physics.lua

   1 local world
   2 local xGravity = 0
   3 local yGravity = -1
   4
   5 --[[
   6 creates a world (love.physics.world) and sets properties and callback functions
   7 ]]--
   8 function physics_createWorld()
   9         love.physics.setMeter(1) -- number of pixels in one meter, set to 1 because of bugs
  10         world = love.physics.newWorld(xGravity,yGravity,false) -- num: x gravity, num: y gravity, bool: sleep allowed
  11         world:setCallbacks(beginContact, endContact, preSolve, postSolve)
  12 end
  13
  14 --[[
  15 iterates over all entities and applies forces on them
  16 ]]--
  17 function physics_update(dt)
  18         world:update(dt)
  19         for i,e in ipairs(entities) do
  20                 if (e.speed~=0) then
  21                         e.body:applyForce(e.speed,0,e.body:getX(),e.body:getY())
  22                 end
  23                 e.body:setGravityScale(getWaterDensity(e.body:getY()-e.density))
  24         end
  25 end
  26
  27 --[[
  28 creates a body,a shape and a fixture (combined)
  29 TODO massData und damping besser machen
  30 ]]--
  31 function physics_createBodyWithShape(xPos,yPos,shape)
  32         local body = love.physics.newBody(world,xPos,yPos,"dynamic")
  33         body:setMassData( 100, 100, 2, 0 ) -- num: mass center x, mass center y, mass, inertia
  34         body:setLinearDamping(2)
  35         local shape = love.physics.newChainShape(true,unpack(shape))
  36         local fixture = love.physics.newFixture(body,shape,0) -- body, shape, density
  37         return body, shape, fixture
  38 end
  39
  40 --[[
  41 creates a body without shape and fixture
  42 ]]--
  43 function physics_createBody(xPos,yPos)
  44         local body = love.physics.newBody(world,xPos,yPos,"dynamic")
  45         return body
  46 end
  47
  48 --[[
  49 generates walls from a given map-matrix
  50 ]]--
  51 function physics_createWalls(map)
  52         for i = 1,#map.matrix do
  53                 for j = 1,#map.matrix[1] do
  54                         if map.matrix[i][j] == 2 then
  55                                 physics_createStaticWall(i*map.realTileSize,j*map.realTileSize,map.realTileSize)
  56                         end
  57                 end
  58         end
  59
  60 end
  61
  62 --[[
  63 creates static body with rectangle shape (quad -> walls)
  64 returns nothing
  65 ]]--
  66 function physics_createStaticWall(xPos,yPos,size)
  67         local body = love.physics.newBody(world,xPos,yPos,"static")
  68         local shape = love.physics.newRectangleShape(-(size/2),-(size/2),size,size)
  69         local fixture = love.physics.newFixture(body,shape,0)
  70 end
  71
  72 --[[
  73 just returns given value, maybe changed sometimes
  74 ]]--
  75 function getWaterDensity(depth)
  76         return depth
  77 end
  78
  79 function beginContact()
  80 end
  81
  82 function endContact()
  83 end
  84
  85 function preSolve()
  86 end
  87
  88 function postSolve()
  89 end