initial commit

Signed-off-by: Peter Siegmund <mars3142@noreply.mars3142.dev>

libs/wxWidgets-3.3.1/include/wx/private/rescale.h

@@ -0,0 +1,146 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/private/rescale.h
+// Purpose:     Helpers for rescaling coordinates
+// Author:      Vadim Zeitlin
+// Created:     2021-07-13
+// Copyright:   (c) 2021 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_PRIVATE_RESCALE_H_
+#define _WX_PRIVATE_RESCALE_H_
+
+#include "wx/gdicmn.h"
+#include "wx/math.h"
+
+#ifdef __WINDOWS__
+    // Required in order to use wxMulDivInt32().
+    #include "wx/msw/wrapwin.h"
+#endif
+
+// wxRescaleCoord is used to scale the components of the given wxSize by the
+// ratio between 2 scales, with rounding. It doesn't scale the components
+// if they're set to -1 (wxDefaultCoord), as this value is special in wxSize.
+//
+// The way it's used is special because we want to ensure there is no confusion
+// between the scale being converted from and the scale being converted to, so
+// instead of just using a single function, we use an intermediate object,
+// which is not supposed to be used directly, but is only returned by From() in
+// order to allow calling To() on it.
+//
+// Another complication is that we want this to work for both wxSize and
+// wxPoint, as well as for just plain coordinate values, so wxRescaleCoord() is
+// an overloaded function and the helper classes are templates, with their
+// template parameter being either wxSize, wxPoint or int.
+
+namespace wxPrivate
+{
+
+template <typename T> class wxRescaleCoordWithValue;
+
+template <typename T>
+class wxRescaleCoordWithFrom
+{
+public:
+    T To(wxSize newScale) const
+    {
+        T value(m_value);
+
+        if ( value.x != wxDefaultCoord )
+            value.x = wxMulDivInt32(value.x, newScale.x, m_oldScale.x);
+
+        if ( value.y != wxDefaultCoord )
+            value.y = wxMulDivInt32(value.y, newScale.y, m_oldScale.y);
+
+        return value;
+    }
+
+    T To(int newScaleX, int newScaleY) const
+    {
+        return To(wxSize(newScaleX, newScaleY));
+    }
+
+private:
+    wxRescaleCoordWithFrom(T value, wxSize oldScale)
+        : m_value(value), m_oldScale(oldScale)
+    {
+    }
+
+    const T m_value;
+    const wxSize m_oldScale;
+
+    // Only it can create objects of this class.
+    friend class wxRescaleCoordWithValue<T>;
+};
+
+// Specialization for just a single value.
+template <>
+class wxRescaleCoordWithFrom<int>
+{
+public:
+    int To(wxSize newScale) const
+    {
+        return m_value == wxDefaultCoord
+                ? wxDefaultCoord
+                : wxMulDivInt32(m_value, newScale.x, m_oldScale.x);
+    }
+
+private:
+    wxRescaleCoordWithFrom(int value, wxSize oldScale)
+        : m_value(value), m_oldScale(oldScale)
+    {
+    }
+
+    const int m_value;
+    const wxSize m_oldScale;
+
+    // Only it can create objects of this class.
+    friend class wxRescaleCoordWithValue<int>;
+};
+
+template <typename T>
+class wxRescaleCoordWithValue
+{
+public:
+    explicit wxRescaleCoordWithValue(T value)
+        : m_value(value)
+    {
+    }
+
+    wxRescaleCoordWithFrom<T> From(wxSize oldScale)
+    {
+        return wxRescaleCoordWithFrom<T>(m_value, oldScale);
+    }
+
+    wxRescaleCoordWithFrom<T> From(int oldScaleX, int oldScaleY)
+    {
+        return From(wxSize(oldScaleX, oldScaleY));
+    }
+
+private:
+    const T m_value;
+};
+
+} // namespace wxPrivate
+
+inline wxPrivate::wxRescaleCoordWithValue<int> wxRescaleCoord(int coord)
+{
+    return wxPrivate::wxRescaleCoordWithValue<int>(coord);
+}
+
+inline wxPrivate::wxRescaleCoordWithValue<wxSize> wxRescaleCoord(wxSize sz)
+{
+    return wxPrivate::wxRescaleCoordWithValue<wxSize>(sz);
+}
+
+inline wxPrivate::wxRescaleCoordWithValue<wxSize> wxRescaleCoord(int x, int y)
+{
+    return wxPrivate::wxRescaleCoordWithValue<wxSize>(wxSize(x, y));
+}
+
+inline wxPrivate::wxRescaleCoordWithValue<wxPoint> wxRescaleCoord(wxPoint pt)
+{
+    return wxPrivate::wxRescaleCoordWithValue<wxPoint>(pt);
+}
+
+#endif // _WX_PRIVATE_RESCALE_H_