#include "LinearCurveEvaluator.h"
#include <assert.h>

void LinearCurveEvaluator::evaluateCurve(const std::vector<Point>& ptvCtrlPts, 
										 std::vector<Point>& ptvEvaluatedCurvePts, 
										 const float& fAniLength, 
										 const bool& bWrap) const
{
	int iCtrlPtCount = ptvCtrlPts.size();

	ptvEvaluatedCurvePts.assign(ptvCtrlPts.begin(), ptvCtrlPts.end());

	float x = 0.0;
	float y1;

	if (bWrap) {
		// if wrapping is on, interpolate the y value at xmin and
		// xmax so that the slopes of the lines adjacent to the
		// wraparound are equal.

		if ((ptvCtrlPts[0].x + fAniLength) - ptvCtrlPts[iCtrlPtCount - 1].x > 0.0f) {
			y1 = (ptvCtrlPts[0].y * (fAniLength - ptvCtrlPts[iCtrlPtCount - 1].x) + 
				  ptvCtrlPts[iCtrlPtCount - 1].y * ptvCtrlPts[0].x) /
				 (ptvCtrlPts[0].x + fAniLength - ptvCtrlPts[iCtrlPtCount - 1].x);
		}
		else 
			y1 = ptvCtrlPts[0].y;
	}
	else {
		// if wrapping is off, make the first and last segments of
		// the curve horizontal.

		y1 = ptvCtrlPts[0].y;
    }

	ptvEvaluatedCurvePts.push_back(Point(x, y1));

	/// set the endpoint based on the wrap flag.
	float y2;
    x = fAniLength;
    if (bWrap)
		y2 = y1;
    else
		y2 = ptvCtrlPts[iCtrlPtCount - 1].y;

	ptvEvaluatedCurvePts.push_back(Point(x, y2));
}