47 lines
1.1 KiB
C
47 lines
1.1 KiB
C
// Fixed-point math can be useful where e.g. smooth movement is desired, but
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// using float would make the application too slow and big.
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// cvu_f is a 10.6 fixed point type. 10.6 has been chosen to ensure that the
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// type can represent coordinates on the ColecoVision screen and in some
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// "buffer" space surrounding it (to allow calculation of e.g. reflection).
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#ifndef CVU_F_H
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#define CVU_F_H 1
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#include <stdint.h>
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#include <limits.h>
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typedef int16_t cvu_f; // 10.6 fixed-point type.
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#define CVU_F_R 6
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#define CVU_F_PI 201
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#define CVU_F_PI_2 100
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#define CVU_F_SQRT2 90
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#define CVU_F_SQRT1_2 45
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#define CVU_F_MIN INT16_MIN
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#define CVU_F_MAX INT16_MAX
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// Convert integer to fixed-point
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#define CVU_F2I(l) ((l) >> CVU_F_R)
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// Convert fixed-point to integer
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#define CVU_I2F(l) ((l) << CVU_F_R)
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// Fixed-point multiplication
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extern cvu_f cvu_fmul2(cvu_f l, cvu_f r);
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// Fixed-point division
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extern cvu_f cvu_fdiv2(cvu_f l, cvu_f r);
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// Fixed-point sine
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extern cvu_f cvu_fsin(cvu_f x);
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// Fixed-point cosine
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extern cvu_f cvu_fcos(cvu_f x);
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// Fixed-point arcus tangens of x / y.
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extern cvu_f cvu_fatan2(cvu_f y, cvu_f x);
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#endif
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