1 files changed, 73 insertions, 0 deletions
diff --git a/compat/slider.cpp b/compat/slider.cpp
new file mode 100644
index 00000000..be1aaeb8
--- /dev/null
+++ b/compat/slider.cpp
@@ -0,0 +1,73 @@
+#include "slider.hpp"
+#include <cmath>
+
+namespace options {
+
+slider_value::slider_value(double cur, double min, double max) :
+    cur_(cur),
+    min_(min),
+    max_(max)
+{
+    if (min_ > max_)
+        min_ = max_;
+    if (cur_ > max_)
+        cur_ = max;
+    if (cur_ < min_)
+        cur_ = min_;
+}
+
+slider_value::slider_value(const slider_value& v) : slider_value(v.cur(), v.min(), v.max())
+{
+}
+
+slider_value::slider_value() : slider_value(0, 0, 0)
+{
+}
+
+slider_value& slider_value::operator=(const slider_value& v)
+{
+    cur_ = v.cur_;
+
+    min_ = v.min_;
+    max_ = v.max_;
+
+    return *this;
+}
+
+bool slider_value::operator==(const slider_value& v) const
+{
+    using std::fabs;
+
+    static constexpr double eps = 1e-3;
+
+    return (fabs(v.cur_ - cur_) < eps &&
+            fabs(v.min_ - min_) < eps &&
+            fabs(v.max_ - max_) < eps);
+}
+
+slider_value slider_value::update_from_slider(int pos, int q_min, int q_max) const
+{
+    slider_value v(*this);
+
+    const int q_diff = q_max - q_min;
+    const double sv_pos = q_diff == 0
+                          ? -1e6
+                          : (((pos - q_min) * (v.max() - v.min())) / q_diff + v.min());
+
+    if (sv_pos < v.min())
+        v = slider_value(v.min(), v.min(), v.max());
+    else if (sv_pos > v.max())
+        v = slider_value(v.max(), v.min(), v.max());
+    else
+        v = slider_value(sv_pos, v.min(), v.max());
+    return v;
+}
+
+int slider_value::to_slider_pos(int q_min, int q_max) const
+{
+    const int q_diff = q_max - q_min;
+
+    return int(std::round(((cur() - min() * q_diff) / (max() - min())) + q_min));
+}
+
+} // end ns options