50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
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#ifndef __MATH16_H__
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#define __MATH16_H__
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#ifdef __cplusplus
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extern "C" {
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#endif
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#define SHFTBITS 16
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#define LOWMASK ((1 << SHFTBITS)-1)
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#define HGHMASK (~LOWMASK)
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#define LOWBITS(x) ((x) & LOWMASK)
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#define HGHBITS(x) ((x) & HGHMASK)
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#define LSHFT(x) ((x) << SHFTBITS)
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#define RSHFT(x) ((x) >> SHFTBITS)
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#define PI (3373259427 >> (30-SHFTBITS))
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#define TWOPI (PI << 1)
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#define PIOVER2 (PI >> 1)
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#define Need(dw) (dw & 0xFF000000 ? 32 : (dw & 0x00FF0000 ? 24 : (dw & 0x0000FF00 ? 16 : 8)))
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int Div16(int iX,int iY);
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int Sigmoid16(int iX);
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// Greg's multiplication algorithm:
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typedef struct {
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unsigned short frac;
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short whole;
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} FIX1616, *PFIX1616;
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#define Mul16(a,b,c) { \
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int i1, i2; \
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FIX1616 fix1, fix2; \
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i1=(a); \
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i2=(b); \
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fix1 = *(PFIX1616)&i1; \
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fix2 = *(PFIX1616)&i2; \
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c = (unsigned int)(fix1.frac*fix2.frac) >> 16; \
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c += fix1.frac*fix2.whole + fix1.whole*fix2.frac; \
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c += (fix1.whole*fix2.whole) << 16; \
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}
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#ifdef __cplusplus
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}
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#endif
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#endif // __MATH16_H__
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