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 Author: Pokun [ Tue Sep 06, 2016 7:07 am ] Post subject: Calculate sprite coordinates on the nametable Let's say I want to draw a 8x8 sprite so that it exactly covers a 8x8 BG tile. Is there an easy way to calculate the X- and Y-coordinates of the sprite if I know the nametable address? The scroll register is 0.

 Author: tepples [ Tue Sep 06, 2016 7:34 am ] Post subject: Re: Calculate sprite coordinates on the nametable X coordinate: (((address << 3) & 0xF8) - camera_x) % 256Y coordinate: (((address >> 2) & 0xF8) - (camera_y + 1)) % 240A simplification is possible if your scroll position is (0, 0), as you mentioned:X coordinate: (address << 3) & 0xF8Y coordinate: ((address >> 2) & 0xF8) - 1Translation of these expressions from C to 6502 assembly code is an exercise for the reader.

 Author: Pokun [ Tue Sep 06, 2016 8:21 am ] Post subject: Re: Calculate sprite coordinates on the nametable Thanks a lot! These formulas works like a charm!

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