CC3Vector CC3Camera::calculateLocationToShowAllOf( CC3Node* aNode, const CC3Vector& targLoc, const CC3Vector& aDirection, GLfloat padding, bool checkScene )
{
ensureSceneUpdated( checkScene );
// Complementary unit vectors pointing towards camera from node, and vice versa
CC3Vector camDir = aDirection.normalize();
CC3Vector viewDir = camDir.negate();
// The camera's new forward direction will be viewDir. Use a matrix to detrmine
// the camera's new up and right directions assuming the same scene up direction.
CC3Matrix3x3 rotMtx;
CC3Matrix3x3PopulateToPointTowards(&rotMtx, viewDir, getReferenceUpDirection());
CC3Vector upDir = CC3Matrix3x3ExtractUpDirection(&rotMtx);
CC3Vector rtDir = CC3Matrix3x3ExtractRightDirection(&rotMtx);
// Determine the eight vertices, of the node's bounding box, in the global coordinate system
CC3Box gbb = aNode->getGlobalBoundingBox();
CC3Vector targetLoc = targLoc;
// If a target location has not been specified, use the center of the node's global bounding box
if ( targetLoc.isNull() )
targetLoc = gbb.getCenter();
CC3Vector bbMin = gbb.minimum;
CC3Vector bbMax = gbb.maximum;
CC3Vector bbVertices[8];
bbVertices[0] = cc3v(bbMin.x, bbMin.y, bbMin.z);
bbVertices[1] = cc3v(bbMin.x, bbMin.y, bbMax.z);
bbVertices[2] = cc3v(bbMin.x, bbMax.y, bbMin.z);
bbVertices[3] = cc3v(bbMin.x, bbMax.y, bbMax.z);
bbVertices[4] = cc3v(bbMax.x, bbMin.y, bbMin.z);
bbVertices[5] = cc3v(bbMax.x, bbMin.y, bbMax.z);
bbVertices[6] = cc3v(bbMax.x, bbMax.y, bbMin.z);
bbVertices[7] = cc3v(bbMax.x, bbMax.y, bbMax.z);
// Express the camera's FOV in terms of ratios of the near clip bounds to
// the near clip distance, so we can determine distances using similar triangles.
CCSize fovRatios = getFovRatios();
// Iterate through all eight vertices of the node's bounding box, and calculate
// the largest distance required to place the camera away from the center of the
// node in order to fit all eight vertices within the camera's frustum.
// Simultaneously, calculate the extra distance from the center of the node to
// the vertex that will be farthest from the camera, so we can ensure that all
// vertices will fall within the frustum's far end.
GLfloat maxCtrDist = 0;
GLfloat maxVtxDeltaDist = 0;
GLfloat minVtxDeltaDist = 0;
for (int i = 0; i < 8; i++)
{
// Get a vector from the target location to the vertex
CC3Vector relVtx = bbVertices[i] - targetLoc;
// Project that vector onto each of the camera's new up and right directions,
// and use similar triangles to determine the distance at which to place the
// camera so that the vertex will fit in both the up and right directions.
GLfloat vtxDistUp = fabs(relVtx.dot( upDir ) / fovRatios.height);
GLfloat vtxDistRt = fabs(relVtx.dot( rtDir ) / fovRatios.width);
GLfloat vtxDist = MAX(vtxDistUp, vtxDistRt);
// Calculate how far along the view direction the vertex is from the center
GLfloat vtxDeltaDist = relVtx.dot( viewDir );
GLfloat ctrDist = vtxDist - vtxDeltaDist;
// Accumulate the maximum distance from the node's center to the camera
// required to fit all eight points, and the distance from the node's
// center to the vertex that will be farthest away from the camera.
maxCtrDist = MAX(maxCtrDist, ctrDist);
maxVtxDeltaDist = MAX(maxVtxDeltaDist, vtxDeltaDist);
minVtxDeltaDist = MIN(minVtxDeltaDist, vtxDeltaDist);
}
// Add some padding so we will have a bit of space around the node when it fills the view.
maxCtrDist *= (1 + padding);
// Determine if we need to move the far end of the camera frustum farther away
GLfloat farClip = viewDir.scaleUniform(maxCtrDist + maxVtxDeltaDist).length();
farClip *= (GLfloat)(1 + kCC3FrustumFitPadding); // Include a little bit of padding
if (farClip > getFarClippingDistance())
setFarClippingDistance( farClip );
// Determine if we need to move the near end of the camera frustum closer
GLfloat nearClip = viewDir.scaleUniform(maxCtrDist + minVtxDeltaDist).length();
nearClip *= (GLfloat)(1 - kCC3FrustumFitPadding); // Include a little bit of padding
if (nearClip < getNearClippingDistance())
setNearClippingDistance( nearClip );
//LogTrace(@"%@ moving to %@ to show %@ at %@ within %@ with new farClip: %.3f", self,
// NSStringFromCC3Vector(CC3VectorAdd(targLoc, CC3VectorScaleUniform(camDir, maxCtrDist))),
// aNode, NSStringFromCC3Vector(targLoc), _frustum, self.farClippingDistance);
// Return the new location of the camera,
return targetLoc.add( camDir.scaleUniform( maxCtrDist ) );
}
CC3Vector CC3LocalContentNode::getLocalContentCenterOfGeometry()
{
CC3Box bb = getLocalContentBoundingBox();
return bb.isNull() ? CC3Vector::kCC3VectorZero : bb.getCenter();
}