Shaders? How Can I Use This COOL THING!

[TheP3]

Hi,

So, I have not really ever programmed any glsl shader, and I saw that Love2D supports them! Making all kinds of cool FX. I really want to learn how to use glsl with Love2D! Can anyone point to the wiki location/demos for programming Love2D with shaders! I really like advice too, because, I have not seen a set example on how to use shaders in Love2D.

Thanks!

[xXxMoNkEyMaNxXx]

Look through the old forum posts, and find lots of projects using glsl. (Try a search). Examine what they do, then look at the code. The main thing you need is the effect function. I'm sure you can figure it out To start, take a look at my file Trippy.love, somewhere...

[xXxMoNkEyMaNxXx]

Here:
viewtopic.php?f=4&t=12354

[TheP3]

Here:
viewtopic.php?f=4&t=12354

Thank you,

Do you think maybe you could go into detail about the shader

Code: Select all

extern number t;
vec4 effect(vec4 colour, Image img, vec2 txy, vec2 sxy)
{
	return vec4(pow(cos(sxy.x/20+t),2),pow(sin(sxy.y/20+t),2),abs(1/(1+tan(length(sxy/20)+t))),1);
}

I understand how you pass an argument into the t(var?). However, how does it know to apply that shader just to the rectangle? Also, you never called or executed effect. How did that get executed? Is it a default for Love2D or something? One last thing, the effect function was not called, so how did it get its arguments for: vec4 colour, Image img, vec2 txy, vec2 sxy?

[Zer0]

However, how does it know to apply that shader just to the rectangle?

The pixelEffect ( shader ) only applies to things being rendered ( in this case the square )

Also, you never called or executed effect. How did that get executed? Is it a default for Love2D or something? One last thing, the effect function was not called, so how did it get its arguments for: vec4 colour, Image img, vec2 txy, vec2 sxy?

The effect function is called by default onto everything that is rendered on screen ( it will say )

A pixel with color 1,0,0,1 not part of an image and at coordinates 15,18 will give

{1,0,0,1} as color
nil as image ( I think )
nil as txy ( there's no image so no image coordinates )
{15,18} as sxy

essential part: effect() is called for every pixel rendered in the window

[TheP3]

However, how does it know to apply that shader just to the rectangle?

The pixelEffect ( shader ) only applies to things being rendered ( in this case the square )

Also, you never called or executed effect. How did that get executed? Is it a default for Love2D or something? One last thing, the effect function was not called, so how did it get its arguments for: vec4 colour, Image img, vec2 txy, vec2 sxy?

The effect function is called by default onto everything that is rendered on screen ( it will say )

A pixel with color 1,0,0,1 not part of an image and at coordinates 15,18 will give

{1,0,0,1} as color
nil as image ( I think )
nil as txy ( there's no image so no image coordinates )
{15,18} as sxy

essential part: effect() is called for every pixel rendered in the window

Are there any other shader functions Love2D comes with? Is there a wiki page? I really don't feel like looking through the source... haha

[Zer0]

Are there any other shader functions Love2D comes with? Is there a wiki page? I really don't feel like looking through the source... haha

https://www.love2d.org/wiki/love.graphi ... ixelEffect
https://www.love2d.org/wiki/PixelEffect

wiki pages