Collision check with double For - Each
BlitzPlus Forums/BlitzPlus Programming/Collision check with double For - Each
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| Hello, I try to made a new Version from comet busters 1994, because it do not work on 64-bit-machine. But I have a little Problem in understannding the For-Each in my code every "circle" had to check if it collide with a other one. But x2,y2 and r2 gets every loop the same value like x1,y2 and r1? For c.circle = Each circle ;define values for Circle1 x1 = c\pos_x y1 = c\pos_y r1 = c\radius For c2.circle = Each circle ;define values for Circle2 x2 = c2\pos_x y2 = c2\pos_y r2 = c2\radius ;calculate distance and sum of diameter r = r1+r2 dist_x = x2-x1 dist_y = y2-y1 dist = Sqr((dist_x*dist_x)+(dist_y*dist_y)) ;on collision If dist <= r ;Explosion(c2\pos_x, c2\pos_y, 4, 10, 0, 360, 4, 0, EndIf Next Next I hope someone can help me - thx =) |
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| Well one thing you need is to make sure that you don't end up comparing a circle to itself - since the inner loop also examines all circles, it will at some stage reach the same circle being described by the outer loop. This has the unfortunate effect that every circle will collide with itself, and explode immediately. To correct this, just place everything within the c2 loop inside an If block with 'c <> c2' as the condition check. That should help. |
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| Here's an example of working with two list items, but checking each pair just once. In the example t1 always precedes t2 in the list. Type thing Field n End Type Local t1.thing, t2.thing For k = 1 To 4 t1 = New thing t1\n = k Next t1 = First thing While t1 <> Null t2 = After t1 While t2 <> Null Print "Check things " + t1\n + " and " + t2\n t2 = After t2 Wend t1 = After t1 Wend WaitKey |
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| That is amazing. I'm coding some stuff as hobby. Since school on the Casio GTX. I coded something like this very often. But never efficient like this. I needed a sheet of paper with lots of arrows on it to understand how it works. Thank you very much! Is the greatest thing to learn something by understanding it. Best Regards from Germany |
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