Block Breaker Block Collisions

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Socoder -> Blitz -> Block Breaker Block Collisions
Thu, 13 Sep 2007, 13:38
mole	Yo yo yo! Mmkay, I have my lil block breaker game coming along relatively nicely. It is currently at a very basic stage, it supports the following fun features: - A mouse controlled paddle! - A ball! - Some blocks in a grid-like pattern! - A few collision things! OK, the the collisions between the ball and the blocks is my problem. If the ball hits the TOP or the BOTTOM of a block, it works fine, bouncing off in that well known, happy fashion. The ball simply goes ploughing straight through the sides of the blocks, though! Can you believe it? Well I could. Anyways, this is the code I currently have that works great for the TOP and BOTTOM of the blocks: Function HandleBall() For block.block = Each block If block\alive = 1 If b\x >= block\x And b\x <= (block\x+60) And b\y >= block\y And b\y <= (block\y+30) Then ;ball vs block collision b\dy# = -b\dy# block\alive = 0 Exit EndIf If b\y >= block\y+30 And b\x >= block\x And b\x <= block\x+30 And b\y <= block\y Then b\dx# = -b\dx# block\alive = 0 Exit EndIf EndIf Next If b\x >= scrx Then b\dx = -b\dx If b\x <= 0 Then b\dx = -b\dx If b\y >= scry Then b\dy = -b\dy If b\y <= 0 Then b\dy = -b\dy If b\x >= p\x And b\x <= p\x + 60 And b\y >= p\y And b\y <= p\y+10 Then b\dy = -b\dy EndIf b\x# = b\x# + b\dx# b\y# = b\y# + b\dy# DrawImage b\image, b\x, b\y End Function --v Pretty simple, basic stuff So basically, I need someone to tell me just how I can get it to register hits to the side. Cheers
Thu, 13 Sep 2007, 14:06
Forklift_Fred	Oooh, that's interesting! I don't understand the second If statement though. The first one checks for a collision and if the ball is 'inside' the block, it reverses the y direction. In the second one, The b\y checks don't seem to match up. If one if true then the other one can't be so the If is always going top be false. You are asking if the ball is below the block and above the block I think you need to specify where the ball was last cycle to determine which way it has hit the block. -=-=- Come rain or shine...
Thu, 13 Sep 2007, 14:35
mole	That second If was sumint random i put in in a vain attemp to solve my problems. In retrospect I find it useless xD. I have never got block breaker collisions working properly; i suck at it, so a bit of real/psuedo/theory code stuffz would help me lol.. Anyone remember "gimme da codez"? xD
Thu, 13 Sep 2007, 14:50
magicman	i would recommend using a imagescollide command instead of using a math function. takes less space, is easier, and will work. -=-=- Stuff... Yeah...
Thu, 13 Sep 2007, 15:00
Jayenkai	But at the same time, If you've got a big Multiball thing going, and you're checking 10+ balls against 100+ blocks, the maths would most certainly be quicker than imagecollides. I'll be honest and say that I've never quite got it right, either. I can get basic brick bouncing working, but as soon as the ball starts hopping around inside clumps of bricks it all starts to go heywire!! -=-=- ''Load, Next List!''
Thu, 13 Sep 2007, 15:21
Forklift_Fred	That's a very good point. One thing you could try is breaking down the block into segments or zones. If a collision is detected then, before deleting the block check where the collision is. You could do this with images easier if you have one for each zone of the block, divided something like this: (I know I didn't need to label them but... meh!) You may want to change the order in which the zones are checked depending on which way the ball is moving. If it's going up-left then check bottom, right, top, left. I can't quite explain why but it makes sense to me to prevent false readings. You may be able to use some maths to determine whether the line between the ball's last position and current position crosses each of the lines around the block similar to HERE. Ultimately, given Jay's thinking, this could be your best bet. -=-=- Come rain or shine...
Fri, 14 Sep 2007, 05:21
JL235	I'm busy over the next few days, but a per-pixel collision detection function I wrote in Java could be used for this. In this case I wouldn't actually be checking any pixels. Rather then simply going along each horizontal line of pixels in turn, it went around edge working inward. In this case you could check if the ball and rectangle's position overlaps somewhere and return if it was checking on the top, left, right or bottom edge. It could also return a no collision value too.
Fri, 14 Sep 2007, 07:13
Jayenkai	I think that this is one of those "Over-thinking it" issues. All of this stuff seems insanely complex. Megaball on the Amiga had it down perfectly, in fact most of the original Breakout's worked just as well.. And I'm pretty sure that those versions weren't doing this much work! There must be a really easy solution to doing this. It's just a case of figuring out what that solution is! -=-=- ''Load, Next List!''
Fri, 14 Sep 2007, 12:44
Forklift_Fred	Genius! We need more people like you Jay, that last sentence really nailed the problem That is a very valid point though. I can't image a great deal of work going into "Thro' The Wall" on the original Spectrum 48K introduction tape! -=-=- Come rain or shine...
Fri, 14 Sep 2007, 14:17
Teasy	Yeah, Arkanoid's a real killer (of the brain ) There are zillions of ways of doing it (most are complex), but I've outlined 2 'easier' implementations below. First, a solution using diagonals, basically like Forklift_Fred's pic, where you divide each block into 4 triangles: \| v o------------------------o \|`^-.,_ _,.-^`\| --> \| `^-.,__,.-^` \| <-- \| _,.-^``^-.,_ \| \|_,.-^` `^-.,_\| o------------------------o ^ \| --v You can do this, for example, using the following function, which checks which side of a line a point is on: ; check which side of line point is on ; - returns any positive value when point p1 is below line a->b ; - returns any negative value when point p1 is above line a->b ; - returns 0 when point p1 is on line a->b Function point_line_side#( p1x#,p1y# , ax#,ay#,bx#,by# ) ; original by Warpy ; cross product Return (bx - ax) * (p1y - ay) - (p1x - ax) * (by - ay) End Function --v Then you just check the ball (point) with 2 lines to know which zone/triangle it is in. Here's an example program to demonstrate how it works: ; diagonal zonetest Const sx = 400 Const sy = 300 SetBuffer BackBuffer() Repeat Line 0,0 , sx-1,sy-1 Line 0,sy-1 , sx-1,0 ; difference mx = MouseX() my = MouseY() px = sx/2 py = sy/2 ; lower-right If point_line_side( mx,my , px-sx/2,py+sy/2 , px+sx/2,py-sy/2 ) >= 0 Text sx/2,sy/2-10 , "Lower-Right" , True,True ; upper-right If point_line_side( mx,my , px-sx/2,py-sy/2 , px+sx/2,py+sy/2 ) <= 0 ; right Text sx/2,sy/2 , "Right" , True,True Else ; lower Text sx/2,sy/2 , "Lower" , True,True EndIf ; upper-left Else Text sx/2,sy/2-10 , "Upper-Right" , True,True ; lower-left If point_line_side( mx,my , px-sx/2,py-sy/2 , px+sx/2,py+sy/2 ) >= 0 ; left Text sx/2,sy/2 , "Left" , True,True Else ; upper Text sx/2,sy/2 , "Upper" , True,True EndIf EndIf Flip Cls Until KeyHit( 1 ) End ; returns any positive value when point p1 is below line a->b ; returns any negative value when point p1 is above line a->b ; returns 0 when point p1 is on line a->b Function point_line_side#( p1x#,p1y# , ax#,ay#,bx#,by# ) ; original by Warpy ; cross product Return (bx - ax) * (p1y - ay) - (p1x - ax) * (by - ay) End Function --v And, I've taken the liberty to mess with your original code and take it a little further, which now also includes the above algorithm, and a bunch of other things: AppTitle "Paddle ball" Const scrx = 400 Const scry = 300 Graphics scrx,scry , 0,3 SetBuffer BackBuffer() SeedRnd MilliSecs() HidePointer Const paddle_width = 60 Const paddle_height = 20 Type paddle Field x,y End Type Local p.paddle Const ball_speed = 5 Type ball Field x#,y# Field dx#,dy# Field collision End Type Local b.ball Const block_width = 60 Const block_height = 30 Type block Field alive Field x,y End Type Local block.block p = New paddle p\x = scrx/2 p\y = scry-scry/12-1 For x = 1 To 4 For y = 2 To 4 block = New block block\x = xblock_width 1.5 - block_width block\y = yblock_height1.5 - block_height block\alive = Rand( 1,10 ) Next Next Repeat ; balls For b = Each ball ; motion b\x = b\x + b\dx b\y = b\y + b\dy ; block collision For block = Each block If block\alive ; inside If RectsOverlap( b\x,b\y,1,1 , block\x,block\y,block_width,block_height ) ; put number of steps back until no longer inside While RectsOverlap( b\x,b\y,1,1 , block\x,block\y,block_width,block_height ) ; 1 pixel steps b\x = b\x - b\dx / ball_speed b\y = b\y - b\dy / ball_speed Wend ; ball is in lower-right area of center of block If point_line_side( b\x,b\y , block\x,block\y+block_height , block\x+block_width,block\y ) >= 0 ; ball is in upper-right area of center of block If point_line_side( b\x,b\y , block\x,block\y , block\x+block_width,block\y+block_height ) <= 0 ; right triangle b\dx = -b\dx Else ; lower triangle b\dy = -b\dy EndIf ; ball is in upper-left area of center of block Else Text sx/2,sy/2-10 , "Upper-Right" , True,True ; ball is in lower-left area of center of block If point_line_side( b\x,b\y , block\x,block\y , block\x+block_width,block\y+block_height ) >= 0 ; left triangle b\dx = -b\dx Else ; upper triangle b\dy = -b\dy EndIf EndIf block\alive = block\alive - 1 EndIf EndIf Next ; screen collision If b\x >= scrx Or b\x < 0 b\dx = -b\dx EndIf If b\y < 0 b\dy = -b\dy ElseIf b\y >= scry Delete b Exit EndIf ; paddle collision If RectsOverlap( b\x,b\y,1,1 , p\x,p\y,paddle_width,paddle_height ) b\dy = -b\dy EndIf ; visualize Rect b\x-2,b\y-2 , 4,4 Next ; blocks For block = Each block Rect block\x,block\y , block_width,block_height , block\alive If block\alive Color 0,0,0 Text block\x+block_width/2,block\y+block_height/2 , block\alive , True,True Color 255,255,255 EndIf Next ; paddle If Not MouseDown( 2 ) ; right button p\x = MouseX() Else ; target Rect MouseX()-2,MouseY()-2 , 4,4 , False Line MouseX(),MouseY() , p\x+paddle_width/2,p\y-paddle_height/4 EndIf If MouseHit( 1 ) ; left button If MouseDown( 2 ) ; right button b = New ball ; center on paddle, slightly above b\x = p\x + paddle_width/2 b\y = p\y - paddle_height/4 ; calculate angle from paddle to mouse (0 = up) angle = 180-ATan2( MouseX()-(p\x+paddle_width/2),MouseY()-(p\y+paddle_height/2) ) ; direction vector (at ball speed) b\dx = Sin( angle ) * ball_speed b\dy = Sin( angle-90 ) * ball_speed EndIf EndIf Rect p\x,p\y , paddle_width,paddle_height , False ; reset blocks If KeyHit( 57 ) ; space For block.block = Each block block\alive = Rand( 1,10 ) Next EndIf ; interface Text 0, 0 , "Move mouse left/right to control paddle." Text 0,10 , "Press right button to lock paddle," Text 0,20 , "then move mouse to aim at target," Text 0,30 , "and press left button to fire ball." Flip Cls Until KeyHit( 1 ) ; escape End ; check which side of line point is on ; - returns any positive value when point p1 is below line a->b ; - returns any negative value when point p1 is above line a->b ; - returns 0 when point p1 is on line a->b Function point_line_side#( p1x#,p1y# , ax#,ay#,bx#,by# ) ; original by Warpy ; cross product Return (bx - ax) * (p1y - ay) - (p1x - ax) * (by - ay) End Function --v The next problem is being able to affect the ball angle, using the paddle, depending on: - where the ball hits - and at what speed you move the paddle Btw I also found one of my old BlitzCoder tutorials called The way of Pong, which uses a tilemap (faster), rather than a set of tile objects, and only images without (too) (many) complicated maths or algorithms. ; Yes, doing collisions for a pong game can be very cumbersome. ; However, the program below will not use any complicated maths. ; Just a logic algorithm. ; ; When running the program, press <space> to toggle debug 'mode'. ; In debug 'mode' additional visuals and a delay is introduced ; to demonstrate the problem areas in collisions. ; Kinda like a what-you-see-is-what-you-get approach. Global User_Debug = True Graphics 640 , 480 , 0 , 1 ; Force full screen (read below) ; Size of the tile map (from data) Const TileMapSizeX = 20 Const TileMapSizeY = 15 Global Block = CreateBlockImage ( 32 , 32 ) ; Detect (grab) the tile size from image Global TileSizeX = ImageWidth ( Block ) Global TileSizeY = ImageHeight ( Block ) Global Ball = CreateBallImage ( 16 , 16 ) ; Center the hotspot, so drawing/collision/positioning is from center of image MidHandle Ball ; Center hotspot ; Grab ball sizes from image Global BallSizeX = ImageWidth ( Ball ) Global BallSizeY = ImageHeight ( Ball ) ; Starting position and direction Global BallPosX = 64 Global BallPosY = 72 Global BallDirX = 1 Global BallDirY = 1 ; Actual tilemap Dim Tiles( TileMapSizeY , TileMapSizeX ) Restore TileMap For TileY = 0 To TileMapSizeY-1 For TileX = 0 To TileMapSizeX-1 Read Tiles( TileY , TileX ) Next Next SetBuffer BackBuffer () Repeat ; To get perfect collisions in a Pong game you'll need 1 pixel step movement for the ball ; or more complicated maths :P The idea is to update the ball (or all logics) more times ; than showing it on the screen, making it more independent. This way you can also increase ; the ball speed (e.g. by increasing the number of times to update the ball/collision). ; It is possible to convert the ball position and direction to floating point values with ; a max value of 1 for direction to get that Arkanoid style bouncing. Ofcourse you'll also ; need those complicated maths for accurate bouncing, like having special objects instead ; of a tilemap. ; Update logic For GameSpeed = 1 To 3 Collision UpdateBall Next If KeyHit ( 57 ) Then User_Debug = Not User_Debug ; Spacebar toggles debug 'mode' ; Update screen DrawTiles DrawBall Flip Cls Until KeyHit ( 1 ) End Function DrawTiles () ; Draw tiles as usual, but using array For TileY = 0 To TileMapSizeY-1 For TileX = 0 To TileMapSizeX-1 If Tiles( TileY , TileX ) = 1 DrawImage Block , TileX * TileSizeX , TileY * TileSizeY End If Next Next End Function Function DrawBall () DrawImage Ball , BallPosX , BallPosY End Function Function UpdateBall () ; Update ball position using direction BallPosX = BallPosX + BallDirX BallPosY = BallPosY + BallDirY End Function Function Collision () ; This function has become huge. Also to easily show which tiles are collided with, I've temporary ; set the drawing buffer to the front buffer, which is set back to the back buffer after the function ; is done. This means that the result is only visible in full screen (Graphics 640 , 480 , 0 , 1). ; Precalculate future position, to prevent the ball from overlapping tiles. BallNewX = BallPosX + BallDirX BallNewY = BallPosY + BallDirY SetBuffer FrontBuffer () ; Precalculate the tile under the ball. BallTileX = BallNewX / TileSizeX BallTileY = BallNewY / TileSizeY ; Loop only through the 8 tiles next to the ball and the tile under the ball. ; This ofcourse will crash if the ball gets too close to the edge (but the map is closed on all sides ; so this won't happen). For TileY = BallTileY-1 To BallTileY+1 For TileX = BallTileX-1 To BallTileX+1 ; Draw the tile currently being checked for collisions. If User_Debug Color 0 , 0 , 255 Rect TileX * TileSizeX , TileY * TileSizeY , TileSizeX , TileSizeY , False End If If Tiles( TileY , TileX ) = 1 If ImagesCollide ( Block , TileX * TileSizeX , TileY * TileSizeY , 0 , Ball , BallNewX , BallNewY , 0 ) Collision = True ; Set a flag to know which tile has collided with the ball. If TileY = BallTileY - 1 And TileX = BallTileX Then TileAbove = True ; Above If TileY = BallTileY + 1 And TileX = BallTileX Then TileBelow = True ; Below If TileY = BallTileY And TileX = BallTileX - 1 Then TileLeft = True ; Left If TileY = BallTileY And TileX = BallTileX + 1 Then TileRight = True ; Right If TileY = BallTileY - 1 And TileX = BallTileX - 1 Then TileUpLt = True ; Upper left If TileY = BallTileY - 1 And TileX = BallTileX + 1 Then TileUpRt = True ; Upper right If TileY = BallTileY + 1 And TileX = BallTileX - 1 Then TileLowLt = True ; Lower left If TileY = BallTileY + 1 And TileX = BallTileX + 1 Then TileLowRt = True ; Lower right ; Visual collision display. If User_Debug Color 255 , 0 , 0 Rect TileX * TileSizeX , TileY * TileSizeY , TileSizeX , TileSizeY , True End If End If End If Next Next ; For the exceptions, knowing the absolute heading of the ball is required. If BallDirX < 0 And BallDirY < 0 Then HeadingUpLt = True ; Upper left If BallDirX < 0 And BallDirY > 0 Then HeadingLowLt = True ; Lower left If BallDirX > 0 And BallDirY < 0 Then HeadingUpRt = True ; Upper right If BallDirX > 0 And BallDirY > 0 Then HeadingLowRt = True ; Lower right ; In case of any collisions, reverse the direction in question. If Collision ; Any corner (when the ball is pixel-perfectly cornered) If TileLeft And TileAbove Or TileLeft And TileBelow Or TileRight And TileAbove Or TileRight And TileBelow ; Reverse all directions BallDirX = -BallDirX BallDirY = -BallDirY Else ; Only left or right side If TileLeft Or TileRight BallDirX = -BallDirX ; Only upper or lower side ElseIf TileAbove Or TileBelow BallDirY = -BallDirY ; Exception: Vertical single edges ElseIf ( HeadingUpLt And TileLowLt ) Or ( HeadingLowLt And TileUpLt ) Or ( HeadingUpRt And TileLowRt ) Or ( HeadingLowRt And TileUpRt ) BallDirX = -BallDirX ; Exception: Horizontal single edges ElseIf ( HeadingUpLt And TileUpRt ) Or ( HeadingUpRt And TileUpLt ) Or ( HeadingLowLt And TileLowRt ) Or ( HeadingLowRt And TileLowLt ) BallDirY = -BallDirY ; Exception: Sharp edges (complete bounce) ElseIf TileUpLt Or TileUpRt Or TileLowLt Or TileLowRt BallDirX = -BallDirX BallDirY = -BallDirY ; Unknown exception Else If User_Debug Color 255 , 255 , 0 Oval BallTileX * TileSizeX , BallTileY * TileSizeY , TileSizeX , TileSizeY WaitKey End If End If End If If User_Debug Then Delay 100 End If SetBuffer BackBuffer () End Function .TileMap Data 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 Data 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 Data 1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,1 Data 1,0,1,1,0,0,0,1,0,1,1,0,0,1,1,0,0,0,0,1 Data 1,0,1,1,0,0,0,1,0,1,1,0,0,0,0,0,1,1,0,1 Data 1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,1,0,1 Data 1,0,0,0,0,0,0,1,0,0,0,0,1,1,0,0,0,0,0,1 Data 1,0,1,1,0,0,0,1,0,0,0,0,1,1,0,1,1,0,0,1 Data 1,0,1,1,0,0,0,1,0,1,1,0,0,0,0,1,1,0,0,1 Data 1,0,0,0,0,0,0,1,0,1,1,0,0,0,0,0,0,0,0,1 Data 1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,1 Data 1,0,0,1,1,0,0,1,0,0,0,1,1,0,0,1,1,0,0,1 Data 1,0,0,1,1,0,0,1,0,0,0,1,1,0,0,1,1,0,0,1 Data 1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,1 Data 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 ; Functions for image independence Function CreateBlockImage ( SizeX , SizeY ) Image = CreateImage ( SizeX , SizeY ) SetBuffer ImageBuffer ( Image ) Color 64 , 96 , 128 Rect 0 , 0 , SizeX , SizeY , True Color 128 , 192 , 255 Line 0 , 0 , SizeX-2 , 0 Line 0 , 0 , 0 , SizeY-2 Color 32 , 48 , 64 Line 0 , SizeY-1 , SizeX-1 , SizeY-1 Line SizeX-1 , 0 , SizeX-1 , SizeY-1 Color 255 , 255 , 255 Plot 0 , 0 Return Image End Function Function CreateBallImage ( SizeX , SizeY ) Image = CreateImage ( SizeX , SizeY ) SetBuffer ImageBuffer ( Image ) For x = 0 To SizeX/2-1 c = x191/(SizeX/2)+64 Color c2/3 , c3/4 , c y = Float xSizeY/SizeX Oval x , y , (SizeX-x2) , (SizeY-y2) , True Next Return Image End Function --v Well I hope you (or anyone) will find something useful in there Lemme know if something is unclear. \|edit\| Oops, almost forgot! \|edit\| Here's a remake of a game I played when I was very young on a computer from the good'ol days Basically; Capture The Balls. (nowadays I play Capture The Flag ) Const ScreenWidth = 640 Const ScreenHeight = 480 Const ScreenCenterX = ScreenWidth / 2 Const ScreenCenterY = ScreenHeight / 2 Graphics ScreenWidth , ScreenHeight TFormFilter False SeedRnd MilliSecs () Const HBarHeight = 10 Const HBarWidth = ScreenWidth / 3 - HBarHeight / 2 + hbarheight Const VBarWidth = HBarHeight Const VBarHeight = ScreenHeight / 3 - VBarWidth / 2 + hbarheight Color 255 , 255 , 255 Const ShapeRect = 1 Const ShapeOval = 2 Function CreateShape ( Shape , ShapeWidth , ShapeHeight ) Image = CreateImage ( ShapeWidth , ShapeHeight ) SetBuffer ImageBuffer ( Image ) Select Shape Case ShapeRect : gradRect 0,0 , ShapeWidth,ShapeHeight , 128,192,255 Case ShapeOval : gradOval 0,0 , ShapeWidth,ShapeHeight , 128,255,192 End Select Return Image End Function Global HBarImage = CreateShape ( ShapeRect , HBarWidth , HBarHeight ) Global VBarImage = CreateShape ( ShapeRect , VBarWidth , VBarHeight ) Const VBarLeftX = ScreenWidth / 3 - VBarWidth / 2 Const VBarLeftY = ScreenCenterY - VBarHeight / 2 Const VBarRightX = ScreenWidth * 2 / 3 - VBarWidth / 2 Const VBarRightY = ScreenCenterY - VBarHeight / 2 Const HBarTopX = ScreenCenterX - HBarWidth / 2 Const HBarTopY = ScreenHeight / 3 - HBarHeight / 2 Const HBarBottomX = ScreenCenterX - HBarWidth / 2 Const HBarBottomY = ScreenHeight * 2 / 3 - HBarHeight / 2 Const HBarMin = -HBarWidth Const HBarMax = +HBarWidth Const VBarMin = -VBarHeight Const VBarMax = +VBarHeight Global HBarPos = 0 Global VBarPos = 0 Const BarSpeed = 2 Const BallWidth = 10 Const BallHeight = 10 Global BallImage = CreateShape ( ShapeOval , BallWidth , BallHeight ) MidHandle BallImage Type Ball Field PosX Field PosY Field DirX Field DirY Field Inside End Type Function CreateBall ( PosX , PosY , DirX , DirY ) Local Ball.Ball Ball = New Ball Ball\PosX = PosX Ball\PosY = PosY Ball\DirX = DirX Ball\DirY = DirY End Function Global NumberOfBalls Function RecreateBalls() Delete Each Ball For BallNumber = 1 To NumberOfBalls Repeat PosX = Rand ( BallWidth , ScreenWidth - 1 - BallWidth ) PosY = Rand ( BallHeight , ScreenHeight - 1 - BallHeight ) Until Not PointWithin ( PosX,PosY , VBarLeftX-BallWidth,HBarTopY-BallHeight , VBarRightX+VBarWidth+BallWidth , HBarBottomY+HBarHeight+BallHeight ) CreateBall PosX , PosY , Rand(0,1)2-1 , Rand(0,1)2-1 ; -1 or 1 Next End Function Function PointWithin ( PointX , PointY , RectX1 , RectY1 , RectX2 , RectY2 ) If PointX >= RectX1 If PointY >= RectY1 If PointX <= RectX2 If PointY <= RectY2 Return True End If End If End If End If Return False End Function Const BallSpeed = 2 Global UpperLeftX Global UpperLeftY Global LowerLeftX Global LowerLeftY Global UpperRightX Global UpperRightY Global LowerRightX Global LowerRightY SetBuffer BackBuffer () FlushKeys Const MessageDuration = 5000 Const ControlsLockedDuration = 1000 Global ControlsLocked Global ControlsLockedTime SetFont LoadFont( "FixedSys" ) Type Message Field Contents$ Field TimeCreated End Type Function UpdateMessages () For Msg.Message = Each Message If MilliSecs () > Msg\TimeCreated + MessageDuration Delete Msg End If Next End Function Function DrawMessages () Color 128,192,255 For Msg.Message = Each Message Text 0 , CurrentLine10 , Msg\Contents CurrentLine = CurrentLine + 1 Next End Function Function AddMsg ( MessageContents$ ) OldMsg.Message = First Message If OldMsg <> Null If Instr ( OldMsg\Contents , MessageContents ) OldMsg\TimeCreated = MilliSecs () FoundChar = Instr ( OldMsg\Contents , "~" ) If FoundChar Count = Mid ( OldMsg\Contents , FoundChar+1 , Len ( OldMsg\Contents ) - FoundChar ) OldMsg\Contents = Mid ( OldMsg\Contents , 1 , FoundChar ) + (Count+1) Else OldMsg\Contents = OldMsg\Contents + " ~2" End If Else CreateNew = True End If Else CreateNew = True End If If CreateNew NewMsg.Message = New Message NewMsg\Contents = MessageContents NewMsg\TimeCreated = MilliSecs () ;Insert NewMsg Before First Message End If End Function Function LockControls() ControlsLocked = True ControlsLockedTime = MilliSecs() End Function Function AdvanceGame() LockControls Select NumberOfBalls Case 0 NumberOfBalls = 1 AddMsg "Try capturing this ball" Case 1 AddMsg "Congratulations!" NumberOfBalls = NumberOfBalls2 AddMsg "Now try 2 balls" Default AddMsg "All "+NumberOfBalls+" balls have been captured!" NumberOfBalls = NumberOfBalls2 AddMsg "Can you capture "+NumberOfBalls+" balls?" End Select RecreateBalls HBarPos = 0 VBarPos = 0 End Function AdvanceGame Repeat ControlBars For UpdateNumber = 1 To BallSpeed If BarsCollide() If BallsCaptured() = NumberOfBalls AdvanceGame EndIf EndIf CollideBalls ; with bars MoveBalls Next UpdateMessages DrawMessages DrawBars DrawBalls Flip Cls Until KeyHit ( 1 ) End Function BarsCollide() If ImagesOverlap( HBarImage , HBarTopX+HBarPos,HBarTopY , VBarImage , VBarLeftX ,VBarLeftY +VBarPos ) If ImagesOverlap( HBarImage , HBarTopX+HBarPos,HBarTopY , VBarImage , VBarRightX,VBarRightY+VBarPos ) If ImagesOverlap( HBarImage , HBarBottomX+HBarPos,HBarBottomY , VBarImage , VBarLeftX ,VBarLeftY +VBarPos ) If ImagesOverlap( HBarImage , HBarBottomX+HBarPos,HBarBottomY , VBarImage , VBarRightX,VBarRightY+VBarPos ) Return True EndIf EndIf EndIf EndIf End Function Function BallsCaptured() Local pBall.Ball Local NumCaptured For pBall = Each Ball NumCaptured = NumCaptured + PointWithin( pBall\PosX,pBall\PosY , VBarLeftX,HBarTopY , VBarRightX+VBarWidth,HBarBottomY+HBarHeight ) Next Return NumCaptured End Function Function DrawBars () DrawImage HBarImage , HBarTopX + HBarPos , HBarTopY DrawImage HBarImage , HBarBottomX + HBarPos , HBarBottomY DrawImage VBarImage , VBarLeftX , VBarLeftY + VBarPos DrawImage VBarImage , VBarRightX , VBarRightY + VBarPos End Function Function DrawBalls () Local Ball.Ball For Ball = Each Ball DrawImage BallImage , Ball\PosX , Ball\PosY Next End Function Function CollideBalls () ; with bars Local Ball.Ball For Ball = Each Ball ; Collide with screen edges If Ball\PosX < 0+BallWidth Or Ball\PosX >= ScreenWidth -BallWidth Then Ball\DirX = -Ball\DirX If Ball\PosY < 0+BallHeight Or Ball\PosY >= ScreenHeight-BallHeight Then Ball\DirY = -Ball\DirY ; Collide with bars For BarNumber = 1 To 4 Select BarNumber Case 1 : AssignBarEdges HBarTopX + HBarPos , HBarTopY , HBarWidth , HBarHeight Case 2 : AssignBarEdges HBarBottomX + HBarPos , HBarBottomY , HBarWidth , HBarHeight Case 3 : AssignBarEdges VBarLeftX , VBarLeftY + VBarPos , VBarWidth , VBarHeight Case 4 : AssignBarEdges VBarRightX , VBarRightY + VBarPos , VBarWidth , VBarHeight End Select If BarNumber < 3 Then BarImage = HBarImage Else BarImage = VBarImage Collision = ImagesCollide ( BarImage , UpperLeftX , UpperLeftY , 0 , BallImage , Ball\PosX , Ball\PosY , 0 ) If (Collision) And (Ball\Inside <> BarNumber) And (Not Ball\Inside) ; Put ball back 1 update to prevent another ImagesCollide Ball\PosX = Ball\PosX - Ball\DirX Ball\PosY = Ball\PosY - Ball\DirY ; Prevent ball from bouncing into eternity Ball\Inside = BarNumber ; Check where ball is compared to bar to know how to bounce ; UpperLeft, LowerLeft, UpperRight, LowerRight If (Ball\PosX<UpperLeftX And Ball\PosY<UpperLeftY) Or (Ball\PosX<LowerLeftX And Ball\PosY>LowerLeftY) Or (Ball\PosX>UpperRightX And Ball\PosY<UpperRightY) Or (Ball\PosX>LowerRightX And Ball\PosY>LowerRightY) ChangeBallDirection Ball , -1 , -1 ; Left Else If (Ball\PosX<UpperLeftX And Ball\PosY>=UpperLeftY And Ball\PosY<=LowerRightY) ChangeBallDirection Ball , -1 , 1 ; Right Else If (Ball\PosX>LowerRightX And Ball\PosY>=UpperLeftY And Ball\PosY<=LowerRightY) ChangeBallDirection Ball , -1 , 1 ; Above Else If (Ball\PosY<UpperLeftY And Ball\PosX>=UpperLeftX And Ball\PosX<=LowerRightX) ChangeBallDirection Ball , 1 , -1 ; Below Else If (Ball\PosY>LowerRightY And Ball\PosX>=UpperLeftX And Ball\PosX<=LowerRightX) ChangeBallDirection Ball , 1 , -1 End If End If If (Not Collision) And (Ball\Inside = BarNumber) Ball\Inside = False End If Next Next End Function Function ChangeBallDirection ( Ball.Ball , DirXFactor , DirYFactor ) Ball\DirX = Ball\DirX DirXFactor Ball\DirY = Ball\DirY * DirYFactor End Function Function AssignBarEdges ( PosX , PosY , SizeX , SizeY ) UpperLeftX = PosX UpperLeftY = PosY LowerLeftX = PosX LowerLeftY = PosY + SizeY UpperRightX = PosX + SizeX UpperRightY = PosY LowerRightX = PosX + SizeX LowerRightY = PosY + SizeY End Function Function MoveBalls () Local Ball.Ball For Ball = Each Ball Ball\PosX = Ball\PosX + Ball\DirX Ball\PosY = Ball\PosY + Ball\DirY Next End Function Function ControlBars () If ControlsLocked If MilliSecs()-ControlsLockedTime >= ControlsLockedDuration ControlsLocked = False End If EndIf If Not ControlsLocked If KeyDown ( 200 ) ; Up VBarPos = VBarPos - BarSpeed If VBarPos < VBarMin Then VBarPos = VBarMin End If If KeyDown ( 208 ) ; Down VBarPos = VBarPos + BarSpeed If VBarPos > VBarMax Then VBarPos = VBarMax End If If KeyDown ( 203 ) ; Left HBarPos = HBarPos - BarSpeed If HBarPos < HBarMin Then HBarPos = HBarMin End If If KeyDown ( 205 ) ; Right HBarPos = HBarPos + BarSpeed If HBarPos > HBarMax Then HBarPos = HBarMax End If End If End Function Function gradoval ( x , y , w , h , r , g , b ) w0 = w/2 - 1 For i = 0 To w0 r0 = i * r / w0 g0 = i * g / w0 b0 = i * b / w0 Color 64+r0/1.25 , 64+g0/1.25 , 64+b0/1.25 h0 = i * h / 2 / w0 w1 = ( w0 - i ) * 2 h1 = ( w0 - i ) * h / w0 Oval x + i , y + h0 , w1 , h1 Next End Function Function gradrect( x,y , w,h , r,g,b ) If w>h gradhrect x,y , w,h , r,g,b Else gradvrect x,y , w,h , r,g,b EndIf End Function Function gradhrect ( x , y , w , h , r , g , b ) ;;msd w0 = w/2 - 1 For i = 0 To w0 r0 = i * r / w0 g0 = i * g / w0 b0 = i * b / w0 Color 64+r0/1.25 , 64+g0/1.25 , 64+b0/1.25 h0 = i * h / 2 / w0 w1 = ( w0 - i ) * 2 h1 = ( w0 - i ) * h / w0 Rect x + i , y + h0 , w1 , h1 Next End Function Function gradvrect ( x , y , w , h , r , g , b ) ;;msd h0 = h/2 - 1 For i = 0 To h0 r0 = i * r / h0 g0 = i * g / h0 b0 = i * b / h0 Color 64+r0/1.25 , 64+g0/1.25 , 64+b0/1.25 w0 = i * w / 2 / h0 h1 = ( h0 - i ) * 2 w1 = ( h0 - i ) * w / h0 Rect x+w0,y+i , w1,h1 Next End Function --v
Mon, 17 Sep 2007, 11:33
mole	Thanks for all this info, guys. "The Way of Pong" source posted by Teasy is particularly helpful, I find. So helpful, in fact, that I am shoe-horning my game into it. Muahaha! In all seriousness, who is the author? Much thanks to them indeed!
Thu, 20 Sep 2007, 09:43
Teasy	Hihihi Actually, that would be me I'm very happy that you find the code useful, and expand on it to make something cool out of it That's the great thing about teamwork!
Fri, 21 Sep 2007, 05:17
mole	Well thank you very much Teasy ^^ Now.... I have another problem. Almost completely unrelated to the specifics of block breaker, but as I'm here, I'l shove it here. I am trying to make power ups, and I want to load them from a text file (so I can make a power-up editor hopefully). Basically, the power ups are going to be 16*16, in a text file with (currently) the numbers 1-4 representing a different colour. I did a bit of coding and thought "wow, theis must work!". Lo, it didn't. ImageArray(16,16) Function LoadDataImage(x,y,source$) DataFile = ReadFile(source$) If DataFile = 0 Then RuntimeError("Error loading the image file: "+source$) img = CreateImage(x,y) For a = 0 To x-1 For b = 0 To y-1 ImageArray(a,b) = ReadByte(DataFile) Next Next CloseFile(DataFile) SetBuffer(ImageBuffer(img)) For a = 0 To x-1 For b = 0 To y-1 Select ImageArray(a,b) Case 1 : Color 255,255,255 : Plot a,b Case 2 : Color 255,0,0 : Plot a,b Case 3 : Color 0,255,0 : Plot a,b Case 4 : Color 0,0,255 : Plot a,b Case 5 : Color 0,0,0 : Plot a,b End Select Next Next SetBuffer(BackBuffer()) End Function --v It is called like so: Global InvinciballPwr = LoadDataImage(16,16,"data/Power ups/invinciball.dat") --v The file format looks like this: 1111111111111111 1211111111111131 1211444444441131 1211111441111131 1211111441111131 1211111441111131 1211111441111131 1311111441111131 1311111441111121 1311111441111121 1311111441111121 1311111441111121 1311111441111121 1311444444441121 1311111111111121 1311111111111121 --v When it runs, it throws the runtime error in my face. I'm sure it is not a wrong directory issue. I have B+ V1.35, V1.10, V1.36, so is it a version issue? Or is it simply that I have completely forgotten how to do this stuff ? Cheers for all help ^^
Fri, 21 Sep 2007, 14:38
Forklift_Fred	There is a lot wrong with that, mole. I'm trying to get my head around the bits that I think should work but in the mean time... You need to put Dim in front of ImageArray(16,16) ReadByte is not what you want. If you add the line *Text a20,b20,ImageArray(a,b)* after it to write what it has just read, you'll see that rather than the numbers 1 to 4, it is trying to use the values like 49, 13, 51 etc. You also need to have your For...Next loops the other way around so it's b then a because you are stepping through the rows and then, within each row, stepping through the columns. Otherwise your image will come out sideways. You could get away with ReadByte if you first use WriteByte to write your 1,2,3,4 data to the file. But that would make life more complicated. My option would be to use a string as it works with the dat file you already have. Read the file line by line and then step through it... For b = 0 To y-1 I$ = ReadLine(DataFile) For a = 0 To x-1 ImageArray(a,b)=Mid$(I$,a+1,1) Text a10,b10,ImageArray(a,b) Next Next --v You also need to end your function with a Return command otherwise nothing is put into the InvinciballPwr variable and you'll get an "Image does not exist" error. Finally, you can do away with the whole ImageArray(a,b) array and draw straight from the data to the image. There's no point in looping through the data twice. Et Voila: Function LoadDataImage(x,y,source$) DataFile = ReadFile(source$) If DataFile = 0 Then RuntimeError("Error loading the image file: "+source$) img = CreateImage(x,y) SetBuffer(ImageBuffer(img)) For b = 0 To y-1 RowData$ = ReadLine(DataFile) For a = 0 To x-1 pixel=Mid$(RowData$,a+1,1) Select pixel Case 1 : Color 255,255,255 : Plot a,b Case 2 : Color 255,0,0 : Plot a,b Case 3 : Color 0,255,0 : Plot a,b Case 4 : Color 0,0,255 : Plot a,b Case 5 : Color 0,0,0 : Plot a,b End Select Next Next CloseFile(DataFile) SetBuffer(BackBuffer()) Return img End Function --v You need to use a+1 because strings start at 1 not 0 (don't you just love Blitz!) You could change the For loop to For a = 1 To x and then use Mid$(RowData$,a,1) but that just confuses things when you look at the co-ordinates! That should do the trick -=-=- Come rain or shine...
Sat, 22 Sep 2007, 01:43
mole	I am so glad you are here :x Thanks a lot!
Sat, 22 Sep 2007, 14:02
Forklift_Fred	I amaze myself sometime It helps that I already had a similar bit of code on my Think Pink! Workshop entry to make a pink mouse-pointer. I'd done it with Data statements so that the whole game worked straight from source but I've also done some work with extracting employee details from data reports so that helped as well. The important thing to remember is that you were heading in the right direction I like this kind of puzzle! -=-=- Come rain or shine...