#include
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) return y;
return 0.0f;
}
int main() {
for (float z = 1.5f; z > -1.5f; z -= 0.05f) {
for (float x = -1.5f; x < > float v = f(x, 0.0f, z);
if (v float y0 = h(x, z);
float ny = 0.01f;
float nx = h(x + ny, z) - y0;
float nz = h(x, z + ny) - y0;
float nd = 1.0f / sqrtf(nx * nx + ny * ny + nz * nz);
float d = (nx + ny - nz) * nd * 0.5f + 0.5f;
putchar(".:-=+*#%@"[(int)(d * 5.0f)]);
}
else
putchar(' ');
}
putchar('\n');
}
}
