From b34d2c547f4c1082fd719b0268cc7b224f396070 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Tue, 31 Jan 2012 00:42:58 +0000
Subject: [PATCH] Use wxAutoBufferedPaintDC rather than manual double-buffering
 in BaseGrid, as it's simpler and slightly faster

Originally committed to SVN as r6389.
---
 aegisub/src/base_grid.cpp | 23 +++++------------------
 aegisub/src/base_grid.h   |  1 -
 2 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/aegisub/src/base_grid.cpp b/aegisub/src/base_grid.cpp
index 0954b8354..ea7c9b852 100644
--- a/aegisub/src/base_grid.cpp
+++ b/aegisub/src/base_grid.cpp
@@ -42,8 +42,7 @@
 #include <iterator>
 #include <numeric>
 
-#include <wx/dcclient.h>
-#include <wx/dcmemory.h>
+#include <wx/dcbuffer.h>
 #include <wx/kbdstate.h>
 #include <wx/menu.h>
 #include <wx/sizer.h>
@@ -91,7 +90,6 @@ BaseGrid::BaseGrid(wxWindow* parent, agi::Context *context, const wxSize& size,
 , lineHeight(1) // non-zero to avoid div by 0
 , holding(false)
 , scrollBar(new wxScrollBar(this, GRID_SCROLLBAR, wxDefaultPosition, wxDefaultSize, wxSB_VERTICAL))
-, bmp(0)
 , byFrame(false)
 , extendRow(-1)
 , active_line(0)
@@ -110,6 +108,8 @@ BaseGrid::BaseGrid(wxWindow* parent, agi::Context *context, const wxSize& size,
 
 	SetSizerAndFit(scrollbarpositioner);
 
+	SetBackgroundStyle(wxBG_STYLE_PAINT);
+
 	UpdateStyle();
 	OnHighlightVisibleChange(*OPT_GET("Subtitle/Grid/Highlight Subtitles in Frame"));
 
@@ -140,7 +140,6 @@ BaseGrid::BaseGrid(wxWindow* parent, agi::Context *context, const wxSize& size,
 
 BaseGrid::~BaseGrid() {
 	ClearMaps();
-	delete bmp;
 	delete context_menu;
 }
 
@@ -445,13 +444,6 @@ void BaseGrid::OnPaint(wxPaintEvent &) {
 	wxSize cs = GetClientSize();
 	cs.SetWidth(cs.GetWidth() - scrollBar->GetSize().GetWidth());
 
-	// Prepare bitmap
-	if (bmp && (bmp->GetWidth() < cs.GetWidth() || bmp->GetHeight() < cs.GetHeight())) {
-		delete bmp;
-		bmp = 0;
-	}
-	if (!bmp) bmp = new wxBitmap(cs);
-
 	// Find which columns need to be repainted
 	bool paint_columns[11];
 	memset(paint_columns, 0, sizeof paint_columns);
@@ -466,13 +458,8 @@ void BaseGrid::OnPaint(wxPaintEvent &) {
 		}
 	}
 
-	// Draw bitmap
-	wxMemoryDC bmpDC;
-	bmpDC.SelectObject(*bmp);
-	DrawImage(bmpDC, paint_columns);
-
-	wxPaintDC dc(this);
-	dc.Blit(wxPoint(0, 0), cs, &bmpDC, wxPoint(0, 0));
+	wxAutoBufferedPaintDC dc(this);
+	DrawImage(dc, paint_columns);
 }
 
 void BaseGrid::DrawImage(wxDC &dc, bool paint_columns[]) {
diff --git a/aegisub/src/base_grid.h b/aegisub/src/base_grid.h
index 4e24309a8..07992e38a 100644
--- a/aegisub/src/base_grid.h
+++ b/aegisub/src/base_grid.h
@@ -69,7 +69,6 @@ class BaseGrid : public wxWindow, public BaseSelectionController<AssDialogue> {
 	bool holding;           ///< Is a drag selection in process?
 	wxFont font;            ///< Current grid font
 	wxScrollBar *scrollBar; ///< The grid's scrollbar
-	wxBitmap *bmp;          ///< Back buffer which the grid is rendered into
 	bool byFrame;           ///< Should times be displayed as frame numbers
 
 	/// Row from which the selection shrinks/grows from when selecting via the