//-----------------------------------------------------------------------------
// Name: XBUtil_InitLight()
// Desc: Initializes a D3DLIGHT structure, setting the light position. The
// diffuse color is set to white, specular and ambient left as black.
//-----------------------------------------------------------------------------
VOID XBUtil_InitLight( D3DLIGHT8& light, D3DLIGHTTYPE ltType,
FLOAT x, FLOAT y, FLOAT z )
{
ZeroMemory( &light, sizeof(D3DLIGHT8) );
light.Type = ltType;
light.Diffuse.r = 1.0f;
light.Diffuse.g = 1.0f;
light.Diffuse.b = 1.0f;
light.Position = D3DXVECTOR3(x,y,z);
light.Position.x = x;
light.Position.y = y;
light.Position.z = z;
D3DXVECTOR3 vSource(x,y,z);
D3DXVec3Normalize( (D3DXVECTOR3*)&light.Direction, &vSource );
light.Range = 1000.0f;
}
void ConstraintVisualizer::RenderSpring (IVRenderInterface* pRenderer, const hkvVec3& startPos, const hkvVec3& endPos)
{
// Calculate the look at matrix
hkvVec3 vSource(startPos.x, startPos.y, startPos.z);
hkvVec3 vTarget(endPos.x, endPos.y, endPos.z);
hkvMat3 lookAtMat;
lookAtMat.setLookInDirectionMatrix (vTarget - vSource);
// Calculate the length and thickness of the spring
float fVecLen = (vTarget - vSource).getLength();
float fSpringThickness = fVecLen / 40.0f;
// Render the spring
hkvVec3 vOldPos;
for (int i = -5; i < 105; i++)
{
// Calculate the position on the spring line
float fPosOnLine = fVecLen * ((float) i / 100.0f);
fPosOnLine = hkvMath::clamp (fPosOnLine, 0.0f, fVecLen);
hkvVec3 vCurrentPos = vSource + lookAtMat.getAxis(0) * fPosOnLine;
// Calculate the local offset (to visualize circles)
float fAngle = ((float)(i % 10)) * 2 * hkvMath::pi () / 10.0f;
float diffX = sin(fAngle);
float diffY = cos(fAngle);
vCurrentPos += lookAtMat.getAxis(1) * fSpringThickness * diffX;
vCurrentPos += lookAtMat.getAxis(2) * fSpringThickness * diffY;
// Render the next line fragment
if (!vOldPos.isZero (0.0f))
{
VColorRef color(255, 255, 0);
pRenderer->DrawLine(vOldPos, hkvVec3(vCurrentPos.x, vCurrentPos.y, vCurrentPos.z), color, 2);
}
vOldPos = hkvVec3(vCurrentPos.x, vCurrentPos.y, vCurrentPos.z);
}
}
