Easy way to make fancy glowing vector lines?

[JamesGecko]

I'm messing around with the basics of a vector game, sort of like Asteroids, Bitfighter, or Geometry Wars. For optimum coolness factor, I'm trying to figure out a convenient way to make the lines sort of shimmer or glow, like they did on those old arcade screens.

Kenta Cho uses the effect a lot in his games, but from his source code, it looks like he makes some OpenGL calls to accomplish it. Does Love has access to this stuff, or do I need to use an external library or something?

A non-OpenGL method of doing this seems to be to copy a portion of the drawing surface, blur it (maybe increase saturation?), then slap it down right before the next drawn frame. The blur has to be very efficient though; otherwise things start crawling. I'm looking at Love's documentation though, and I don't see an easy way to do that, either. Am I missing something?
http://www.blackpawn.com/texts/blur/default.html
http://incubator.quasimondo.com/process ... stblur.pde

Thanks!

[Kaze]

I'm messing around with the basics of a vector game, sort of like Asteroids, Bitfighter, or Geometry Wars. For optimum coolness factor, I'm trying to figure out a convenient way to make the lines sort of shimmer or glow, like they did on those old arcade screens.

Kenta Cho uses the effect a lot in his games, but from his source code, it looks like he makes some OpenGL calls to accomplish it. Does Love has access to this stuff, or do I need to use an external library or something?

A non-OpenGL method of doing this seems to be to copy a portion of the drawing surface, blur it (maybe increase saturation?), then slap it down right before the next drawn frame. The blur has to be very efficient though; otherwise things start crawling. I'm looking at Love's documentation though, and I don't see an easy way to do that, either. Am I missing something?
http://www.blackpawn.com/texts/blur/default.html
http://incubator.quasimondo.com/process ... stblur.pde

Thanks!

I don't quite understand what you mean, but if you want to change the alpha of something for a "pulse" effect, use:

Code: Select all

math.sin(os.clock())*255

for the alpha

[rude]

If it's glowing, it probably involves additive blending. [love.graphics.setBlendMode(love.blend_additive)]

http://love2d.org/demos/particles.love

[JamesGecko]

I was going for an effect sort of like this or this.

There seems to be very little difference between the love.blend_additive and love.blend_normal modes on my Intel graphics card. It looks like it just makes lines a little smoother. Maybe I'm not using it properly? The glowing particles demo looked pretty neat.

Using Kaze's pulse with love.color_modulate looks pretty neat, but it's still not exactly what I was going for.

More techniques for glowyness:
In GridWars, they appear to just prerender everything as sprites with the glowy effect, but I'd rather have the flexibility offered by vectors rather than manipulate sprites.

[zapwow]

Hi JamesGecko,
Unless you have several items on-screen in the same area, the additive effect will not be much different from the normal blend mode.
I think you might be able to achieve your desired effect by rendering your object multiple times. See attached.

[rude]

I also made this demo to showcase additive blending. You should be able to make some pretty cool effects with lines + additive blending alone, but it will take some work.

http://love2d.org/demos/glow.love

[JamesGecko]

Ah, excellent. Thanks for your help. :-)

[counterfactual_jones]

I think you might be able to achieve your desired effect by rendering your object multiple times. See attached.

*Yoink*

[Lesbian Viking]

I also made this demo to showcase additive blending. You should be able to make some pretty cool effects with lines + additive blending alone, but it will take some work.

http://love2d.org/demos/glow.love

Anywhere I can get this demo now?

[Nephilim]

Without pretending to know what I'm talking about:

Couldn't you surround the line with particles with a certain alpha value?