implemented bezier interpolation into parameters inputs

2019-12-28 23:21:07 +11:00
parent 1d3d52db9b
commit 994d8be961
9 changed files with 157 additions and 11 deletions
@@ -0,0 +1,42 @@
+#include "bezier.h"
+
+#include <QtMath>
+
+double Bezier::QuadraticXtoT(double x, double a, double b, double c)
+{
+  return (a - b + qSqrt(a*x + c*x - 2*b*x + qPow(b, 2) - a*c))/(a - 2*b + c);
+}
+
+double Bezier::QuadraticTtoY(double a, double b, double c, double t)
+{
+  return qPow(1.0 - t, 2)*a + 2*(1.0 - t)*t*b + qPow(t, 2)*c;
+}
+
+double Bezier::CubicXtoT(double x_target, double a, double b, double c, double d)
+{
+  double tolerance = 0.0001;
+
+  double lower = 0.0;
+  double upper = 1.0;
+
+  double percent = 0.5;
+  double x = CubicTtoY(a, b, c, d, percent);
+
+  while (qAbs(x_target - x) > tolerance) {
+    if (x_target > x) {
+      lower = percent;
+    } else {
+      upper = percent;
+    }
+
+    percent = (upper + lower) / 2.0;
+    x = CubicTtoY(a, b, c, d, percent);
+  }
+
+  return percent;
+}
+
+double Bezier::CubicTtoY(double a, double b, double c, double d, double t)
+{
+  return qPow(1.0 - t, 3)*a + 3*qPow(1.0 - t, 2)*t*b + 3*(1.0 - t)*qPow(t, 2)*c + qPow(t, 3)*d;
+}