#include "Painty.h"
#include <cmath>

Painty::Painty()
{

}

void Painty::setXY(int idx, float x, float y) {
	if (points.size() < idx+1) {points.resize(idx+1);}
	points[idx] = QPointF(x,y);
	emit update();
}

void Painty::setSigma(double s) {
	this->sigma = s;
	emit update();
}

#include <QPainter>
void Painty::paint(QPainter* p) {

	p->setPen(Qt::blue);
	p->drawLine(0,0,100,100);

	const double s = sigma;

	static QImage img(width(), height(), QImage::Format_ARGB32);
	std::vector<double> vec;

	if (points.size() < 3) {return;}

	double max = 0;
	for (int y = 0; y < height(); ++y) {
		for (int x = 0; x < width(); ++x) {
			double sum = 0;
			for (const QPointF p : points) {
				const double dx = x-p.x();
				const double dy = y-p.y();
				const double dist = std::sqrt(dx*dx+dy*dy);
				sum += 1.0 / std::sqrt(2*M_PI*s*s) * std::exp(- (dist*dist)/(2*s*s) );
			}
			vec.push_back(sum);
			if (sum > max) {max = sum;}
		}
	}

	for (size_t idx = 0; idx < vec.size(); ++idx) {
		int x = idx % (int) width();
		int y = idx / width();
		double h = 1.0 - vec[idx]/max;
		QColor c = QColor::fromHsvF(h, 0.5, 1);
		img.setPixelColor(x, y, c);

	}

	p->drawImage(0, 0, img);



}