// LineBlockTracer.h
// Declares the cLineBlockTracer class representing a cBlockTracer that traces along a straight line between two points
#pragma once
#include "BlockTracer.h"
// fwd: Chunk.h
class cChunk;
class cLineBlockTracer:
public cBlockTracer
{
using Super = cBlockTracer;
public:
enum eLineOfSight
{
// Bit flags used for LineOfSightTrace's Sight parameter:
losAir = 1, // Can see through air
losWater = 2, // Can see through water
losLava = 4, // Can see through lava
// Common combinations:
losAirWaterLava = losAir | losWater | losLava,
losAirWater = losAir | losWater,
};
cLineBlockTracer(cWorld & a_World, cCallbacks & a_Callbacks);
/** Traces one line between Start and End; returns true if the entire line was traced (until OnNoMoreHits()) */
bool Trace(Vector3d a_Start, Vector3d a_End);
// Utility functions for simple one-line usage:
/** Traces one line between Start and End; returns true if the entire line was traced (until OnNoMoreHits()) */
static bool Trace(cWorld & a_World, cCallbacks & a_Callbacks, const Vector3d a_Start, const Vector3d a_End);
/** Returns true if the two positions are within line of sight (not obscured by blocks).
a_Sight specifies which blocks are considered transparent for the trace, is an OR-combination of eLineOfSight constants. */
static bool LineOfSightTrace(cWorld & a_World, const Vector3d & a_Start, const Vector3d & a_End, int a_Sight);
/** Traces until the first solid block is hit (or until end, whichever comes first.
If a solid block was hit, returns true and fills a_HitCoords, a_HitBlockCoords and a_HitBlockFace.
If a_End is encountered without hitting any solid block, returns false and doesn't touch a_HitCoords, a_HitBlockCoords nor a_HitBlockFace.
a_HitCoords is the exact coords of the hit,
a_HitBlockCoords are the coords of the solid block that was hit,
a_HitBlockFace is the face of the solid block that was hit. */
static bool FirstSolidHitTrace(
cWorld & a_World,
const Vector3d & a_Start, const Vector3d & a_End,
Vector3d & a_HitCoords,
Vector3i & a_HitBlockCoords,
eBlockFace & a_HitBlockFace
);
protected:
/** The start point of the trace */
Vector3d m_Start;
/** The end point of the trace */
Vector3d m_End;
/** The difference in coords, End - Start */
Vector3d m_Diff;
/** The increment at which the block coords are going from Start to End; either +1 or -1 */
Vector3i m_Dir;
/** The current block */
Vector3i m_Current;
/** The face through which the current block has been entered */
eBlockFace m_CurrentFace;
/** Adjusts the start point above the world to just at the world's top */
void FixStartAboveWorld(void);
/** Adjusts the start point below the world to just at the world's bottom */
void FixStartBelowWorld(void);
/** Calculates the XZ coords of an intersection with the specified Yconst plane; assumes that such an intersection exists */
void CalcXZIntersection(double a_Y, double & a_IntersectX, double & a_IntersectZ);
/** Moves m_Current to the next block on the line; returns false if no move is possible (reached the end) */
bool MoveToNextBlock(void);
bool ChunkCallback(cChunk * a_Chunk);
} ;
