GetUpdateRectangle Method

Summary

Gets the update rectangle in the target image during an animation playback.

Syntax

Objective-C

C++/CLI

Python

public LeadRect GetUpdateRectangle( 
   bool clear 
)

- (LeadRect)getUpdateRectangle:(BOOL)clear error:(NSError **)error NS_SWIFT_NAME(getUpdateRectangle(clear:));

public: 
LeadRect GetUpdateRectangle(  
   bool clear 
)

def GetUpdateRectangle(self,clear):

Parameters

clear
true if you want to clear the rectangle; false if you do not.

Return Value

A LeadRect that this method will fill with the coordinates of the update rectangle.

Remarks

The rectangle uses image coordinates, and it is cumulative.

You usually call this after the following states, which you can get with the State property:

Value	Meaning
RasterImageAnimatorState.PostClear	Indicates that the target image has been cleared
RasterImageAnimatorState.PostRender	that a frame has been rendered to the target image
RasterImageAnimatorState.PostDispose	Indicates that the current frame has been disposed of. The index is incremented after processing this state

This method uses image coordinates to specify the update rectangle. Therefore, you must account for the image's view perspective. For more information, refer to Accounting for View Perspective.

Example

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:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

RasterImageAnimator Class

RasterImageAnimator Members

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Help Version 22.0.2023.5.16

Leadtools Assembly

Introduction

Getting Started

Namespaces

Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies