private float PaintGroup(StaveGroup group, float totalHeight, ICanvas canvas)
{
// paint into canvas
var height = group.Height + (GroupSpacing * Scale);
canvas.BeginRender(Width, height);
Renderer.Canvas.Color = Renderer.RenderingResources.MainGlyphColor;
Renderer.Canvas.TextAlign = TextAlign.Left;
// NOTE: we use this negation trick to make the group paint itself to 0/0 coordinates
// since we use partial drawing
group.Paint(0, -group.Y, canvas);
// calculate coordinates for next group
totalHeight += height;
var result = canvas.EndRender();
var args = new RenderFinishedEventArgs();
args.TotalWidth = Width;
args.TotalHeight = totalHeight;
args.Width = Width;
args.Height = height;
args.RenderResult = result;
args.FirstMasterBarIndex = group.FirstBarIndex;
args.LastMasterBarIndex = group.LastBarIndex;
Renderer.OnPartialRenderFinished(args);
return(height);
}