会跳动的心

#include <stdio.h>
#include <math.h>
#include <windows.h>
#include <tchar.h>

float f(float x, float y, float z)
{
    float a = x * x + 9.0f / 4.0f * y * y + z *z - 1;
    return a * a * a - x * x * z * z * z - 9.0f/ 80.0f * y * y * z * z * z;
}

float h(float x, float z)
{
    for (float y = 1.0f; y >= 0.0f; y -=0.001f)
        if (f(x, y, z) <= 0.0f)
            return y;
    return 0.0f;
}

int main()
{
    HANDLE o = GetStdHandle(STD_OUTPUT_HANDLE);
    _TCHAR buffer[25][80] = { _T(' ') };
    _TCHAR ramp[] = _T(".:-=+*#%@");

    for (float t = 0.0f;; t += 0.1f)
    {
        int sy = 0;
        float s = sinf(t);
        float a = s * s * s * s * 0.2f;
        for (float z = 1.3f; z > -1.2f; z -=0.1f)
        {
            _TCHAR* p = &buffer[sy++][0];
            float tz = z * (1.2f - a);
            for (float x = -1.5f; x < 1.5f; x +=0.05f)
            {
                float tx = x * (1.2f + a);
                float v = f(tx, 0.0f, tz);
                if (v <= 0.0f)
                {
                    float y0 = h(tx, tz);
                    float ny = 0.01f;
                    float nx = h(tx + ny, tz) - y0;
                    float nz = h(tx, tz + ny) - y0;
                    float nd = 1.0f / sqrtf(nx * nx + ny * ny +nz * nz);
                    float d = (nx + ny - nz) * nd * 0.5f +0.5f;
                    *p++ = ramp[(int)(d * 5.0f)];
                }
                else
                    *p++ = ' ';
            }
        }

        for (sy = 0; sy < 25; sy++)
        {
            COORD coord = { 0, sy };
            SetConsoleCursorPosition(o, coord);
            WriteConsole(o, buffer[sy], 79, NULL, 0);
        }
        Sleep(33);
    }
}