/*
  Copyright (c) 2021 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener alex@ludobloom.com
*/

#include "audiosynth/SplineInfo.h"
#include "gamemath/BezierCurve.h"
#include "utilities/IOUtilities.h"
#include "utilities/lookup3.h"
#include <stdlib.h>
#include <string.h>

SplineInfo initSplineInfo(unsigned int pointCount, struct SplinePoint * points, float xMax, float yMin, float yMax, unsigned int sampleIterations) {
	SplineInfo spline = {pointCount, memdup(points, pointCount * sizeof(*points)), xMax, yMin, yMax, sampleIterations};
	return spline;
}

SplineInfo copySplineInfo(SplineInfo * spline) {
	SplineInfo copy = {spline->pointCount, memdup(spline->points, spline->pointCount * sizeof(*spline->points)), spline->xMax, spline->yMin, spline->yMax, spline->sampleIterations};
	return copy;
}

bool isSplineInfoEqual(SplineInfo * spline1, SplineInfo * spline2) {
	if (spline1->pointCount != spline2->pointCount || spline1->sampleIterations != spline2->sampleIterations) {
		return false;
	}
	for (unsigned int pointIndex = 0; pointIndex < spline1->pointCount; pointIndex++) {
		struct SplinePoint point1 = spline1->points[pointIndex];
		struct SplinePoint point2 = spline2->points[pointIndex];
		if (point1.position.x != point2.position.x || point1.position.y != point2.position.y ||
		    point1.leadingControlPoint.x != point2.leadingControlPoint.x || point1.leadingControlPoint.y != point2.leadingControlPoint.y ||
		    point1.trailingControlPoint.x != point2.trailingControlPoint.x || point1.trailingControlPoint.y != point2.trailingControlPoint.y) {
			return false;
		}
	}
	return true;
}

uint32_t hashSplineInfo(SplineInfo * spline, uint32_t initval) {
	initval = hashlittle(&spline->sampleIterations, sizeof(spline->sampleIterations), initval);
	for (unsigned int pointIndex = 0; pointIndex < spline->pointCount; pointIndex++) {
		initval = hashlittle(&spline->points[pointIndex].position.x, sizeof(spline->points[pointIndex].position.x), initval);
		initval = hashlittle(&spline->points[pointIndex].position.y, sizeof(spline->points[pointIndex].position.y), initval);
		initval = hashlittle(&spline->points[pointIndex].leadingControlPoint.x, sizeof(spline->points[pointIndex].leadingControlPoint.x), initval);
		initval = hashlittle(&spline->points[pointIndex].leadingControlPoint.y, sizeof(spline->points[pointIndex].leadingControlPoint.y), initval);
		initval = hashlittle(&spline->points[pointIndex].trailingControlPoint.x, sizeof(spline->points[pointIndex].trailingControlPoint.x), initval);
		initval = hashlittle(&spline->points[pointIndex].trailingControlPoint.y, sizeof(spline->points[pointIndex].trailingControlPoint.y), initval);
	}
	return initval;
}

void disposeSplineInfo(SplineInfo * spline) {
	free(spline->points);
}

float sampleSplineYAtX(SplineInfo * spline, float x) {
	if (x < spline->points[0].position.x) {
		return spline->points[0].position.y;
	}
	for (unsigned int pointIndex = 1; pointIndex < spline->pointCount; pointIndex++) {
		if (spline->points[pointIndex].position.x > x && spline->points[pointIndex].position.x > spline->points[pointIndex - 1].position.x) {
			return BezierCurve_sampleYAtX(spline->points[pointIndex - 1].position,
			                              spline->points[pointIndex - 1].trailingControlPoint,
			                              spline->points[pointIndex].leadingControlPoint,
			                              spline->points[pointIndex].position,
			                              x,
			                              spline->sampleIterations);
		}
	}
	return spline->points[spline->pointCount - 1].position.y;
}