- struct Faces {
- bool face[Block::FACE_COUNT];
- Faces &operator =(const Faces &other) noexcept {
- for (int i = 0; i < Block::FACE_COUNT; ++i) {
- face[i] = other.face[i];
- }
- return *this;
+ // generation properties
+ /// whether to use this block in generation at all
+ bool generate;
+
+ // min/mid/max points for the respective properties
+ // should all be in the (-1,1) range
+ class Distribution {
+
+ public:
+ Distribution(float min, float mid, float max)
+ : xmin(min), xmid(mid), xmax(max) { Update(); }
+
+ bool Valid(float x) const noexcept {
+ return x >= xmin && x <= xmax;
+ }
+ float Map(float x) const noexcept {
+ // previous algo as was used by Generator
+ //return 4.0f - ((x - xmid) * (x - xmid));
+
+ // linear mapping of [min,mid,max] to [-1,0,1]
+ x -= xmid;
+ x *= (x < 0) ? inv_neg : inv_pos;
+
+ // smoothing: x^4 - 2x^2 + 1
+ x *= x;
+ return x * x - 2.0f * x + 1.0f;