[backend]将testdata/下的测例替换为了赛方测试用例，更新了测试脚本

testdata/h_functional/38_light2d.sy

@@ -0,0 +1,117 @@
+// reference: https://zhuanlan.zhihu.com/p/30748318
+
+const int W = 12, H = 12, N = 24;
+
+const float PI = 3.14159265359, TWO_PI = 6.28318530718;
+const int MAX_STEP = 10;
+const float MAX_DISTANCE = 2.0;
+const float EPSILON = 1e-6;
+
+const int RAND_MAX = 100000007 - 1;
+int seed = 0;
+
+int rand() {
+  seed = (seed * 19980130 + 23333) % 100000007;
+  if (seed < 0) seed = seed + 100000007;
+  return seed;
+}
+
+float my_fabs(float x) {
+  if (x > 0) return x;
+  return -x;
+}
+
+float my_sqrt(float x) {
+  float t = x / 8 + 0.5 + 2 * x / (4 + x);
+  int c = 10;
+  while (c) {
+    t = (t + x / t) / 2;
+    c = c - 1;
+  }
+  return t;
+}
+
+float p(float x) { return 3 * x - 4 * x * x * x; }
+
+float my_sin_impl(float x) {
+  if (my_fabs(x) <= EPSILON) return x;
+  return p(my_sin_impl(x / 3.0));
+}
+
+float my_sin(float x) {
+  if (x > TWO_PI || x < -TWO_PI) {
+    int xx = x / TWO_PI;
+    x = x - xx * TWO_PI;
+  }
+  if (x > PI) x = x - TWO_PI;
+  if (x < -PI) x = x + TWO_PI;
+  return my_sin_impl(x);
+}
+
+float my_cos(float x) { return my_sin(x + PI / 2); }
+
+float circle_sdf(float x, float y, float cx, float cy, float r) {
+  float ux = x - cx, uy = y - cy;
+  return my_sqrt(ux * ux + uy * uy) - r;
+}
+
+void scene(float x, float y, float ret[]) {
+  float sd0 = circle_sdf(x, y, 0.4, 0.4, 0.10),
+        sd1 = circle_sdf(x, y, 0.6, 0.6, 0.05);
+  if (sd0 < sd1) {
+    ret[0] = sd0;
+    ret[1] = 3.0;
+  } else {
+    ret[0] = sd1;
+    ret[1] = 0.0;
+  }
+}
+
+float trace(float ox, float oy, float dx, float dy) {
+  float t = 0.0;
+  int i = 0;
+  while (i < MAX_STEP && t < MAX_DISTANCE) {
+    float ret[2];
+    scene(ox + dx * t, oy + dy * t, ret);
+    if (ret[0] < EPSILON) return ret[1];
+    t = t + ret[0];
+    i = i + 1;
+  }
+  return 0.0;
+}
+
+float sample(float x, float y) {
+  float sum = 0.0;
+  int i = 0;
+  while (i < N) {
+    float rnd = rand();
+    float a = TWO_PI * (i + rnd / RAND_MAX) / N;
+    sum = sum + trace(x, y, my_cos(a), my_sin(a));
+    i = i + 1;
+  }
+  return sum / N;
+}
+
+void write_pgm() {
+  putch(80); putch(50); putch(10); // P2
+  putint(W); putch(32); putint(H); putch(32); putint(255); putch(10); // W H 255
+  int y = 0;
+  while (y < H) {
+    int x = 0;
+    while (x < W) {
+      float xx = x, yy = y;
+      int p = sample(xx / W, yy / H) * 255.0;
+      if (p > 255) p = 255;
+      putint(p);
+      putch(32);
+      x = x + 1;
+    }
+    putch(10);
+    y = y + 1;
+  }
+}
+
+int main() {
+  write_pgm();
+  return 0;
+}