Add benchmarks for wxImage methods.

Build a GUI version of the benchmark program too and use it to benchmark
wxImage loading methods for now (more will be added later).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74319 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/benchmarks/image.cpp

@@ -0,0 +1,57 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        tests/benchmarks/image.cpp
+// Purpose:     wxImage benchmarks
+// Author:      Vadim Zeitlin
+// Created:     2013-06-30
+// Copyright:   (c) 2013 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#include "wx/image.h"
+
+#include "bench.h"
+
+BENCHMARK_FUNC(LoadBMP)
+{
+    wxImage image;
+    return image.LoadFile("horse.bmp");
+}
+
+BENCHMARK_FUNC(LoadJPEG)
+{
+    static bool s_handlerAdded = false;
+    if ( !s_handlerAdded )
+    {
+        s_handlerAdded = true;
+        wxImage::AddHandler(new wxJPEGHandler);
+    }
+
+    wxImage image;
+    return image.LoadFile("horse.jpg");
+}
+
+BENCHMARK_FUNC(LoadPNG)
+{
+    static bool s_handlerAdded = false;
+    if ( !s_handlerAdded )
+    {
+        s_handlerAdded = true;
+        wxImage::AddHandler(new wxPNGHandler);
+    }
+
+    wxImage image;
+    return image.LoadFile("horse.png");
+}
+
+BENCHMARK_FUNC(LoadTIFF)
+{
+    static bool s_handlerAdded = false;
+    if ( !s_handlerAdded )
+    {
+        s_handlerAdded = true;
+        wxImage::AddHandler(new wxTIFFHandler);
+    }
+
+    wxImage image;
+    return image.LoadFile("horse.tif");
+}