/// <summary>
/// Preloads a shape within the slide to reduce lag. Call after the animations for the shape have been created.
/// </summary>
public static void PreloadShape(PowerPointSlide animationSlide, PowerPoint.Shape shape, bool addCoverImage=true)
{
// The cover image is used to cover the screen while the preloading happens behind the cover image.
PowerPoint.Shape coverImage = null;
if (addCoverImage)
{
coverImage = shape.Duplicate()[1];
coverImage.Left = shape.Left;
coverImage.Top = shape.Top;
animationSlide.RemoveAnimationsForShape(coverImage);
}
float originalWidth = shape.Width;
float originalHeight = shape.Height;
float originalLeft = shape.Left;
float originalTop = shape.Top;
// fit the shape exactly in the screen for preloading.
float scaleRatio = Math.Min(PowerPointPresentation.Current.SlideWidth / shape.Width,
PowerPointPresentation.Current.SlideHeight / shape.Height);
animationSlide.RelocateShapeWithoutPath(shape, 0, 0, shape.Width * scaleRatio, shape.Height * scaleRatio);
var trigger = PowerPoint.MsoAnimTriggerType.msoAnimTriggerWithPrevious;
var effectMotion = AddMotionAnimation(animationSlide, shape, shape.Left, shape.Top, originalLeft + (originalWidth - shape.Width) / 2, originalTop + (originalHeight - shape.Height) / 2, 0, ref trigger);
var effectResize = AddResizeAnimation(animationSlide, shape, shape.Width, shape.Height, originalWidth, originalHeight, 0, ref trigger);
// Make "cover" image disappear after preload.
PowerPoint.Effect effectDisappear = null;
if (addCoverImage)
{
var sequence = animationSlide.TimeLine.MainSequence;
effectDisappear = sequence.AddEffect(coverImage, PowerPoint.MsoAnimEffect.msoAnimEffectFade,
PowerPoint.MsoAnimateByLevel.msoAnimateLevelNone,
PowerPoint.MsoAnimTriggerType.msoAnimTriggerWithPrevious);
effectDisappear.Exit = Office.MsoTriState.msoTrue;
effectDisappear.Timing.Duration = 0.01f;
}
int firstEffectIndex = animationSlide.IndexOfFirstEffect(shape);
// Move the animations to just before the index of the first effect.
if (effectDisappear != null) effectDisappear.MoveTo(firstEffectIndex);
if (effectResize != null) effectResize.MoveTo(firstEffectIndex);
if (effectMotion != null) effectMotion.MoveTo(firstEffectIndex);
}