y0, float x1, float y1, float x2, float y2, float x3, float y3) -{ - // float linx, liny; - - float d = (x1 - x0) * (y3 - y2) - (y1 - y0) * (x3 - x2); - if (std::abs(d) < 0.001) - { - return 0; - } - - float AB = ((y0 - y2) * (x3 - x2) - (x0 - x2) * (y3 - y2)) / d; - if ((AB >= 0.0) && (AB <= 1.0)) - { - float CD = ((y0 - y2) * (x1 - x0) - (x0 - x2) * (y1 - y0)) / d; - if ((CD >= 0.0) && (CD <= 1.0)) - { - // linx = x0 + AB * (x1 - x0); - // liny = y0 + AB * (y1 - y0); - return 1; - } - } - return 0; -} - - - - - -// intersect3D_SegmentPlane(): intersect a segment and a plane -// Input: a_Ray = a segment, and a_Plane = a plane = {Point V0; Vector n;} -// Output: *I0 = the intersect point (when it exists) -// Return: 0 = disjoint (no intersection) -// 1 = intersection in the unique point *I0 -// 2 = the segment lies in the plane -int cTracer::intersect3D_SegmentPlane(const Vector3f & a_Origin, const Vector3f & a_End, const Vector3f & a_PlanePos, const Vector3f & a_PlaneNormal) -{ - Vector3f u = a_End - a_Origin; // a_Ray.P1 - S.P0; - Vector3f w = a_Origin - a_PlanePos; // S.P0 - Pn.V0; - - float D = a_PlaneNormal.Dot(u); // dot(Pn.n, u); - float N = -(a_PlaneNormal.Dot(w)); // -dot(a_Plane.n, w); - - if (std::abs(D) < FLOAT_EPSILON) - { - // segment is parallel to plane - if (N == 0.0) - { - // segment lies in plane - return 2; - } - return 0; // no intersection - } - - // they are not parallel - // compute intersect param - float sI = N / D; - if ((sI < 0) || (sI > 1)) - { - return 0; // no intersection - } - - // Vector3f I (a_Ray->GetOrigin() + sI * u);// S.P0 + sI * u; // compute segment intersect point - RealHit = a_Origin + u * sI; - return 1; -} - - - - - -int cTracer::GetHitNormal(const Vector3f & a_Start, const Vector3f & a_End, const Vector3i & a_BlockPos) -{ - Vector3i SmallBlockPos = a_BlockPos; - BLOCKTYPE BlockID = static_cast<BLOCKTYPE>(m_World->GetBlock(a_BlockPos.x, a_BlockPos.y, a_BlockPos.z)); - - if ((BlockID == E_BLOCK_AIR) || IsBlockWater(BlockID)) - { - return 0; - } - - Vector3f BlockPos; - BlockPos = Vector3f(SmallBlockPos); - - Vector3f Look = (a_End - a_Start); - Look.Normalize(); - - float dot = Look.Dot(Vector3f(-1, 0, 0)); // first face normal is x -1 - if (dot < 0) - { - int Lines = LinesCross(a_Start.x, a_Start.y, a_End.x, a_End.y, BlockPos.x, BlockPos.y, BlockPos.x, BlockPos.y + 1); - if (Lines == 1) - { - Lines = LinesCross(a_Start.x, a_Start.z, a_End.x, a_End.z, BlockPos.x, BlockPos.z, BlockPos.x, BlockPos.z + 1); - if (Lines == 1) - { - intersect3D_SegmentPlane(a_Start, a_End, BlockPos, Vector3f(-1, 0, 0)); - return 1; - } - } - } - dot = Look.Dot(Vector3f(0, 0, -1)); // second face normal is z -1 - if (dot < 0) - { - int Lines = LinesCross(a_Start.z, a_Start.y, a_End.z, a_End.y, BlockPos.z, BlockPos.y, BlockPos.z, BlockPos.y + 1); - if (Lines == 1) - { - Lines = LinesCross(a_Start.z, a_Start.x, a_End.z, a_End.x, BlockPos.z, BlockPos.x, BlockPos.z, BlockPos.x + 1); - if (Lines == 1) - { - intersect3D_SegmentPlane(a_Start, a_End, BlockPos, Vector3f(0, 0, -1)); - return 2; - } - } - } - dot = Look.Dot(Vector3f(1, 0, 0)); // third face normal is x 1 - if (dot < 0) - { - int Lines = LinesCross(a_Start.x, a_Start.y, a_End.x, a_End.y, BlockPos.x + 1, BlockPos.y, BlockPos.x + 1, BlockPos.y + 1); - if (Lines == 1) - { - Lines = LinesCross(a_Start.x, a_Start.z, a_End.x, a_End.z, BlockPos.x + 1, BlockPos.z, BlockPos.x + 1, BlockPos.z + 1); - if (Lines == 1) - { - intersect3D_SegmentPlane(a_Start, a_End, BlockPos + Vector3f(1, 0, 0), Vector3f(1, 0, 0)); - return 3; - } - } - } - dot = Look.Dot(Vector3f(0, 0, 1)); // fourth face normal is z 1 - if (dot < 0) - { - int Lines = LinesCross(a_Start.z, a_Start.y, a_End.z, a_End.y, BlockPos.z + 1, BlockPos.y, BlockPos.z + 1, BlockPos.y + 1); - if (Lines == 1) - { - Lines = LinesCross(a_Start.z, a_Start.x, a_End.z, a_End.x, BlockPos.z + 1, BlockPos.x, BlockPos.z + 1, BlockPos.x + 1); - if (Lines == 1) - { - intersect3D_SegmentPlane(a_Start, a_End, BlockPos + Vector3f(0, 0, 1), Vector3f(0, 0, 1)); - return 4; - } - } - } - dot = Look.Dot(Vector3f(0, 1, 0)); // fifth face normal is y 1 - if (dot < 0) - { - int Lines = LinesCross(a_Start.y, a_Start.x, a_End.y, a_End.x, BlockPos.y + 1, BlockPos.x, BlockPos.y + 1, BlockPos.x + 1); - if (Lines == 1) - { - Lines = LinesCross(a_Start.y, a_Start.z, a_End.y, a_End.z, BlockPos.y + 1, BlockPos.z, BlockPos.y + 1, BlockPos.z + 1); - if (Lines == 1) - { - intersect3D_SegmentPlane(a_Start, a_End, BlockPos + Vector3f(0, 1, 0), Vector3f(0, 1, 0)); - return 5; - } - } - } - dot = Look.Dot(Vector3f(0, -1, 0)); // sixth face normal is y -1 - if (dot < 0) - { - int Lines = LinesCross(a_Start.y, a_Start.x, a_End.y, a_End.x, BlockPos.y, BlockPos.x, BlockPos.y, BlockPos.x + 1); - if (Lines == 1) - { - Lines = LinesCross(a_Start.y, a_Start.z, a_End.y, a_End.z, BlockPos.y, BlockPos.z, BlockPos.y, BlockPos.z + 1); - if (Lines == 1) - { - intersect3D_SegmentPlane(a_Start, a_End, BlockPos, Vector3f(0, -1, 0)); - return 6; - } - } - } - return 0; -} |