我需要限制圖片的移動LOVE2D

Question

我使用Love2d和Lua來製作遊戲。目前，我有一個人，從左到右「滑行」。我希望能夠限制他的動作，所以他不會掉出屏幕。我試着做一個if語句來檢測他的X是否大於800，（因爲我的窗口大小是800x600），但它只是結束了毛刺。這是代碼。請幫忙？

function love.load() 
love.graphics.setBackgroundColor(92,217,255) 
person={} 
person.image=love.graphics.newImage('/sprites/spriteTest.png') 
person.x=400 
person.y=303 
person.speed=200 
hills=love.graphics.newImage('/sprites/spriteHills.png') 
end 
function love.update(dt) 

if (person.x>735) then 

    if (love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
     if (love.keyboard.isDown('left') or love.keyboard.isDown('a')) then 
      person.x=person.x+(person.speed*dt) 
     else 
      person.x=person.x 
     end 

    elseif (love.keyboard.isDown('left') or love.keyboard.isDown('a')) then 
     if (love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
      person.x=person.x+(person.speed*dt) 
     else 
      person.x=person.x 
     end 

    end 

elseif (person.x<0) then 

    if (love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
     if (love.keyboard.isDown('left') or love.keyboard.isDown('a')) then 
      person.x=person.x+(person.speed*dt) 
     else 
      person.x=person.x 
     end 

    elseif (love.keyboard.isDown('left') or love.keyboard.isDown('a')) then 
     if (love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
      person.x=person.x+(person.speed*dt) 
     else 
      person.x=person.x 
     end 

    end 

else 

    if (love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
     person.x=person.x+(person.speed*dt) 
    elseif (love.keyboard.isDown('left') or love.keyboard.isDown('a')) then 
     person.x=person.x-(person.speed*dt) 
    end 

end 

end 
function love.draw() 
love.graphics.draw(hills, 0, 0) 
love.graphics.draw(person.image, person.x, person.y) 
end 

Answer 1

我找到了答案。這裏的代碼

function love.update(dt) 

if (player.x>735) then 

    if (love.keyboard.isDown('left') or love.keyboard.isDown('a') or love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
     player.x=player.x-(player.speed*dt) 
    end 

elseif (player.x<-10) then 

    if (love.keyboard.isDown('left') or love.keyboard.isDown('a') or love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
     player.x=player.x+(player.speed*dt) 
    end 

else 

    if (love.keyboard.isDown('right') or love.keyboard.isDown('d')) then 
     person.x=person.x+(person.speed*dt) 
    elseif (love.keyboard.isDown('left') or love.keyboard.isDown('a')) then 
     person.x=person.x-(person.speed*dt) 
    end 

end 

end 

它似乎不會修復它，但它爲我解決了它。我只是說，如果他處於邊緣，它不會讓他走得更遠。

Answer 2

這個怎麼樣update方法：

function love.update(dt) 
    if ((love.keyboard.isDown('right') or love.keyboard.isDown('d')) and person.x < 735) then 
    person.x = person.x + person.speed * dt 
    end 
    if ((love.keyboard.isDown('left') or love.keyboard.isDown('a')) and person.x > 0) then 
    person.x = person.x - person.speed * dt 
    end 
end 

基本上你想說if a movement key is down和the object can move然後移動。

此外，我會使用精靈的底部邊緣的中心作爲支點。那麼假設你有一個64×64的精靈，你將需要使用ox = 32和ox = 64（原點偏移）。