Angry Bunny Slingshot... collision detection between projectile and flying objects not working!
Posted on Sun, 2012-01-08 19:36
Hello fellow Corona Developers!
I have been having some major issues with implementing the "Angry Bunny" slingshot example by FIXDIT Ltd. (Thank you for sharing your code! :).
Anyways, I have the slingshot part to quite well. However, when I try to make the projectile to trigger and event when it hits a dynamic object flying from the bottom of the screen, it works rather strangely. What I mean is that I have noticed that most of the times the projectile goes THROUGH the objects that's supposed to hit and create the event (collision). In other cases, the projectile, according to some print I have included within the collision function, hits the flying dynamic objects, but at a rather strange, x,y location: the collision happens at a different X and Y location on the screen.
Here's the projectile.lua file, from the code example by FIXDIT Ltd.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 | -- -- Abstract: Part of a tutorial documenting how to put together an 'Angry Birds'/'Hot Cross Bunnies' elastic catapult in CoronaSDK. -- Visit: http://www.fixdit.com regarding support and more information on this tutorial. -- Hot Cross Bunnies is now available in the iTunes App Store: http://itunes.apple.com/app/hot-cross-bunnies/id432734772?mt=8 -- -- Version: 1.0 -- -- Copyright (C) 2011 FIXDIT Ltd. All Rights Reserved. -- -- Permission is hereby granted, free of charge, to any person obtaining a copy of -- this software and associated documentation files (the "Software"), to deal in the -- Software without restriction, including without limitation the rights to use, copy, -- modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, -- and to permit persons to whom the Software is furnished to do so, subject to the -- following conditions: -- -- The above copyright notice and this permission notice shall be included in all copies -- or substantial portions of the Software. -- -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, -- INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR -- PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE -- FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR -- OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER -- DEALINGS IN THE SOFTWARE. -- main.lua (Part of a tutorial documenting how to put together an 'Angry Birds'/'Hot Cross Bunnies' elastic catapult in CoronaSDK.) module(..., package.seeall) _W = display.contentWidth _H = display.contentHeight -- Pass state reference state = {}; -- Bullet starts off in-active ready = false; -- Pass audio references shot = {}; band_stretch = {}; pop = {} local tin_sound = audio.loadSound("tin_sound.mp3") local playTinSound = function() audio.play(tinsound) end function newProjectile() -- Import easing plugin local easingx = require("easing"); -- Bullet properties local bun_bullet = { name = "fruta", type = "bullet", density=0.15, friction=0.2, bounce=0.5, size = 26, rotation = 1 } -- Init bullet local bullet = display.newImageRect("" .. bun_bullet.name .. ".png", 40,40); -- Place bullet bullet.x = 149; bullet.y = _H + 123 ; bullet.myName = "bullet" bullet.hit = "bullet" bullet.type = "bullet" bullet.isBullet = true -- Set up physical properties physics.addBody(bullet, "kinematic", {density=bun_bullet.density, friction=bun_bullet.friction, bounce=bun_bullet.bounce, radius=bun_bullet.size}); bullet.linearDamping = 0.3; bullet.angularDamping = 0.2; bullet.isBullet = true; bullet.isSensor = true; -- add collision here to see.. --OnCollision With floor local function onBulletCollision(self, event) bullet.bodyType = "dynamic" if (event.other.hit == "obstacle") then audio.play(tin_sound) print("Hit BARREL") end if ( event.other.hit == "vase" ) then audio.play(tin_sound) print("BULLET!") self:removeSelf() return true end end bullet.collision = onBulletCollision bullet:addEventListener( "collision" , bullet ) -- Transition the bullet into position each time it's spawned transition.to(bullet, {time=900, y=_H - 140, transition = easingx.easeOutElastic}); return bullet; end |
And here's the targetVase.lua file which creates a vase object that I later use to spawn flying vases (IGNORE FUNCTION checkThreshold():
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 | module(..., package.seeall); _W = display.contentWidth _H = display.contentHeight --Thresholds fed from game.lua thresholds = {}; --Pass the state machine reference state = {}; --Helper function for comparing balloon height (obj1) to threshold (obj2) local function checkThreshold(obj1,obj2) if(obj1 and obj2) then if(obj1.y < obj2[1].boundary and obj1.y > obj2[2].boundary) then --Fire a method once, if you want if(obj1.multiplier == nil) then --Do something end --In case you want to see the threshold change in the terminal window --print(obj2[1].multiplier .. ": thresh 1"); obj1.multiplier = obj2[1].multiplier; elseif(obj1.y < obj2[2].boundary and obj1.y > obj2[3].boundary) then --Fire a method once, if you want if(obj1.multiplier == obj2[1].multiplier) then obj1:flash(); end --In case you want to see the threshold change in the terminal window --print(obj2[2].multiplier .. ": thresh 2"); obj1.multiplier = obj2[2].multiplier; elseif(obj1.y < obj2[3].boundary and obj1.y > -10) then --Fire a method once, if you want if(obj1.multiplier == obj2[2].multiplier) then obj1:flash(); end --In case you want to see the threshold change in the terminal window --print(obj2[3].multiplier .. ": thresh 3"); obj1.multiplier = obj2[3].multiplier; elseif(obj1.y < -10) then if(obj1.timer) then obj1:pop(); end end end end function newVase(velocity) local vase = display.newImageRect("vase.png", 45, 50) vase.x = math.random(_W * 0.5 + 139, _W*0.5 + 149) vase.y = 400 vase.rotation = -90 physics.addBody(vase, { radius = 25}); --physics.addBody(cherries, {density=1.2, bounce = 0, radius = 5}) vase.type = "vase" vase.hit = false vase.multiplier = nil vase.points = 1 vase.myName = "vase" --[[local balloon = display.newCircle(0, 0, 40); balloon:setFillColor(m.random(1,255), m.random(1,255), m.random(1,255)); balloon.x = _W/2; balloon.y = _H+20; --Set up some custom properties balloon.type = "balloon"; balloon.hit = false; balloon.multiplier = nil; balloon.points = 1;--]] --Set up properties to store transition.to's vase.tween = {start={},finish={}}; function vase:flash() local xS = self.xScale; local yS = self.yScale; local factor = 0.3 local function tweenBack() transition.to(self, {time=150, xScale = 1, yScale = 1}) end self.tween.finish = tweenBack; self.tween.start = transition.to(self, {time=100, xScale = xS + factor, yScale = yS + factor, onComplete = self.tween.finish}); end -- Collision Detection for the bullet function vase:collision(e) if(e.phase == "began") then if (e.other.type == "bullet") then print("Hit Vase!!") audio.play(tin_sound) -- self: removeSelf() local function collide() --do points and stuff here.. end local tmr = timer.performWithDelay(1, collide, 1) elseif(e.other.type == "rightWall") then print("RIGHT WALL") end elseif(e.phase == "ended") then --if bullet collides with vase if (e.other.type == "vase") then local function collide() --e.other. end elseif (e.other.type =="floor") then local function collide() self:removeSelf() self = nil end local tmr = timer.performWithDelay(1,collide, 1) end end end --end of bullet function collision function vase:pop() --Tell the state machine that a pop has happened state:dispatchEvent({name="change", state="pop"}) --Cancel the object's timer if(self.timer) then timer.cancel(self.timer); self.timer = nil; end --immediately hide the object; self.isVisible = false if(self.tween.start) then self.tween.start = nil; end if(self.tween.finish) then self.tween.finish = nil; end self.tween = nil; --Finally, remove the object self:removeSelf(); self = nil; collectgarbage("collect"); end --Start checking the y threshold continuously using the helper function defined earlier vase.timer = timer.performWithDelay(20, function(e) checkThreshold(balloon, thresholds); end, -1) physics.addBody(vase, "kinematic", {density=0, bounce=0, friction=0, radius=40}); vase:setLinearVelocity(0,velocity * -2.5); return vase; end |
And here's PART of main.lua file where I call all other files for instantiating the vase and slingshot etc...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 | -------------------------- --THE HEART OF SLINGSHOT- -------------------------- -- BULLET COLLISION --SPAWN CHERRIES UPWARDS-- local spawnCherries = function() physics.setGravity(0, - 0.6); --cherries = display.newImage("cherries.png", math.random(206), 406); cherries = display.newImageRect("vase.png", 45, 50) -- cherries = display.newImageRect("cherries.png", 40,40) -- cherries.x = math.random( 12, 50) cherries.x = math.random(_W * 0.5 + 139, _W*0.5 + 149) cherries.y = 400 cherries.rotation = -90 physics.addBody(cherries, { radius = 25}); --physics.addBody(cherries, {density=1.2, bounce = 0, radius = 5}) cherries.hit = "cherries" cherries.myName = "cherries" local function splashPoints300(object) gushCircle = display.newImageRect ( "points_300.png",64, 64 ) gushCircle.x = _W*0.5 + 200 gushCircle.y = _H*0.5 + 12 function transtion1( event ) trans = transition.to(gushCircle, { tim = 1000, alpha = 0.8, onComplete=finishFunction1}) end function finishFunction1( event ) trans = transition.to(gushCircle, { time = 10100, alpha = 0, onComplete=transition1}) end transition.to(gushCircle, { time = 1600, y = gushCircle.y - 110, x = gushCircle.x +20, alpha = 0,onComplete= transition1} ) end local function splashAnimation800(object) audio.play(tin_sound) print("Vase Hit from splash!") gushCircle = display.newImageRect ( "grapes_splash.png",64, 64 ) gushCircle.x = _W*0.5 + 200 gushCircle.y = _H*0.5 + 59 function transtion1( event ) trans = transition.to(gushCircle, { time = 1000, alpha = 0.8, onComplete=finishFunction1}) end function finishFunction1( event ) trans = transition.to(gushCircle, { time = 10100, alpha = 0, onComplete=transition1}) end transition.to(gushCircle, { time = 1600, y = gushCircle.y - 110, x = gushCircle.x + 24, alpha = 0,onComplete= transition1} ) end --onCollision With barrel local function onObstacleCollision(self, event) if ( event.other.hit == "obstacle" ) then --audio.play(tin_sound) --splashAnimationGrapes() print("HIT OBSTACLE!") splashAnimation800() splashPoints300() --print("Vase Hit!") self:removeSelf() return true elseif ( event.other.hit =="rightWall") then print("HIT WALL!") end end obstacle.collision = onObstacleCollision obstacle:addEventListener( "collision" , obstacle ) --OnCollision With floor local function onCherriesCollision(self, event) if ( event.other.hit == "bullet" ) then --audio.play(tin_sound) --splashAnimationGrapes() splashAnimation800() splashPoints300() --print("Vase Hit!") self:removeSelf() return true elseif ( event.other.hit =="rightWall") then self:removeSelf() print("HIT WALL!") end end cherries.collision = onCherriesCollision cherries:addEventListener( "collision" , cherries ) end local function spawnVase(number) local function spawn(e) --Create an instance of a balloon --and assign it a random linear velocity -- local v = vases.newVase(m.random(100,370)); local v = vases.newVase(m.random(50, 100)) --Store the balloon instance in the balloons table --using the table number as the index vaso[v] =v; vaso[v].x = m.random(_W * 0.5 + 139, _W*0.5 + 149); --Flag the balloon for removal later vaso[v].remove = true; --insert the balloon into the foreground group localGroup:insert(vaso[v]); --cancel and nil timer when done if(e.count == number) then timer.cancel(tmr); tmr = nil; end end tmr = timer.performWithDelay(2000, spawn, number); end local function spawnProjectile() -- If there is a projectile available then... if(projectile.ready)then projectiles_container = projectile.newProjectile(); -- Flag projectiles for removal projectiles_container.ready = true; projectiles_container.remove = true; -- Reset the indexing for the visual attributes of the catapult. slingshot_container:insert(slingshot_strut_back); slingshot_container:insert(projectiles_container); slingshot_container:insert(slingshot_strut_front); ---Add an event listener to the projectile. projectiles_container:addEventListener("touch", projectileTouchListener); end end --[[ GAME STATE CHANGE FUNCTION ]]-- function state:change(e) if(e.state == "fire") then --- You fired... -- new projectile please spawnProjectile(); end end ------------------- ---Change Scene----- ------------------- local moveToScene = function(event) --Example scene change with parameters --director:changeScene( { label="Scene Reloaded" }, "screen2","moveFromRight" ) --Example scene change without parameters --director:changeScene( "screen1", "crossfade" ) end ------------------ -- Code here ------------------ background_image = display.newImageRect("mode_3_bg.png", 480, 320) slingshot_strut_front = display.newImage("sling_left.png", true) slingshot_strut_back = display.newImage("sling_right.png", true) --spring = display.newImageRect("spring_good.png", 98, 98) obstacle = display.newImageRect("barrel.png", 64, 64) obstacle.myName = "obstacle" obstacle.hit = "obstacle" leftWall = display.newRect(0,0,0, _H); leftWall.myName = "leftWall" rightWall = display.newRect(_W, 0, 1, _H); rightWall.hit = "rightWall" --invisible_floor = display.newImageRect("invisible_floor.png", 980, 1) --====================================================================-- -- INITIALIZE, Every Display Object must get shoved into the local Display Group -- Example: localGroup:insert( background ) --====================================================================-- local initVars = function () localGroup:insert(background_image) localGroup:insert(leftWall) localGroup:insert(rightWall) localGroup:insert(obstacle) --localGroup:insert(invisible_floor) slingshot_container:insert(slingshot_strut_front) slingshot_container:insert(slingshot_strut_back) --slingshot_container:insert(projectiles_container) --localGroup:insert(spring) -- Transfer variables to the projectile classes projectile.shot = shot projectile.band_stretch = band_stretch --POSITION OBJECTS background_image.x = _W*0.5 background_image.y = _H*0.5 --[[invisible_floor.x = _W; invisible_floor.y = _H; physics.addBody ( invisible_floor, "static", {bounce=0} ) invisible_floor.hit = "floor" invisible_floor.myName = "floor"--]] --slingshot slingshot_strut_front.x = 138 slingshot_strut_front.y = _H - 123 slingshot_strut_front.rotation = -30 slingshot_strut_back.x = 189 slingshot_strut_back.y = _H - 147 slingshot_strut_back.rotation = -23 obstacle.x = _W*0.5 + 120 obstacle.y = _H - 45 --[[spring.x = _W*0.5 + 230 spring.y = _W*0.5 - 200 spring.hit = "trampoline" physics.addBody(spring, "static", { bounce = 1.4, friction = 0.4}) spring.rotation = 230--]] -- Move catapult up slingshot_container.y = 98; slingshot_container.x = -98 --WRAPPIN WALLS WITH PHYSICS ENGINE -- physics.addBody(leftWall, "static", {bounce = 0.01}); physics.addBody(rightWall, "static", {bounce = 0.01}); physics.addBody(obstacle, "static", {bounce = 0.04}) ----LISTENERS--- -- Tell the projectile it's good to go! projectile.ready = true; -- Spawn the first projectile. spawnProjectile(); -- Create listnener for state changes in the game state:addEventListener("change", state); timerSpawnCherries = timer.performWithDelay( 2000, spawnCherries, 0) -- spawnVase(21) end |
I have been trying to figure this one out for a while now, and I can't seem to find the solution for this. Essentially, all I want to be able to do is have the player stretch the slingshot( which is working fine), and launch the projectile, which in return will hit flying objects and destroy/break that object (or objects if it hits more than one at once). That's all I want to be able to do. Your help will be highly appreciated.
Thank you in advance.
Replies
Posted on Sun, 2012-01-08 22:49
#2
You are absolutely right, Peach! I should not have put all that code in here... what was I thinking :(. I was pretty desperate, I guess! :) My apologies.
I will follow your advice. Thanks again, Peach!
Posted on Mon, 2012-01-09 04:06
#3
Heh, no need to apologize, I'd just like to see it get sorted which is a lot easier with less code ;)
Peach :)
Posted on Wed, 2012-02-08 01:26
#4
I have the same problem, I cannot get the projectile to collide with physics body,
any fixs yet ?
Posted on Wed, 2012-02-08 10:42
#5
Incicive - read the first comment. Code is too long, isolate problem then ask.
If projectile isn't colliding you need to also specify details - is it flying straight though, what body type is it, are objects sleeping, etc.
Posted on Tue, 2012-02-21 03:40
#6
Might it have anything to do with the "Bounce=0.5" ?
Because on the tutorial for collisions it mentioned they have to be equal to collide, but i tried it and it doesn't seem to work.
Posted on Tue, 2012-02-21 08:45
#7
Bounce doesn't have to be equal to collide, no.
There it a tutorial on collision on Techority, Corona for Newbies - Part 4 :)
Posted on Fri, 2012-02-24 06:36
#8
Still trying too figure this out :S
I don't think it has anything too too with the Kinematic or dymaic or even static settings,
But I'm confused completely, could you link me this newbies tutorial please ?
Posted on Fri, 2012-02-24 20:38
#9
Certainly; http://techority.com/2011/06/19/corona-for-newbies-part-4-physics/
Peach :)
Wow, that's long - you would be better off looking at Premium Support for this because to go through your code would take a good amount of time.
Alternatively you could try to isolate the parts of your code that aren't working correctly and share those - that would be much easier for people to have a crack at.
Peach :)