void dxRenderSphere(Sphere* sphere, const Color* color, Matrix* ltm)
{
Vector circleVertex[SPHERE_DETAILS +1];
Line circleLines[SPHERE_DETAILS];
// generate circle in XY plane
int i;
for( i=0; i<SPHERE_DETAILS + 1; i++)
{
circleVertex[i].x = cos(i / (SPHERE_DETAILS / 2.0f) * D3DX_PI) * sphere->radius;
circleVertex[i].y = sin(i / (SPHERE_DETAILS / 2.0f) * D3DX_PI) * sphere->radius;
circleVertex[i].z = 0;
}
for( i=0; i<SPHERE_DETAILS; i++ )
{
circleLines[i].start = circleVertex[i], circleLines[i].end = circleVertex[i+1];
}
Matrix m;
Vector temp( 1,1,0 );
Vector scale, translation;
float transf;
for( i=0; i<SPHERE_BELTS; i++ )
{
D3DXMatrixIdentity( &m );
dxRotate( &m, &oY, 180.0f / SPHERE_BELTS * i );
dxTranslate( &m, &sphere->center );
dxRenderLines( SPHERE_DETAILS, circleLines, color, &m );
D3DXMatrixIdentity( &m );
transf = 1.0f/(SPHERE_BELTS)*i;
scale = temp * sin( acos( transf ) );
dxScale( &m, &scale );
translation = Vector( 0,0, transf * sphere->radius );
dxTranslate( &m, &translation );
dxRotate( &m, &oX, 90 );
dxTranslate( &m, &sphere->center );
dxRenderLines( SPHERE_DETAILS, circleLines, color, &m );
D3DXMatrixIdentity( &m );
dxScale( &m, &scale );
translation = Vector( 0,0, -transf * sphere->radius );
dxTranslate( &m, &translation );
dxRotate( &m, &oX, 90 );
dxTranslate( &m, &sphere->center );
dxRenderLines( SPHERE_DETAILS, circleLines, color, &m );
}
}
void Frame::rotateRelative(const Vector3f& axis, float angle)
{
Vector pos = dxPos( &TransformationMatrix );
TransformationMatrix._41 =
TransformationMatrix._42 =
TransformationMatrix._43 = 0.0f;
TransformationMatrix._44 = 1.0f;
dxRotate( &TransformationMatrix, &wrap( axis ), angle );
TransformationMatrix._41 = pos.x,
TransformationMatrix._42 = pos.y,
TransformationMatrix._43 = pos.z,
TransformationMatrix._44 = 1.0f;
dirty();
}
void Frame::rotate(const Vector3f& axis, float angle)
{
dxRotate( &TransformationMatrix, &wrap( axis ), angle );
dirty();
}
void Rain::onUpdate(float dt)
{
// actual dt
dt *= _propTimeSpeed;
// squared size of emission sphere
float emissionSphereSq = _emissionSphere * _emissionSphere;
// offset of emission center
_centerOffset = _propCenter - _centerOffset;
bool predictionIsAvaiable = ( D3DXVec3LengthSq( &_centerOffset ) < emissionSphereSq );
// rough speed of emission center
D3DXVec3Scale( &_centerVelocity, &_centerOffset, 1.0f/dt );
// motion direction of of emission center
Vector centerMotionN;
D3DXVec3Normalize( ¢erMotionN, &_centerVelocity );
// normal of particle velocity
Vector velocityN;
D3DXVec3Normalize( &velocityN, &_propVelocity );
// magnitude of particle initial velocity
float velocityM = D3DXVec3Length( &_propVelocity );
// pass all of particles
Vector r,axis;
Matrix m;
float space;
RainParticle* particle;
unsigned int i;
for( i=0; i<_numParticles; i++ )
{
// current particle
particle = _particles + i;
// check particle is outside of emission sphere
D3DXVec3Subtract( &r, &particle->pos, &_propCenter );
if( D3DXVec3LengthSq( &r ) > emissionSphereSq )
{
// randomize position
if( predictionIsAvaiable )
{
r.x = getCore()->getRandToolkit()->getUniform( -1,1 );
r.y = getCore()->getRandToolkit()->getUniform( -1,1 );
r.z = getCore()->getRandToolkit()->getUniform( -1,1 );
D3DXVec3Normalize( &r, &r );
r += centerMotionN;
}
else
{
r.x = getCore()->getRandToolkit()->getUniform( -1,1 );
r.y = getCore()->getRandToolkit()->getUniform( -1,1 );
r.z = getCore()->getRandToolkit()->getUniform( -1,1 );
}
D3DXVec3Normalize( &r, &r );
space = getCore()->getRandToolkit()->getUniform( 0, _emissionSphere );
D3DXVec3Scale( &particle->pos, &r, space );
particle->pos += _propCenter;
// predict position by velocity of emission center
if( predictionIsAvaiable ) particle->pos += _centerVelocity * dt;
// setup particle velocity
if( _propNBias > 0 )
{
m = identity;
axis.x = getCore()->getRandToolkit()->getUniform( -1,1 );
axis.y = getCore()->getRandToolkit()->getUniform( -1,1 );
axis.z = getCore()->getRandToolkit()->getUniform( -1,1 );
D3DXVec3Normalize( &axis, &axis );
dxRotate( &m, &axis, getCore()->getRandToolkit()->getUniform( - _propNBias, _propNBias ) );
D3DXVec3TransformNormal( &r, &velocityN, &m );
D3DXVec3Scale( &particle->vel, &r, velocityM );
}
else
{
particle->vel = _propVelocity;
}
// carefully move particle towards edge of emission sphere
// (this feature avaiable is for each second particle)
if( _useEdgeOffset )
{
_useEdgeOffset = 0;
D3DXVec3Normalize( &r, &particle->vel );
space = _emissionSphere - space;
r.x *= space, r.y *= space, r.z *= space;
particle->pos -= r;
}
else
{
_useEdgeOffset = 1;
}
}
}
// pass all of particles
for( i=0; i<_numParticles; i++ )
{
// current particle
particle = _particles + i;
// move particle
particle->pos += particle->vel * dt;
}
// store current emission center
_centerOffset = _propCenter;
}