From 93ffd99b0c0f6f889cdf8f3b7604c3c3b6db54e4 Mon Sep 17 00:00:00 2001
From: peri4 <peri4ko@yandex.ru>
Date: Fri, 19 Nov 2021 20:19:58 +0300
Subject: [PATCH] Graphic patch - new UGLWidget creates only on first show or
 when visible

---
 libs/graphic/graphic.cpp | 37 ++++++++++++++++++++++++++++++-------
 libs/graphic/graphic.h   |  3 ++-
 2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/libs/graphic/graphic.cpp b/libs/graphic/graphic.cpp
index 2eab36a..b8fa775 100644
--- a/libs/graphic/graphic.cpp
+++ b/libs/graphic/graphic.cpp
@@ -216,6 +216,21 @@ void Graphic::resizeEvent(QResizeEvent *) {
 }
 
 
+void Graphic::showEvent(QShowEvent *) {
+	if (need_createGL && !canvas_gl) {
+		//qDebug() << "create GL on show";
+		canvas_gl = new UGLWidget();
+		ui->layoutCanvas->addWidget(canvas_gl);
+		connect(canvas_gl, SIGNAL(paintSignal()), this, SLOT(canvasPaintEvent()));
+		prepareCanvas(canvas_gl);
+		ui->canvas_raster->hide();
+		canvas_gl->show();
+		canvas = canvas_gl;
+	}
+	need_createGL = false;
+}
+
+
 void Graphic::timerEvent(QTimerEvent * ) {
 	pause_phase += 0.02;
 	if (pause_phase > 1.)
@@ -930,16 +945,24 @@ void Graphic::exportGraphics(QString filename) {
 void Graphic::setOpenGL(bool on) {
 #ifdef HAS_GL
 	isOGL = on;
+	need_createGL = false;
 	if (on && !m_fakeGL) {
 		if (!canvas_gl) {
-			canvas_gl = new UGLWidget();
-			ui->layoutCanvas->addWidget(canvas_gl);
-			connect(canvas_gl, SIGNAL(paintSignal()), this, SLOT(canvasPaintEvent()));
-			prepareCanvas(canvas_gl);
+			if (!isVisible())
+				need_createGL = true;
+			else {
+				//qDebug() << "create GL on setter";
+				canvas_gl = new UGLWidget();
+				ui->layoutCanvas->addWidget(canvas_gl);
+				connect(canvas_gl, SIGNAL(paintSignal()), this, SLOT(canvasPaintEvent()));
+				prepareCanvas(canvas_gl);
+			}
+		}
+		if (canvas_gl) {
+			ui->canvas_raster->hide();
+			canvas_gl->show();
+			canvas = canvas_gl;
 		}
-		ui->canvas_raster->hide();
-		canvas_gl->show();
-		canvas = canvas_gl;
 	} else {
 		if (canvas_gl)
 			canvas_gl->hide();
diff --git a/libs/graphic/graphic.h b/libs/graphic/graphic.h
index 009375a..f8b8e4a 100644
--- a/libs/graphic/graphic.h
+++ b/libs/graphic/graphic.h
@@ -346,6 +346,7 @@ public slots:
 protected:
 	virtual void changeEvent(QEvent * e);
 	virtual void resizeEvent(QResizeEvent * );
+	virtual void showEvent(QShowEvent * );
 	virtual QSize sizeHint() const {return QSize(400, 300);}
 	virtual void timerEvent(QTimerEvent * );
 	virtual bool eventFilter(QObject * o, QEvent * e);
@@ -415,7 +416,7 @@ protected:
 	double gridx, gridy, history, visible_time, inc_x, grid_numbers_x, grid_numbers_y, LN10;
 	double eminx, eminy, emaxx, emaxy, pause_phase, gesture_angle;
 	int lastw, lasth, min_repaint_int, timer_pause, thick;
-	bool aalias, aupdate, grid, guides, isFit, isOGL, isHover, bufferActive, cancel, pause_, gestures, m_LODOptimization, m_fakeGL;
+	bool aalias, aupdate, grid, guides, isFit, isOGL, isHover, bufferActive, cancel, pause_, gestures, m_LODOptimization, m_fakeGL, need_createGL;
 	bool hasLblX, hasLblY, navigation, only_expand_y, only_expand_x, is_lines_update, leg_update, visible_update, fullscr, need_mouse_pan;
 
 protected slots: