tge/engine/terrain/terrCollision.cc
2017-04-17 06:17:10 -06:00

1162 lines
33 KiB
C++
Executable File

//-----------------------------------------------------------------------------
// Torque Game Engine
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------
#include "terrain/terrData.h"
#include "dgl/dgl.h"
#include "editor/editor.h"
const F32 TerrainThickness = 0.5f;
static const U32 MaxExtent = 100;
#define MAX_FLOAT 1e20f
//----------------------------------------------------------------------------
Convex sTerrainConvexList;
// Number of vertices followed by point index
S32 sVertexList[5][5] = {
{ 3, 1,2,3 }, // 135 B
{ 3, 0,1,3 }, // 135 A
{ 3, 0,2,3 }, // 45 B
{ 3, 0,1,2 }, // 45 A
{ 4, 0,1,2,3 } // Convex square
};
#if 1
// This section (as opposed to the #else down below) has been modified
// to remove the left and bottom edges, and right diagonal edges, so
// that the tiling of the terrain does not produce overlapping edges.
// Number of edges followed by edge index pairs
S32 sEdgeList45[16][11] = {
{ 0 }, //
{ 0 },
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0 },
{ 1, 0,1 }, // 0-2
{ 1, 0,1 }, // 1-2
{ 3, 0,1,1,2,2,0 }, // 0-1,1-2,2-0
{ 0 },
{ 0,}, //
{ 0 },
{ 1, 0,1 }, // 0-1,
{ 0, }, //
{ 1, 0,1 }, // 0-2,
{ 1, 0,1 }, // 1-2
{ 3, 0,1,1,2,0,2 },
};
S32 sEdgeList135[16][11] = {
{ 0 },
{ 0 },
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0 },
{ 0 },
{ 1, 0,1 }, // 1-2
{ 2, 0,1,1,2 }, // 0-1,1-2
{ 0 },
{ 0, }, //
{ 1, 0,1 }, // 1-3
{ 2, 0,1,1,2 }, // 0-1,1-3,
{ 0 }, //
{ 0 }, //
{ 2, 0,1,2,0 }, // 1-2,3-1
{ 3, 0,1,1,2,1,3 },
};
// On split squares, the FaceA diagnal is also removed
S32 sEdgeList45A[16][11] = {
{ 0 }, //
{ 0 },
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0 },
{ 0 }, //
{ 1, 0,1 }, // 1-2
{ 2, 0,1,1,2 }, // 0-1,1-2
{ 0 },
{ 0,}, //
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0, }, //
{ 0, 0,1 }, //
{ 1, 0,1 }, // 1-2
{ 3, 0,1,1,2 },
};
S32 sEdgeList135A[16][11] = {
{ 0 },
{ 0 },
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0 },
{ 0 },
{ 1, 0,1 }, // 1-2
{ 2, 0,1,1,2 }, // 0-1,1-2
{ 0 },
{ 0 }, //
{ 0 }, //
{ 1, 0,1 }, // 0-1
{ 0 }, //
{ 0 }, //
{ 1, 0,1 }, // 1-2
{ 3, 0,1,1,2 },
};
#else
// Number of edges followed by edge index pairs
S32 sEdgeList45[16][11] = {
{ 0 }, //
{ 0 },
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0 },
{ 1, 0,1 }, // 0-2
{ 1, 0,1 }, // 1-2
{ 3, 0,1,1,2,2,0 }, // 0-1,1-2,2-0
{ 0 },
{ 1, 0,1 }, // 0-3
{ 0 },
{ 2, 0,1,0,2 }, // 0-1,0-3
{ 1, 0,1 }, // 2-3
{ 3, 0,1,1,2,2,0 }, // 0-2,2-3,3-0
{ 2, 0,1,1,2 }, // 1-2,2-3
{ 5, 0,1,1,2,2,3,3,0,0,2 },
};
S32 sEdgeList135[16][11] = {
{ 0 },
{ 0 },
{ 0 },
{ 1, 0,1 }, // 0-1
{ 0 },
{ 0 },
{ 1, 0,1 }, // 1-2
{ 2, 0,1,1,2 }, // 0-1,1-2
{ 0 },
{ 1, 0,1 }, // 0-3
{ 1, 0,1 }, // 1-3
{ 3, 0,1,1,2,2,0 }, // 0-1,1-3,3-0
{ 1, 0,1 }, // 2-3
{ 2, 0,2,1,2 }, // 0-3,2-3
{ 3, 0,1,1,2,2,0 }, // 1-2,2-3,3-1
{ 5, 0,1,1,2,2,3,3,0,1,3 },
};
#endif
// Number of faces followed by normal index and vertices
S32 sFaceList45[16][9] = {
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 1, 0,0,1,2 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 1, 1,0,1,2 },
{ 0 },
{ 2, 0,0,1,2, 1,0,2,3 },
};
S32 sFaceList135[16][9] = {
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 0 },
{ 1, 0,0,1,2 },
{ 0 },
{ 0 },
{ 1, 1,0,1,2 },
{ 2, 0,0,1,3, 1,1,2,3 },
};
//----------------------------------------------------------------------------
Box3F TerrainConvex::getBoundingBox() const
{
return box;
}
Box3F TerrainConvex::getBoundingBox(const MatrixF&, const Point3F& ) const
{
// Function should not be called....
return box;
}
Point3F TerrainConvex::support(const VectorF& v) const
{
S32 *vp;
if (halfA)
vp = square ? sVertexList[(split45 << 1) | 1]: sVertexList[4];
else
vp = square ? sVertexList[(split45 << 1)] : sVertexList[4];
S32 *ve = vp + vp[0] + 1;
const Point3F *bp = &point[vp[1]];
F32 bd = mDot(*bp,v);
for (vp += 2; vp < ve; vp++)
{
const Point3F* cp = &point[*vp];
F32 dd = mDot(*cp,v);
if (dd > bd)
{
bd = dd;
bp = cp;
}
}
return *bp;
}
inline bool isOnPlane(Point3F& p,PlaneF& plane)
{
F32 dist = mDot(plane,p) + plane.d;
return dist < 0.1f && dist > -0.1f;
}
void TerrainConvex::getFeatures(const MatrixF& mat,const VectorF& n, ConvexFeature* cf)
{
U32 i;
cf->material = 0;
cf->object = mObject;
// Plane is normal n + support point
PlaneF plane;
plane.set(support(n),n);
S32 vertexCount = cf->mVertexList.size();
// Emit vertices on the plane
S32* vertexListPointer;
if (halfA)
vertexListPointer = square ? sVertexList[(split45 << 1) | 1]: sVertexList[4];
else
vertexListPointer = square ? sVertexList[(split45 << 1)] : sVertexList[4];
S32 pm = 0;
S32 numVerts = *vertexListPointer;
vertexListPointer += 1;
for (i = 0; i < numVerts; i++)
{
Point3F& cp = point[vertexListPointer[i]];
cf->mVertexList.increment();
mat.mulP(cp,&cf->mVertexList.last());
pm |= 1 << vertexListPointer[i];
}
// Emit Edges
S32* ep = (square && halfA)?
(split45 ? sEdgeList45A[pm]: sEdgeList135A[pm]):
(split45 ? sEdgeList45[pm]: sEdgeList135[pm]);
S32 numEdges = *ep;
S32 edgeListStart = cf->mEdgeList.size();
cf->mEdgeList.increment(numEdges);
ep += 1;
for (i = 0; i < numEdges; i++)
{
cf->mEdgeList[edgeListStart + i].vertex[0] = vertexCount + ep[i * 2 + 0];
cf->mEdgeList[edgeListStart + i].vertex[1] = vertexCount + ep[i * 2 + 1];
}
// Emit faces
S32* fp = split45 ? sFaceList45[pm]: sFaceList135[pm];
S32 numFaces = *fp;
fp += 1;
S32 faceListStart = cf->mFaceList.size();
cf->mFaceList.increment(numFaces);
for (i = 0; i < numFaces; i++)
{
cf->mFaceList[faceListStart + i].normal = normal[fp[i * 4 + 0]];
cf->mFaceList[faceListStart + i].vertex[0] = vertexCount + fp[i * 4 + 1];
cf->mFaceList[faceListStart + i].vertex[1] = vertexCount + fp[i * 4 + 2];
cf->mFaceList[faceListStart + i].vertex[2] = vertexCount + fp[i * 4 + 3];
}
}
void TerrainConvex::getPolyList(AbstractPolyList* list)
{
list->setTransform(&mObject->getTransform(), mObject->getScale());
list->setObject(mObject);
// Emit vertices
U32 array[4];
U32 curr = 0;
S32 numVerts;
S32* vertsStart;
if (halfA)
{
numVerts = square ? sVertexList[(split45 << 1) | 1][0] : sVertexList[4][0];
vertsStart = square ? &sVertexList[(split45 << 1) | 1][1] : &sVertexList[4][1];
}
else
{
numVerts = square ? sVertexList[(split45 << 1)][0] : sVertexList[4][0];
vertsStart = square ? &sVertexList[(split45 << 1)][1] : &sVertexList[4][1];
}
S32 pointMask = 0;
for (U32 i = 0; i < numVerts; i++) {
const Point3F& cp = point[vertsStart[i]];
array[curr++] = list->addPoint(cp);
pointMask |= (1 << vertsStart[i]);
}
S32 numFaces = split45 ? sFaceList45[pointMask][0] : sFaceList135[pointMask][0];
S32* faceStart = split45 ? &sFaceList45[pointMask][1] : &sFaceList135[pointMask][1];
for (U32 j = 0; j < numFaces; j++)
{
S32 plane = faceStart[0];
S32 v0 = faceStart[1];
S32 v1 = faceStart[2];
S32 v2 = faceStart[3];
list->begin(0, plane);
list->vertex(array[v0]);
list->vertex(array[v1]);
list->vertex(array[v2]);
list->plane(array[v0], array[v1], array[v2]);
list->end();
faceStart += 4;
}
}
//----------------------------------------------------------------------------
void TerrainBlock::buildConvex(const Box3F& box,Convex* convex)
{
sTerrainConvexList.collectGarbage();
//
if (box.max.z < -TerrainThickness || box.min.z > fixedToFloat(gridMap[BlockShift]->maxHeight))
return;
// Transform the bounding sphere into the object's coord space. Note that this
// not really optimal.
Box3F osBox = box;
mWorldToObj.mul(osBox);
AssertWarn(mObjScale == Point3F(1.0f, 1.0f, 1.0f), "Error, handle the scale transform on the terrain");
S32 xStart;
S32 xEnd;
S32 yStart;
S32 yEnd;
if(mTile)
{
xStart = (S32)mFloor( osBox.min.x / squareSize );
xEnd = (S32)mCeil ( osBox.max.x / squareSize );
yStart = (S32)mFloor( osBox.min.y / squareSize );
yEnd = (S32)mCeil ( osBox.max.y / squareSize );
}
else
{
xStart = getMax(0, (S32)mFloor( osBox.min.x / squareSize ));
xEnd = getMin(BlockSize, (S32)mCeil ( osBox.max.x / squareSize ));
yStart = getMax(0, (S32)mFloor( osBox.min.y / squareSize ));
yEnd = getMin(BlockSize, (S32)mCeil ( osBox.max.y / squareSize ));
}
S32 xExt = xEnd - xStart;
if (xExt > MaxExtent)
xExt = MaxExtent;
mHeightMax = floatToFixed(osBox.max.z);
mHeightMin = (osBox.min.z < 0)? 0: floatToFixed(osBox.min.z);
for (S32 y = yStart; y < yEnd; y++)
{
const S32 yi = y & BlockMask;
//
for (S32 x = xStart; x < xEnd; x++)
{
const S32 xi = x & BlockMask;
const GridSquare *gs = findSquare(0, Point2I(xi, yi));
// holes only in the primary terrain block
if (((gs->flags & GridSquare::Empty) && x == xi && y == yi) ||
gs->minHeight > mHeightMax || gs->maxHeight < mHeightMin)
continue;
const U32 sid = (x << 16) + (y & ((1 << 16) - 1));
Convex* cc = NULL;
// See if the square already exists as part of the working set.
CollisionWorkingList& wl = convex->getWorkingList();
for (CollisionWorkingList* itr = wl.wLink.mNext; itr != &wl; itr = itr->wLink.mNext)
{
if (itr->mConvex->getType() == TerrainConvexType &&
static_cast<TerrainConvex*>(itr->mConvex)->squareId == sid) {
cc = itr->mConvex;
break;
}
}
if (cc)
continue;
// Create a new convex.
TerrainConvex* cp = new TerrainConvex;
sTerrainConvexList.registerObject(cp);
convex->addToWorkingList(cp);
cp->halfA = true;
cp->square = 0;
cp->mObject = this;
cp->squareId = sid;
cp->material = getMaterial(xi,yi)->index;
cp->box.min.set(x * squareSize,y * squareSize,fixedToFloat(gs->minHeight));
cp->box.max.x = cp->box.min.x + squareSize;
cp->box.max.y = cp->box.min.y + squareSize;
cp->box.max.z = fixedToFloat(gs->maxHeight);
mObjToWorld.mul(cp->box);
// Build points
Point3F* pos = cp->point;
for (int i = 0; i < 4 ; i++,pos++)
{
S32 dx = i >> 1;
S32 dy = dx ^ (i & 1);
pos->x = (x + dx) * squareSize;
pos->y = (y + dy) * squareSize;
pos->z = fixedToFloat(getHeight(xi + dx, yi + dy));
}
// Build normals, then split into two Convex objects if the
// square is concave
if ((cp->split45 = gs->flags & GridSquare::Split45) == true)
{
VectorF *vp = cp->point;
mCross(vp[0] - vp[1],vp[2] - vp[1],&cp->normal[0]);
cp->normal[0].normalize();
mCross(vp[2] - vp[3],vp[0] - vp[3],&cp->normal[1]);
cp->normal[1].normalize();
if (mDot(vp[3] - vp[1],cp->normal[0]) > 0)
{
TerrainConvex* nc = new TerrainConvex(*cp);
sTerrainConvexList.registerObject(nc);
convex->addToWorkingList(nc);
nc->halfA = false;
nc->square = cp;
cp->square = nc;
}
}
else
{
VectorF *vp = cp->point;
mCross(vp[3] - vp[0],vp[1] - vp[0],&cp->normal[0]);
cp->normal[0].normalize();
mCross(vp[1] - vp[2],vp[3] - vp[2],&cp->normal[1]);
cp->normal[1].normalize();
if (mDot(vp[2] - vp[0],cp->normal[0]) > 0)
{
TerrainConvex* nc = new TerrainConvex(*cp);
sTerrainConvexList.registerObject(nc);
convex->addToWorkingList(nc);
nc->halfA = false;
nc->square = cp;
cp->square = nc;
}
}
}
}
}
//----------------------------------------------------------------------------
static inline void swap(U32*& a,U32*& b)
{
U32* t = b;
b = a;
a = t;
}
static void clrbuf(U32* p, U32 s)
{
U32* e = p + s;
while (p != e)
*p++ = U32_MAX;
}
//----------------------------------------------------------------------------
bool TerrainBlock::buildPolyList(AbstractPolyList* polyList, const Box3F &box, const SphereF&)
{
if (box.max.z < -TerrainThickness || box.min.z > fixedToFloat(gridMap[BlockShift]->maxHeight))
return false;
// Transform the bounding sphere into the object's coord space. Note that this
// not really optimal.
Box3F osBox = box;
mWorldToObj.mul(osBox);
AssertWarn(mObjScale == Point3F(1.0f, 1.0f, 1.0f), "Error, handle the scale transform on the terrain");
// Setup collision state data
polyList->setTransform(&getTransform(), getScale());
polyList->setObject(this);
S32 xStart;
S32 xEnd;
S32 yStart;
S32 yEnd;
if(mTile)
{
xStart = (S32)mFloor( osBox.min.x / squareSize );
xEnd = (S32)mCeil ( osBox.max.x / squareSize );
yStart = (S32)mFloor( osBox.min.y / squareSize );
yEnd = (S32)mCeil ( osBox.max.y / squareSize );
}
else
{
xStart = getMax(0, (S32)mFloor( osBox.min.x / squareSize ));
xEnd = getMin(BlockSize, (S32)mCeil ( osBox.max.x / squareSize ));
yStart = getMax(0, (S32)mFloor( osBox.min.y / squareSize ));
yEnd = getMin(BlockSize, (S32)mCeil ( osBox.max.y / squareSize ));
}
S32 xExt = xEnd - xStart;
if (xExt > MaxExtent)
xExt = MaxExtent;
mHeightMax = floatToFixed(osBox.max.z);
mHeightMin = (osBox.min.z < 0)? 0: floatToFixed(osBox.min.z);
// Index of shared points
U32 bp[(MaxExtent + 1) * 2],*vb[2];
vb[0] = &bp[0];
vb[1] = &bp[xExt + 1];
clrbuf(vb[1],xExt + 1);
bool emitted = false;
for (S32 y = yStart; y < yEnd; y++)
{
const S32 yi = y & BlockMask;
swap(vb[0],vb[1]);
clrbuf(vb[1],xExt + 1);
for (S32 x = xStart; x < xEnd; x++)
{
const S32 xi = x & BlockMask;
const GridSquare *gs = findSquare(0, Point2I(xi, yi));
// holes only in the primary terrain block
if (((gs->flags & GridSquare::Empty) && x == xi && y == yi) ||
gs->minHeight > mHeightMax || gs->maxHeight < mHeightMin)
continue;
emitted = true;
// Add the missing points
U32 vi[5];
for (int i = 0; i < 4 ; i++)
{
S32 dx = i >> 1;
S32 dy = dx ^ (i & 1);
U32* vp = &vb[dy][x - xStart + dx];
if (*vp == U32_MAX)
{
Point3F pos;
pos.x = (x + dx) * squareSize;
pos.y = (y + dy) * squareSize;
pos.z = fixedToFloat(getHeight(xi + dx, yi + dy));
*vp = polyList->addPoint(pos);
}
vi[i] = *vp;
}
U32* vp = &vi[0];
if (!(gs->flags & GridSquare::Split45))
vi[4] = vi[0], vp++;
const U32 material = getMaterial(xi,yi)->index;
const U32 surfaceKey = ((xi << 16) | yi) << 1;
polyList->begin(material,surfaceKey);
polyList->vertex(vp[0]);
polyList->vertex(vp[1]);
polyList->vertex(vp[2]);
polyList->plane(vp[0],vp[1],vp[2]);
polyList->end();
polyList->begin(material,surfaceKey + 1);
polyList->vertex(vp[0]);
polyList->vertex(vp[2]);
polyList->vertex(vp[3]);
polyList->plane(vp[0],vp[2],vp[3]);
polyList->end();
}
}
return emitted;
}
//----------------------------------------------------------------------------
BSPNode *TerrainBlock::buildCollisionBSP(BSPTree *tree, const Box3F &box, const SphereF& /*sphere*/)
{
S32 xStart = (S32)mFloor( box.min.x / squareSize );
S32 xEnd = (S32)mCeil ( box.max.x / squareSize );
S32 yStart = (S32)mFloor( box.min.y / squareSize );
S32 yEnd = (S32)mCeil ( box.max.y / squareSize );
mTree = tree;
S32 yExt = yEnd - yStart;
S32 xExt = xEnd - xStart;
S32 maxPlaneCount = yExt - 1 + (xExt - 1) * yExt + xExt * yExt * 4;
if (box.max.z < -TerrainThickness || box.min.z > fixedToFloat(gridMap[BlockShift]->maxHeight))
return 0;
mHeightMax = floatToFixed(box.max.z);
mHeightMin = (box.min.z < 0)? 0: floatToFixed(box.min.z);
BSPNode *backTree = buildXTree(yStart, xStart, xEnd);
for(S32 y = yStart + 1; y < yEnd; y++)
{
BSPNode *branch = mTree->alloc();
branch->plane.setXZ(y * squareSize);
branch->frontNode = buildXTree(y, xStart, xEnd);
branch->backNode = backTree;
if(branch->frontNode == branch->backNode)
{
AssertFatal(!branch->frontNode, "TerrainBlock::Internal Error: Bad equal nodes.");
backTree = branch->frontNode;
}
else
backTree = branch;
}
return backTree;
}
BSPNode *TerrainBlock::buildXTree(S32 y, S32 xStart, S32 xEnd)
{
BSPNode *backTree = buildSquareTree(y, xStart);
for(S32 x = xStart + 1; x < xEnd; x++)
{
BSPNode *branch = mTree->alloc();
branch->plane.setYZ(x * squareSize);
branch->frontNode = buildSquareTree(y, x);
branch->backNode = backTree;
if(branch->frontNode == branch->backNode)
{
AssertFatal(!branch->frontNode, "TerrainBlock::Internal Error: Bad equal nodes.");
backTree = branch->frontNode;
}
else
backTree = branch;
}
return backTree;
}
BSPNode *TerrainBlock::buildSquareTree(S32 y, S32 x)
{
// coords are in, mask off for heightMap lookup:
S32 xi = x & BlockMask;
S32 yi = y & BlockMask;
GridSquare *gs = findSquare(0, Point2I(xi, yi));
// trivial check on min/max heights:
// we compare > on height max so we can add thickness to the terrain.
// holes only in the primary terrain block
if (((gs->flags & GridSquare::Empty) && x == xi && y == yi) ||
gs->minHeight > mHeightMax || gs->maxHeight < mHeightMin)
return 0;
F32 zBottomLeft = fixedToFloat(getHeight(xi, yi));
F32 zBottomRight = fixedToFloat(getHeight(xi + 1, yi));
F32 zTopLeft = fixedToFloat(getHeight(xi, yi + 1));
F32 zTopRight = fixedToFloat(getHeight(xi + 1, yi + 1));
// trivial check failed - construct planes.
Point3F normal1, normal2, normal3;
Point3F squarePos, testPoint;
// test point is point on p2 that is not on the line from p1 to p2.
if(gs->flags & GridSquare::Split45)
{
squarePos.set(x * squareSize, y * squareSize, zBottomLeft);
normal1.set(zBottomLeft - zBottomRight, zBottomRight - zTopRight, squareSize);
normal2.set(zTopLeft - zTopRight, zBottomLeft - zTopLeft, squareSize);
normal3.set(-squareSize,squareSize,0);
testPoint.set(x * squareSize, (y+1) * squareSize, zTopLeft);
}
else
{
squarePos.set((x + 1) * squareSize, y * squareSize, zBottomRight);
normal1.set(zTopLeft - zTopRight, zBottomRight - zTopRight, squareSize);
normal2.set(zBottomLeft - zBottomRight, zBottomLeft - zTopLeft, squareSize);
normal3.set(-squareSize,-squareSize,0);
testPoint.set(x * squareSize, y * squareSize, zBottomLeft);
}
// Solid terrain node with material type
BSPNode* solidNode = mTree->alloc();
solidNode->material = getMaterial(xi,yi)->index;
solidNode->frontNode = solidNode->backNode = 0;
// Make plane 1 node:
BSPNode *p1Node = mTree->alloc();
p1Node->plane.set(squarePos, normal1);
p1Node->frontNode = 0;
p1Node->backNode = solidNode;
F32 dist = p1Node->plane.distToPlane(testPoint);
if(dist != 0)
{
// Square is not flat, we need to build more nodes
// Make plane 2 node:
BSPNode *p2Node = mTree->alloc();
p2Node->plane.set(squarePos, normal2);
p2Node->frontNode = 0;
p2Node->backNode = solidNode;
// Make vertical split node:
BSPNode *psNode = mTree->alloc();
psNode->plane.set(squarePos, normal3);
psNode->frontNode = p2Node;
psNode->backNode = p1Node;
p1Node = psNode;
}
// Add in a bottom plane if we extend past the bottom of the terrain.
if(gs->minHeight >= mHeightMin - TerrainThickness)
{
BSPNode *belowNode = mTree->alloc();
belowNode->plane.setXY(fixedToFloat(gs->minHeight) - TerrainThickness);
belowNode->plane.invert();
belowNode->frontNode = 0;
belowNode->backNode = p1Node;
return belowNode;
}
return p1Node;
}
//----------------------------------------------------------------------------
static bool calcInterceptX;
static bool calcInterceptY;
static U32 lineCount;
static Point3F lineStart, lineEnd;
static void drawLineTest(F32 startT, F32 endT, bool collide)
{
glEnable(GL_DEPTH_TEST);
if(lineCount & 1)
{
if(collide)
glColor3f(1.0f, 0.0f, 0.0f);
else
glColor3f(1.0f, 1.0f, 1.0f);
}
else
{
if(collide)
glColor3f(0.0f, 1.0f, 0.0f);
else
glColor3f(0.0f, 0.0f, 0.0f);
}
lineCount++;
glBegin(GL_LINES);
Point3F pt;
pt.interpolate(lineStart, lineEnd, startT);
glVertex3fv(pt);
pt.interpolate(lineStart, lineEnd, endT);
glVertex3fv(pt);
Point3F ptUp = pt;
ptUp.z += 4.0f;
glVertex3fv(pt);
glVertex3fv(ptUp);
glEnd();
}
bool TerrainBlock::castRay(const Point3F &start, const Point3F &end, RayInfo *info)
{
return castRayI(start, end, info, false);
}
bool TerrainBlock::castRayI(const Point3F &start, const Point3F &end, RayInfo *info, bool collideEmpty)
{
lineCount = 0;
lineStart = start;
lineEnd = end;
info->object = this;
if(start.x == end.x && start.y == end.y)
{
if (end.z == start.z)
return false;
F32 height;
if(!getNormalAndHeight(Point2F(start.x, start.y), &info->normal, &height, true))
return false;
F32 t = (height - start.z) / (end.z - start.z);
if(t < 0.0f || t > 1.0f)
return false;
info->t = t;
//
return true;
}
F32 invBlockWorldSize = 1.0f / F32(squareSize * BlockSquareWidth);
Point3F pStart(start.x * invBlockWorldSize, start.y * invBlockWorldSize, start.z);
Point3F pEnd(end.x * invBlockWorldSize, end.y * invBlockWorldSize, end.z);
int blockX = (S32)mFloor(pStart.x);
int blockY = (S32)mFloor(pStart.y);
int dx, dy;
F32 invDeltaX;
if(pEnd.x == pStart.x)
{
calcInterceptX = false;
invDeltaX = 0.0f;
dx = 0;
}
else
{
invDeltaX = 1.0f / (pEnd.x - pStart.x);
calcInterceptX = true;
if(pEnd.x < pStart.x)
dx = -1;
else
dx = 1;
}
F32 invDeltaY;
if(pEnd.y == pStart.y)
{
calcInterceptY = false;
invDeltaY = 0.0f;
dy = 0;
}
else
{
invDeltaY = 1.0f / (pEnd.y - pStart.y);
calcInterceptY = true;
if(pEnd.y < pStart.y)
dy = -1;
else
dy = 1;
}
F32 startT = 0.0f;
for(;;)
{
const F32 nextXInt = calcInterceptX ? (((blockX + (dx == 1)) - pStart.x) * invDeltaX) : MAX_FLOAT;
const F32 nextYInt = calcInterceptY ? (((blockY + (dy == 1)) - pStart.y) * invDeltaY) : MAX_FLOAT;
F32 intersectT = 1.0f;
if(nextXInt < intersectT)
intersectT = nextXInt;
if(nextYInt < intersectT)
intersectT = nextYInt;
if(castRayBlock(pStart, pEnd, Point2I(blockX * BlockSquareWidth, blockY * BlockSquareWidth), BlockShift, invDeltaX, invDeltaY, startT, intersectT, info, collideEmpty)) {
info->normal.z *= BlockSquareWidth * squareSize;
info->normal.normalize();
return true;
}
startT = intersectT;
if(intersectT >= 1.0f)
break;
if(nextXInt < nextYInt)
blockX += dx;
else if(nextYInt < nextXInt)
blockY += dy;
else
{
blockX += dx;
blockY += dy;
}
}
return false;
}
struct TerrLOSStackNode
{
F32 startT;
F32 endT;
Point2I blockPos;
U32 level;
};
bool TerrainBlock::castRayBlock(const Point3F &pStart, const Point3F &pEnd, const Point2I &aBlockPos, U32 aLevel, F32 invDeltaX, F32 invDeltaY, F32 aStartT, F32 aEndT, RayInfo *info, bool collideEmpty)
{
static const F32 invBlockSize = 1.0f / F32(BlockSquareWidth);
static TerrLOSStackNode stack[BlockShift * 3 + 1];
U32 stackSize = 1;
stack[0].startT = aStartT;
stack[0].endT = aEndT;
stack[0].blockPos = aBlockPos;
stack[0].level = aLevel;
if(!mTile && !aBlockPos.isZero())
return false;
while(stackSize--)
{
TerrLOSStackNode *sn = stack + stackSize;
U32 level = sn->level;
F32 startT = sn->startT;
F32 endT = sn->endT;
Point2I blockPos = sn->blockPos;
GridSquare *sq = findSquare(level, Point2I(blockPos.x & BlockMask, blockPos.y & BlockMask));
F32 startZ = startT * (pEnd.z - pStart.z) + pStart.z;
F32 endZ = endT * (pEnd.z - pStart.z) + pStart.z;
F32 minHeight = fixedToFloat(sq->minHeight);
if(startZ <= minHeight && endZ <= minHeight)
{
//drawLineTest(startT, sn->endT, false);
continue;
}
F32 maxHeight = fixedToFloat(sq->maxHeight);
if(startZ >= maxHeight && endZ >= maxHeight)
{
//drawLineTest(startT, endT, false);
continue;
}
if (!collideEmpty && (sq->flags & GridSquare::Empty) &&
blockPos.x == (blockPos.x & BlockMask) && blockPos.y == (blockPos.y & BlockMask))
{
//drawLineTest(startT, endT, false);
continue;
}
if(level == 0)
{
F32 xs = blockPos.x * invBlockSize;
F32 ys = blockPos.y * invBlockSize;
F32 zBottomLeft = fixedToFloat(getHeight(blockPos.x, blockPos.y));
F32 zBottomRight= fixedToFloat(getHeight(blockPos.x + 1, blockPos.y));
F32 zTopLeft = fixedToFloat(getHeight(blockPos.x, blockPos.y + 1));
F32 zTopRight = fixedToFloat(getHeight(blockPos.x + 1, blockPos.y + 1));
PlaneF p1, p2;
PlaneF divider;
Point3F planePoint;
if(sq->flags & GridSquare::Split45)
{
p1.set(zBottomLeft - zBottomRight, zBottomRight - zTopRight, invBlockSize);
p2.set(zTopLeft - zTopRight, zBottomLeft - zTopLeft, invBlockSize);
planePoint.set(xs, ys, zBottomLeft);
divider.x = 1.0f;
divider.y = -1.0f;
divider.z = 0.0f;
}
else
{
p1.set(zTopLeft - zTopRight, zBottomRight - zTopRight, invBlockSize);
p2.set(zBottomLeft - zBottomRight, zBottomLeft - zTopLeft, invBlockSize);
planePoint.set(xs + invBlockSize, ys, zBottomRight);
divider.x = 1.0f;
divider.y = 1.0f;
divider.z = 0.0f;
}
p1.setPoint(planePoint);
p2.setPoint(planePoint);
divider.setPoint(planePoint);
F32 t1 = p1.intersect(pStart, pEnd);
F32 t2 = p2.intersect(pStart, pEnd);
F32 td = divider.intersect(pStart, pEnd);
F32 dStart = divider.distToPlane(pStart);
F32 dEnd = divider.distToPlane(pEnd);
// see if the line crosses the divider
if((dStart >= 0 && dEnd < 0) || (dStart < 0 && dEnd >= 0))
{
if(dStart < 0)
{
F32 temp = t1;
t1 = t2;
t2 = temp;
}
if(t1 >= startT && t1 && t1 <= td && t1 <= endT)
{
info->t = t1;
info->normal = p1;
return true;
}
if(t2 >= td && t2 >= startT && t2 <= endT)
{
info->t = t2;
info->normal = p2;
return true;
}
}
else
{
F32 t;
if(dStart >= 0) {
t = t1;
info->normal = p1;
}
else {
t = t2;
info->normal = p2;
}
if(t >= startT && t <= endT)
{
info->t = t;
return true;
}
}
continue;
}
int squareWidth = 1 << level;
int subSqWidth = 1 << (level - 1);
F32 xIntercept = (blockPos.x + subSqWidth) * invBlockSize;
F32 xInt = calcInterceptX ? ((xIntercept - pStart.x) * invDeltaX) : MAX_FLOAT;
F32 yIntercept = (blockPos.y + subSqWidth) * invBlockSize;
F32 yInt = calcInterceptY ? ((yIntercept - pStart.y) * invDeltaY) : MAX_FLOAT;
F32 startX = startT * (pEnd.x - pStart.x) + pStart.x;
F32 startY = startT * (pEnd.y - pStart.y) + pStart.y;
if(xInt < startT)
xInt = MAX_FLOAT;
if(yInt < startT)
yInt = MAX_FLOAT;
U32 x0 = (startX > xIntercept) * subSqWidth;
U32 y0 = (startY > yIntercept) * subSqWidth;
U32 x1 = subSqWidth - x0;
U32 y1 = subSqWidth - y0;
U32 nextLevel = level - 1;
// push the items on the stack in reverse order of processing
if(xInt > endT && yInt > endT)
{
// only test the square the point started in:
stack[stackSize].blockPos.set(blockPos.x + x0, blockPos.y + y0);
stack[stackSize].level = nextLevel;
stackSize++;
}
else if(xInt < yInt)
{
F32 nextIntersect = endT;
if(yInt <= endT)
{
stack[stackSize].blockPos.set(blockPos.x + x1, blockPos.y + y1);
stack[stackSize].startT = yInt;
stack[stackSize].endT = endT;
stack[stackSize].level = nextLevel;
nextIntersect = yInt;
stackSize++;
}
stack[stackSize].blockPos.set(blockPos.x + x1, blockPos.y + y0);
stack[stackSize].startT = xInt;
stack[stackSize].endT = nextIntersect;
stack[stackSize].level = nextLevel;
stack[stackSize+1].blockPos.set(blockPos.x + x0, blockPos.y + y0);
stack[stackSize+1].startT = startT;
stack[stackSize+1].endT = xInt;
stack[stackSize+1].level = nextLevel;
stackSize += 2;
}
else if(yInt < xInt)
{
F32 nextIntersect = endT;
if(xInt <= endT)
{
stack[stackSize].blockPos.set(blockPos.x + x1, blockPos.y + y1);
stack[stackSize].startT = xInt;
stack[stackSize].endT = endT;
stack[stackSize].level = nextLevel;
nextIntersect = xInt;
stackSize++;
}
stack[stackSize].blockPos.set(blockPos.x + x0, blockPos.y + y1);
stack[stackSize].startT = yInt;
stack[stackSize].endT = nextIntersect;
stack[stackSize].level = nextLevel;
stack[stackSize+1].blockPos.set(blockPos.x + x0, blockPos.y + y0);
stack[stackSize+1].startT = startT;
stack[stackSize+1].endT = yInt;
stack[stackSize+1].level = nextLevel;
stackSize += 2;
}
else
{
stack[stackSize].blockPos.set(blockPos.x + x1, blockPos.y + y1);
stack[stackSize].startT = xInt;
stack[stackSize].endT = endT;
stack[stackSize].level = nextLevel;
stack[stackSize+1].blockPos.set(blockPos.x + x0, blockPos.y + y0);
stack[stackSize+1].startT = startT;
stack[stackSize+1].endT = xInt;
stack[stackSize+1].level = nextLevel;
stackSize += 2;
}
}
return false;
}