root
36 lines
1.3 KiB
ArmAsm
36 lines
1.3 KiB
ArmAsm
; PURSUE -- point the engine at the nearest asteroid and burn.
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; Crude: it makes no attempt to match velocity, so it will fly straight past.
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;
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.equ P_THROTTLE 0x20
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.equ P_AZIMUTH 0x21
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.equ P_PITCH 0x22
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.equ P_SELECT 0x30
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.equ P_NEAREST 0x31
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.equ P_RELX 0x32
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.equ P_RELY 0x33
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.equ P_RELZ 0x34
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.equ P_MATHX 0x80
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.equ P_MATHY 0x81
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.equ P_ATAN2 0x83
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.equ P_HYPOT 0x84
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in r1, P_NEAREST ; id of the nearest asteroid
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out P_SELECT, r1 ; track it
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ldi r7, 1000
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out P_THROTTLE, r7 ; full power
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aim: in r1, P_RELX ; where is it?
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in r2, P_RELY
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in r3, P_RELZ
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out P_MATHX, r1
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out P_MATHY, r2
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in r4, P_ATAN2 ; azimuth = atan2(dy, dx)
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out P_AZIMUTH, r4
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in r5, P_HYPOT ; horizontal range = hypot(dx, dy)
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out P_MATHX, r5
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out P_MATHY, r3
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in r6, P_ATAN2 ; elevation = atan2(dz, range)
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out P_PITCH, r6
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yield
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jmp aim
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