Skip to content

VNCCanvas: fix faint ghost edges left by a moving cursor #303

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
michael-adler wants to merge 1 commit into
base: master
Choose a base branch
from
Open

VNCCanvas: fix faint ghost edges left by a moving cursor #303

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
135 changes: 56 additions & 79 deletions src/gui/ViewerWindow.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@


#include <cmath>
#include <vector>
#include <wx/gdicmn.h>
#include <wx/log.h>
Expand All @@ -8,6 +9,7 @@
#include <wx/clipbrd.h>
#include <wx/dataobj.h>
#include <wx/dcclient.h>
#include <wx/dcmemory.h>
#include <wx/tokenzr.h>
#include "keyboardgrab/KeyboardGrabber.h"
#include "res/vnccursor.xbm"
Expand Down Expand Up @@ -54,9 +56,16 @@ class VNCCanvas: public wxPanel
VNCCanvas(wxWindow* parent, VNCConn* c);
void grab_keyboard();
void ungrab_keyboard();
// called on the GUI thread as update notifications for `conn` arrive
void updateCache(const wxRect& rect);

VNCConn* conn;
wxRegion updated_area;

// Native-resolution framebuffer copy, kept current by updateCache() and
// always blitted whole in onPaint() -- see onUpdateTimer for why.
wxBitmap fb_cache;
bool dirty = false;

double scale_factor = 1.0;
bool do_keyboard_grab;
std::vector<VNCConn*> sync_targets;
Expand Down Expand Up @@ -137,48 +146,58 @@ void VNCCanvas::ungrab_keyboard()



void VNCCanvas::onUpdateTimer(wxTimerEvent& event)
void VNCCanvas::updateCache(const wxRect& rect)
{
// get the update rect list
wxRegionIterator upd(updated_area);
while(upd)
#ifndef NDEBUG
wxLongLong t0 = wxGetLocalTimeMillis();
#endif

wxSize fb_size(conn->getFrameBufferWidth(), conn->getFrameBufferHeight());
if(fb_size.GetWidth() <= 0 || fb_size.GetHeight() <= 0)
return;

// (re)allocate on first use or framebuffer resize
if(!fb_cache.IsOk() || fb_cache.GetSize() != fb_size)
fb_cache = wxBitmap(fb_size, 32);

// scope the expensive per-pixel copy to just what changed
const wxBitmap& changed = conn->getFrameBufferRegion(rect);
if(changed.IsOk())
{
wxRect update_rect(upd.GetRect());

if(scale_factor != 1.0) {
update_rect.x *= scale_factor;
update_rect.y *= scale_factor;
update_rect.width *= scale_factor;
update_rect.height *= scale_factor;

// fixes artifacts. +2 because double->int cuttofs can happen for x,y _and_ w,h scaling
update_rect.width += 2;
update_rect.height += 2;
}

wxLogDebug(wxT("VNCCanvas %p: invalidating updated rect: (%i,%i,%i,%i)"),
this,
update_rect.x,
update_rect.y,
update_rect.width,
update_rect.height);

// triggers onPaint()
Refresh(false, &update_rect);
++upd;
wxMemoryDC dc(fb_cache);
dc.DrawBitmap(changed, rect.x, rect.y);
}

updated_area.Clear();
dirty = true;

#ifndef NDEBUG
wxLongLong t1 = wxGetLocalTimeMillis();
wxLogDebug(wxT("VNCCanvas %p: updateCache rect (%i,%i,%i,%i), %f megapixels, took %lld ms"),
this,
rect.x, rect.y, rect.width, rect.height,
(double)(rect.width * rect.height)/(1024.0*1024.0),
(t1-t0).GetValue());
#endif
}


void VNCCanvas::onUpdateTimer(wxTimerEvent& event)
{
// Partial-rect invalidation is unreliable on this wx port -- some
// changed rects never get repainted. Always invalidate the whole
// canvas instead; fb_cache keeps that cheap.
if(dirty)
{
Refresh(false);
dirty = false;
}
}


void VNCCanvas::onPaint(wxPaintEvent &WXUNUSED(event))
{
#ifndef NDEBUG
wxLongLong t0 = wxGetLocalTimeMillis();
size_t nr_rects = 0;
size_t nr_pixels = 0;
#endif

// this happens on GTK even if our size is (0,0)
Expand All @@ -188,56 +207,14 @@ void VNCCanvas::onPaint(wxPaintEvent &WXUNUSED(event))
wxPaintDC dc(this);
dc.SetUserScale(scale_factor, scale_factor);

// get the update rect list
wxRegionIterator upd(GetUpdateRegion());
while(upd)
{
wxRect update_rect(upd.GetRect());

if(scale_factor != 1.0) {
update_rect.x /= scale_factor;
update_rect.y /= scale_factor;
update_rect.width /= scale_factor;
update_rect.height /= scale_factor;

// fixes artifacts. +2 because double->int cuttofs can happen for x,y _and_ w,h scaling
update_rect.width += 2;
update_rect.height += 2;

// make sure this is always within the framebuffer boudaries;
// might not always be due to the artifact fix above, would not be drawn then
update_rect.Intersect(wxRect(0,
0,
conn->getFrameBufferWidth(),
conn->getFrameBufferHeight()));
}

wxLogDebug(wxT("VNCCanvas %p: got repaint event: (%i,%i,%i,%i)"),
this,
update_rect.x,
update_rect.y,
update_rect.width,
update_rect.height);

#ifndef NDEBUG
++nr_rects;
nr_pixels += update_rect.width * update_rect.height;
#endif

const wxBitmap& region = conn->getFrameBufferRegion(update_rect);
if(region.IsOk())
dc.DrawBitmap(region, update_rect.x, update_rect.y);

++upd;
}
// fb_cache is already fully up to date -- just blit it, no per-pixel
// fetch here, and no per-rect tiling that could leave seams
if(fb_cache.IsOk())
dc.DrawBitmap(fb_cache, 0, 0);

#ifndef NDEBUG
wxLongLong t1 = wxGetLocalTimeMillis();
wxLogDebug(wxT("VNCCanvas %p: updating %zu rects (%f megapixels) took %lld ms"),
this,
nr_rects,
(double)nr_pixels/(1024.0*1024.0),
(t1-t0).GetValue());
wxLogDebug(wxT("VNCCanvas %p: paint blit took %lld ms"), this, (t1-t0).GetValue());
#endif
}

Expand Down Expand Up @@ -502,7 +479,7 @@ void ViewerWindow::onVNCConnUpdateNotify(VNCConnUpdateNotifyEvent& event)

// only do something if this is our VNCConn
if(sending_conn == canvas->conn)
canvas->updated_area.Union(event.rect);
canvas->updateCache(event.rect);
}


Expand Down