Re: Drawing and Animation (using Timers?)

• Previous message: Phil Jones: "Drawing and Animation (using Timers?)"
• In reply to: Phil Jones: "Drawing and Animation (using Timers?)"
• Next in thread: Phil Jones: "Re: Drawing and Animation (using Timers?)"
• Reply: Phil Jones: "Re: Drawing and Animation (using Timers?)"
• Messages sorted by: [ date ] [ thread ]

Date: Fri, 20 Aug 2004 23:38:21 -0700

You need some sort of timer to activate the animation logic. The recommended
approach is to use a single high frequency timer that checks each animation
sequence
for a frame advance. A simple example might be:

50 ms resolution timer
Animation Sequence 1: 10 fps (100ms) with some variant frames of +/- a few ms
Animation Sequence 2: 0.5 fps (2000 ms) with some portions of the sequence at
10fps

The general logic here is as follows:
1. Upon each timer elapse check the sequences for a frame advance.
    a) Simple: Current Time > Next Frame Time
    b) Complex: Current Time > Next Frame Time or Next Frame Time within X ms of
Current Time
2. If a frame advance is encountered then call the rendering logic. Rendering
logic should consist of:
    a) Compute clearing regions
    b) Invalidate or Direct Copy of new assets
3. Compute next Frame Advance

The logic here uses a single timer to manage multiple sequences. The ability to
dynamically change the
timing between portions of an animation sequence is key. For instance, you might
have a sequence that
displays a characters face for 2 seconds, then updates the mouth for half a
second at 10fps, and then
shows the face again for another second. Each step in the animation sequence
requires timeslices of
varying lengths. Setting up multiple timers for this is a pain and error prone.
Having a single logical timer
simplifies the situation.

If you are interested in something more complete I might write a small article
on this. Contact me through
my blog if you are interested and then I can drop you a response once the
article is posted.

-- 
Justin Rogers
DigiTec Web Consultants, LLC.
Blog: http://weblogs.asp.net/justin_rogers
"Phil Jones" <phil_newsgroup@hotmail.com> wrote in message
news:O6HjcexhEHA.396@TK2MSFTNGP12.phx.gbl...
> I'm just wondering, in regards to animating a sequence (for instance I'm
> looking at creating some sort of visual transformation between states wtihin
> the control - like sliding things around) what's the general approach to
> take?
>
> I'm thinking of using Timers to force redraws of the control - and then
> successively paint the thing.  But is there a more efficient or correct way
> to use the Drawing framework to achieve this type of thing?
>
> Thanks everyone.
> ===
> Phil - NZ
>
>
>

• Previous message: Phil Jones: "Drawing and Animation (using Timers?)"
• In reply to: Phil Jones: "Drawing and Animation (using Timers?)"
• Next in thread: Phil Jones: "Re: Drawing and Animation (using Timers?)"
• Reply: Phil Jones: "Re: Drawing and Animation (using Timers?)"
• Messages sorted by: [ date ] [ thread ]