112 lines
5.9 KiB
C++
112 lines
5.9 KiB
C++
#include <array>
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#include "fasttrigon.h"
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namespace fasttrigon {
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static const std::array<int8_t, LUT_SIZE> LUT {
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0, 1, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9, 10, 11, 12, 12, 13, 14, 15, 16,
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16, 17, 18, 19, 19, 20, 21, 22, 22, 23, 24, 25, 26, 26, 27, 28, 29,
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29, 30, 31, 32, 32, 33, 34, 35, 35, 36, 37, 38, 38, 39, 40, 41, 41,
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42, 43, 44, 44, 45, 46, 46, 47, 48, 49, 49, 50, 51, 51, 52, 53, 54,
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54, 55, 56, 56, 57, 58, 58, 59, 60, 61, 61, 62, 63, 63, 64, 65, 65,
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66, 67, 67, 68, 69, 69, 70, 71, 71, 72, 72, 73, 74, 74, 75, 76, 76,
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77, 78, 78, 79, 79, 80, 81, 81, 82, 82, 83, 84, 84, 85, 85, 86, 86,
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87, 88, 88, 89, 89, 90, 90, 91, 91, 92, 93, 93, 94, 94, 95, 95, 96,
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96, 97, 97, 98, 98, 99, 99, 100, 100, 101, 101, 102, 102, 102, 103,
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103, 104, 104, 105, 105, 106, 106, 106, 107, 107, 108, 108, 109, 109,
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109, 110, 110, 111, 111, 111, 112, 112, 112, 113, 113, 113, 114, 114,
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114, 115, 115, 115, 116, 116, 116, 117, 117, 117, 118, 118, 118, 118,
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119, 119, 119, 120, 120, 120, 120, 121, 121, 121, 121, 122, 122, 122,
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122, 122, 123, 123, 123, 123, 123, 124, 124, 124, 124, 124, 124, 125,
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125, 125, 125, 125, 125, 125, 126, 126, 126, 126, 126, 126, 126, 126,
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126, 126, 126, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
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127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
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127, 127, 127, 127, 126, 126, 126, 126, 126, 126, 126, 126, 126, 126,
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126, 125, 125, 125, 125, 125, 125, 125, 124, 124, 124, 124, 124, 124,
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123, 123, 123, 123, 123, 122, 122, 122, 122, 122, 121, 121, 121, 121,
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120, 120, 120, 120, 119, 119, 119, 118, 118, 118, 118, 117, 117, 117,
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116, 116, 116, 115, 115, 115, 114, 114, 114, 113, 113, 113, 112, 112,
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112, 111, 111, 111, 110, 110, 109, 109, 109, 108, 108, 107, 107, 106,
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106, 106, 105, 105, 104, 104, 103, 103, 102, 102, 102, 101, 101, 100,
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100, 99, 99, 98, 98, 97, 97, 96, 96, 95, 95, 94, 94, 93, 93, 92, 91,
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91, 90, 90, 89, 89, 88, 88, 87, 86, 86, 85, 85, 84, 84, 83, 82, 82,
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81, 81, 80, 79, 79, 78, 78, 77, 76, 76, 75, 74, 74, 73, 72, 72, 71,
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71, 70, 69, 69, 68, 67, 67, 66, 65, 65, 64, 63, 63, 62, 61, 61, 60,
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59, 58, 58, 57, 56, 56, 55, 54, 54, 53, 52, 51, 51, 50, 49, 49, 48,
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47, 46, 46, 45, 44, 44, 43, 42, 41, 41, 40, 39, 38, 38, 37, 36, 35,
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35, 34, 33, 32, 32, 31, 30, 29, 29, 28, 27, 26, 26, 25, 24, 23, 22,
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22, 21, 20, 19, 19, 18, 17, 16, 16, 15, 14, 13, 12, 12, 11, 10, 9, 9,
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8, 7, 6, 5, 5, 4, 3, 2, 2, 1, 0, -1, -2, -2, -3, -4, -5, -5, -6, -7,
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-8, -9, -9, -10, -11, -12, -12, -13, -14, -15, -16, -16, -17, -18,
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-19, -19, -20, -21, -22, -22, -23, -24, -25, -26, -26, -27, -28, -29,
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-29, -30, -31, -32, -32, -33, -34, -35, -35, -36, -37, -38, -38, -39,
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-40, -41, -41, -42, -43, -44, -44, -45, -46, -46, -47, -48, -49, -49,
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-50, -51, -51, -52, -53, -54, -54, -55, -56, -56, -57, -58, -58, -59,
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-60, -61, -61, -62, -63, -63, -64, -65, -65, -66, -67, -67, -68, -69,
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-69, -70, -71, -71, -72, -72, -73, -74, -74, -75, -76, -76, -77, -78,
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-78, -79, -79, -80, -81, -81, -82, -82, -83, -84, -84, -85, -85, -86,
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-86, -87, -88, -88, -89, -89, -90, -90, -91, -91, -92, -93, -93, -94,
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-94, -95, -95, -96, -96, -97, -97, -98, -98, -99, -99, -100, -100,
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-101, -101, -102, -102, -102, -103, -103, -104, -104, -105, -105,
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-106, -106, -106, -107, -107, -108, -108, -109, -109, -109, -110,
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-110, -111, -111, -111, -112, -112, -112, -113, -113, -113, -114,
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-114, -114, -115, -115, -115, -116, -116, -116, -117, -117, -117,
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-118, -118, -118, -118, -119, -119, -119, -120, -120, -120, -120,
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-121, -121, -121, -121, -122, -122, -122, -122, -122, -123, -123,
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-123, -123, -123, -124, -124, -124, -124, -124, -124, -125, -125,
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-125, -125, -125, -125, -125, -126, -126, -126, -126, -126, -126,
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-126, -126, -126, -126, -126, -127, -127, -127, -127, -127, -127,
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-127, -127, -127, -127, -127, -127, -127, -127, -127, -127, -127,
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-127, -127, -127, -127, -127, -127, -127, -127, -127, -127, -127,
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-127, -126, -126, -126, -126, -126, -126, -126, -126, -126, -126,
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-126, -125, -125, -125, -125, -125, -125, -125, -124, -124, -124,
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-124, -124, -124, -123, -123, -123, -123, -123, -122, -122, -122,
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-122, -122, -121, -121, -121, -121, -120, -120, -120, -120, -119,
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-119, -119, -118, -118, -118, -118, -117, -117, -117, -116, -116,
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-116, -115, -115, -115, -114, -114, -114, -113, -113, -113, -112,
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-112, -112, -111, -111, -111, -110, -110, -109, -109, -109, -108,
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-108, -107, -107, -106, -106, -106, -105, -105, -104, -104, -103,
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-103, -102, -102, -102, -101, -101, -100, -100, -99, -99, -98, -98,
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-97, -97, -96, -96, -95, -95, -94, -94, -93, -93, -92, -91, -91, -90,
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-90, -89, -89, -88, -88, -87, -86, -86, -85, -85, -84, -84, -83, -82,
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-82, -81, -81, -80, -79, -79, -78, -78, -77, -76, -76, -75, -74, -74,
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-73, -72, -72, -71, -71, -70, -69, -69, -68, -67, -67, -66, -65, -65,
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-64, -63, -63, -62, -61, -61, -60, -59, -58, -58, -57, -56, -56, -55,
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-54, -54, -53, -52, -51, -51, -50, -49, -49, -48, -47, -46, -46, -45,
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-44, -44, -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -35, -35,
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-34, -33, -32, -32, -31, -30, -29, -29, -28, -27, -26, -26, -25, -24,
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-23, -22, -22, -21, -20, -19, -19, -18, -17, -16, -16, -15, -14, -13,
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-12, -12, -11, -10, -9, -9, -8, -7, -6, -5, -5, -4, -3, -2, -2, -1
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};
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int32_t fastsin(int32_t arg)
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{
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bool neg = arg < 0;
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uint32_t idx;
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if(neg) {
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idx = (-arg) % LUT_SIZE;
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return -LUT[idx];
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} else {
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idx = arg % LUT_SIZE;
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return LUT[idx];
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}
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}
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int32_t fastcos(int32_t arg)
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{
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return fastsin(arg + LUT_SIZE/4);
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}
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int32_t fasttan(int32_t arg)
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{
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int32_t denom = fastcos(arg);
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if(denom == 0) {
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return 0x7FFFFFFF;
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}
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int32_t numer = fastsin(arg);
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return numer * 127 / denom;
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}
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}
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