C语言画各种圣诞树

时间：03-25来源：作者：点击数：81

C语言画各种圣诞树

普通圣诞树

#include <stdlib.h>
 
int main(int argc, char* argv[]) {
    int n = argc > 1 ? atoi(argv[1]) : 4;
    for (int j = 1; j <= n; j++) {
        int s = 1 << j, k = (1 << n) - s, x;
        for (int y = s - j; y >= 0; y--, putchar('\n')) {
            for (x = 0; x < y + k; x++) printf(" ");
            for (x = 0; x + y < s; x++) printf("%c ", '!' ^ y & x);
            for (x = 1; x + y < s; x++) printf("%c ", '!' ^ y & (s - y - x - 1));
        }
    }
}

加上树干

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
 
#define PI 3.14159265359
 
float sx, sy;
 
float sdCircle(float px, float py, float r) {
  float dx = px - sx, dy = py - sy;
  return sqrtf(dx * dx + dy * dy) - r;
}
 
float opUnion(float d1, float d2) {
  return d1 < d2 ? d1 : d2;
}
 
#define T px + scale * r * cosf(theta), py + scale * r * sin(theta)
 
float f(float px, float py, float theta, float scale, int n) {
  float d = 0.0f;
  for (float r = 0.0f; r < 0.8f; r += 0.02f)
    d = opUnion(d, sdCircle(T, 0.05f * scale * (0.95f - r)));
 
  if (n > 0)
    for (int t = -1; t <= 1; t += 2) {
      float tt = theta + t * 1.8f;
      float ss = scale * 0.9f;
      for (float r = 0.2f; r < 0.8f; r += 0.1f) {
        d = opUnion(d, f(T, tt, ss * 0.5f, n - 1));
        ss *= 0.8f;
      }
    }
 
  return d;
}
 
int main(int argc, char* argv[]) {
  int n = argc > 1 ? atoi(argv[1]) : 3;
  for (sy = 0.8f; sy > 0.0f; sy -= 0.02f, putchar('\n'))
    for (sx = -0.35f; sx < 0.35f; sx += 0.01f)
      putchar(f(0, 0, PI * 0.5f, 1.0f, n) < 0 ? '*' : ' ');
}

加上装饰和丝带

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

int ribbon() {
  float x = (fmodf(sy, 0.1f) / 0.1f - 0.5f) * 0.5f;
  return sx >= x - 0.05f && sx <= x + 0.05f;
}
 
int main(int argc, char* argv[]) {
  int n = argc > 1 ? atoi(argv[1]) : 3;
  float zoom = argc > 2 ? atof(argv[2]) : 1.0f;
  for (sy = 0.8f; sy > 0.0f; sy -= 0.02f / zoom, putchar('\n'))
    for (sx = -0.35f; sx < 0.35f; sx += 0.01f / zoom) {
      if (f(0, 0, PI * 0.5f, 1.0f, n) < 0.0f) {
        if (sy < 0.1f)
          putchar('.');
        else {
          if (ribbon())
            putchar('=');
          else
            putchar("............................#j&o"[rand() % 32]);
        }
      }
      else
        putchar(' ');
    }
}

3D版圣诞树

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#define PI 3.14159265359f
 
float sx, sy;
 
typedef float Mat[4][4];
typedef float Vec[4];
 
void scale(Mat* m, float s) {
  Mat temp = { {s,0,0,0}, {0,s,0,0 }, { 0,0,s,0 }, { 0,0,0,1 } };
  memcpy(m, &temp, sizeof(Mat));
}
 
void rotateY(Mat* m, float t) {
  float c = cosf(t), s = sinf(t);
  Mat temp = { {c,0,s,0}, {0,1,0,0}, {-s,0,c,0}, {0,0,0,1} };
  memcpy(m, &temp, sizeof(Mat));
}
 
void rotateZ(Mat* m, float t) {
  float c = cosf(t), s = sinf(t);
  Mat temp = { {c,-s,0,0}, {s,c,0,0}, {0,0,1,0}, {0,0,0,1} };
  memcpy(m, &temp, sizeof(Mat));
}
 
void translate(Mat* m, float x, float y, float z) {
  Mat temp = { {1,0,0,x}, {0,1,0,y}, {0,0,1,z}, {0,0,0,1} };
  memcpy(m, &temp, sizeof(Mat));
}
 
void mul(Mat* m, Mat a, Mat b) {
  Mat temp;
  for (int j = 0; j < 4; j++)
    for (int i = 0; i < 4; i++) {
      temp[j][i] = 0.0f;
      for (int k = 0; k < 4; k++)
        temp[j][i] += a[j][k] * b[k][i];
    }
  memcpy(m, &temp, sizeof(Mat)); 
}
 
void transformPosition(Vec* r, Mat m, Vec v) {
  Vec temp = { 0, 0, 0, 0 };
  for (int j = 0; j < 4; j++)
    for (int i = 0; i < 4; i++)
      temp[j] += m[j][i] * v[i];
  memcpy(r, &temp, sizeof(Vec)); 
}
 
float transformLength(Mat m, float r) {
  return sqrtf(m[0][0] * m[0][0] + m[0][1] * m[0][1] + m[0][2] * m[0][2]) * r;
}
 
float sphere(Vec c, float r) {
  float dx = c[0] - sx, dy = c[1] - sy;
  float a = dx * dx + dy * dy;
  return a < r * r ? sqrtf(r * r - a) + c[2] : -1.0f;
}
 
float opUnion(float z1, float z2) {
  return z1 > z2 ? z1 : z2;
}
 
float f(Mat m, int n) {
  float z = -1.0f;
  for (float r = 0.0f; r < 0.8f; r += 0.02f) {
    Vec v = { 0.0f, r, 0.0f, 1.0f };
    transformPosition(&v, m, v);
    z = opUnion(z, sphere(v, transformLength(m, 0.05f * (0.95f - r))));
  }
 
  if (n > 0) {
    Mat ry, rz, s, t, m2, m3;
    rotateZ(&rz, 1.8f);
 
    for (int p = 0; p < 6; p++) {
      rotateY(&ry, p * (2 * PI / 6));
      mul(&m2, ry, rz);
      float ss = 0.45f;
      for (float r = 0.2f; r < 0.8f; r += 0.1f) {
        scale(&s, ss);
        translate(&t, 0.0f, r, 0.0f);
        mul(&m3, s, m2);
        mul(&m3, t, m3);
        mul(&m3, m, m3);
        z = opUnion(z, f(m3, n - 1));
        ss *= 0.8f;
      }
    }
  }
 
  return z;
}
 
float f0(float x, float y, int n) {
  sx = x;
  sy = y;
  Mat m;
  scale(&m, 1.0f);
  return f(m, n);
}
 
int main(int argc, char* argv[]) {
  int n = argc > 1 ? atoi(argv[1]) : 3;
  float zoom = argc > 2 ? atof(argv[2]) : 1.0f;
  for (float y = 0.8f; y > -0.0f; y -= 0.02f / zoom, putchar('\n'))
    for (float x = -0.35f; x < 0.35f; x += 0.01f / zoom) {
      float z = f0(x, y, n);
      if (z > -1.0f) {
        float nz = 0.001f;
        float nx = f0(x + nz, y, n) - z;
        float ny = f0(x, y + nz, n) - z;
        float nd = sqrtf(nx * nx + ny * ny + nz * nz);
        float d = (nx - ny + nz) / sqrtf(3) / nd;
        d = d > 0.0f ? d : 0.0f;
        // d = d < 1.0f ? d : 1.0f;
        putchar(".-:=+*#%@@"[(int)(d * 9.0f)]);
      }
      else
        putchar(' ');
    }
}

更新

float f(Mat m, int n) {
  // Culling
  {
    Vec v = { 0.0f, 0.5f, 0.0f, 1.0f };
    transformPosition(&v, m, v);   
    if (sphere(v, transformLength(m, 0.55f)) == -1.0f)
      return -1.0f;
  }
 
  float z = -1.0f;
 
  if (n == 0) { // Leaf
    Vec v = { 0.0f, 0.5f, 0.0f, 1.0f };
    transformPosition(&v, m, v);   
    z = sphere(v, transformLength(m, 0.3f));
  }
  else { // Branch
    for (float r = 0.0f; r < 0.8f; r += 0.02f) {
      Vec v = { 0.0f, r, 0.0f, 1.0f };
      transformPosition(&v, m, v);
      z = opUnion(z, sphere(v, transformLength(m, 0.05f * (0.95f - r))));
    }
  }
 
  // ...
}