public static void Draw(GameTime gameTime, Matrix4x4 view, Matrix4x4 projection)
{
// Update our effect with the matrices.
_effect.View = view.ToXNA();
_effect.Projection = projection.ToXNA();
// Calculate the total number of vertices we're going to be rendering.
int vertexCount = 0;
foreach (var shape in _activeShapes)
vertexCount += shape.LineCount * 2;
// If we have some vertices to draw
if (vertexCount > 0)
{
// Make sure our array is large enough
if (_verts.Length < vertexCount)
{
// If we have to resize, we make our array twice as large as necessary so
// we hopefully won't have to resize it for a while.
_verts = new VertexPositionColor[vertexCount * 2];
}
// Now go through the shapes again to move the vertices to our array and
// add up the number of lines to draw.
int lineCount = 0;
int vertIndex = 0;
foreach (DebugShape shape in _activeShapes)
{
lineCount += shape.LineCount;
int shapeVerts = shape.LineCount * 2;
for (int i = 0; i < shapeVerts; i++)
_verts[vertIndex++] = shape.Vertices[i];
}
// Start our effect to begin rendering.
_effect.CurrentTechnique.Passes[0].Apply();
// We draw in a loop because the Reach profile only supports 65,535 primitives. While it's
// not incredibly likely, if a game tries to render more than 65,535 lines we don't want to
// crash. We handle this by doing a loop and drawing as many lines as we can at a time, capped
// at our limit. We then move ahead in our vertex array and draw the next set of lines.
int vertexOffset = 0;
while (lineCount > 0)
{
// Figure out how many lines we're going to draw
int linesToDraw = Math.Min(lineCount, 65535);
// Draw the lines
_graphics.DrawUserPrimitives(PrimitiveType.LineList, _verts, vertexOffset, linesToDraw);
// Move our vertex offset ahead based on the lines we drew
vertexOffset += linesToDraw * 2;
// Remove these lines from our total line count
lineCount -= linesToDraw;
}
}
// Go through our active shapes and retire any shapes that have expired to the
// cache list.
bool resort = false;
for (int i = _activeShapes.Count - 1; i >= 0; i--)
{
DebugShape s = _activeShapes[i];
s.Lifetime -= (float)gameTime.ElapsedGameTime.TotalSeconds;
if (s.Lifetime <= 0)
{
_cachedShapes.Add(s);
_activeShapes.RemoveAt(i);
resort = true;
}
}
// If we move any shapes around, we need to resort the cached list
// to ensure that the smallest shapes are first in the list.
if (resort)
_cachedShapes.Sort(CachedShapesSort);
}
public static void SetValue(this EffectParameter collection, Matrix4x4 value)
{
Contract.Requires(collection != null);
collection.SetValue(value.ToXNA());
}
public static void SetValue(this EffectParameter collection, Matrix4x4 value)
{
collection.SetValue(value.ToXNA());
}
