Penetrator (Geometry lib)

[jjmafiae]

OHH GOD, why does so many libs have these kind of names.

[mickeyjm]

OHH GOD, why does so many libs have these kind of names.

Its kinda a tradition around here

[Ranguna259]

Well it's called penetrator because the first function that I added to the lib was getInter() which gives you the "penetration" rectangle area of both intersecting rectangles, I don't know what else that name would refer to

[jjmafiae]

Well it's called penetrator because the first function that I added to the lib was getInter() which gives you the "penetration" rectangle area of both intersecting rectangles, I don't know what else that name would refer to

The Penetrator in saints row the third

[Ranguna259]

The Penetrator in saints row the third

Oh that, hum.. well, I-I'm hmmm, heh you got me

[jjmafiae]

The Penetrator in saints row the third

Oh that, hum.. well, I-I'm hmmm, heh you got me

lol

[jonyzz]

Sorry, but your code is not very good and much too long. Here is a shorter version:

Code: Select all

function isInter(a, b)
	local ax2,ay2,bx2,by2 = a.x + a.width, a.y + a.height, b.x + b.width, b.y + b.height
	return a.x < bx2 and ax2 > b.x and a.y < by2 and ay2 > b.y
end

function getInter(a, b)
	if not isInter(a, b) then return end

	if a.x > b.x then a,b = b,a end
	local x = b.x
	local w = a.x + a.width - b.x

	if a.y > b.y then a,b = b,a end
	local y = b.y
	local h = a.y + a.height - b.y

	return newRect(x,y,w,h)
end

...
Your code doesn't work when obj2 has bigger or smaller width or height, that's why the code is big, this is not a collision detection lib, it's just a geometry lib.. Wait don't tell me that the libs you said do what this does do they ?

This one should work:

Code: Select all

local function getInter(a, b)
    local left = math.max(a.x, b.x)
    local right = math.min(a.x + a.width, b.x + b.width)
    local top = math.max(a.y, b.y)
    local bottom = math.min(a.y + a.height, b.y + b.height)
    if left < right and top < bottom then
        return newRect(left, top, right - left, bottom - top)
    end
end

[Ranguna259]

This one should work:

Code: Select all

local function getInter(a, b)
    local left = math.max(a.x, b.x)
    local right = math.min(a.x + a.width, b.x + b.width)
    local top = math.max(a.y, b.y)
    local bottom = math.min(a.y + a.height, b.y + b.height)
    if left < right and top < bottom then
        return newRect(left, top, right - left, bottom - top)
    end
end

Yep it works nicely, thanks jonyzz.
You code has been added to the source and to github.

Found rectangle.java source code, I'm gonna start converting now, anyone who want to help is free to, just pick up the code in the link, convert it to löve and post it here or on GitHub.

[xXxMoNkEyMaNxXx]

Does anyone have code for the area of intersection of two squares with arbitrary size, position, and rotation? I could make a perfect image resize and rotate with it. I might make it eventually if no one else has.

[Ranguna259]

The code for the area part would just be the code in getInter and then it'd just multiply the width for the height and the position is just the x and the y coord of the output rectangle (I'll code both of them tomorrow) but rotation.. Can we rotate rectangles in löve ?