ImagesCollide
BlitzMax Forums/BlitzMax Beginners Area/ImagesCollide
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| Argh. Why can't I figure out how to use ImagesCollide? Ok so it's :- ImagesCollide(TImage1,x,y,frame1,TImage2,x,y,frame2) I don't get why you need you need frame1 and frame2. In Regular Blitz i just use (Image1,x,y,Image2,x,y) and everything works. If I don't specify a frame then I get errors and when I fill in 0 for the 2 frames I just don't get any results at all. Nothing happens in game at all. What am I doing wrong? HELP! :) |
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| In regular blitz you'd get an error 'not enough parameters' if you didn't specify a frame with imagescollide. This works in Bmax... Graphics 640,480 image1:TImage=CreateImage(128,128) image2:Timage=CreateImage(128,128) SetColor 255,0,0 DrawRect 0,0,128,128 GrabImage(image1,0,0) Cls SetColor 0,0,255 DrawOval (0,0,128,128) GrabImage(image2,0,0) SetColor 255,255,255 While Not KeyHit(key_escape) Cls DrawImage image1,100,100 DrawImage image2,MouseX(),MouseY() If ImagesCollide(image1,100,100,0,image2,MouseX(),MouseY(),0) DrawText "Collided",0,0 Flip Wend End Can you show some code? <edited to include generated images> |
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| hi ; yap this works but i must check allframes from a image if i dont know which frame is plotted ... hmm need a better (faster way) ... |
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| For a fast version, will hopefully document soon, there is some source here: http://www.blitzbasic.com/logs/userlog.php?user=5&log=491 It is not the simplest method to do fast collisions which would be to call CollideImage with every DrawImage to build a collision map of the scene while you're rendering it. The game's update loop can then collide everything quickly with the collision maps created in the previous flip. |
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| I might be missing something here. Why would you have to check all frames from an image? If you're displaying an image with multiple frames then you'd have to use something like a 'curframe' variable to display the frame you want... wouldn't you? This is the frame you check the collisions with. As in BB, for multiple enemies, couldn't you check collisions for all enemies on a list by looping? Having said that I haven't really checked collision layers much yet. |
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| This *really* needs documenting properly. I'm pretty sure I know what it's doing and I've got it working in a simple example but aproperly documented example would be a great help. |
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| I agree... more documentation on the subject (if possible, some illustrations would be nice too) is needed... |
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| Realise this is an old thread, but I'm damned if I can get ImagesCollide to return anything other than 0. The documentation appears to be as useless as it was eight months ago when this thread was started. :/ If ImagesCollide(imgMouse,MouseX(),MouseY(),0,tiles,xstart,ystart,0) DrawText "Collided!",0,0 EndIf Why doesn't this work??? |
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| It looks like it should work accoring to the docs. I haven't used that one yet; been using CollideImage instead which DOES work. Try making a mini app and post an example for us to test. Or just force a collision by changing your mouseX and Y and startX and Y to 0 and making 100% sure there is some graphics at the same position in your tiles image. |
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| I found CollideImage but the documentation doesn't make any sense. What's a collision layer??? How do I use the Writemask and Collisionmask parameters? Come on, who wrote this nonsense?? I'm starting to despise Blitzmax. :/ |
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| CollideImage writes the image to a layer (you have 16 of them). To which layer an image is written, is defined through the writemask. If you want to check if an image collides with anything, you do that basing on the layers as well. But this time you have to write the needed layer flag to the collision mask. Quite simple :-) Don't forget to call resetcollisions after you check all collisions. |
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| Heheh, man those were the days, 8 months ago too! I never did quite figure why ImagesCollide didn't work. In the end I gave up and since then have been using my own bounding box and circle collision code that I wrote ever since. If that's making you pull your hair out then you should have a tinker with drawrect and then try to resist not making a '4 line inside a function' MyDrawRect function ;) > I'm starting to despise Blitzmax. :/ Don't despair Dave! It sorta gets better later, I've had 12 months of crazy Blitzmax things to deal with. Besides, just wait until you start putting sound in your game..... |
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| @Gfk, Does that example I posted with ImagesCollide work? If it does then post your code and somebody will see what's happening. There are lots of good examples on how collideimage is used hidden away. Shame some of them couldn't have been used in the doc. e.g. Collideimage1 Wiki Collideimage entry Collideimage wrapper Extra doc which doesn't seem to have made it |
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| The thing with the CollideImage is to look very carefully at the flags in the help example. The first call "Writes" to layer 1 and the second call "Checks" the specified object against layer 1. It's quite cool in a way actually. |
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| Well, I think the original problem was something to do with the image I was using. I re-exported it from Photoshop, and everything works fine now. I've since bumped into a mouse lag problem, which after a dig through the forums I've managed to work around (GrabPixmap), but that REALLY needs fixed. :/ I still maintain that the documentation is hopelessly vague in places, though. |
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Gfk: This is the best mouse fix problem, by Indiepath, add straight after Flip:Function FlushGraphics:Int() ?Win32 If TD3D7Max2DDriver(_max2dDriver) Local sdesc:DDSurfaceDesc2 = New DDSurfaceDesc2 sdesc.dwSize = SizeOf(sdesc) Local res:Int = PrimaryDevice.backbuffer.Lock(Null,sdesc,DDLOCK_WAIT|DDLOCK_READONLY,Null) PrimaryDevice.backbuffer.unlock(Null) Return res EndIf ? End Function |
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| Thanks - beaker suggested exactly that fix at about 2am this morning but I didn't get chance to try it til just now. Hope this gets fixed 'officially' in the next update anyway. :) |
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| Me too :) |
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| Me Three and a few more things too like the vertical tearing in Windowed Mode and the sound channel bugs. |
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| and proper streaming music audio. |
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| How about audio that doesn't crackle on 98? |
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| I was actually considering start a thread call High Priority Bugs that we could post proper big known bugs that really affect us all as opposed to tiny bugs that aren't much of an issue right now... |
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| A proper media library would already be good enough ... loading times like hell for OGG is a serious problem. |
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| I've started a "Major Requests" thread http://www.blitzbasic.com/Community/posts.php?topic=59005 Be cool if people added stuff there, like streaming oggs. |
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| I had this problem. But have solved it now. I don't know why it doesn't just let you specify: If Sprite Collision 1,2 Else Endif But for some reason were defining Images and not sprites. Pain in the Arse. If anyone is still confused it is thus: If ImagesCollide(YOUR_IMAGE_A_NAME,YOUR_IMAGE_A_XPOS,YOUR_IMAGE_A_YPOS,0,YOUR_IMAGE_B_NAME,YOUR_IMAGE_B_XPOS+WIDTH OF IMAGE,YOUR_IMAGE_B_YPOS+HEIGHT OF IMAGE,0) DrawText "Collided!",0,0 EndIf YOUR_IMAGE_A_NAME YOUR_IMAGE_A_XPOS=THE X POSITION ON THE SCREEN OF YOUR_IMAGE YOUR_IMAGE_A_YPOS=THE Y POSITION ON THE SCREEN OF YOUR_IMAGE 0 THEN YOUR_IMAGE_B_NAME YOUR_IMAGE_B'S X POSITION+WIDTH OF YOUR IMAGE YOUR_IMAGE_B'S Y POSITION+HEIGHT OF YOUR IMAGE Remember that the computer doesn't know you've got a sprite at the Mousex() and Mousey() positions! And that it is merely checking if the two have overlapped WITHIN THE BOX you have created with YOUR_IMAGE_A_XPOS,YOUR_IMAGE_A_YPOS and YOUR_IMAGE_B'S X POSITION+WIDTH OF IMAGE B YOUR_IMAGE_B'S Y POSITION+WIDTH OF IMAGE B Cheers V |
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