gistfile1.txt

thomas@thomas-pc:~/tmp$ w64-clang++ x.cpp -static-libgcc -Wall -Wextra -Wpedantic -O0 && ./a.out 
-0.00 -1.10    80002.00   -0.50
thomas@thomas-pc:~/tmp$ w64-clang++ x.cpp -static-libgcc -Wall -Wextra -Wpedantic -O3 && ./a.out 
-4.00 -2.70    80002.00   -0.50
thomas@thomas-pc:~/tmp$ cat x.cpp 
#include <math.h>
#include <stdlib.h>
#include <stdio.h>

float whscale = 2.0f;
float whoffset = 2.0f;

int wx1, wy1, wx2, wy2, wsize;

#define WATER_AMPLITUDE 0.4f
#define WATER_OFFSET 1.1f


static inline void vertw(float v1, float v2, float v3)
{
    (void)v3;
    float angle = (v1-wx1)*(v2-wy1)*(v1-wx2)*(v2-wy2)*whscale+whoffset;
    float s = angle - (int)(angle) - 0.5f;
    float x = s;
    s = s * (8.0f - (fabs(s)*16.0f));
    float h = WATER_AMPLITUDE*s-WATER_OFFSET;
    printf("%.2f %.2f    %.2f   %.2f\n", s, h, angle, x);
}

int main()
{
    float v1 = 10.0f, v2 = 20.0f, v3 = 30.0f;
    vertw(v1, v2, v3);
    return 0;
}