LÖVE

Code: Select all

x = 100
y = 50
point = {x = 50, y = 50}

function foo()
	a = math.atan2(y-point.y, x-point.x)
	x = x + sin(a)
	y = y + cos(a)
end

Code: Select all

--#region
Vector2 = {}
Vector2.__index = vector2
function vector2(x, y)
  vec2 = {}
  setmetatable(Vector2, vec2)
  vec2.x = x
  vec2.y = y
  return vec2
end
--#endregion

-- sun
sunPos = vector2(0, 0)
sunGM = 100

--planet1
Planet1 = {R_min  = 50, R_max = 125, tilt = math.pi/3, phase = 0, orbit = vector2(50, 0)}
Planet1.color = {0.2, 1, 0.2, 1}
Planet1.pos = vector2(0, 0)
Planet1.angle = Planet1.phase

--planet2
Planet2 = {R_min  = 150, R_max = 100, tilt = math.pi/6, phase = 0, orbit = vector2(0, 40)}
Planet2.color = {1, 0.2, 0.2, 1}
Planet2.pos = vector2(0, 0)
Planet2.angle = Planet2.phase


function initPlanetPos(planet)
    local p = planet.phase
    
    local x = planet.orbit.x
    local y = planet.orbit.y
    
    local R = planet.R_max
    local r = planet.R_min

    planet.pos.x, planet.pos.y = x + R * math.cos(p), y + r * math.sin(p)
end

function updatePlanetPos(planet, dt)
    local a = planet.angle
    --local v = planet.velocity
    local R = planet.R_max
    local r = planet.R_min
    local d1 = planet.pos.x - sunPos.x
    local d2 = planet.pos.y - sunPos.y
    local d = math.sqrt(d1 * d1 + d2 * d2)
    local v = math.sqrt(sunGM * (2 / d - 1 / R))
    a = (a + v * dt) % (2 * math.pi)
    planet.angle = a
    planet.pos.x, planet.pos.y = planet.orbit.x + R * math.cos(a), planet.orbit.y + r * math.sin(a)
end

function love.load(arg)
  love.window.setTitle("Galaxy example 0.5")
  love.window.setMode(512, 512, {msaa = 16, vsync = true}) --if disable the vsync the spiral decreases the curve
  initPlanetPos(Planet1)
  initPlanetPos(Planet2)
end



function love.update(dt)
  if not paused then
    updatePlanetPos(Planet1, dt)
    updatePlanetPos(Planet2, dt)
  else
    --paused
  end
end

function love.draw()
  --if not paused then
  love.graphics.translate(256, 256)

  love.graphics.setColor(Planet1.color)
  
  love.graphics.rotate(-Planet1.tilt)
  love.graphics.ellipse( "line", Planet1.orbit.x, Planet1.orbit.y, Planet1.R_max, Planet1.R_min, 32 )
  love.graphics.rotate(Planet1.tilt)

  love.graphics.setColor(Planet2.color)
  
  love.graphics.rotate(-Planet2.tilt)
  love.graphics.ellipse( "line", Planet2.orbit.x, Planet2.orbit.y, Planet2.R_max, Planet2.R_min, 32 )
  love.graphics.rotate(Planet2.tilt)
  
  love.graphics.setColor(1, 0.7, 0, 1)
  love.graphics.circle("fill", sunPos.x, sunPos.y, 32)

  love.graphics.setColor(Planet1.color)

  love.graphics.rotate(-Planet1.tilt)
  love.graphics.circle("fill", Planet1.pos.x, Planet1.pos.y, 8)
  love.graphics.rotate(Planet1.tilt)

  love.graphics.setColor(Planet2.color)

  love.graphics.rotate(-Planet2.tilt)
  love.graphics.circle("fill", Planet2.pos.x, Planet2.pos.y, 8)
  love.graphics.rotate(Planet2.tilt)
  
  --else
    --paused
  --end
end

function love.keypressed(key, scancode, isrepeat)
  if key == "escape" then
    paused = not paused
  end
end