//find where in graph image each values would correspond to and add this info to a new array
private List<DataPoint> FillOffsetList(HeartbeatMeasurement[] dataSet, RenderingOptions options, float Width, float Height)
{
if (dataSet == null || dataSet.Length <= 0)
{
return null;
}
var valueDiff = options.MaxValue - options.MinValue;
float tickOffset = (Width / dataSet.Length);
List<DataPoint> offsetList = new List<DataPoint>();
float currentOffset = 0;
for (int i = 0; i < dataSet.Length; i++)
{
var currentDiff = options.MaxValue - dataSet[i].HeartbeatValue;
offsetList.Add(new DataPoint
{
OffsetX = currentOffset,
OffsetY = (currentDiff / valueDiff) * Height,
Value = dataSet[i].HeartbeatValue //just in case we would have functionality to show the actual value, we'll store it here
});
currentOffset += tickOffset;
}
return offsetList;
}
//draws the value texts
private void DrawYAxisTexts(CanvasDrawingSession ds, float height, RenderingOptions options)
{
// if needed do add CanvasTextFormat
ds.DrawText(options.MaxValueBuffered.ToString("#.#"), new Vector2(RIGHT_TEXT_MARGIN, 0), VALUESTEXT_COLOR);
var percent = (options.MaxValueBuffered - options.MinValueBuffered) * (1.0 / (DEFAULT_GRADIENTS));
for (int i = 1; i < DEFAULT_GRADIENTS; i++)
{
var percentVal = options.MaxValueBuffered - (percent * i);
// do add CanvasTextFormat
ds.DrawText(percentVal.ToString("#.#"), new Vector2(RIGHT_TEXT_MARGIN, (i * (height / DEFAULT_GRADIENTS))), VALUESTEXT_COLOR);
}
// do add CanvasTextFormat
ds.DrawText(options.MinValueBuffered.ToString("#.#"), new Vector2(RIGHT_TEXT_MARGIN, (height - BOTTOM_TEXT_MARGIN)), VALUESTEXT_COLOR);
}
private void DrawCharData(CanvasDevice device, RenderingOptions options, HeartbeatMeasurement[] data)
{
//Size restrictions descriped in : http://microsoft.github.io/Win2D/html/P_Microsoft_Graphics_Canvas_CanvasDevice_MaximumBitmapSizeInPixels.htm
float useHeight = (float)ChartWin2DCanvas.Size.Height > device.MaximumBitmapSizeInPixels ? device.MaximumBitmapSizeInPixels : (float)ChartWin2DCanvas.Size.Height;
float useWidth = data.Length > device.MaximumBitmapSizeInPixels ? device.MaximumBitmapSizeInPixels : data.Length;
//this will change the values array to array with drawing-line-points for the graph
List<DataPoint> dataList = FillOffsetList(data, options, useWidth, useHeight);
//reset zoom & moving values
_zoomFactor = 100;
_graphDrawingPoint = new Point(0, 0);
_graphDrawingSource = new Size(useWidth, useHeight);
//create the graph image
_offscreenChartImage = new CanvasRenderTarget(device, useWidth, useHeight, 96);
using (CanvasDrawingSession ds = _offscreenChartImage.CreateDrawingSession())
{
//This creates drawing geometry from the drawing-line-points
CanvasGeometry chart = getDrawChartGeometry(device, dataList);
//and then we simply draw it with defined color
ds.DrawGeometry(chart, 0, 0, GRAPG_COLOR);
}
}
private void DrawBackGround(CanvasDevice device, RenderingOptions options)
{
float useHeight = (float)ChartWin2DCanvas.Size.Height;
float useWidth = (float)ChartWin2DCanvas.Size.Width;
//this is always drawn in the size of control, so all texts drawn in it are sharp
_offscreenBackGround = new CanvasRenderTarget(device, useWidth, useHeight, 96);
using (CanvasDrawingSession ds = _offscreenBackGround.CreateDrawingSession())
{
ds.Clear(BACKGROUND_COLOR);
//draw lines
DrawGraphValueLines(ds, useWidth, useHeight);
//draw value texts
DrawYAxisTexts(ds, useHeight, options);
}
}
private RenderingOptions CreateRenderingOptions(HeartbeatMeasurement[] dataSet)
{
RenderingOptions renderingOptions = null;
if (dataSet != null)
{
renderingOptions = new RenderingOptions();
//set initial end-of-range values
renderingOptions.MinValue = double.MaxValue;
renderingOptions.MaxValue = double.MinValue;
//find if we have bigger or smaller than what we have with current values
for (int i = 0; i < dataSet.Length; i++)
{
renderingOptions.MinValue = Math.Min(dataSet[i].HeartbeatValue, renderingOptions.MinValue);
renderingOptions.MaxValue = Math.Max(dataSet[i].HeartbeatValue, renderingOptions.MaxValue);
}
//and see if default values are more suitable
if (renderingOptions.MinValue > MIN_VALUE_DEFAULT)
{
renderingOptions.MinValue = MIN_VALUE_DEFAULT;
}
if (renderingOptions.MaxValue < MAX_VALUE_DEFAULT)
{
renderingOptions.MaxValue = MAX_VALUE_DEFAULT;
}
var valueDiff = renderingOptions.MaxValue - renderingOptions.MinValue;
var diffBuffer = (valueDiff > 0) ? (valueDiff * 0.1) : 2;
//values used with value texts
renderingOptions.MaxValueBuffered = renderingOptions.MaxValue + diffBuffer;
renderingOptions.MinValueBuffered = renderingOptions.MinValue - diffBuffer;
renderingOptions.MinValueBuffered = (renderingOptions.MinValueBuffered > 0) ? renderingOptions.MinValueBuffered : 0;
}
return renderingOptions;
}
private int CreateRenderingOptions()
{
int startIndex = 0;
_renderingOptions = null;
if (_data != null)
{
_renderingOptions = new RenderingOptions();
_renderingOptions.MinValue = double.MaxValue;
_renderingOptions.MaxValue = double.MinValue;
startIndex = (_data.Length < DataPointCount) ? 0 : _data.Length - DataPointCount;
System.Diagnostics.Debug.WriteLine("startIndex : " + startIndex + ", DataPointCount : " + DataPointCount + ", _data.Length : " + _data.Length);
for (int i = startIndex; i < _data.Length; i++)
{
_renderingOptions.MinValue = Math.Min(_data[i].HeartbeatValue, _renderingOptions.MinValue);
_renderingOptions.MaxValue = Math.Max(_data[i].HeartbeatValue, _renderingOptions.MaxValue);
}
if (_renderingOptions.MinValue > MIN_VALUE_DEFAULT)
{
_renderingOptions.MinValue = MIN_VALUE_DEFAULT;
}
if (_renderingOptions.MaxValue < MAX_VALUE_DEFAULT)
{
_renderingOptions.MaxValue = MAX_VALUE_DEFAULT;
}
var valueDiff = _renderingOptions.MaxValue - _renderingOptions.MinValue;
var diffBuffer = (valueDiff > 0) ? (valueDiff * 0.1) : 2;
_renderingOptions.MaxValueBuffered = _renderingOptions.MaxValue + diffBuffer;
_renderingOptions.MinValueBuffered = _renderingOptions.MinValue - diffBuffer;
_renderingOptions.MinValueBuffered = (_renderingOptions.MinValueBuffered > 0) ? _renderingOptions.MinValueBuffered : 0;
}
return startIndex;
}