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authorJedidiah Barber <contact@jedbarber.id.au>2021-07-14 11:49:10 +1200
committerJedidiah Barber <contact@jedbarber.id.au>2021-07-14 11:49:10 +1200
commitd24f813f3f2a05c112e803e4256b53535895fc98 (patch)
tree601e6ae9a1cd44bcfdcf91739a5ca36aedd827c9 /src/charts/ChartScene.cpp
Initial mirror commitHEADmaster
Diffstat (limited to 'src/charts/ChartScene.cpp')
-rw-r--r--src/charts/ChartScene.cpp111
1 files changed, 111 insertions, 0 deletions
diff --git a/src/charts/ChartScene.cpp b/src/charts/ChartScene.cpp
new file mode 100644
index 0000000..559ecc5
--- /dev/null
+++ b/src/charts/ChartScene.cpp
@@ -0,0 +1,111 @@
+#include "ChartScene.h"
+#include "ChartAxes.h"
+#include <cstdlib>
+#include <cmath>
+#include "ChartDataLine.h"
+
+const QSizeF ChartScene::Margin(30, 20);
+const QSizeF ChartScene::Padding(20, 20);
+const QSizeF ChartScene::DataSetPadding(10, 10);
+
+ChartScene::ChartScene(Chart* chart):
+ QGraphicsScene(chart), chart(chart), dataDirection(1)
+{
+ setSceneRect(0, 0, 600, 300);
+}
+
+void ChartScene::setDataSet(const QList<DataPoint>& dataSet, int xTickInterval)
+{
+ clear();
+ this->dataSet = dataSet;
+ initYScale();
+ ChartAxes(this, xTickInterval).paint();
+ ChartDataLine(this).paint();
+}
+
+void ChartScene::initYScale()
+{
+ yMin = computeMinY();
+ yMax = computeMaxY();
+ yTickSpacing = computeYTickSpacing();
+ extendYMinMax();
+ yScale = getDataSetSize().height() / getYDiff();
+}
+
+int ChartScene::computeMinY() const
+{
+ int min = 1000000;
+ foreach(DataPoint point, dataSet)
+ if(point.value < min)
+ min = point.value;
+ return min;
+}
+
+int ChartScene::computeMaxY() const
+{
+ int max = -1000000;
+ foreach(DataPoint point, dataSet)
+ if(point.value > max)
+ max = point.value;
+ return max;
+}
+
+int ChartScene::computeYTickSpacing() const
+{
+ const int higherZonesLimit = 4;
+ const int lowerZonesLimit = 3;
+
+ double order = floor(log10(getYDiff()));
+ double base = pow(10, order);
+ double zonesNum = ceil(getYDiff() / base);
+ if(zonesNum > higherZonesLimit)
+ base *= 2;
+ else if(zonesNum < lowerZonesLimit)
+ base /= 2;
+ int res = (int)base;
+ if(res == 0)
+ res = 10;
+ return res;
+}
+
+void ChartScene::extendYMinMax()
+{
+ yMin = int(floor(yMin / double(yTickSpacing))) * yTickSpacing;
+ yMax = int(ceil(yMax / double(yTickSpacing))) * yTickSpacing;
+ if (yMax == yMin)
+ yMax = yMin + yTickSpacing;
+}
+
+QSizeF ChartScene::getBorder()
+{
+ return Margin + Padding;
+}
+
+QRectF ChartScene::getChartRect() const
+{
+ QSizeF border = getBorder();
+ return sceneRect().adjusted(border.width(), border.height(),
+ -border.width(), -border.height());
+}
+
+QPointF ChartScene::getChartOrigin() const
+{
+ QRectF chartRect = getChartRect();
+ return QPointF(chartRect.left(), chartRect.bottom());
+}
+
+QSizeF ChartScene::getDataSetSize() const
+{
+ QSizeF dataSetBorder(2 * getBorder() + DataSetPadding);
+ return sceneRect().size() - dataSetBorder;
+}
+
+qreal ChartScene::getXTickSpacing() const
+{
+ return getDataSetSize().width() / (dataSet.size() - 1);
+}
+
+qreal ChartScene::getYPosFromValue(int value) const
+{
+ return yScale * value;
+}