RasterImageAnimator Class

Summary

Animates an image that has time-based frames.

Syntax

Objective-C

C++/CLI

Python

public class RasterImageAnimator : IDisposable

@interface LTRasterImageAnimator : NSObject

public ref class RasterImageAnimator : public System.IDisposable

class RasterImageAnimator(IDisposable):

Remarks

To load and play an animated file, such as GIF, you can load the frames into a RasterImage object from the file, then play the list to a target image in a loop that displays each change in the target image. You can also create an animation sequence from scratch and save the images to create an animated GIF file.

The following is an outline of possible steps:

Load a multi-frame image using Load
Use the RasterImage constructor to create a target image that is the size of the images in the multi-frame image
Use the RasterImageAnimator class to create an animation playback that references multi-frame image and the target image
In a loop that processes each frame in the multi-frame image, do the following:
1. Use RasterImageAnimator.Process to process the current state and get the next state of the animation
2. Use RasterImageAnimator.GetUpdateRectangle to get the update rectangle (the portion of the target image that has changed)
3. Use RasterImagePainter.Paint to paint the changed portion of the image. To paint only the changed portion, use the update rectangle as the source clipping rectangle.

The animation loop can have a number of states, and you should only paint the changes in an appropriate state (for example, when the next state is RasterImageAnimatorState.PostRender. For a list of possible states, refer to RasterImageAnimatorState.

The RasterImage.AnimationDisposalMethod property in the target RasterImage determines what happens to the image in the playback loop after rendering and after any wait state, when the next state is RasterImageAnimatorState.PostDispose. The options are as follows: keep the image as it is, restore the background, or restore the previous image. (Restoring the background is a common option for animation.)

The animation loop goes continuously through the list of frames. If you want to stop at the end of the list, you can exit the loop when the next state is RasterImageAnimatorState.End.

The RasterImageAnimator class also implements the IDisposable interface, it is recommended that you follow the standard .NET dispose pattern when using the RasterImageAnimator class. For more information, refer to IDisposable.

Example

This example will load an animated GIF file and paint on the surface of the given Panel.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.Drawing; 
 
 
public void RasterImageAnimatorExample(Panel panel) 
{ 
	// Initialize the RasterCodecs object 
	RasterCodecs codecs = new RasterCodecs(); 
 
	// When loading the animated GIF file, we have two means to load all pages into memory 
	// Option 1: Set the Load All Pages to true, then specify just the filename 
	string fileName = Path.Combine(LEAD_VARS.ImagesDir, "Eye.gif"); 
	codecs.Options.Load.AllPages = true; 
	RasterImage animatedImage = codecs.Load(fileName); 
 
	// Option 2: Specify which pages to load, -1 means all pages 
	// Load the animated GIF file  
	//RasterImage animatedImage = codecs.Load(filename, 0, CodecsLoadByteOrder.Bgr, 1, -1) 
 
	// Create the target image, we want it to be in the animated image size 
	RasterImage targetImage = new RasterImage( 
	   RasterMemoryFlags.Conventional, 
	   animatedImage.AnimationGlobalSize.Width, 
	   animatedImage.AnimationGlobalSize.Height, 
	   animatedImage.BitsPerPixel, 
	   animatedImage.Order, 
	   animatedImage.ViewPerspective, 
	   null, 
	   IntPtr.Zero, 
	   0); 
 
	// Copy the palette from the animated image to this newly created image 
	animatedImage.CopyPaletteTo(targetImage); 
 
	// Create the RasterImageAnimator object 
	RasterImageAnimator animator = new RasterImageAnimator(targetImage, animatedImage); 
 
	// Animate it 
 
	// Use GDI+ paint engine to support transparent colors 
	RasterPaintProperties props = RasterPaintProperties.Default; 
	props.PaintEngine = RasterPaintEngine.GdiPlus; 
 
	Graphics g = panel.CreateGraphics(); 
 
	RasterImageAnimatorState state; 
	do 
	{ 
		LeadRect srcRect = new LeadRect(0, 0, targetImage.ImageWidth, targetImage.ImageHeight); 
		LeadRect updateRect; 
		LeadRect destRect; 
 
		state = animator.Process(); 
 
		switch (state) 
		{ 
			case RasterImageAnimatorState.WaitDelay: 
			case RasterImageAnimatorState.WaitInputDelay: 
			case RasterImageAnimatorState.Render: 
				// Continue processing 
				break; 
 
			case RasterImageAnimatorState.WaitInput: 
				// In case the animated image has the "wait for user input" flags, 
				// cancel the waiting 
				animator.CancelWait(); 
				break; 
 
			case RasterImageAnimatorState.PostClear: 
			case RasterImageAnimatorState.PostRender: 
				// Get the area in the target image that has changed 
				updateRect = animator.GetUpdateRectangle(true); 
 
				// Paint it 
				destRect = new LeadRect(0, 0, targetImage.ImageWidth, targetImage.ImageHeight); 
 
				RasterImagePainter.Paint(targetImage, g, srcRect, updateRect, destRect, destRect, props); 
				break; 
 
			default: 
				break; 
		} 
	} 
	while (state != RasterImageAnimatorState.End); 
 
	g.Dispose(); 
 
	animator.Dispose(); 
 
	targetImage.Dispose(); 
	animatedImage.Dispose(); 
 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

Requirements

Target Platforms

Reference

RasterImageAnimator Members

Leadtools Namespace

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