Those physics

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Mizore
Prole
Posts: 6
Joined: Wed Aug 11, 2010 5:56 pm

Those physics

Post by Mizore »

Hello, i have been messing with this awesome system. Apparently for some reason i cant get physics work properly.

Code: Select all

tile = {}
tile_s = 24

map=
{
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,8,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,1,1,1,1,1,1,1,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{1,1,1,1,1,5,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{2,2,2,2,2,3,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,1,1,1,1,1},
{2,2,2,2,2,3,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,7,2,2,2,2,2,2,2},
{2,2,2,2,2,3,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,7,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,3,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,8,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,7,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,3,0,0,0,0,0,0,6,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,8,7,4,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,4,1,1,1,1,1,1,7,3,0,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,4,1,1,1,1,1,7,2,2,4,1,1,1,1,1,1,5,0,0,0,0,0,0,0,0,0,0,0,0,8,1,1,1,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,8,1,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0,0,0,0,8,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,4,1,1,1,1,1,1,1,1,1,1,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,4,1,1,1,1,1,1,1,1,7,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2},
{2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2}
}

tile[0] = love.graphics.newImage("images/map/tileEmpty.png")
tile[1] = love.graphics.newImage("images/map/tileGrass1.png")
tile[2] = love.graphics.newImage("images/map/tileDirt1.png")
tile[3] = love.graphics.newImage("images/map/tileDirtEdge1.png")
tile[4] = love.graphics.newImage("images/map/tileGrassDirtEdge1.png")
tile[5] = love.graphics.newImage("images/map/tileGrassEdge1.png")
tile[6] = love.graphics.newImage("images/map/tileDirtEdge2.png")
tile[7] = love.graphics.newImage("images/map/tileGrassDirtEdge2.png")
tile[8] = love.graphics.newImage("images/map/tileGrassEdge2.png")

boxes = {}
boxes[0] = love.graphics.newImage("images/other/box.png")
boxes[1] = love.graphics.newImage("images/other/collisionbox.png")

font['menu'] = love.graphics.newFont(24)
font['small'] = love.graphics.newFont(10)

love.graphics.setFont(font['small'])

map_offset_x = 0
map_offset_y = 0
mapScrollSpeed = 500

world = love.physics.newWorld(2400, 600)
world:setGravity(0, 100)
world:setMeter(64)

bodies = {}
shapes = {}

mapbodies = {}
mapshapes = {}

n = 0

for y, yl in pairs(map) do
	for x, xl in pairs(map[1]) do
		if map[y][x] == 0 then
			
		else
			mapbodies[n] = love.physics.newBody(world, ((x - 1) * tile_s) + map_offset_x, ((y - 1) * tile_s) + map_offset_y, 0, 0)
			mapshapes[n] = love.physics.newRectangleShape(mapbodies[n], 0, 0, 24, 24)
			n = n + 1
		end
	end
end

for i = 0, 10 do
	bodies[i] = love.physics.newBody(world, 650/2+i*30, 50, 15, 1) --place the body in the center of the world, with a mass of 15
	shapes[i] = love.physics.newRectangleShape(bodies[i], 0, 0, 24, 24)
end

function love.draw()
	for i = 0, 10 do
		love.graphics.draw(boxes[0], bodies[i]:getX() + map_offset_x, bodies[i]:getY() + map_offset_y, bodies[i]:getAngle())
	end
	
	generateMap()
	
	
	n = 0
	for i, l in pairs(mapbodies) do
		love.graphics.draw(
			boxes[1],
			mapbodies[i]:getX() + map_offset_x,
			mapbodies[i]:getY() + map_offset_y,
			mapbodies[i]:getAngle()
		)
		n = n + 1
	end
end

function love.keypressed(key)
	if key == "escape" then
		love.filesystem.load("main.lua")()
		love.load()
	end
end

function love.update(dt)
	world:update(dt)
	if love.keyboard.isDown("left") then
		map_offset_x = map_offset_x + mapScrollSpeed * dt
	end
	if love.keyboard.isDown("right") then
		map_offset_x = map_offset_x - mapScrollSpeed * dt
	end
	
	if love.keyboard.isDown("d") then --press the right arrow key to push the ball to the right
		bodies[1]:applyForce(400, 0)
	elseif love.keyboard.isDown("a") then --press the left arrow key to push the ball to the left
		bodies[1]:applyForce(-400, 0)
	elseif love.keyboard.isDown("w") then --press the up arrow key to set the ball in the air
		bodies[1]:applyForce(0, -400)
	end
end

function generateMap()
	for y, yl in pairs(map) do
		for x, xl in pairs(map[1]) do
			love.graphics.draw(tile[map[y][x]], ((x - 1) * tile_s)+  map_offset_x, ((y - 1) * tile_s) + map_offset_y)
		end
	end
end
And i have video to show where is problem. (the red boxes are map collision boxes)

(Video may still be processing.)

Thank you.
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Robin
The Omniscient
Posts: 6506
Joined: Fri Feb 20, 2009 4:29 pm
Location: The Netherlands
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Re: Those physics

Post by Robin »

Thing is, you combine two things here that aren't meant to co-exist: tiles and physics. First you need to decide whether you need tiles or physics, then get the other part out. I'd say you need tiles, but I'm not sure.
Help us help you: attach a .love.
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Mizore
Prole
Posts: 6
Joined: Wed Aug 11, 2010 5:56 pm

Re: Those physics

Post by Mizore »

I don't actually understand why they can coexist with each other, map is design is made of tiles, and invisible stationary physics blocks as non collide-able platform.
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Jasoco
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Re: Those physics

Post by Jasoco »

Yeah. I hate to say it... again... but 2d side-scrollers and Physics just don't work together. You need to make your own engine and "physics" like Nintendo does and Pixel (Who made Cave Story) and other companies, Sega, everyone. Everyone has a side-scrolling engine. It's not impossible to make. Just hard to perfect.

I tried a few times and failed myself. But one day I will get one.

Edit: One day SOMEONE here will make a working side-scroller engine framework and offer it as an example to Löve users so we can stop getting these same questions every week.
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Regret
Prole
Posts: 8
Joined: Sun Nov 29, 2009 12:37 am

Re: Those physics

Post by Regret »

The problem is with assuming that :getX() returns a value that you can directly use to draw rectangles.

:getX() returns the exact middle of a physics object, so to properly draw a rectangle you need to substract it's width / height to get the top left corner.

Furthermore, to properly draw a rotating rectangle you have to use something like this:

Code: Select all

local ax,ay =  boxshape:getPoints()  --actually returns the coordinates that make up the polygonal shape (for rectangle its 8 variables)
love.graphics.draw(boximage,ax + offsetx,ay + offsety,boxbody:getAngle())
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Mizore
Prole
Posts: 6
Joined: Wed Aug 11, 2010 5:56 pm

Re: Those physics

Post by Mizore »

Regret wrote:The problem is with assuming that :getX() returns a value that you can directly use to draw rectangles.

:getX() returns the exact middle of a physics object, so to properly draw a rectangle you need to substract it's width / height to get the top left corner.

Furthermore, to properly draw a rotating rectangle you have to use something like this:

Code: Select all

local ax,ay =  boxshape:getPoints()  --actually returns the coordinates that make up the polygonal shape (for rectangle its 8 variables)
love.graphics.draw(boximage,ax + offsetx,ay + offsety,boxbody:getAngle())
Thanks. Fixed few issues. Collisions work perfectly without rotation, if rotation is enabled... it f*s up.
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Robin
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Posts: 6506
Joined: Fri Feb 20, 2009 4:29 pm
Location: The Netherlands
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Re: Those physics

Post by Robin »

Still, you need to roll your own physics.

love.physics is very capable, but using it here is using a hammer to drive screws in the wall.
Help us help you: attach a .love.
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Mizore
Prole
Posts: 6
Joined: Wed Aug 11, 2010 5:56 pm

Re: Those physics

Post by Mizore »

And, now i wonder how to make my own physics...
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Regret
Prole
Posts: 8
Joined: Sun Nov 29, 2009 12:37 am

Re: Those physics

Post by Regret »

Mizore wrote:Collisions work perfectly without rotation, if rotation is enabled... it f*s up.
Again as I said the problem is in drawing. Collisions work fine, you are drawing your world wrong.
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bartbes
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Re: Those physics

Post by bartbes »

Instead of correcting the x and y values, use the offsets to set the origin to center (ox and oy). (it'll fix rotation)
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