Amebis/wxWidgets
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix wxMemoryDC::Blit() with itself as source in wxMSW

Browse Source 
Don't use StretchDIBits() native function as it doesn't seem to handle the
case when its source and destination are the same correctly.

Closes #17666.
This commit is contained in:
Tim Roberts
2016-09-21 22:56:16 +02:00
committed by Vadim Zeitlin
parent 6bd6c94511
commit 607b800444
3 changed files with 44 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
tests/graphics/bitmap.cpp
View File

@@ -17,8 +17,14 @@
#endif
#include "wx/bitmap.h"
#include "wx/rawbmp.h"
#include "wx/dcmemory.h"
#define ASSERT_EQUAL_RGB(c, r, g, b) \
CPPUNIT_ASSERT_EQUAL( r, (int)c.Red() ); \
CPPUNIT_ASSERT_EQUAL( g, (int)c.Green() ); \
CPPUNIT_ASSERT_EQUAL( b, (int)c.Blue() )
// ----------------------------------------------------------------------------
// test class
// ----------------------------------------------------------------------------
@@ -34,9 +40,11 @@ public:
private:
CPPUNIT_TEST_SUITE( BitmapTestCase );
CPPUNIT_TEST( Mask );
CPPUNIT_TEST( OverlappingBlit );
CPPUNIT_TEST_SUITE_END();
void Mask();
void OverlappingBlit();
wxBitmap m_bmp;
@@ -80,3 +88,35 @@ void BitmapTestCase::Mask()
m_bmp.SetMask(mask2);
}
void BitmapTestCase::OverlappingBlit()
{
m_bmp.SetMask( NULL );
// Clear to white.
wxMemoryDC dc(m_bmp);
dc.SetBackground( *wxWHITE );
dc.Clear();
// Draw red line across the top.
dc.SetPen(*wxRED_PEN);
dc.DrawLine(0, 0, 10, 0);
// Scroll down one line.
dc.Blit( 0, 1, 10, 9, &dc, 0, 0 );
// Now, lines 0 and 1 should be red, lines 2++ should still be white.
wxNativePixelData npd( m_bmp );
wxNativePixelData::Iterator it( npd );
ASSERT_EQUAL_RGB( it, 255, 0, 0 );
it.OffsetY( npd, 1 );
ASSERT_EQUAL_RGB( it, 255, 0, 0 );
it.OffsetY( npd, 1 );
ASSERT_EQUAL_RGB( it, 255, 255, 255 );
it.OffsetY( npd, 1 );
ASSERT_EQUAL_RGB( it, 255, 255, 255 );
}