I think I would need write a lot of documentary alone on these parameters of the light. I try to give the short version.
There are 2 types of light (second param), 0 = spot light, 1 = point light. I'll just explain point light here.
shaderLamp(0, 1, {1000,500,1000}, {0,0,0},{1,0,0}, {0,0,0}, {1,0,1}, 1, 90, 1)
1 - index of the light, if you set shaderActivateLighting(3) you have 3 source, and the last id is 2.
2 - type, 1 = point light
3 - position in 3d space, x and y are equivalent to screen space, z means how close the light is to the screen, if you move it far away it light the screen very even, but you need to remove the falloff, as you won't see anything or it blow out. If you move it very close, it will light only a small portion, why ? Think of reflectivity, if the light is faaar away it reflects directly into your eye because it's a straight way. If it's really close it doesn't reflect, I'll put an image to that down there.
4 - target position, point lights don't have targets, so {0,0,0}
5 - falloff, very tricky parameter, first component is constant attenuation, means it doesn't fall off over distance, so it's more like exposure but inverted (to get it brighter make it smaller, like 0.01). Second component, linear attenuation, means this is how much the distance makes the light darker, or linear falloff. Third component, quadratic falloff, like linear but it's quadratic so it drops off very fast.
6 - ambient color, fun part starts, {r, g, b} simple as that. I have added a hsv function if you hate rgb. So it's fromHSV(0, 1, 1) that's red. HSV means hue, saturation and value/volume/lightness. All components from 0-1. Ambient color is much stronger than the diffuse color, use with care.
7 - diffuse color, again a color, but this is multiplied with your scene color, so it tints the screen.
8 - diffuse factor, how strong is the diffuse color, you can make it brighter by setting values higher than 1 or darker with lower 1
9 - only for spotlights (you can leave them out)
10 - only for spotlights
More info:
https://developer.valvesoftware.com/wiki/Constant-Linear-Qua...So shaderLamp(0, 1, {1000,500,1000}, {0,0,0},{1,0,0}, {0,0,0}, {1,0,1}, 1) would light the screen pretty evenly. If you move the Lamp closer you get a vignette effect. But you will need to change the falloff settings due the light getting darker.
If wanted I can also write some about spotlights.