Try rounding the values when resizing wxImage instead of truncating.

This would seem to make more sense and might also fix the test failures
resulting from tiny differences in arithmetic operations when compiled with
different compilers/under different architectures.

Regenerate the test files and commit (disabled) change to the unit test
allowing to do it again in the future.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75715 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/image.cpp

@@ -769,9 +769,9 @@ wxImage wxImage::ResampleBilinear(int width, int height) const
 
             // result lines
 
-            dst_data[0] = static_cast<unsigned char>(r1 * dy1 + r2 * dy);
+            dst_data[0] = static_cast<unsigned char>(r1 * dy1 + r2 * dy + .5);
-            dst_data[1] = static_cast<unsigned char>(g1 * dy1 + g2 * dy);
+            dst_data[1] = static_cast<unsigned char>(g1 * dy1 + g2 * dy + .5);
-            dst_data[2] = static_cast<unsigned char>(b1 * dy1 + b2 * dy);
+            dst_data[2] = static_cast<unsigned char>(b1 * dy1 + b2 * dy + .5);
             dst_data += 3;
 
             if ( src_alpha )

tests/image/image.cpp

@@ -1346,7 +1346,14 @@ void ImageTestCase::BMPFlippingAndRLECompression()
 }
 
 
+// The 0 below can be replaced with 1 to generate, instead of comparing with,
+// the test files.
 #define ASSERT_IMAGE_EQUAL_TO_FILE(image, file) \
+    if ( 0 ) \
+    { \
+        CPPUNIT_ASSERT_MESSAGE( "Failed to save " file, image.SaveFile(file) ); \
+    } \
+    else \
     { \
         wxImage imageFromFile(file); \
         CPPUNIT_ASSERT_MESSAGE( "Failed to load " file, imageFromFile.IsOk() ); \