public void Draw(TextBuilder characters, UILineBatcher lines, TextBatcher text)
{
//Collect information to define data window ranges.
int minX = int.MaxValue;
int maxX = int.MinValue;
var minY = double.MaxValue;
var maxY = double.MinValue;
for (int i = 0; i < graphSeries.Count; ++i)
{
var data = graphSeries[i].Data;
if (minX > data.Start)
{
minX = data.Start;
}
if (maxX < data.End)
{
maxX = data.End;
}
for (int j = data.Start; j < data.End; ++j)
{
var value = data[j];
if (minY > value)
{
minY = value;
}
if (maxY < value)
{
maxY = value;
}
}
}
//If no data series contain values, then just use a default size.
if (minY == float.MinValue)
{
minY = 0;
maxY = 1;
}
//You could make use of this earlier to avoid comparisons but it doesn't really matter!
if (description.ForceVerticalAxisMinimumToZero)
{
minY = 0;
if (maxY < 0)
{
maxY = 1;
}
}
//Calculate the data span that takes into account rounding. We want intervals to be evenly spaced, but also to match nicely rounded numbers.
//That means the span must be equal to some rounded number multiplied by the number of intervals.
var yDataSpan = maxY - minY;
var yIntervalCount = description.TargetVerticalTickCount + 1;
var rawIntervalLength = yDataSpan / yIntervalCount;
var roundingOffset = 0.5 * Math.Pow(0.1, description.VerticalIntervalLabelRounding);
yDataSpan = Math.Round(rawIntervalLength * description.VerticalIntervalValueScale + roundingOffset, description.VerticalIntervalLabelRounding) *
(yIntervalCount / description.VerticalIntervalValueScale);
//Draw the graph body axes.
var lowerLeft = description.BodyMinimum + new Vector2(0, description.BodySpan.Y);
var upperRight = description.BodyMinimum + new Vector2(description.BodySpan.X, 0);
var lowerRight = description.BodyMinimum + description.BodySpan;
lines.Draw(description.BodyMinimum, lowerLeft, description.AxisLineRadius, description.BodyLineColor);
lines.Draw(lowerLeft, lowerRight, description.AxisLineRadius, description.BodyLineColor);
//Draw axis labels.
characters.Clear().Append(description.HorizontalAxisLabel);
var baseAxisLabelDistance = description.IntervalTickLength + description.IntervalTextHeight * description.LineSpacingMultiplier;
var verticalAxisLabelDistance = baseAxisLabelDistance + 2 * description.VerticalTickTextPadding;
var horizontalAxisLabelDistance = baseAxisLabelDistance + 2 * description.HorizontalTickTextPadding + description.AxisLabelHeight * description.LineSpacingMultiplier;
text.Write(characters,
lowerLeft +
new Vector2((description.BodySpan.X - GlyphBatch.MeasureLength(characters, description.Font, description.AxisLabelHeight)) * 0.5f, horizontalAxisLabelDistance),
description.AxisLabelHeight, description.TextColor, description.Font);
characters.Clear().Append(description.VerticalAxisLabel);
text.Write(characters,
description.BodyMinimum +
new Vector2(-verticalAxisLabelDistance, (description.BodySpan.Y + GlyphBatch.MeasureLength(characters, description.Font, description.AxisLabelHeight)) * 0.5f),
description.AxisLabelHeight, new Vector2(0, -1), description.TextColor, description.Font);
//Position tickmarks, tick labels, and background lines along the axes.
{
var xDataIntervalSize = (maxX - minX) / (description.TargetHorizontalTickCount + 1f);
var previousTickValue = int.MinValue;
float valueToPixels = description.BodySpan.X / (maxX - minX);
for (int i = 0; i < description.TargetHorizontalTickCount + 2; ++i)
{
//Round pen offset such that the data tick lands on an integer.
var valueAtTick = i * xDataIntervalSize;
var tickValue = (int)Math.Round(valueAtTick);
if (tickValue == previousTickValue)
{
//Don't bother creating redundant ticks.
continue;
}
previousTickValue = tickValue;
var penPosition = lowerLeft + new Vector2(tickValue * valueToPixels, 0);
var tickEnd = penPosition + new Vector2(0, description.IntervalTickLength);
var backgroundEnd = penPosition - new Vector2(0, description.BodySpan.Y);
lines.Draw(penPosition, tickEnd, description.IntervalTickRadius, description.BodyLineColor);
lines.Draw(penPosition, backgroundEnd, description.BackgroundLineRadius, description.BodyLineColor);
characters.Clear().Append(tickValue);
text.Write(characters, tickEnd +
new Vector2(GlyphBatch.MeasureLength(characters, description.Font, description.IntervalTextHeight) * -0.5f,
description.HorizontalTickTextPadding + description.IntervalTextHeight * description.LineSpacingMultiplier),
description.IntervalTextHeight, description.TextColor, description.Font);
}
}
{
var yDataIntervalSize = yDataSpan / (description.TargetVerticalTickCount + 1f);
var previousTickValue = double.MinValue;
//Note the inclusion of the scale. Rounding occurs post-scale; moving back to pixels requires undoing the scale.
var valueToPixels = description.BodySpan.Y / (yDataSpan * description.VerticalIntervalValueScale);
for (int i = 0; i < description.TargetVerticalTickCount + 2; ++i)
{
var tickValue = Math.Round((minY + yDataIntervalSize * i) * description.VerticalIntervalValueScale, description.VerticalIntervalLabelRounding);
if (tickValue == previousTickValue)
{
//Don't bother creating redundant ticks.
continue;
}
previousTickValue = tickValue;
var penPosition = lowerLeft - new Vector2(0, (float)(tickValue * valueToPixels));
var tickEnd = penPosition - new Vector2(description.IntervalTickLength, 0);
var backgroundEnd = penPosition + new Vector2(description.BodySpan.X, 0);
lines.Draw(penPosition, tickEnd, description.IntervalTickRadius, description.BodyLineColor);
lines.Draw(penPosition, backgroundEnd, description.BackgroundLineRadius, description.BodyLineColor);
characters.Clear().Append(tickValue, description.VerticalIntervalLabelRounding);
text.Write(characters,
tickEnd + new Vector2(-description.VerticalTickTextPadding, 0.5f * GlyphBatch.MeasureLength(characters, description.Font, description.IntervalTextHeight)),
description.IntervalTextHeight, new Vector2(0, -1), description.TextColor, description.Font);
}
}
//Draw the line graphs on top of the body.
{
var dataToPixelsScale = new Vector2(description.BodySpan.X / (maxX - minX), (float)(description.BodySpan.Y / yDataSpan));
Vector2 DataToScreenspace(int x, double y)
{
var graphCoordinates = new Vector2(x - minX, (float)(y - minY)) * dataToPixelsScale;
var screenCoordinates = graphCoordinates;
screenCoordinates.Y = description.BodySpan.Y - screenCoordinates.Y;
screenCoordinates += description.BodyMinimum;
return(screenCoordinates);
}
for (int i = 0; i < graphSeries.Count; ++i)
{
var series = graphSeries[i];
var data = series.Data;
var count = data.End - data.Start;
if (count > 0)
{
var previousScreenPosition = DataToScreenspace(data.Start, data[data.Start]);
if (count > 1)
{
for (int j = data.Start + 1; j < data.End; ++j)
{
var currentScreenPosition = DataToScreenspace(j, data[j]);
lines.Draw(previousScreenPosition, currentScreenPosition, series.LineRadius, series.LineColor);
previousScreenPosition = currentScreenPosition;
}
}
else
{
//Only one datapoint. Draw a zero length line just to draw a dot. (The shader can handle it without producing nans.)
lines.Draw(previousScreenPosition, previousScreenPosition, series.LineRadius, series.LineColor);
}
}
}
}
//Draw the legend entry last. Alpha blending will put it on top in case the legend is positioned on top of the body.
{
var penPosition = description.LegendMinimum;
var legendLineSpacing = description.LegendNameHeight * 1.5f;
penPosition.Y += legendLineSpacing;
for (int i = 0; i < graphSeries.Count; ++i)
{
var series = graphSeries[i];
var lineStart = new Vector2(penPosition.X, penPosition.Y);
var lineEnd = lineStart + new Vector2(description.LegendLineLength, -0.7f * description.LegendNameHeight);
lines.Draw(lineStart, lineEnd, series.LineRadius, series.LineColor);
var textStart = new Vector2(lineEnd.X + series.LineRadius + description.LegendNameHeight * 0.2f, penPosition.Y);
characters.Clear().Append(series.Name);
text.Write(characters, textStart, description.LegendNameHeight, description.TextColor, description.Font);
penPosition.Y += legendLineSpacing;
}
}
}
/// <summary>
/// Called when graphics resources need to be loaded. Override this
/// method to load any game-specific graphics resources.
/// </summary>
protected override void LoadContent()
{
base.LoadContent();
glyphBatch = new GlyphBatch(graphics.GraphicsDevice);
}
