Create sine lookup table in C++

Question

How can I rewrite the following pseudocode in C++?

real array sine_table[-1000..1000]
    for x from -1000 to 1000
        sine_table[x] := sine(pi * x / 100         


        

Answer 1

another approximation from a book or something

streamin ramp;
streamout sine;

float x,rect,k,i,j;

x = ramp -0.5;

rect = x * (1 - x < 0 & 2);
k = (rect + 0.42493299) *(rect -0.5) * (rect - 0.92493302) ;
i = 0.436501 + (rect * (rect + 1.05802));
j = 1.21551 + (rect * (rect - 2.0580201));
sine = i*j*k*60.252201*x;

full discussion here: http://synthmaker.co.uk/forum/viewtopic.php?f=4&t=6457&st=0&sk=t&sd=a

I presume that you know, that using a division is a lot slower than multiplying by decimal number, /5 is always slower than *0.2

it's just an approximation.

also:

streamin ramp;
streamin x;  // 1.5 = Saw   3.142 = Sin   4.5 = SawSin
streamout sine;
float saw,saw2;
saw = (ramp * 2 - 1) * x;
saw2 = saw * saw;

sine = -0.166667 + saw2 * (0.00833333 + saw2 * (-0.000198409 + saw2 * (2.7526e-006+saw2 * -2.39e-008)));
sine = saw * (1+ saw2 * sine);