void DrawNode::drawCardinalSpline(PointArray *config, float tension, unsigned int segments, const Color4F &color)
{
Vec2* vertices = new (std::nothrow) Vec2[segments + 1];
if( ! vertices )
return;
ssize_t p;
float lt;
float deltaT = 1.0f / config->count();
for( unsigned int i=0; i < segments+1;i++) {
float dt = (float)i / segments;
// border
if( dt == 1 ) {
p = config->count() - 1;
lt = 1;
} else {
p = dt / deltaT;
lt = (dt - deltaT * (float)p) / deltaT;
}
// Interpolate
Vec2 pp0 = config->getControlPointAtIndex(p-1);
Vec2 pp1 = config->getControlPointAtIndex(p+0);
Vec2 pp2 = config->getControlPointAtIndex(p+1);
Vec2 pp3 = config->getControlPointAtIndex(p+2);
Vec2 newPos = ccCardinalSplineAt( pp0, pp1, pp2, pp3, tension, lt);
vertices[i].x = newPos.x;
vertices[i].y = newPos.y;
}
drawPoly(vertices, segments+1, false, color);
CC_SAFE_DELETE_ARRAY(vertices);
}
void CCCatmullRomSprite::populatePoints(const CCPointList& controlPoints, CCPointList& points) {
// clear
points.clear();
m_segmentPointIndices.clear();
// populate points segment by segment
int totalSeg = controlPoints.getCount() - 1;
for(int curSeg = 0; curSeg < totalSeg; curSeg++) {
// add start index of segment
m_segmentPointIndices.push_back(points.getCount());
// four control points
CCPoint cp0 = controlPoints.getPointAt(curSeg - 1);
CCPoint cp1 = controlPoints.getPointAt(curSeg);
CCPoint cp2 = controlPoints.getPointAt(curSeg + 1);
CCPoint cp3 = controlPoints.getPointAt(curSeg + 2);
// segment length, desired points
float curSegLen = ccpLength(ccpSub(cp2, cp1));
int curSegPoints = (int)ceilf(curSegLen / m_patternLength) + 1;
float step = 1.0f / (curSegPoints - 1);
// populate points for this segments
float lt = 0;
while(lt < 1) {
CCPoint pos = ccCardinalSplineAt(cp0, cp1, cp2, cp3, m_tension, lt);
points.addPoint(pos);
lt += step;
}
}
// last point
points.addPoint(controlPoints.getPointAt(controlPoints.getCount() - 1));
// last placeholder
m_segmentPointIndices.push_back(points.getCount());
}
