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Fix using wxGCDC (Cairo) with scrolled wxDC (wxMSW)

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Since 4f9186f (Increase usable scrolling range in wxMSW by a
factor of 10,000, 2022-04-30) the shift of wxDC origin is not passed
through HDC so we need to apply it as an internal transform of
Cairo context. This transform is for internal purposes only and is
not exposed with GetTransform().

See #22480.
See #22914.
This commit is contained in:
Artur Wieczorek 2022-10-25 11:01:25 +02:00
parent 3fa1e9bd2b
commit b16fdd50db
1 changed files with 21 additions and 6 deletions
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27
src/generic/graphicc.cpp
View file

@ -525,7 +525,7 @@ protected:
void Init(cairo_t *context);
enum ApplyTransformMode { Apply_directly, Apply_scaled_dev_origin };
enum ApplyTransformMode { Apply_directly, Apply_scaled_dev_origin, Apply_scaled_dev_origin_only };
void ApplyTransformFromDC(const wxDC& dc, ApplyTransformMode mode = Apply_directly);
#ifdef __WXQT__
@ -2021,6 +2021,12 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, const wxWindowDC&
m_mswStateSavedDC = ::SaveDC(hdc);
m_mswSurface = cairo_win32_surface_create(hdc);
Init( cairo_create(m_mswSurface) );
// We don't set HDC origin at MSW level in wxDC because this limits it to
// 2^27 range and we prefer to handle it ourselves to allow using the full
// 2^32 range of int coordinates, but we need to let Cairo know about the
// origin shift by storing it as an internal transformation
// (which is not going to be exposed).
ApplyTransformFromDC(dc, Apply_scaled_dev_origin_only);
#endif
#ifdef __WXGTK3__
@ -2234,6 +2240,10 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, const wxMemoryDC&
// to Cairo context on our own, if required.
if ( adjustTransformFromDC )
ApplyTransformFromDC(dc);
else
// Let Cairo know about the origin shift by storing it as an internal
// transformation (which is not going to be exposed).
ApplyTransformFromDC(dc, Apply_scaled_dev_origin_only);
#endif // __WXMSW__
#ifdef __WXGTK3__
@ -2555,17 +2565,22 @@ void wxCairoContext::ApplyTransformFromDC(const wxDC& dc, ApplyTransformMode mod
sy *= lsy;
wxPoint org = dc.GetDeviceOrigin();
if ( mode == Apply_scaled_dev_origin )
if ( mode == Apply_scaled_dev_origin || mode == Apply_scaled_dev_origin_only )
// This is used when mapping mode has been changed
// under wxMSW from MM_ANISOTROPIC to MM_TEXT.
// under wxMSW from MM_ANISOTROPIC to MM_TEXT
// or when we need to take into account device origin
// which is not passed to HDC under wxMSW
cairo_matrix_translate(&m_internalTransform, org.x/sx, org.y/sy);
else
cairo_matrix_translate(&m_internalTransform, org.x, org.y);
cairo_matrix_scale(&m_internalTransform, sx, sy);
if ( mode != Apply_scaled_dev_origin_only )
{
cairo_matrix_scale(&m_internalTransform, sx, sy);
org = dc.GetLogicalOrigin();
cairo_matrix_translate(&m_internalTransform, -org.x, -org.y);
org = dc.GetLogicalOrigin();
cairo_matrix_translate(&m_internalTransform, -org.x, -org.y);
}
cairo_set_matrix(m_context, &m_internalTransform);
}