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 03172013, 02:15 AM #1Member
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 03172013, 03:16 AM #2Senior Member
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Re: Rendering 16x16 tiles, confused with the math behind it.
Java Code:public final int MAP_SIZE = 64; public final int MAP_SIZE_MASK = MAP_SIZE  1; ... int tileIndex = ((xx >> 4) & MAP_SIZE_MASK) + ((yy >> 4) & MAP_SIZE_MASK) * MAP_SIZE; pixels[x + y * width] = tiles[tileIndex];
For every bit you shift right, you are dividing by 2.
For every bit you shift left, you are multiplying by 2.
the & is a bitwise AND operation and the  (veritical bar) is a bitwise OR. In this case the former is to zero out unwanted Higher Order Bits.
so the tileIndex = xx/16 + (yy/16) * MAP_SIZE
Using bit manipulation sometimes makes things clearer. Here, the code author used mixed methods.
I recommend checking the web for binary or bit operations for a more in depth understanding of the subject.
Regards,
JimThe Java™ Tutorial  SSCCE  Java Naming Conventions
Poor planning our your part does not constitute an emergency on my part.
 03172013, 04:00 AM #3
Re: Rendering 16x16 tiles, confused with the math behind it.
If you're forever cleaning cobwebs, it's time to get rid of the spiders.
 03172013, 04:02 AM #4
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