public void Draw(DrawArgs drawArgs)
{
_prerenderProvider.CreatePrerenders(drawArgs, _map.Size);
// apply view matrix
drawArgs.PushScale(_zoom);
drawArgs.PushTranslation(_pan);
// apply level of detail
var drawLod = _zoom > 0.5 ? DrawLevelOfDetail.Normal : DrawLevelOfDetail.Low;
drawArgs.LevelOfDetail = drawLod;
// calculate viewport transform, used for zoom/pan
Matrix3x2.Invert(drawArgs.CurrentTransform, out _mapTransform);
// calculate visible field coords
var bottomLeftFieldCoords = TranslateToFieldCoords(_bottomLeftViewLimit);
var blx = bottomLeftFieldCoords.X;
var bly = bottomLeftFieldCoords.Y;
var topRightFieldCoords = TranslateToFieldCoords(_topRightViewLimit);
var urx = topRightFieldCoords.X;
var ury = topRightFieldCoords.Y;
// have agents draw themselves layer by layer
foreach (var drawLayer in DrawLayers)
{
drawArgs.Layer = drawLayer;
var prerender = _prerenderProvider.GetPrerender(drawLod, drawLayer);
if (prerender != null)
{
drawArgs.Ds.DrawImage(prerender, -_tileRadius, -2.0f * _tileRadiusH);
}
else
{
// find indicators which are currently on screen
var culledIndicators = _indicatorRegistry
.GetIndicators(drawLod, drawLayer)
.Where(tm => blx <= tm.Position.X && tm.Position.X <= urx && bly <= tm.Position.Y && tm.Position.Y <= ury);
foreach (var indicator in culledIndicators)
{
indicator.Draw(drawArgs);
}
}
}
// restore view matrix
drawArgs.Pop();
drawArgs.Pop();
}
private void CreatePrerender(PrerenderedLayer prerender, DrawArgs drawArgs, Vector2 size)
{
prerender.DestroyResources();
var indicators = _indicatorRegistry.GetIndicators(prerender.LevelOfDetail, prerender.Layer);
prerender.Version = _indicatorRegistry.GetVersion(prerender.LevelOfDetail, prerender.Layer);
CanvasRenderTarget offscreen = new CanvasRenderTarget(drawArgs.Ds.Device, size.X + 2 * _tileRadius, size.Y + 4 * _tileRadiusH, drawArgs.Ds.Dpi);
using (CanvasDrawingSession ds = offscreen.CreateDrawingSession())
{
var prerenderArgs = new DrawArgs(ds, drawArgs.CurrentTransform, drawArgs.FrameId);
prerenderArgs.PushTranslation(_tileRadius, 2.0f * _tileRadiusH);
foreach (var indicator in indicators)
{
indicator.Draw(prerenderArgs);
}
}
prerender.Render = offscreen;
}