From 4f847aa6717b4a5cbb19a0f3dd98f6f47ef15f7a Mon Sep 17 00:00:00 2001
From: thepra <agge92@live.it>
Date: Mon, 28 Aug 2017 11:44:07 +0200
Subject: [PATCH] rendering astroid

---
 .gitignore     |  1 +
 renderarea.cpp | 19 ++++++++++++++++++-
 renderarea.h   |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 1bc216a..f6b6889 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 QtCurvesCpp.pro.user
 QtCurvesCpp.pro.user.9311c87
 QtCurvesCpp.pro.user
+QtCurvesCpp.pro.user
diff --git a/renderarea.cpp b/renderarea.cpp
index 82d3f1c..d65a863 100644
--- a/renderarea.cpp
+++ b/renderarea.cpp
@@ -10,6 +10,11 @@ RenderArea::RenderArea(QWidget *parent) :
 
 }
 
+QPointF RenderArea::ComputeAstroid(float t){
+	double cos_t{cos(t)},sin_t{sin(t)},x{2*cos_t*cos_t*cos_t},y{2*sin_t*sin_t*sin_t};
+	return QPointF{x,y};
+}
+
 QSize RenderArea::minimumSizeHint() const
 {
 	return QSize(100,100);
@@ -48,5 +53,17 @@ void RenderArea::paintEvent(QPaintEvent* event)
 	painter.setPen(mShapeColour);
 
 	painter.drawRect(this->rect());
-	painter.drawLine(this->rect().topLeft(),this->rect().bottomRight());
+
+	QPoint center{this->rect().center()};
+	int stepCount{1024};
+	double scale{40},intervalLenght{2 * M_PI},step{intervalLenght / stepCount};
+	for(float t = 0; t < intervalLenght; t += step){
+		QPointF point = ComputeAstroid(t);
+
+		QPoint pixel;
+		pixel.setX(point.x() * scale + center.x());
+		pixel.setY(point.y() * scale + center.y());
+
+		painter.drawPoint(pixel);
+	}
 }
diff --git a/renderarea.h b/renderarea.h
index f6c1e74..fa1ef0c 100644
--- a/renderarea.h
+++ b/renderarea.h
@@ -33,6 +33,7 @@ class RenderArea : public QWidget
 	public slots:
 
 	private:
+		QPointF ComputeAstroid(float t);
 		QColor mBackgroundColour;
 		QColor mShapeColour;
 		ShapesType mShape;