private void DrawGraph()
{
if (DataAvailable)
{
Graphics g = Graphics.FromImage(_gridBitmap);
g.PageUnit = GraphicsUnit.Pixel;
int xo = UnitsConverter.MM2Pixel(_drawingArea.Left);
int yo = UnitsConverter.MM2Pixel(_drawingArea.Bottom);
for (int i = 0; i < _xVector.Length; i++)
{
int x = (int)((_xVector[i] - _xVector[0]) * _xScale);
if (_yVector[i] > 0) // binned histogram might have zero frequencies
{
int y = (int)(_yScale * Math.Log10(_yVector[i]));
g.DrawLine(new Pen(ForeColor), xo + x, yo, xo + x, yo - y);
}
}
}
}
private void CreateGridBitmap()
{
float axesOffset = _drawAxes ? _axesOffset : 0;
// create the bitmap object
_gridBitmap = new Bitmap(ClientRectangle.Width, ClientRectangle.Height, PixelFormat.Format32bppArgb);
Graphics g = Graphics.FromImage(_gridBitmap);
g.PageUnit = GraphicsUnit.Millimeter;
// clear its background
Brush br = new SolidBrush(BackColor);
g.FillRectangle(br, 0F, 0F, _gridBitmap.Width, _gridBitmap.Height);
_origin = new PointF(axesOffset, UnitsConverter.Pixel2MM(ClientRectangle.Bottom) - axesOffset);
// I'm subtracting 1 from width as the 3d frame of the control overrites the last pixel (odd! it shouldn't be part of the client area
// but this what i noticed). This issue started to show up once i changed to 3D frame and wasn't these with thin frame.
_drawingArea = new RectangleF(axesOffset, 0, UnitsConverter.Pixel2MM(ClientRectangle.Width - 1) - axesOffset, UnitsConverter.Pixel2MM(ClientRectangle.Height) - axesOffset);
int axesOffsetPixels = UnitsConverter.MM2Pixel(axesOffset);
_drawingAreaPixels = new Rectangle(axesOffsetPixels, 0, ClientRectangle.Width - axesOffsetPixels - 1, ClientRectangle.Height - axesOffsetPixels);
// draw 2 axes
if (_drawAxes)
{
Pen axisPen = new Pen(AxisColor, AxisThickness);
g.DrawLine(Pens.Black, UnitsConverter.Pixel2MM(ClientRectangle.Left), UnitsConverter.Pixel2MM(ClientRectangle.Bottom) - axesOffset + AxisThickness, UnitsConverter.Pixel2MM(ClientRectangle.Right), UnitsConverter.Pixel2MM(ClientRectangle.Bottom) - axesOffset + AxisThickness);
g.DrawLine(Pens.Black, UnitsConverter.Pixel2MM(ClientRectangle.Left) + axesOffset - AxisThickness, UnitsConverter.Pixel2MM(ClientRectangle.Top), UnitsConverter.Pixel2MM(ClientRectangle.Left) + axesOffset - AxisThickness, UnitsConverter.Pixel2MM(ClientRectangle.Bottom));
}
// draw grid. I draw starting from axes so I'm sure both axis wil be snapped to the grid
Pen p = new Pen(GridColor, GridLineThickness);
float x = _drawingArea.Left;
while (x <= _drawingArea.Right)
{
x += GridSpacing;
g.DrawLine(p, x, 0, x, _gridBitmap.Height);
}
if (!_logYScale)
{
float y = _drawingArea.Bottom;
while (y > _drawingArea.Top)
{
y -= GridSpacing;
g.DrawLine(p, 0, y, _drawingArea.Right, y);
}
}
else
{
float decades = 4;
float dy = _drawingArea.Height / decades;
for (float yy = _drawingArea.Bottom; yy > _drawingArea.Top; yy -= dy)
{
for (int i = 1; i <= 10; i++)
{
float y = yy - (float)Math.Log10(i) * dy;
g.DrawLine(p, 0, y, _drawingArea.Right, y);
}
}
}
}