static bool PickBlock(Game game, PickedPos pos)
{
if (!game.CanPick(t.Block))
{
return(false);
}
// This cell falls on the path of the ray. Now perform an additional bounding box test,
// since some blocks do not occupy a whole cell.
float t0, t1;
if (!Intersection.RayIntersectsBox(t.Origin, t.Dir, t.Min, t.Max, out t0, out t1))
{
return(false);
}
Vector3 I = t.Origin + t.Dir * t0;
// Only pick the block if the block is precisely within reach distance.
float lenSq = (I - t.Origin).LengthSquared;
float reach = game.LocalPlayer.ReachDistance;
if (lenSq <= reach * reach)
{
pos.SetAsValid(t.X, t.Y, t.Z, t.Min, t.Max, t.Block, I);
}
else
{
pos.SetAsInvalid();
}
return(true);
}
static bool CameraClip(Game game, PickedPos pos)
{
if (BlockInfo.Draw[t.Block] == DrawType.Gas || BlockInfo.Collide[t.Block] != CollideType.Solid)
{
return(false);
}
float t0, t1;
const float adjust = 0.1f;
if (!Intersection.RayIntersectsBox(t.Origin, t.Dir, t.Min, t.Max, out t0, out t1))
{
return(false);
}
Vector3 I = t.Origin + t.Dir * t0;
pos.SetAsValid(t.X, t.Y, t.Z, t.Min, t.Max, t.Block, I);
switch (pos.Face)
{
case BlockFace.XMin: pos.Intersect.X -= adjust; break;
case BlockFace.XMax: pos.Intersect.X += adjust; break;
case BlockFace.YMin: pos.Intersect.Y -= adjust; break;
case BlockFace.YMax: pos.Intersect.Y += adjust; break;
case BlockFace.ZMin: pos.Intersect.Z -= adjust; break;
case BlockFace.ZMax: pos.Intersect.Z += adjust; break;
}
return(true);
}
// http://www.xnawiki.com/index.php/Voxel_traversal
// https://web.archive.org/web/20120113051728/http://www.xnawiki.com/index.php?title=Voxel_traversal
/// <summary> Determines the picked block based on the given origin and direction vector.<br/>
/// Marks pickedPos as invalid if a block could not be found due to going outside map boundaries
/// or not being able to find a suitable candiate within the given reach distance. </summary>
public static void CalculatePickedBlock(Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos)
{
// Implementation based on: "A Fast Voxel Traversal Algorithm for Ray Tracing"
// John Amanatides, Andrew Woo
// http://www.cse.yorku.ca/~amana/research/grid.pdf
// http://www.devmaster.net/articles/raytracing_series/A%20faster%20voxel%20traversal%20algorithm%20for%20ray%20tracing.pdf
// The cell in which the ray starts.
Vector3I start = Vector3I.Floor(origin); // Rounds the position's X, Y and Z down to the nearest integer values.
int x = start.X, y = start.Y, z = start.Z;
Vector3I step, cellBoundary;
Vector3 tMax, tDelta;
CalcVectors(origin, dir, out step, out cellBoundary, out tMax, out tDelta);
Map map = game.Map;
BlockInfo info = game.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
// For each step, determine which distance to the next voxel boundary is lowest (i.e.
// which voxel boundary is nearest) and walk that way.
while (iterations < 10000)
{
byte block = GetBlock(map, x, y, z, origin);
Vector3 min = new Vector3(x, y, z) + info.MinBB[block];
Vector3 max = new Vector3(x, y, z) + info.MaxBB[block];
float dx = Math.Min(Math.Abs(origin.X - min.X), Math.Abs(origin.X - max.X));
float dy = Math.Min(Math.Abs(origin.Y - min.Y), Math.Abs(origin.Y - max.Y));
float dz = Math.Min(Math.Abs(origin.Z - min.Z), Math.Abs(origin.Z - max.Z));
if (dx * dx + dy * dy + dz * dz > reachSquared)
{
pickedPos.SetAsInvalid();
return;
}
if (game.CanPick(block))
{
// This cell falls on the path of the ray. Now perform an additional bounding box test,
// since some blocks do not occupy a whole cell.
float t0, t1;
if (Intersection.RayIntersectsBox(origin, dir, min, max, out t0, out t1))
{
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid(x, y, z, min, max, block, intersect);
return;
}
}
Step(ref tMax, ref tDelta, ref step, ref x, ref y, ref z);
iterations++;
}
throw new InvalidOperationException("did over 10000 iterations in CalculatePickedBlock(). " +
"Something has gone wrong. (dir: " + dir + ")");
}
/// <summary> Determines the picked block based on the given origin and direction vector.<br/>
/// Marks pickedPos as invalid if a block could not be found due to going outside map boundaries
/// or not being able to find a suitable candiate within the given reach distance. </summary>
public static void CalculatePickedBlock(Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos)
{
tracer.SetRayData(origin, dir);
World map = game.World;
BlockInfo info = game.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
Vector3I pOrigin = Vector3I.Floor(origin);
while (iterations < 10000)
{
int x = tracer.X, y = tracer.Y, z = tracer.Z;
byte block = GetBlock(map, x, y, z, pOrigin);
Vector3 min = new Vector3(x, y, z) + info.MinBB[block];
Vector3 max = new Vector3(x, y, z) + info.MaxBB[block];
if (info.IsLiquid[block])
{
min.Y -= 1.5f / 16; max.Y -= 1.5f / 16;
}
float dx = Math.Min(Math.Abs(origin.X - min.X), Math.Abs(origin.X - max.X));
float dy = Math.Min(Math.Abs(origin.Y - min.Y), Math.Abs(origin.Y - max.Y));
float dz = Math.Min(Math.Abs(origin.Z - min.Z), Math.Abs(origin.Z - max.Z));
if (dx * dx + dy * dy + dz * dz > reachSquared)
{
pickedPos.SetAsInvalid(); return;
}
if (game.CanPick(block))
{
// This cell falls on the path of the ray. Now perform an additional bounding box test,
// since some blocks do not occupy a whole cell.
float t0, t1;
if (Intersection.RayIntersectsBox(origin, dir, min, max, out t0, out t1))
{
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid(x, y, z, min, max, block, intersect);
return;
}
}
tracer.Step();
iterations++;
}
throw new InvalidOperationException("did over 10000 iterations in CalculatePickedBlock(). " +
"Something has gone wrong. (dir: " + dir + ")");
}
static bool PickBlock(Game game, PickedPos pos)
{
if (!game.CanPick(t.Block))
{
return(false);
}
// This cell falls on the path of the ray. Now perform an additional bounding box test,
// since some blocks do not occupy a whole cell.
float t0, t1;
if (!Intersection.RayIntersectsBox(t.Origin, t.Dir, t.Min, t.Max, out t0, out t1))
{
return(false);
}
Vector3 I = t.Origin + t.Dir * t0;
pos.SetAsValid(t.X, t.Y, t.Z, t.Min, t.Max, t.Block, I);
return(true);
}
/// <summary> Determines the picked block based on the given origin and direction vector.<br/>
/// Marks pickedPos as invalid if a block could not be found due to going outside map boundaries
/// or not being able to find a suitable candiate within the given reach distance. </summary>
public static void CalculatePickedBlock( Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos )
{
tracer.SetRayData( origin, dir );
World map = game.World;
BlockInfo info = game.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
Vector3I pOrigin = Vector3I.Floor( origin );
while( iterations < 10000 ) {
int x = tracer.X, y = tracer.Y, z = tracer.Z;
byte block = GetBlock( map, x, y, z, pOrigin );
Vector3 min = new Vector3( x, y, z ) + info.MinBB[block];
Vector3 max = new Vector3( x, y, z ) + info.MaxBB[block];
float dx = Math.Min( Math.Abs( origin.X - min.X ), Math.Abs( origin.X - max.X ) );
float dy = Math.Min( Math.Abs( origin.Y - min.Y ), Math.Abs( origin.Y - max.Y ) );
float dz = Math.Min( Math.Abs( origin.Z - min.Z ), Math.Abs( origin.Z - max.Z ) );
if( dx * dx + dy * dy + dz * dz > reachSquared ) {
pickedPos.SetAsInvalid(); return;
}
if( game.CanPick( block ) ) {
// This cell falls on the path of the ray. Now perform an additional bounding box test,
// since some blocks do not occupy a whole cell.
float t0, t1;
if( Intersection.RayIntersectsBox( origin, dir, min, max, out t0, out t1 ) ) {
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid( x, y, z, min, max, block, intersect );
return;
}
}
tracer.Step();
iterations++;
}
throw new InvalidOperationException( "did over 10000 iterations in CalculatePickedBlock(). " +
"Something has gone wrong. (dir: " + dir + ")" );
}
static bool CameraClip(Game game, PickedPos pos)
{
if (BlockInfo.Draw[t.Block] == DrawType.Gas || BlockInfo.Collide[t.Block] != CollideType.Solid)
{
return(false);
}
float t0, t1;
if (!Intersection.RayIntersectsBox(t.Origin, t.Dir, t.Min, t.Max, out t0, out t1))
{
return(false);
}
// Need to collide with slightly outside block, to avoid camera clipping issues
t.Min -= adjust; t.Max += adjust;
Intersection.RayIntersectsBox(t.Origin, t.Dir, t.Min, t.Max, out t0, out t1);
Vector3 I = t.Origin + t.Dir * t0;
pos.SetAsValid(t.X, t.Y, t.Z, t.Min, t.Max, t.Block, I);
return(true);
}
public static void ClipCameraPos( Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos )
{
if( !game.CameraClipping ) {
pickedPos.SetAsInvalid();
pickedPos.IntersectPoint = origin + dir * reach;
return;
}
tracer.SetRayData( origin, dir );
World map = game.World;
BlockInfo info = game.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
Vector3I pOrigin = Vector3I.Floor( origin );
while( iterations < 10000 ) {
int x = tracer.X, y = tracer.Y, z = tracer.Z;
byte block = GetBlock( map, x, y, z, pOrigin );
Vector3 min = new Vector3( x, y, z ) + info.MinBB[block];
Vector3 max = new Vector3( x, y, z ) + info.MaxBB[block];
float dx = Math.Min( Math.Abs( origin.X - min.X ), Math.Abs( origin.X - max.X ) );
float dy = Math.Min( Math.Abs( origin.Y - min.Y ), Math.Abs( origin.Y - max.Y ) );
float dz = Math.Min( Math.Abs( origin.Z - min.Z ), Math.Abs( origin.Z - max.Z ) );
if( dx * dx + dy * dy + dz * dz > reachSquared ) {
pickedPos.SetAsInvalid();
pickedPos.IntersectPoint = origin + dir * reach;
return;
}
if( info.Collide[block] == CollideType.Solid && !info.IsAir[block] ) {
float t0, t1;
const float adjust = 0.1f;
if( Intersection.RayIntersectsBox( origin, dir, min, max, out t0, out t1 ) ) {
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid( x, y, z, min, max, block, intersect );
switch( pickedPos.BlockFace) {
case CpeBlockFace.XMin:
pickedPos.IntersectPoint.X -= adjust; break;
case CpeBlockFace.XMax:
pickedPos.IntersectPoint.X += adjust; break;
case CpeBlockFace.YMin:
pickedPos.IntersectPoint.Y -= adjust; break;
case CpeBlockFace.YMax:
pickedPos.IntersectPoint.Y += adjust; break;
case CpeBlockFace.ZMin:
pickedPos.IntersectPoint.Z -= adjust; break;
case CpeBlockFace.ZMax:
pickedPos.IntersectPoint.Z += adjust; break;
}
return;
}
}
tracer.Step();
iterations++;
}
throw new InvalidOperationException( "did over 10000 iterations in ClipCameraPos(). " +
"Something has gone wrong. (dir: " + dir + ")" );
}
// http://www.xnawiki.com/index.php/Voxel_traversal
public static void GetPickedBlockPos( Game window, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos )
{
// Implementation is based on:
// "A Fast Voxel Traversal Algorithm for Ray Tracing"
// John Amanatides, Andrew Woo
// http://www.cse.yorku.ca/~amana/research/grid.pdf
// http://www.devmaster.net/articles/raytracing_series/A%20faster%20voxel%20traversal%20algorithm%20for%20ray%20tracing.pdf
// NOTES:
// * This code assumes that the ray's position and direction are in 'cell coordinates', which means
// that one unit equals one cell in all directions.
// * When the ray doesn't start within the voxel grid, calculate the first position at which the
// ray could enter the grid. If it never enters the grid, there is nothing more to do here.
// * Also, it is important to test when the ray exits the voxel grid when the grid isn't infinite.
// * The Point3D structure is a simple structure having three integer fields (X, Y and Z).
// The cell in which the ray starts.
Vector3I start = Vector3I.Floor( origin ); // Rounds the position's X, Y and Z down to the nearest integer values.
int x = start.X;
int y = start.Y;
int z = start.Z;
// Determine which way we go.
int stepX = Math.Sign( dir.X );
int stepY = Math.Sign( dir.Y );
int stepZ = Math.Sign( dir.Z );
// Calculate cell boundaries. When the step (i.e. direction sign) is positive,
// the next boundary is AFTER our current position, meaning that we have to add 1.
// Otherwise, it is BEFORE our current position, in which case we add nothing.
Vector3I cellBoundary = new Vector3I(
x + ( stepX > 0 ? 1 : 0 ),
y + ( stepY > 0 ? 1 : 0 ),
z + ( stepZ > 0 ? 1 : 0 ) );
// NOTE: For the following calculations, the result will be Single.PositiveInfinity
// when ray.Direction.X, Y or Z equals zero, which is OK. However, when the left-hand
// value of the division also equals zero, the result is Single.NaN, which is not OK.
// Determine how far we can travel along the ray before we hit a voxel boundary.
Vector3 tMax = new Vector3(
( cellBoundary.X - origin.X ) / dir.X, // Boundary is a plane on the YZ axis.
( cellBoundary.Y - origin.Y ) / dir.Y, // Boundary is a plane on the XZ axis.
( cellBoundary.Z - origin.Z ) / dir.Z ); // Boundary is a plane on the XY axis.
if( Single.IsNaN( tMax.X ) || Single.IsInfinity( tMax.X ) ) tMax.X = Single.PositiveInfinity;
if( Single.IsNaN( tMax.Y ) || Single.IsInfinity( tMax.Y ) ) tMax.Y = Single.PositiveInfinity;
if( Single.IsNaN( tMax.Z ) || Single.IsInfinity( tMax.Z ) ) tMax.Z = Single.PositiveInfinity;
// Determine how far we must travel along the ray before we have crossed a gridcell.
Vector3 tDelta = new Vector3(
stepX / dir.X, // Crossing the width of a cell.
stepY / dir.Y, // Crossing the height of a cell.
stepZ / dir.Z ); // Crossing the depth of a cell.
if( Single.IsNaN( tDelta.X ) ) tDelta.X = Single.PositiveInfinity;
if( Single.IsNaN( tDelta.Y ) ) tDelta.Y = Single.PositiveInfinity;
if( Single.IsNaN( tDelta.Z ) ) tDelta.Z = Single.PositiveInfinity;
Map map = window.Map;
BlockInfo info = window.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
// For each step, determine which distance to the next voxel boundary is lowest (i.e.
// which voxel boundary is nearest) and walk that way.
while( iterations < 10000 ) {
byte block = GetBlock( map, x, y, z, origin );
Vector3 min = new Vector3( x, y, z ) + info.MinBB[block];
Vector3 max = new Vector3( x, y, z ) + info.MaxBB[block];
float dx = Math.Min( Math.Abs( origin.X - min.X ), Math.Abs( origin.X - max.X ) );
float dy = Math.Min( Math.Abs( origin.Y - min.Y ), Math.Abs( origin.Y - max.Y ) );
float dz = Math.Min( Math.Abs( origin.Z - min.Z ), Math.Abs( origin.Z - max.Z ) );
if( dx * dx + dy * dy + dz * dz > reachSquared ) {
pickedPos.SetAsInvalid();
return;
}
if( window.CanPick( block ) ) {
// This cell falls on the path of the ray. Now perform an additional bounding box test,
// since some blocks do not occupy a whole cell.
float t0, t1;
if( Intersection.RayIntersectsBox( origin, dir, min, max, out t0, out t1 ) ) {
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid( min, max, block, intersect );
return;
}
}
if( tMax.X < tMax.Y && tMax.X < tMax.Z ) {
// tMax.X is the lowest, an YZ cell boundary plane is nearest.
x += stepX;
tMax.X += tDelta.X;
} else if( tMax.Y < tMax.Z ) {
// tMax.Y is the lowest, an XZ cell boundary plane is nearest.
y += stepY;
tMax.Y += tDelta.Y;
} else {
// tMax.Z is the lowest, an XY cell boundary plane is nearest.
z += stepZ;
tMax.Z += tDelta.Z;
}
iterations++;
}
throw new InvalidOperationException( "did over 10000 iterations in GetPickedBlockPos(). " +
"Something has gone wrong. (dir: " + dir + ")" );
}
public static void ClipCameraPos(Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos)
{
if (!game.CameraClipping)
{
pickedPos.SetAsInvalid();
pickedPos.IntersectPoint = origin + dir * reach;
return;
}
Vector3I start = Vector3I.Floor(origin);
int x = start.X, y = start.Y, z = start.Z;
Vector3I step, cellBoundary;
Vector3 tMax, tDelta;
CalcVectors(origin, dir, out step, out cellBoundary, out tMax, out tDelta);
Map map = game.Map;
BlockInfo info = game.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
while (iterations < 10000)
{
byte block = GetBlock(map, x, y, z, origin);
Vector3 min = new Vector3(x, y, z) + info.MinBB[block];
Vector3 max = new Vector3(x, y, z) + info.MaxBB[block];
float dx = Math.Min(Math.Abs(origin.X - min.X), Math.Abs(origin.X - max.X));
float dy = Math.Min(Math.Abs(origin.Y - min.Y), Math.Abs(origin.Y - max.Y));
float dz = Math.Min(Math.Abs(origin.Z - min.Z), Math.Abs(origin.Z - max.Z));
if (dx * dx + dy * dy + dz * dz > reachSquared)
{
pickedPos.SetAsInvalid();
pickedPos.IntersectPoint = origin + dir * reach;
return;
}
if (info.CollideType[block] == BlockCollideType.Solid && !info.IsAir[block])
{
float t0, t1;
const float adjust = 0.1f;
if (Intersection.RayIntersectsBox(origin, dir, min, max, out t0, out t1))
{
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid(x, y, z, min, max, block, intersect);
switch (pickedPos.BlockFace)
{
case CpeBlockFace.XMin:
pickedPos.IntersectPoint.X -= adjust; break;
case CpeBlockFace.XMax:
pickedPos.IntersectPoint.X += adjust; break;
case CpeBlockFace.YMin:
pickedPos.IntersectPoint.Y -= adjust; break;
case CpeBlockFace.YMax:
pickedPos.IntersectPoint.Y += adjust; break;
case CpeBlockFace.ZMin:
pickedPos.IntersectPoint.Z -= adjust; break;
case CpeBlockFace.ZMax:
pickedPos.IntersectPoint.Z += adjust; break;
}
return;
}
}
Step(ref tMax, ref tDelta, ref step, ref x, ref y, ref z);
iterations++;
}
throw new InvalidOperationException("did over 10000 iterations in ClipCameraPos(). " +
"Something has gone wrong. (dir: " + dir + ")");
}
public static void ClipCameraPos(Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos)
{
if (!game.CameraClipping)
{
pickedPos.SetAsInvalid();
pickedPos.IntersectPoint = origin + dir * reach;
return;
}
tracer.SetRayData(origin, dir);
World map = game.World;
BlockInfo info = game.BlockInfo;
float reachSquared = reach * reach;
int iterations = 0;
Vector3I pOrigin = Vector3I.Floor(origin);
while (iterations < 10000)
{
int x = tracer.X, y = tracer.Y, z = tracer.Z;
byte block = GetBlock(map, x, y, z, pOrigin);
Vector3 min = new Vector3(x, y, z) + info.MinBB[block];
Vector3 max = new Vector3(x, y, z) + info.MaxBB[block];
if (info.IsLiquid[block])
{
min.Y -= 1.5f / 16; max.Y -= 1.5f / 16;
}
float dx = Math.Min(Math.Abs(origin.X - min.X), Math.Abs(origin.X - max.X));
float dy = Math.Min(Math.Abs(origin.Y - min.Y), Math.Abs(origin.Y - max.Y));
float dz = Math.Min(Math.Abs(origin.Z - min.Z), Math.Abs(origin.Z - max.Z));
if (dx * dx + dy * dy + dz * dz > reachSquared)
{
pickedPos.SetAsInvalid();
pickedPos.IntersectPoint = origin + dir * reach;
return;
}
if (info.Collide[block] == CollideType.Solid && !info.IsAir[block])
{
float t0, t1;
const float adjust = 0.1f;
if (Intersection.RayIntersectsBox(origin, dir, min, max, out t0, out t1))
{
Vector3 intersect = origin + dir * t0;
pickedPos.SetAsValid(x, y, z, min, max, block, intersect);
switch (pickedPos.BlockFace)
{
case CpeBlockFace.XMin:
pickedPos.IntersectPoint.X -= adjust; break;
case CpeBlockFace.XMax:
pickedPos.IntersectPoint.X += adjust; break;
case CpeBlockFace.YMin:
pickedPos.IntersectPoint.Y -= adjust; break;
case CpeBlockFace.YMax:
pickedPos.IntersectPoint.Y += adjust; break;
case CpeBlockFace.ZMin:
pickedPos.IntersectPoint.Z -= adjust; break;
case CpeBlockFace.ZMax:
pickedPos.IntersectPoint.Z += adjust; break;
}
return;
}
}
tracer.Step();
iterations++;
}
throw new InvalidOperationException("did over 10000 iterations in ClipCameraPos(). " +
"Something has gone wrong. (dir: " + dir + ")");
}
