Add a new test checking wxGraphicsContext implementation correctness.

This test verifies that the output of wxGraphicsContext on the current system
matches the pregenerated reference output.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76164 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/drawing/testimagefile.h

@@ -0,0 +1,97 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        tests/drawing/testimagefile.h
+// Purpose:     Functions to test whether the content of files or images files
+//              are equal
+// Author:      Armel Asselin
+// Created:     2014-02-28
+// Copyright:   (c) 2014 Ellié Computing <opensource@elliecomputing.com>
+///////////////////////////////////////////////////////////////////////////////
+
+
+#ifndef _WX_TESTS_TESTIMAGEFILE_H_
+#define _WX_TESTS_TESTIMAGEFILE_H_
+
+bool AreFilesContentsEqual(const wxString &filename, const wxString &refFilename)
+{
+    wxFileInputStream input(filename);
+    wxFileInputStream refInput(refFilename);
+
+    wxFileOffset refLength = refInput.GetLength();
+    if (refLength != input.GetLength())
+        return false;
+
+    wxUint8 buffer[1024], refBuffer[sizeof(buffer)];
+
+    wxFileOffset remainingLength = refLength;
+    while (remainingLength != 0)
+    {
+        input.Read (buffer, wxMin(remainingLength, sizeof(buffer)));
+        refInput.Read(refBuffer, wxMin(remainingLength, sizeof(refBuffer)));
+
+        size_t refLastRead = refInput.LastRead();
+        if (input.LastRead() != refLastRead)
+            return false;
+
+        if (memcmp (buffer, refBuffer, refLastRead) != 0)
+            return false;
+
+        remainingLength -= refLastRead;
+    }
+
+    return true;
+}
+
+#define WX_ASSERT_SAME_AS_FILE(filename1, filename2) \
+    WX_ASSERT_MESSAGE(\
+        ("Files \"%s\" and \"%s\" differ.",\
+            filename1, filename2),\
+        AreImagesFilesContentsEqual(filename1, filename2))
+
+bool AreImagesFilesContentsEqual(const wxString &filename,
+                                 const wxString &refFilename)
+{
+    wxImage input(filename);
+    wxImage refInput(refFilename);
+
+    // assertion_traits<wxImage> could do part of the job or maybe the contrary
+    // there should probably be somethin common at least
+
+    if (!input.Ok() || !refInput.Ok())
+        return false;
+    if (input.GetSize() != refInput.GetSize())
+        return false;
+    if (input.HasAlpha() != refInput.HasAlpha())
+        return false;
+    if (input.HasMask() != refInput.HasMask())
+        return false;
+
+    long pixelsCount = input.GetSize().GetWidth() * input.GetSize().GetHeight();
+    const unsigned char *data = input.GetData();
+    const unsigned char *refData = refInput.GetData();
+    if (memcmp (data, refData, pixelsCount*3) != 0)
+        return false;
+
+    if (input.HasAlpha())
+    {
+        const unsigned char *alpha = input.GetAlpha();
+        const unsigned char *refAlpha = refInput.GetAlpha();
+        if (memcmp (alpha, refAlpha, pixelsCount) != 0)
+            return false;
+    }
+
+    if (input.HasMask() &&
+        (input.GetMaskRed() != refInput.GetMaskRed() ||
+         input.GetMaskGreen() != refInput.GetMaskGreen() ||
+         input.GetMaskBlue() != refInput.GetMaskBlue()))
+         return false;
+
+    return true;
+}
+
+#define WX_ASSERT_SAME_AS_IMAGE_FILE(filename1, filename2) \
+    WX_ASSERT_MESSAGE(\
+        ("Image files \"%s\" and \"%s\" differ.",\
+            filename1, filename2),\
+        AreImagesFilesContentsEqual(filename1, filename2))
+
+#endif // _WX_TESTS_TESTIMAGEFILE_H_