// Trace a line through the world to simulate, eg, a bullet http://www.youtube.com/watch?v=USjbg5QXk3g
bool CGame::TraceLine(const Vector& v0, const Vector& v1, Vector& vecIntersection, CCharacter*& pHit)
{
float flLowestFraction = 1;
Vector vecTestIntersection;
float flTestFraction;
pHit = nullptr;
for (size_t i = 0; i < MAX_CHARACTERS; i++)
{
CCharacter* pCharacter = GetCharacterIndex(i);
if (!pCharacter)
continue;
// Only monsters and boxes get hit by traces. The player doesn't, he's immune to his own attacks.
if (!pCharacter->m_bHitByTraces)
continue;
Matrix4x4 mInverse = pCharacter->GetGlobalTransform().InvertedTR();
// The v0 and v1 are in the global coordinate system and we need to transform it to the target's
// local coordinate system to use axis-aligned intersection. We do so using the inverse transform matrix.
// http://youtu.be/-Fn4atv2NsQ
if (LineAABBIntersection(pCharacter->m_aabbSize, mInverse*v0, mInverse*v1, vecTestIntersection, flTestFraction) && flTestFraction < flLowestFraction)
{
// Once we have the result we can use the regular transform matrix to get it back in
// global coordinates. http://youtu.be/-Fn4atv2NsQ
vecIntersection = pCharacter->GetGlobalTransform()*vecTestIntersection;
flLowestFraction = flTestFraction;
pHit = pCharacter;
}
}
// Intersect with the floor.
// Line-Plane Intersection algorithm: http://youtu.be/fIu_8b2n8ZM
if (LinePlaneIntersection(Vector(0, 1, 0), Vector(0, 0, 0), v0, v1, vecTestIntersection, flTestFraction) && flTestFraction < flLowestFraction)
{
vecIntersection = vecTestIntersection;
flLowestFraction = flTestFraction;
pHit = nullptr;
}
if (flLowestFraction < 1)
return true;
return false;
}
bool RayIntersectTriangle(Vector3 rayStart, Vector3 rayDirection, Vector3 a, Vector3 b, Vector3 c)
{
float t;
Vector3 ba = b - a;
Vector3 cb = c - b;
Vector3 ac = a - c;
Vector3 normal = ba.Cross(ac);
if (LinePlaneIntersection(rayStart, rayDirection, a, normal, t)) {
if (t >= 0.f) {
Vector3 q = rayStart + t * rayDirection;
Vector3 qa = q - a;
Vector3 qb = q - b;
Vector3 qc = q - c;
return ba.Cross(qa).Dot(normal) >= 0
&& cb.Cross(qb).Dot(normal) >= 0
&& ac.Cross(qc).Dot(normal) >= 0;
}
// Behind the ray
return false;
}
// Parallel
return false;
}
static void generated_grid(const char* OutPutFile, GzRender* renderer)
{
static float up_bias = 30.0f, forward_bias = 20.0f;
float u, v;
float meshTri1V1[4];
float meshTri1V2[4];
float meshTri1V3[4];
float meshTri2V1[4];
float meshTri2V2[4];
float meshTri2V3[4];
xRes = 1.0f/RECT_MAX_X;
yRes = 1.0f/RECT_MAX_Z;
CTransMatrix MProjection;
CTransMatrix XiwTrans, XpiTrans;
//set Xsp, Ximage elements
GzCoord view_vector;
VectorSubtract(renderer->camera.lookat, renderer->camera.position, view_vector);
Normalize(view_vector);
if(view_vector[1] < 0.0f) //look at y=0
{
GzCoord camera_pos;
Scale(renderer->camera.position, 1.0f, camera_pos);
renderer->camera.position[1] = camera_pos[1] + up_bias;
renderer->camera.lookat[0] = camera_pos[0] - camera_pos[1]/view_vector[1]*view_vector[0];
renderer->camera.lookat[1] = 0.0f;
renderer->camera.lookat[2] = camera_pos[2] - camera_pos[1]/view_vector[1]*view_vector[2];
GzPutCamera(renderer, &renderer->camera);
}
else //look away from y=0
{
GzCoord camera_pos;
Scale(renderer->camera.position, 1.0f, camera_pos);
GzCoord camera_forward = {view_vector[0], 0.0f, view_vector[2]};
Normalize(camera_forward);
renderer->camera.position[1] = camera_pos[1] + up_bias;
renderer->camera.lookat[0] = camera_pos[0] + forward_bias * camera_forward[0];
renderer->camera.lookat[1] = 0.0f;
renderer->camera.lookat[2] = camera_pos[2] + forward_bias * camera_forward[2];
GzPutCamera(renderer, &renderer->camera);
}
for (int i=0;i<4;i++)
{
for (int j=0;j<4;j++)
{
XiwTrans.SetElementValue(i,j,(double)renderer->camera.Xiw[i][j]);
XpiTrans.SetElementValue(i,j,(double)renderer->camera.Xpi[i][j]);
}
}
MProjection = XpiTrans;
MProjection *=XiwTrans;
MatrixInverse(MProjection.matrixData, MProjection.matrixData);
//transform and output the vertices
FILE *outfile ;
outfile = fopen ( OutPutFile , "wb" );
//Transform four corners of the grid
float leftbottomper[4] = {-1.0f, -1.0f, -1.0f, 1.0f},
rightbottomper[4] = {1.0f, -1.0f, -1.0f, 1.0f},
lefttopper[4] = {-1.0f, 1.0f, -1.0f, 1.0f},
righttopper[4] = {1.0f, 1.0f, -1.0f, 1.0f};
float leftbottom1[4], rightbottom1[4], lefttop1[4], righttop1[4];
float leftbottom2[4], rightbottom2[4], lefttop2[4], righttop2[4];
//transform leftbottom to world space
//set z to -1
leftbottomper[2] = -1;
MProjection.GetTransformedHVertex(leftbottomper,leftbottom1);
leftbottomper[2] = 1;
MProjection.GetTransformedHVertex(leftbottomper,leftbottom2);
LinePlaneIntersection(leftbottom1, leftbottom2, m_LeftBottom);
//transform rightbottom to world space
rightbottomper[2] = -1;
MProjection.GetTransformedHVertex(rightbottomper,rightbottom1);
rightbottomper[2] = 1;
MProjection.GetTransformedHVertex(rightbottomper,rightbottom2);
LinePlaneIntersection(rightbottom1, rightbottom2, m_RightBottom);
//transform lefttop to world space
lefttopper[2] = -1;
MProjection.GetTransformedHVertex(lefttopper,lefttop1);
lefttopper[2] = 1;
MProjection.GetTransformedHVertex(lefttopper,lefttop2);
LinePlaneIntersection(lefttop1, lefttop2, m_LeftTop);
//transform righttop to world space
righttopper[2] = -1;
MProjection.GetTransformedHVertex(righttopper,righttop1);
righttopper[2] = 1;
MProjection.GetTransformedHVertex(righttopper,righttop2);
LinePlaneIntersection(righttop1, righttop2, m_RightTop);
//interpolate homegeneous coordinates
float current_Vertex[4];
for (int i=0; i<RECT_MAX_X;i++ )
{
for (int j=0;j<RECT_MAX_Z;j++)
{
fprintf( outfile, "Triangle\r\n");
InterpolateHomoCoord(i,j,meshTri1V1);
u = i*xRes; v= j*yRes;
fprintf( outfile, "%f %f %f " , meshTri1V1[X], meshTri1V1[Y], meshTri1V1[Z] );
fprintf( outfile, "0.00 1.00 0.00 ");//normal
fprintf( outfile, "%f %f\r\n", u,v);
InterpolateHomoCoord(i+1,j,meshTri1V2);
u = (i+1)*xRes; v= j*yRes;
fprintf( outfile, "%f %f %f " , meshTri1V2[X], meshTri1V2[Y], meshTri1V2[Z] );
fprintf( outfile, "0.00 1.00 0.00 ");//normal
fprintf( outfile, "%f %f\r\n", u,v);
InterpolateHomoCoord(i+1,j+1,meshTri1V3);
u = (i+1)*xRes; v= (j+1)*yRes;
fprintf( outfile, "%f %f %f " , meshTri1V3[X], meshTri1V3[Y], meshTri1V3[Z] );
fprintf( outfile, "0.00 1.00 0.00 ");//normal
fprintf( outfile, "%f %f\r\n", u,v);
//Second triangle vertices
fprintf( outfile, "Triangle\r\n");
u = i*xRes; v= j*yRes;
fprintf( outfile, "%f %f %f " , meshTri1V1[X], meshTri1V1[Y], meshTri1V1[Z] );
fprintf( outfile, "0.00 1.00 0.00 ");//normal
fprintf( outfile, "%f %f\r\n", u,v);
u = (i+1)*xRes; v= (j+1)*yRes;
fprintf( outfile, "%f %f %f " , meshTri1V3[X], meshTri1V3[Y], meshTri1V3[Z] );
fprintf( outfile, "0.00 1.00 0.00 ");//normal
fprintf( outfile, "%f %f\r\n", u,v);
InterpolateHomoCoord(i,j+1,meshTri2V3);
u = i*xRes; v= (j+1)*yRes;
fprintf( outfile, "%f %f %f " , meshTri2V3[X], meshTri2V3[Y], meshTri2V3[Z] );
fprintf( outfile, "0.00 1.00 0.00 ");//normal
fprintf( outfile, "%f %f\r\n", u,v);
}
}
}
