Deprecate wxTransformMatrix to prepare for its removal later

This class is redundant with wxAffineMatrix2D, which is actually used by
the library itself and documented, so it gets to stay, while this one is
scheduled for removal.

Closes https://github.com/wxWidgets/wxWidgets/pull/2083

Closes #13114.

include/wx/matrix.h

@@ -11,7 +11,13 @@
 #ifndef _WX_MATRIXH__
 #define _WX_MATRIXH__
 
-//! headerfiles="matrix.h wx/object.h"
+#include "wx/defs.h"
+
+// Contents of this file is deprecated and shouldn't be used in the new code,
+// please see wxAffineMatrix2D instead.
+
+#if WXWIN_COMPATIBILITY_3_0
+
 #include "wx/object.h"
 #include "wx/math.h"
 
@@ -31,7 +37,11 @@
 //  at a certain coordinate and angle within another parent picture.
 //  At all times m_isIdentity is set if the matrix itself is an Identity matrix.
 //  It is used where possible to optimize calculations.
-class WXDLLIMPEXP_CORE wxTransformMatrix: public wxObject
+class
+#ifndef WXBUILDING
+wxDEPRECATED_MSG("use wxAffineMatrix2D instead")
+#endif
+WXDLLIMPEXP_CORE wxTransformMatrix: public wxObject
 {
 public:
     wxTransformMatrix();
@@ -226,9 +236,11 @@ inline bool wxTransformMatrix::IsIdentity1() const
 }
 
 // Calculates the determinant of a 2 x 2 matrix
-inline double wxCalculateDet(double a11, double a21, double a12, double a22)
-{
+wxDEPRECATED_BUT_USED_INTERNALLY_INLINE(
+    inline double wxCalculateDet(double a11, double a21, double a12, double a22),
     return a11 * a22 - a12 * a21;
-}
+)
+
+#endif // WXWIN_COMPATIBILITY_3_0
 
 #endif // _WX_MATRIXH__

src/common/matrix.cpp

@@ -15,6 +15,8 @@
 #include "wx/wxprec.h"
 
 
+#if WXWIN_COMPATIBILITY_3_0
+
 #include "wx/matrix.h"
 
 #ifndef WX_PRECOMP
@@ -595,3 +597,5 @@ void wxTransformMatrix::SetRotation(double rotation)
     Rotate(-GetRotation(), x, y);
     Rotate(rotation, x, y);
 }
+
+#endif // WXWIN_COMPATIBILITY_3_0

tests/allheaders.h

@@ -217,7 +217,9 @@
 #include <wx/longlong.h>
 #include <wx/lzmastream.h>
 #include <wx/math.h>
+/* Intentionally excluded to avoid deprecation warnings.
 #include <wx/matrix.h>
+*/
 #include <wx/mdi.h>
 #include <wx/mediactrl.h>
 #include <wx/memconf.h>