doublemax wrote: ↑Thu Jul 29, 2021 6:15 pm
You don't need the wxStaticBitmap.
Your paint event handler should look something like this:
Code: Select all
void MainFrame::OnPaintPlayhead(wxPaintEvent& event)
{
wxPaintDC dc(m_TopWaveformPanel);
// OnRenderPlayhead(dc); i don't know what this does but it probably goes into the UpdateWaveformBitmap() method
const wxSize size = m_TopWaveformPanel->GetClientSize();
if(!m_bitmap.IsOk()
|| m_bitmap.GetWidth() != size.x
|| m_bitmap.GetHeight() != size.y
|| anyVisiblePropertyOfTheWaveformHasChanged() )
{
m_bitmap.Create(size.x, size.y, 32);
UpdateWaveformBitmap();
}
dc.DrawBitmap(m_bitmap, 0, 0, false);
// draw other stuff here, e.g. position indicator etc.
}
Code: Select all
void MainFrame::UpdateWaveformBitmap()
{
wxMemoryDC mdc(m_bitmap);
// render waveform into bitmap here
}
Okay, I made some progress, I was drawing the bitmap without rendering anything to it, so I made some changes,
Code: Select all
void MainFrame::OnPaint(wxPaintEvent& event)
{
wxPaintDC dc(m_TopWaveformPanel);
const wxSize size = m_TopWaveformPanel->GetClientSize();
if(!m_WaveformBitmap.IsOk()
|| m_WaveformBitmap.GetWidth() != size.x
|| m_WaveformBitmap.GetHeight() != size.y
/* || anyVisiblePropertyOfTheWaveformHasChanged() */ )
{
m_WaveformBitmap.Create(size.x, size.y, 32);
UpdateWaveformBitmap(dc);
}
if (!dc.IsOk())
return;
wxMemoryDC mdc(m_WaveformBitmap);
if (!mdc.IsOk())
return;
UpdateWaveformBitmap(mdc);
dc.Blit(m_TopWaveformPanel->GetSize().GetWidth() - (m_TopWaveformPanel->GetSize().GetWidth() - 1),
m_TopWaveformPanel->GetSize().GetHeight() - (m_TopWaveformPanel->GetSize().GetHeight() - 1),
m_WaveformBitmap.GetWidth(), m_WaveformBitmap.GetHeight(), &mdc, 0, 0);
dc.DrawBitmap(m_WaveformBitmap, 0, 0, false);
OnRenderPlayhead(dc);
}
And the render code is,
Code: Select all
/*===========================Draw code============================*/
wxMemoryDC mdc(m_WaveformBitmap);
dc.SetPen(wxPen(wxColour(0, 0, 0, 255), 2, wxPENSTYLE_SOLID));
for(int i = 0; i < waveform.size() - 1; i++)
{
dc.DrawLine((display_width * i) / waveform.size(), waveform[i] + display_height / 2.0f,
(display_width * i) / waveform.size(), (waveform[i] / samples_per_pixel) + display_height / 2.0f);
}
I think I am creating 2 different wxMemoryDC's, but anything else I try causes a error or crash.
This seems to work, and this also takes care of resizing the waveform, when the window is resized or splitter is resized. But the performance is still not great, for example for small samples, 1-2 second long, it does fine, but if the sample is 10-15 seconds, it takes a while to render the bitmap, then it finally loads, and also the position marker moves very slowly, not smooth movement.
