void Camera::renderRayBoxIntersection(unsigned int width, unsigned int height, float m_bgcolor[], float m_boxcolor[], std::string& outputFile){
BMP file;
file.SetSize(width,height);
file.SetBitDepth(24);
Vector myVectorEyetoMiddle(m_direction.normalize());
double tanfovx = tan(m_fovRad)*double(width)/height ;
Vector myEyeVectorX = myVectorEyetoMiddle.crossProduct(m_up) ; //A
Vector myEyeVectorY = myEyeVectorX.crossProduct(myVectorEyetoMiddle) ; //B
Vector myMiddlePoint = myVectorEyetoMiddle + m_position;
Vector myImageVectorX = myEyeVectorX * ( myVectorEyetoMiddle.normalize().length() * tanfovx / myEyeVectorX.length() ); //H
Vector myImageVectorY = myEyeVectorY * ( myVectorEyetoMiddle.normalize().length() * tan(m_fovRad) / myEyeVectorY.length() ); //V
RGBApixel BGColor;
BGColor.Red = (ebmpBYTE) m_bgcolor[0]*255;
BGColor.Green = (ebmpBYTE) m_bgcolor[1]*255;
BGColor.Blue = (ebmpBYTE) m_bgcolor[2]*255;
BGColor.Alpha = 0;
RGBApixel BoxColor;
BoxColor.Red = (ebmpBYTE) m_boxcolor[0]*255;
BoxColor.Green = (ebmpBYTE) m_boxcolor[1]*255;
BoxColor.Blue = (ebmpBYTE) m_boxcolor[2]*255;
BoxColor.Alpha = 0;
double UnitCube[2][3] = { {0, 0, -1}, {1, 1, 0} }; //cube
double a1 = UnitCube[0][0] - m_position[0];
double a2 = UnitCube[1][0] - m_position[0];
double b1 = UnitCube[0][1] - m_position[1];
double b2 = UnitCube[1][1] - m_position[1];
double c1 = UnitCube[0][2] - m_position[2];
double c2 = UnitCube[1][2] - m_position[2];
for(unsigned int i=0;i<width;i++){
for(unsigned int j=0;j<height;j++){
double t1x, t2x, t1y, t2y, t1z, t2z;
double sx,sy;
sx = double(i)/width;
sy = double(j)/height;
Vector P = myImageVectorX*(2*sx-1) + myImageVectorY*(2*sy-1) + myMiddlePoint ;
Vector myRayCasting = (P - m_position)*(1.0 / (P - m_position).normalize().length()); //RayDirection = (P - E)/normalize(P - E);
t1x = a1 / myRayCasting[0];
t2x = a2 / myRayCasting[0];
t1y = b1 / myRayCasting[1];
t2y = b2 / myRayCasting[1];
t1z = c1 / myRayCasting[2];
t2z = c2 / myRayCasting[2];
bool hit = RayBoxIntersection( t1x, t2x, t1y, t2y, t1z, t2z );
if (!hit)
file.SetPixel(i, height-j-1, BGColor);
else
file.SetPixel(i, height-j-1, BoxColor);
}
}
file.WriteToFile(outputFile.c_str());
}
bool PhysicsWorld::Intersects(const StaticPhysicsEntity &s, const DynamicPhysicsEntity &d, Vec &outNormal, Vec &outDir)
{
float dmin = 0, radiusSquared;
Vec min, max, center, scale;
min = vec(-1, -1, -1, 0);
max = vec(1, 1, 1, 0);
scale = vec(1, 1, 1, 0);
Mat m, sc;
center = entGetTransform(d.ent)->GetPosition();
entGetTransform(s.ent)->GetMatrix(&m);
entGetTransform(d.ent)->GetMatrix(&sc);
// scale the unit vector and take the largest component
// as the radius for the sphere; as long as we don't do
// silly rotations we should be ok
matMulVec(&scale, sc, scale);
radiusSquared = vecMax(scale);
radiusSquared *= radiusSquared;
// we don't have an inv matrix of anything so instead
// we transform everything to worldspace and do the
// calculations there
// rot + scale
matMulVec(&min, m, min);
matMulVec(&max, m, max);
// pos
Vec p = entGetTransform(s.ent)->GetPosition();
min = vecAdd(min, p);
max = vecAdd(max, p);
// the actual intersection test (don't test w)
for(int i = 0; i < 3; i++)
{
float C = vecGetElem(center, i);
float Bmin = vecGetElem(min, i);
float Bmax = vecGetElem(max, i);
if(C < Bmin) dmin += square(C - Bmin);
else if(C > Bmax) dmin += square(C - Bmax);
}
if(dmin <= radiusSquared)
{
Ray r;
r.o = center;
r.d = vecSub(p, center);
r.d = vecNormalize(r.d);
float dist;
bool hit = RayBoxIntersection(r, min, max, dist, outNormal);
outDir = vecMul(r.d, vec(dist));
return hit;
}
return false;
}
