Shadow demo

[Ref]

Shadows in 2D? Oxymoron?
Thought I'd just try to simulate shadows from first principles.
Expected a bigger hit in fps from such a simple approach (line projection) but turns out not to be as bad as 'fill' or 'text'.
Probably not too good for a lot of objects as it uses trig functions (atan2,sin,cos).
Enjoy!

[10$man]

Looks nice and runs at a solid 960 FPS on my PC

Also, as the height gets closer to the object, the shadow should get smaller.

[Ref]

Probably right about height.
Still, pretty boring demo.
Was wondering how to create a shadow for a hollow polygon.
Recalled someone asking about how to create a hollow square that got a number of responses.
Didn't see how any of the suggested approaches would be easy to create a shadow for but than the light dawned - really simple.
Can just use the same shadow function with a simple poly drawing.
Care to guess how?
(Hit 'f' key in the attached demo to see how I did it.)
fps still good.
Now the hard part - how to do something useful this this.

[Ubermann]

Pretty interesting IMO.

~60 FPS in my box.

I guess if it works in Android.
If you were not using any OS specific thing, I don't know any reason why it wouldn't work in Android.
Let me try it and will give you feedback.

[Ref]

Just a straight forward Love approach with nothing special.
Hopefully system independent?????
Suspect your lower frame rate is due to vsync as I get ~600 fps on my donkey.

[Ubermann]

It rather works on Android.
This is what i get for the square example:

njRZW.png (6.27 KiB) Viewed 225 times

And this is what I get for the hollow example:

FOZ14.png (7.01 KiB) Viewed 225 times

[Ref]

Very interesting!
Evidently, love.graphics.polygon has a problem for you.
Updated version of script with added figure in original posting but has nothing to do with your problem.
If you can draw a figure using love.graphics.polygon( 'fill', polygon ), you can create a shadow for it
using shadow.polygon( polygon, light ) where light = { x = #, y = #, height = # }.
Question:
Does

Code: Select all

polygon = { 100,100, 50,100, 50,50, 100,50 }
love.graphics.polygon( 'fill', polygon )

give you a nice little square?

[Nixola]

I have to add a fifth vertex (100, 100) to the table to get a nice square on my LG Optimus L5

[Ref]

Does

Code: Select all

polygon = { 100,100, 50,100, 50,50, 100,50 }
love.graphics.polygon( 'line', polygon )

give you a closed figure?
(it does for me on window 7 and 'fill' gives me a closed filled figure.)

Ubermann's example seems to be adding the polygon's center coordinates as the last point.

I have no problems with this using Love 0.8 or lovejit.

The WIKI example doesn't use an additional point to close the polygon.

Anybody know what's going on here or have I miss something here (as usual)?

[Nixola]

It's something in love-android, I think, the same code works fine here
Anyway it seems that it adds the center here too