Animation: A Moment of Panic

[richmond62]

I got "all hot and sweaty" today when I came across something called sprite masking, which has to
do with the way sprite images pass each other:

https://www.reddit.com/r/Unity3D/commen ... on_top_of/

When I realised that LiveCode is so fantastic that there is no need to even consider that:
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https://www.dropbox.com/s/a7skk4wyujf8j ... e.zip?dl=0
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Use the 'A', 'D', 'J' and 'L' keys to move the 2 monsters.

[richmond62]

This is certainly a worthwhile port-of-call (especially if you cannot draw anything semi-decent like me):

https://craftpix.net/categorys/sprites/
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[richmond62]

The reason I panicked was threefold:

1. I had never heard of sprite masks before.
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2. I had forgotten I was not programming for the BBC Micro.

3. I had forgotten about LAYERS in LiveCode.

Code: Select all

on rawKeyDown RD
   switch RD
      case 97
         set the layer of grc "mRIGHT" to top
         put item 1 of the loc of grc "mRIGHT" into RLR
         put item 2 of the loc of grc "mRIGHT" into RUD
         subtract 20 from RLR
         move grc "mRIGHT" to RLR,RUD
         add 1 to fld "RR"
         if fld "RR" > 17 then
            put 0 into fld "RR"
         end if
         put fld "RR" into RX
         set the backGroundPattern of grc "mRIGHT" to the ID of img ("Minotaur_01_Walking_" & RX & ".png")
         break
      case 100
         set the layer of grc "mRIGHT" to top
         put item 1 of the loc of grc "mRIGHT" into RLR
         put item 2 of the loc of grc "mRIGHT" into RUD
         add 20 to RLR
         move grc "mRIGHT" to RLR,RUD
         add 1 to fld "RR"
         if fld "RR" > 17 then
            put 0 into fld "RR"
         end if
         put fld "RR" into RX
         set the backGroundPattern of grc "mRIGHT" to the ID of img ("Minotaur_01_Walking_" & RX & ".png")
         break
      case 106
         set the layer of grc "mLEFT" to top
         put item 1 of the loc of grc "mLEFT" into LLR
         put item 2 of the loc of grc "mLEFT" into LUD
         subtract 20 from LLR
         move grc "mLEFT" to LLR,LUD
         add 1 to fld "LL"
         if fld "LL" > 17 then
            put 0 into fld "LL"
         end if
         put fld "LL" into LX
         set the backGroundPattern of grc "mLEFT" to the ID of img ("Minotaur_03_Walking_" & LX & ".png")
         break
      case 108
         set the layer of grc "mLEFT" to top
         put item 1 of the loc of grc "mLEFT" into LLR
         put item 2 of the loc of grc "mLEFT" into LUD
         add 20 to LLR
         move grc "mLEFT" to LLR,LUD
         add 1 to fld "LL"
         if fld "LL" > 17 then
            put 0 into fld "LL"
         end if
         put fld "LL" into LX
         set the backGroundPattern of grc "mLEFT" to the ID of img ("Minotaur_03_Walking_" & LX & ".png")
         break
   end switch
end rawKeyDown

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I really ought to get out more: but the chains cramp my style.

[richmond62]

Oo-er:

https://docs.unity3d.com/Manual/class-SpriteMask.html

All very complicated indeed when, in LiveCode all one needs are a bunch of PNG or GIF images.

[richmond62]

UNITY:
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SpriteMask3.png (27.38 KiB) Viewed 3902 times

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LiveCode:
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[Klaus]

Richmond,

some time ago you admitted that I had finally been able to convince you to use "mouseup" instead of "mousedown".
Maybe I can also convince you to use "set the loc of xy to x,y"*** instead of "move xyz to x,y", what you ALWAYS use?

That will make everything much more "snappier"!
Try it here in your "Sprite Fight" example.

***Of course only where you do not need an animation-like "move".

[richmond62]

This thread IS about animation, and that tends to involve movement.

In my stack, the RESET button uses . . set the loc.

[Klaus]

You know what I mean!

[richmond62]

Bloody Hell, mandatory attendance at an enormous piss-up for one my ex-pupils because she has finished high school (sit on your arse and you'll fall out the top oneday), no obvious method of escape.

Back with a vengeance (that means you, Klaus), and a thumping headache tomorrow . . .

[richmond62]

Wait a moment . . . why not just rack
the moveSpeed up well high?

Mind you, if the flaming DJ could turn the volume down
to about 20% round these parts . . .

[richmond62]

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The ONLY significant difference between this stack and the previous one is that it employs
on rawkeyUp instead of rawKeyDown.

https://www.dropbox.com/s/ch9nnqcerx9n7 ... e.zip?dl=0

What that does entail is that each movement is discrete, while in the first stack, by keeping one of
the control keys down the move signal was sent repeatedly.

Generally, when teaching children how to make goofy games I suggest they use rawKeyUp rather than rawKeyDown
just so there is not the 'horrible' problem of backGroundPattern animation happening in graphic rectangles AFTER movement of those graphic rectangles has taken place.

[richmond62]

Klaus, I understand your criticism of using move rather than set to be because,
using move in a rawKeyDown script means that, on keeping a key down,
movement proceeds in jerks, while, by using set that will not happen.

HOWEVER, and it is a 'HOWEVER' that has to be considered:

This stack was NOT conceived of as a way of reproducing Tom-&-Jerry like smooth animation, it was
conceived of as:

1. An illustration how, by using

set the layer of something to top

one did not have to get 'all hot and sweaty' about sprite masking in LiveCode.

2. How this might be implemented in a side-scrolling game.

[richmond62]

[richmond62]

[FourthWorld]

Historical tidbit: sprite masking was implemented as a built-in engine feature for SuperCard 2.0 circa 1995 under the feature name of "filmstrips".