19 lines
665 B
Z80 Assembly
19 lines
665 B
Z80 Assembly
TV_Static_FX:
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;this code runs every time the game boy finishes drawing one row of pixels, unless the interrupt is disabled as described above.
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push hl
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push af
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ld hl,(COSINE_INDEX)
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inc (hl)
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ld a,(hl)
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callpoint:
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call cos ;<--- SMC, gets changed to "CALL SIN" by main game loop when bit 4 of frametimer equals 0, and back to
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;"CALL COS" when bit 4 of frametimer equals 1.
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; returns cos(A) into A
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LD (&FF43),A ;output cos(frametimer) to horizontal scroll register
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done_TV_Static_FX:
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pop af
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pop hl
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reti ;return to main program
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TV_Static_FX_End:
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