我有一个简单的问题。我在玩 Corona 以尝试了解它的外观和感觉，我目前正在编辑其他人的示例代码。我已经添加了一个评分机制，现在我想添加一个组合评分机制，这样当用户砍一个以上的水果时，我可以额外增加5分。只是我不知道如何开始。如果有人能指出我正确的方向，那将非常感谢。:)
或者如果这会更清楚：一个函数可以帮助我检测用户在一次触摸/移动中触摸/切片的对象数量如何？
require ("physics")
local ui = require("ui")
physics.start()
-- physics.setDrawMode ( "hybrid" ) -- Uncomment in order to show in hybrid mode
physics.setGravity( 0, 9.8 * 2)
physics.start()
-- Audio for slash sound (sound you hear when user swipes his/her finger across the screen)
local slashSounds = {slash1 = audio.loadSound("slash1.wav"), slash2 = audio.loadSound("slash2.wav"), slash3 = audio.loadSound("slash3.wav")}
local slashSoundEnabled = true -- sound should be enabled by default on startup
local minTimeBetweenSlashes = 150 -- Minimum amount of time in between each slash sound
local minDistanceForSlashSound = 50 -- Amount of pixels the users finger needs to travel in one frame in order to play a slash sound
-- Audio for chopped fruit
local choppedSound = {chopped1 = audio.loadSound("chopped1.wav"), chopped2 = audio.loadSound("chopped2.wav")}
-- Audio for bomb
local preExplosion = audio.loadSound("preExplosion.wav")
local explosion = audio.loadSound("explosion.wav")
-- Adding a collision filter so the fruits do not collide with each other, they only collide with the catch platform
local fruitProp = {density = 1.0, friction = 0.3, bounce = 0.2, filter = {categoryBits = 2, maskBits = 1}}
local catchPlatformProp = {density = 1.0, friction = 0.3, bounce = 0.2, filter = {categoryBits = 1, maskBits = 2}}
-- Gush filter should not interact with other fruit or the catch platform
local gushProp = {density = 1.0, friction = 0.3, bounce = 0.2, filter = {categoryBits = 4, maskBits = 8} }
-- Will contain all fruits available in the game
local avalFruit = {}
-- Slash line properties (line that shows up when you move finger across the screen)
local maxPoints = 5
local lineThickness = 20
local lineFadeTime = 250
local endPoints = {}
-- Whole Fruit physics properties
local minVelocityY = 850
local maxVelocityY = 1100
local minVelocityX = -200
local maxVelocityX = 200
local minAngularVelocity = 100
local maxAngularVelocity = 200
-- Chopped fruit physics properties
local minAngularVelocityChopped = 100
local maxAngularVelocityChopped = 200
-- Splash properties
local splashFadeTime = 2500
local splashFadeDelayTime = 5000
local splashInitAlpha = .5
local splashSlideDistance = 50 -- The amoutn of of distance the splash slides down the background
-- Contains all the available splash images
local splashImgs = {}
-- Gush properties
local minGushRadius = 10
local maxGushRadius = 25
local numOfGushParticles = 15
local gushFadeTime = 500
local gushFadeDelay = 500
local minGushVelocityX = -350
local maxGushVelocityX = 350
local minGushVelocityY = -350
local maxGushVelocityY = 350
-- Timer references
local bombTimer
local fruitTimer
-- Game properties
local fruitShootingInterval = 1000
local bombShootingInterval = 5000
-- Groups for holding the fruit and splash objects
local splashGroup
local fruitGroup
local sampleVar = true
local score = 0
local scoreText
function main()
score = 0
display.setStatusBar( display.HiddenStatusBar )
setUpBackground()
scoreText = display.newText("Score: 0", 415, 100, native.systemFont, 50)
scoreText:setTextColor(255, 255, 255)
scoreText.text = ("Score: " )..score
pauseAndResume ()
setUpCatchPlatform()
initGroups()
initFruitAndSplash()
Runtime:addEventListener("touch", drawSlashLine)
timer.performWithDelay( 1000, displayScore)
startGame()
end
function displayScore()
scoreText.text = ("Score: " )..score
score = score + 2
end
function startGame()
shootObject("fruit")
bombTimer = timer.performWithDelay(bombShootingInterval, function(event) shootObject("bomb") end, 0)
fruitTimer = timer.performWithDelay(fruitShootingInterval, function(event) shootObject("fruit") end, 0)
end
-- Display the pause button
function pauseAndResume ()
pausebutton = display.newImage ("paused2.png", 10, 100)
pausebutton:addEventListener ("touch" , pauseGame)
resumebutton = display.newImage ("resume.png", 10, 100)
resumebutton.isVisible = false
resumebutton:addEventListener ("touch", resumeGame)
end
function pauseGame (event)
if (event.phase == "ended") then
physics.pause ()
pausebutton.isVisible = false
resumebutton.isVisible = true
timer.pause(fruitTimer)
timer.pause(bombTimer)
sampleVar = false
return true
end
end
function resumeGame (event)
if (event.phase == "ended") then
physics.start()
pausebutton.isVisible = true
resumebutton.isVisible = false
timer.resume(fruitTimer)
timer.resume(bombTimer)
sampleVar = true
return true
end
end
function initGroups()
splashGroup = display.newGroup()
fruitGroup = display.newGroup()
end
function setUpBackground()
local background = display.newImage("bg.png", true)
background.x = display.contentWidth / 2
background.y = display.contentHeight / 2
end
-- Populates avalFruit with all the fruit images and thier widths and heights
function initFruitAndSplash()
local watermelon = {}
watermelon.whole = "watermelonWhole.png"
watermelon.top = "watermelonTop.png"
watermelon.bottom = "watermelonBottom.png"
watermelon.splash = "redSplash.png"
table.insert(avalFruit, watermelon)
local strawberry = {}
strawberry.whole = "strawberryWhole.png"
strawberry.top = "strawberryTop.png"
strawberry.bottom = "strawberryBottom.png"
strawberry.splash = "redSplash.png"
table.insert(avalFruit, strawberry)
-- Initialize splash images
table.insert(splashImgs, "splash1.png")
table.insert(splashImgs, "splash2.png")
table.insert(splashImgs, "splash3.png")
end
function getRandomFruit()
local fruitProp = avalFruit[math.random(1, #avalFruit)]
local fruit = display.newImage(fruitProp.whole)
fruit.whole = fruitProp.whole
fruit.top = fruitProp.top
fruit.bottom = fruitProp.bottom
fruit.splash = fruitProp.splash
return fruit
end
function getBomb()
local bomb = display.newImage( "bomb.png")
return bomb
end
function shootObject(type)
local object = type == "fruit" and getRandomFruit() or getBomb()
fruitGroup:insert(object)
object.x = display.contentWidth / 2
object.y = display.contentHeight + object.height * 2
fruitProp.radius = object.height / 2
physics.addBody(object, "dynamic", fruitProp)
if(type == "fruit") then
object:addEventListener("touch", function(event) chopFruit(object) end)
else
local bombTouchFunction
bombTouchFunction = function(event) explodeBomb(object, bombTouchFunction); end
object:addEventListener("touch", bombTouchFunction)
end
-- Apply linear velocity
local yVelocity = getRandomValue(minVelocityY, maxVelocityY) * -1 -- Need to multiply by -1 so the fruit shoots up
local xVelocity = getRandomValue(minVelocityX, maxVelocityX)
object:setLinearVelocity(xVelocity, yVelocity)
-- Apply angular velocity (the speed and direction the fruit rotates)
local minAngularVelocity = getRandomValue(minAngularVelocity, maxAngularVelocity)
local direction = (math.random() < .5) and -1 or 1
minAngularVelocity = minAngularVelocity * direction
object.angularVelocity = minAngularVelocity
end
function explodeBomb(bomb, listener)
bomb:removeEventListener("touch", listener)
-- The bomb should not move while exploding
bomb.bodyType = "kinematic"
bomb:setLinearVelocity(0, 0)
bomb.angularVelocity = 0
-- Shake the stage
local stage = display.getCurrentStage()
local moveRightFunction
local moveLeftFunction
local rightTrans
local leftTrans
local shakeTime = 50
local shakeRange = {min = 1, max = 25}
moveRightFunction = function(event) rightTrans = transition.to(stage, {x = math.random(shakeRange.min,shakeRange.max), y = math.random(shakeRange.min, shakeRange.max), time = shakeTime, onComplete=moveLeftFunction}); end
moveLeftFunction = function(event) leftTrans = transition.to(stage, {x = math.random(shakeRange.min,shakeRange.max) * -1, y = math.random(shakeRange.min,shakeRange.max) * -1, time = shakeTime, onComplete=moveRightFunction}); end
moveRightFunction()
local linesGroup = display.newGroup()
-- Generate a bunch of lines to simulate an explosion
local drawLine = function(event)
local line = display.newLine(bomb.x, bomb.y, display.contentWidth * 2, display.contentHeight * 2)
line.rotation = math.random(1,360)
line.width = math.random(15, 25)
linesGroup:insert(line)
end
local lineTimer = timer.performWithDelay(100, drawLine, 0)
-- Function that is called after the pre explosion
local explode = function(event)
audio.play(explosion)
blankOutScreen(bomb, linesGroup);
timer.cancel(lineTimer)
stage.x = 0
stage.y = 0
transition.cancel(leftTrans)
transition.cancel(rightTrans)
end
-- Play the preExplosion sound first followed by the end explosion
audio.play(preExplosion, {onComplete = explode})
timer.cancel(fruitTimer)
timer.cancel(bombTimer)
end
function blankOutScreen(bomb, linesGroup)
local gameOver = displayGameOver()
gameOver.alpha = 0 -- Will reveal the game over screen after the explosion
-- Create an explosion animation
local circle = display.newCircle( bomb.x, bomb.y, 5 )
local circleGrowthTime = 300
local dissolveDuration = 1000
local dissolve = function(event) transition.to(circle, {alpha = 0, time = dissolveDuration, delay = 0, onComplete=function(event) gameOver.alpha = 1 end}); gameOver.alpha = 1 end
circle.alpha = 0
transition.to(circle, {time=circleGrowthTime, alpha = 1, width = display.contentWidth * 3, height = display.contentWidth * 3, onComplete = dissolve})
end
function displayGameOver()
-- Will return a group so that we can set the alpha of the entier menu
local group = display.newGroup()
-- Dim the background with a transperent square
local back = display.newRect( 0,0, display.contentWidth, display.contentHeight )
back:setFillColor(0,0,0, 255 * .1)
group:insert(back)
local gameOver = display.newImage( "gameover.png")
gameOver.x = display.contentWidth / 2
gameOver.y = display.contentHeight / 2
group:insert(gameOver)
local replayButton = ui.newButton{
default = "replayButton.png",
over = "replayButton.png",
onRelease = function(event) group:removeSelf(); main() ; end
}
group:insert(replayButton)
replayButton.x = display.contentWidth / 2
replayButton.y = gameOver.y + gameOver.height / 2 + replayButton.height / 2
return group
end
-- Return a random value between 'min' and 'max'
function getRandomValue(min, max)
return min + math.abs(((max - min) * math.random()))
end
function playRandomSlashSound()
audio.play(slashSounds["slash" .. math.random(1, 3)])
end
function playRandomChoppedSound()
audio.play(choppedSound["chopped" .. math.random(1, 2)])
end
function getRandomSplash()
return display.newImage(splashImgs[math.random(1, #splashImgs)])
end
function chopFruit(fruit)
if (sampleVar == true) then
displayScore()
playRandomChoppedSound()
createFruitPiece(fruit, "top")
createFruitPiece(fruit, "bottom")
createSplash(fruit)
createGush(fruit)
fruit:removeSelf()
end
end
-- Creates a gushing effect that makes it look like juice is flying out of the fruit
function createGush(fruit)
local i
for i = 0, numOfGushParticles do
local gush = display.newCircle( fruit.x, fruit.y, math.random(minGushRadius, maxGushRadius) )
gush:setFillColor(255, 0, 0, 255)
gushProp.radius = gush.width / 2
physics.addBody(gush, "dynamic", gushProp)
local xVelocity = math.random(minGushVelocityX, maxGushVelocityX)
local yVelocity = math.random(minGushVelocityY, maxGushVelocityY)
gush:setLinearVelocity(xVelocity, yVelocity)
transition.to(gush, {time = gushFadeTime, delay = gushFadeDelay, width = 0, height = 0, alpha = 0, onComplete = function(event) gush:removeSelf() end})
end
end
function createSplash(fruit)
local splash = getRandomSplash()
splash.x = fruit.x
splash.y = fruit.y
splash.rotation = math.random(-90,90)
splash.alpha = splashInitAlpha
splashGroup:insert(splash)
transition.to(splash, {time = splashFadeTime, alpha = 0, y = splash.y + splashSlideDistance, delay = splashFadeDelayTime, onComplete = function(event) splash:removeSelf() end})
end
-- Chops the fruit in half
-- Uses some trig to calculate the position
-- of the top and bottom part of the chopped fruit (http://en.wikipedia.org/wiki/Rotation_matrix#Rotations_in_two_dimensions)
function createFruitPiece(fruit, section)
local fruitVelX, fruitVelY = fruit:getLinearVelocity()
-- Calculate the position of the chopped piece
local half = display.newImage(fruit[section])
half.x = fruit.x - fruit.x -- Need to have the fruit's position relative to the origin in order to use the rotation matrix
local yOffSet = section == "top" and -half.height / 2 or half.height / 2
half.y = fruit.y + yOffSet - fruit.y
local newPoint = {}
newPoint.x = half.x * math.cos(fruit.rotation * (math.pi / 180)) - half.y * math.sin(fruit.rotation * (math.pi / 180))
newPoint.y = half.x * math.sin(fruit.rotation * (math.pi / 180)) + half.y * math.cos(fruit.rotation * (math.pi / 180))
half.x = newPoint.x + fruit.x -- Put the fruit back in its original position after applying the rotation matrix
half.y = newPoint.y + fruit.y
fruitGroup:insert(half)
-- Set the rotation
half.rotation = fruit.rotation
fruitProp.radius = half.width / 2 -- We won't use a custom shape since the chopped up fruit doesn't interact with the player
physics.addBody(half, "dynamic", fruitProp)
-- Set the linear velocity
local velocity = math.sqrt(math.pow(fruitVelX, 2) + math.pow(fruitVelY, 2))
local xDirection = section == "top" and -1 or 1
local velocityX = math.cos((fruit.rotation + 90) * (math.pi / 180)) * velocity * xDirection
local velocityY = math.sin((fruit.rotation + 90) * (math.pi / 180)) * velocity
half:setLinearVelocity(velocityX, velocityY)
-- Calculate its angular velocity
local minAngularVelocity = getRandomValue(minAngularVelocityChopped, maxAngularVelocityChopped)
local direction = (math.random() < .5) and -1 or 1
half.angularVelocity = minAngularVelocity * direction
end
-- Creates a platform at the bottom of the game "catch" the fruit and remove it
function setUpCatchPlatform()
local platform = display.newRect( 0, 0, display.contentWidth * 4, 50)
platform.x = (display.contentWidth / 2)
platform.y = display.contentHeight + display.contentHeight
physics.addBody(platform, "static", catchPlatformProp)
platform.collision = onCatchPlatformCollision
platform:addEventListener( "collision", platform )
end
function onCatchPlatformCollision(self, event)
-- Remove the fruit that collided with the platform
event.other:removeSelf()
end
-- Draws the slash line that appears when the user swipes his/her finger across the screen
function drawSlashLine(event)
-- Play a slash sound
if(endPoints ~= nil and endPoints[1] ~= nil) then
local distance = math.sqrt(math.pow(event.x - endPoints[1].x, 2) + math.pow(event.y - endPoints[1].y, 2))
if(distance > minDistanceForSlashSound and slashSoundEnabled == true) then
playRandomSlashSound();
slashSoundEnabled = false
timer.performWithDelay(minTimeBetweenSlashes, function(event) slashSoundEnabled = true end)
end
end
-- Insert a new point into the front of the array
table.insert(endPoints, 1, {x = event.x, y = event.y, line= nil})
-- Remove any excessed points
if(#endPoints > maxPoints) then
table.remove(endPoints)
end
for i,v in ipairs(endPoints) do
local line = display.newLine(v.x, v.y, event.x, event.y)
line.width = lineThickness
transition.to(line, {time = lineFadeTime, alpha = 0, width = 0, onComplete = function(event) line:removeSelf() end})
end
if(event.phase == "ended") then
while(#endPoints > 0) do
table.remove(endPoints)
end
end
end
main()