Determing FPS within another FPS .. How?

[TerryRitchie]

I believe DSMan has solved the riddle of how the programmers did it. I started writing patterns down to see if I could store the frame counters into integers and lo and behold this pattern emerged:

Code: (Select All)

123456789012345678901234567890123456789012345678901234567890
------------------------------------------------------------
1  1 1  1 1  1 1  1 1  1 1  1 1  1 1  1 1  1 1  1 1  1 1  1   -24FPS(40%)  10010100101001010010 = 608850  = 94A52
1 1 1  1 1 1  1 1 1 1 1 1  1 1 1  1 1 1 1 1 1  1 1 1  1 1 1   -27FPS(45%)  10101001010100101010 = 693546  = A952A
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1   -30FPS(50%)  10101010101010101010 = 699050  = AAAAA
1 1 11 1 1 1 11 1 1 1 1 11 1 1 1 11 1 1 1 1 11 1 1 1 11 1 1   -33FPS(55%)  10101101010101101010 = 709994  = AD56A
11 1 1 11 11 1 1 11 11 1 1 11 11 1 1 11 11 1 1 11 11 1 1 11   -36FPS(60%)  11010101101101010110 = 875350  = D5B56
11 11 11 1 11 11 11 11 11 11 1 11 11 11 11 11 11 1 11 11 11   -39FPS(65%)  11011011010110110110 = 898486  = DB5B6
11 111 11 11 111 11 11 111 11 11 111 11 11 111 11 11 111 11   -42FPS(70%)  11011101101101110110 = 908150  = DDB76
111 111 111 111 111 111 111 111 111 111 111 111 111 111 111   -45FPS(75%)  11101110111011101110 = 978670  = EEEEE
1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111   -48FPS(80%)  11110111101111011110 = 1014750 = F7BDE
111111 11111 111111 111111 11111 111111 111111 11111 111111   -51FPS(85%)  11111101111101111110 = 1040254 = FDF7E
111111111 111111111 111111111 111111111 111111111 111111111   -54FPS(90%)  11111111101111111110 = 1047550 = FFBFE
1111111111111111111 1111111111111111111 1111111111111111111   -57FPS(95%)  11111111111111111110 = 1048574 = FFFFE
111111111111111111111111111111111111111111111111111111111111  -60FPS(100%) 11111111111111111111 = 1048575 = FFFFF

The patterns repeat three times over a 60 frame span meaning I can store the patterns in 20bit integers. Not sure how the Pac-Man coders got them into even smaller 16bit integers?


Now its a simple task of counting frames and ANDing the counter to the desired frame rate value. Easy peasy.

Thanks DSMan for your work and help with this.