if rects overlap?
Blitz3D Forums/Blitz3D Programming/if rects overlap?
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| This is the code for a simple game I am making just to get the hang of types and to learn collisions. Can someone help me with the colisions part. I am working on the part that tests when a bullet hits the rectangle coming down. The wy I have bin trying to write it is If RectsOverlap (bullet\x,bullet\y,3,20,moveall\x,moveall\y,20,25) Then The resulting eror is " variable must be a type" Here is the code Graphics 640,480 SetBuffer BackBuffer() SeedRnd (MilliSecs ()) ; make random boxes fall and if one reaches the bottom you loose Print "this is a game by matt anthony" Type player Field x Field y Field r,g,b End Type Type rocks Field x Field y Field r,g,b Field fallrate ; alien's fall rate End Type Type bullet Field x Field y Field r,g,b Field bulletrate End Type Const rocknumber = 5 For a = 1 To rocknumber rock.rocks = New rocks rock\x = Rnd(20,620) rock\y = 0 rock\fallrate = Rnd (-1,1.5) + Rnd(1.3,2.8) rock\r=Rnd(100,255) rock\g=Rnd(1,255) rock\b=Rnd(1,255) Next player.player=New player ; Colour: player\r = 25 player\g = 0 player\b = 200 player\x = 320 player\y = 440 Rect player\x, player\y, 50, 10, 1 Color 255, 255, 255 Text player\x+80, player\y, "Player 1" WaitKey() ;start of mainMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM While Not KeyHit(1) ;Cls For moveall.rocks = Each rocks Delay 10 moveall\y = moveall\y + moveall\fallrate Color rock\r, rock\g, rock\b Rect moveall\x, moveall\y, 20, 25,0 ; Draw each invader If moveall\y > 480 Then atbottom = 1 ; If any are at bottom of screen, end! If atbottom=1 Then Print "Game over! The earth is in ashes!":Delay 5000:Print "Hope your happy.":Delay 1000 :End Next ;203=left,205=right If KeyDown(203) player\x=player\x-15 If KeyDown(205) player\x=player\x+15 Color player\r, player\g, player\b Rect player\x, player\y, 50, 10, 1 Rect player\x+5, player\y-8,40,8,1 Rect player\x+20, player\y-16,10,8,1 If KeyHit (57) CreateBullet(player\x,player\y) EndIf UpdateBullets() Flip Cls Wend ;End of mainMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM Function CreateBullet(x,y) ;Create a new bullet bullets.bullet = New bullet bullets\x = x+23 bullets\y = y-20 ;bullets\bulletrate=-4 End Function Function UpdateBullets() For bullet.bullet=Each bullet bullet\y=bullet\y-5 If bullet\y < 0 Delete bullet Else Color 255,200,200 Rect bullet\x,bullet\y,3,20,1 Color 0,0,200 Rect bullet\x,bullet\y+12,3,6,1 Color Rnd (100,255), Rnd (100,255),0 Rect bullet\x,bullet\y+16,3,6,1 EndIf ;RectsOverlap (rect1 X,rect1 Y,rect1 Width,rect1 Height,rect2 X,rect2 Y,rect2 Width,rect2 Height) ;Parameters ;rect1 X = rectangle 1 x location ;rect1 Y = rectangle 1 y location ;rect1 Width = rectangle 1 width ;rect1 Height = rectangle 1 height ;rect2 X = rectangle 2 x location ;rect2 Y = rectangle 2 y location ;rect2 Width = rectangle 2 width ;rect2 Height = rectangle 2 height If RectsOverlap (bullets\x,y,3,20,moveall\x,moveall\y,20,25) Then ;If RectsOverlap ( ;End EndIf Next End Function |
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| --------Changed original Post (I was wrong!) Okay From what I see initially, you have called the types 'Bullets' and 'Bullet' - dunno if these should be consistent??? Also, every time you FOR/NEXT the types, I think you lose the association when the loop has completed, so when you wish to use Bullet(s) and Moveall again, there is no type referenced. I hope this makes sense - Im not too good at explaining it. In short - make a new FOR/NEXT loop to check your types for the RectOverlap check HERES THE WORKING CODE Graphics 640,480 SetBuffer BackBuffer() SeedRnd (MilliSecs ()) ; make random boxes fall and if one reaches the bottom you loose Print "this is a game by matt anthony" Type player Field x Field y Field r,g,b End Type Type rocks Field x Field y Field r,g,b Field fallrate ; alien's fall rate End Type Type bullet Field x Field y Field r,g,b Field bulletrate End Type Const rocknumber = 5 For a = 1 To rocknumber rock.rocks = New rocks rock\x = Rnd(20,620) rock\y = 0 rock\fallrate = Rnd (-1,1.5) + Rnd(1.3,2.8) rock\r=Rnd(100,255) rock\g=Rnd(1,255) rock\b=Rnd(1,255) Next player.player=New player ; Colour: player\r = 25 player\g = 0 player\b = 200 player\x = 320 player\y = 440 Rect player\x, player\y, 50, 10, 1 Color 255, 255, 255 Text player\x+80, player\y, "Player 1" WaitKey() ;start of mainMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM While Not KeyHit(1) ;Cls For moveall.rocks = Each rocks Delay 10 moveall\y = moveall\y + moveall\fallrate Color rock\r, rock\g, rock\b Rect moveall\x, moveall\y, 20, 25,0 ; Draw each invader If moveall\y > 480 Then atbottom = 1 ; If any are at bottom of screen, end! If atbottom=1 Then Print "Game over! The earth is in ashes!":Delay 5000:Print "Hope your happy.":Delay 1000 :End Next ;203=left,205=right If KeyDown(203) player\x=player\x-15 If KeyDown(205) player\x=player\x+15 Color player\r, player\g, player\b Rect player\x, player\y, 50, 10, 1 Rect player\x+5, player\y-8,40,8,1 Rect player\x+20, player\y-16,10,8,1 If KeyHit (57) CreateBullet(player\x,player\y) EndIf UpdateBullets() Flip Cls Wend ;End of mainMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM Function CreateBullet(x,y) ;Create a new bullet bullets.bullet = New bullet bullets\x = x+23 bullets\y = y-20 ;bullets\bulletrate=-4 End Function Function UpdateBullets() For bullet.bullet=Each bullet bullet\y=bullet\y-5 Color 255,200,200 Rect bullet\x,bullet\y,3,20,1 Color 0,0,200 Rect bullet\x,bullet\y+12,3,6,1 Color Rnd (100,255), Rnd (100,255),0 Rect bullet\x,bullet\y+16,3,6,1 For moveall2.rocks = Each rocks If RectsOverlap (bullet\x,bullet\y,3,20,moveall2\x,moveall2\y,20,25) Then ;If RectsOverlap ...... ;End EndIf Next If bullet\y < 0 Delete bullet EndIf Next End Function Note the changes Moveall becomes Moveall2 for the collision check Plus I re-FOR NEXT'ed Moveall to perform the check on each 'rock' you omitted Bullet\y in the line in question and just put y Finally, I moved the whole 'Delete bullet' thing, because otherwise the program deletes bullets that go off screen, but then tries to perform collision check on them - giving an OBJECT DOES NOT EXIST ERROR. The above code now works - quite well too very promising for a simple game! +++++++++++++++++++++++++++++++++++++++++++++++++++ Hope it helps! |
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| I tried it and got an eror "arithmatic oprator cannot be applied to customtype objects" |
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| That maybe because you have a '/' instead of a '\' when dealing with types, RiverRatt |
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| First I tried (bullet\x,bullet\y,3,20,moveall\x,moveall\y,20,25) and got an eror but making moveall into moveall2 seams to be working but I will have to work on it some more becouse now I get "memory access violation" I think it will work though. It seems to me that it should be (bullet\x,bullet\y,3,20,rock\x,rock\y,20,25) but I would have to make a new for each loop ??? |
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| "That maybe because you have a '/' instead of a '\' when dealing with types, RiverRatt" Oh ya thanks! |
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| hmm.... Did you post the actual code you're working with or have you substituted it for loaded images etc??? Also, what versin of Blitz are you using? I made the changes on Blitz3D v1.85 - Try again, cos I have been constantly re-editing the code where I noticed other bits ;) |
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| I dont understand your question. hmm.... Did you post the actual code you're working with or have you substituted it for loaded images etc??? I am writing the code to learn collitions for a 3d game I already have in the works. Models loaded and every thing but all you can do sofar is drive around in a hover craft and look at the pretty stars and lens flares. lots of its code is from the sample folder but changed allot. I am using Blitz3D v1.85 Try again, cos I have been constantly re-editing the code where I noticed other bits ;) Do you meen mistakes by bits? please your input is greatly apreceated, even if my spelling is not. |
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| I dont understand your question. hmm.... Did you post the actual code you're working with or have you substituted it for loaded images etc??? Don't worry- I was just curious. I often try and simplify the mass of code I have problems with when I post on here, to focus on the actual problem. Try again, cos I have been constantly re-editing the code where I noticed other bits ;) Do you meen mistakes by bits? Yeah - I kept editing my post where I noticed other changes. but the code sample I posted now should work, though because it works for me. - So I'm not sure how you are getting errors. Have you tried copying what I have written and pasting it into Blitz? |
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| I see I will try it again I must have got it before you were done. thanks |
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| yup it works! Now I'll have to work on what happens when they collide. Thanks for your help. The blitz comunity rules! |
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| No worries! Good luck - although I am writing the code to learn collitions for a 3d game I already have in the works. Collisions work a lot differently in 3D but that's another story! All the best! |
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| I know, but ya gotta crawl befor you can walk,run ride a bike ,drive a tank, or write a game in c++. Have a great day! |
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