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  1. #include <math.h>
  2. #include <stdio.h>
  3.  
  4. class SinCos
  5. {
  6. public:
  7.     SinCos()
  8.     {
  9.         double step = 6.28318530717958647692 / 4096.0f;
  10.         sinTable = new float[4099];
  11.         cosTable = new float[4099];
  12.         int index = 0;
  13.         for (double i = 0; i < 6.28318530717958647692; i += step)
  14.         {
  15.             sinTable[index] = sin(i);
  16.             cosTable[index] = cos(i);
  17.             index++;
  18.         }
  19.         maxIdx = index;
  20.     }
  21.  
  22.     float getSin(float val)
  23.     {
  24.         val = fmod(val, 6.28318530717958647692);
  25.         return sinTable[(int)(4096.0f * val / 6.28318530717958647692)];
  26.     }
  27.     float getCos(float val)
  28.     {
  29.         val = fmod(val, 6.28318530717958647692);
  30.         return cosTable[(int)(4096.0f * val / 6.28318530717958647692)];
  31.     }
  32.  
  33.     float maxSinDelta();
  34.     float maxCosDelta();
  35.  
  36.     float* sinTable;
  37.     float* cosTable;
  38.     int maxIdx;
  39. };
  40.  
  41. float SinCos::maxCosDelta()
  42. {
  43.     float maxval = 0;
  44.     for(int i = 0; i < maxIdx; ++i)
  45.     {
  46.         float delta = fabs(cosTable[i] - cosTable[(i+1)%maxIdx]);
  47.         if (maxval < delta) maxval = delta;
  48.     }
  49.     return maxval;
  50. }
  51.  
  52. float SinCos::maxSinDelta()
  53. {
  54.     float maxval = 0;
  55.     for(int i = 0; i < maxIdx; ++i)
  56.     {
  57.         float delta = fabs(sinTable[i] - sinTable[(i+1)%maxIdx]);
  58.         if (maxval < delta) maxval = delta;
  59.     }
  60.     return maxval;
  61. }
  62.  
  63.  
  64. int main()
  65. {
  66.     SinCos s;
  67.     printf("MaxDelte sin = %f, cos = %f\n", s.maxSinDelta(), s.maxCosDelta());
  68. }
  69.  
  70.  
Success #stdin #stdout 0s 3468KB
comments (?)
stdin 
Standard input is empty
stdout 
MaxDelte sin = 0.001534, cos = 0.001534
https://ideone.com/T4nigg
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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