/// <summary>Executes some code with a given scissor rectangle (drawing will be limited to the rectangle)</summary>
/// <param name="batch">The <see cref="SpriteBatch"/> being used for drawing calls</param>
/// <param name="scissorRect">The rectangle to limit drawing to</param>
/// <param name="action">The function to execute with the given scissor rectangle</param>
/// <param name="respectExistingScissor">Whether to limit the new scissor rectangle to a subrectangle of the current scissor rectangle</param>
public static void WithScissorRect(this SpriteBatch batch, XnaRectangle scissorRect, Action <SpriteBatch> action, bool respectExistingScissor = true)
{
// Stop the old drawing code
batch.End();
// Keep track of the old scissor rectangle (this needs to come after End() so they're applied to the GraphicsDevice)
XnaRectangle oldScissor = batch.GraphicsDevice.ScissorRectangle;
BlendState oldBlendState = batch.GraphicsDevice.BlendState;
DepthStencilState oldStencilState = batch.GraphicsDevice.DepthStencilState;
RasterizerState oldRasterizerState = batch.GraphicsDevice.RasterizerState;
// Trim current scissor to the existing one if necessary
if (respectExistingScissor)
{
scissorRect = scissorRect.Intersection(oldScissor) ?? new XnaRectangle(0, 0, 0, 0);
}
// Draw with the new scissor rectangle
using (RasterizerState rasterizerState = new RasterizerState {
ScissorTestEnable = true
}) {
batch.Begin(SpriteSortMode.BackToFront, BlendState.AlphaBlend, SamplerState.PointClamp, DepthStencilState.Default, rasterizerState);
// Set scissor rectangle
batch.GraphicsDevice.ScissorRectangle = scissorRect;
// Perform the action
action(batch);
// Draw the batch
batch.End();
}
// Reset scissor rectangle
batch.GraphicsDevice.ScissorRectangle = oldScissor;
// Return to last state
batch.Begin(SpriteSortMode.BackToFront, oldBlendState, SamplerState.PointClamp, oldStencilState, oldRasterizerState);
}
/// <summary>
/// Zeichenauruf für das Control (SpriteBatch ist bereits aktiviert)
/// </summary>
/// <param name="batch">Spritebatch</param>
/// <param name="gameTime">Vergangene Spielzeit</param>
public void Draw(SpriteBatch batch, Rectangle renderMask, GameTime gameTime)
{
if (!Visible) return;
// Controlgröße ermitteln
Rectangle controlArea = new Rectangle(AbsolutePosition, ActualSize);
Rectangle localRenderMask = controlArea.Intersection(renderMask);
// Scissor-Filter aktivieren
batch.GraphicsDevice.ScissorRectangle = localRenderMask.Transform(AbsoluteTransformation);
batch.Begin(rasterizerState: new RasterizerState() { ScissorTestEnable = true }, samplerState: SamplerState.LinearWrap, transformMatrix: AbsoluteTransformation);
OnDraw(batch, controlArea, gameTime);
batch.End();
foreach (var child in Children.AgainstZOrdner())
{
Rectangle clientArea = ActualClientArea;
clientArea.Location += AbsolutePosition;
Rectangle clientRenderMask = clientArea.Intersection(renderMask);
child.Draw(batch, clientRenderMask, gameTime);
}
invalidDrawing = false;
}
