Add monochrome rendering modes

These modes can be used to see the inner workings of colourful artworks that
frequently use "foreground colour, new background, foreground colour",
particularly to show exactly which colours are represented by set or clear
sixels.

One mode renders all characters in white on a black background and the other
mode renders black characters on a white background. The latter could be used
to save ink if the resulting image is printed.

Flash is suppressed in these mono modes, this may or may not change.

src/qteletextdecoder/render.cpp

@@ -60,7 +60,7 @@ TeletextPageRender::TeletextPageRender()
 		m_pageImage[i] = new QImage(864, 250, QImage::Format_ARGB32_Premultiplied);
 
 	m_reveal = false;
-	m_mix = false;
+	m_renderMode = RenderNormal;
 	m_showControlCodes = false;
 	m_flashBuffersHz = 0;
 
@@ -226,6 +226,13 @@ inline void TeletextPageRender::drawBoldOrItalicCharacter(QPainter &painter, int
 
 void TeletextPageRender::renderPage(bool force)
 {
+	if (m_renderMode == RenderWhiteOnBlack) {
+		m_foregroundQColor = Qt::white;
+		m_backgroundQColor = Qt::black;
+	} else if (m_renderMode == RenderBlackOnWhite) {
+		m_foregroundQColor = Qt::black;
+		m_backgroundQColor = Qt::white;
+	}
 	for (int r=0; r<25; r++)
 		renderRow(r, 0, force);
 }
@@ -253,9 +260,11 @@ void TeletextPageRender::renderRow(int r, int ph, bool force)
 			}
 		}
 
-		if (ph == 0) {
+		// Second part of "if" suppresses all flashing on monochrome render modes
+		if (ph == 0 && m_renderMode < RenderWhiteOnBlack) {
 			if (m_decoder->cellFlashMode(r, c) != 0)
 				flashingRow = qMax(flashingRow, (m_decoder->cellFlashRatePhase(r, c) == 0) ? 1 : 2);
+//		} else if (!force)
 		} else
 			force = m_decoder->cellFlashMode(r, c) != 0;
 
@@ -278,36 +287,38 @@ void TeletextPageRender::renderRow(int r, int ph, bool force)
 				characterDiacritical = m_decoder->cellCharacterDiacritical(r, c);
 			}
 
-			if (m_decoder->cellFlashMode(r, c) == 0)
+			if (m_renderMode < RenderWhiteOnBlack) {
-				m_foregroundQColor = m_decoder->cellForegroundQColor(r, c);
+				if (m_decoder->cellFlashMode(r, c) == 0)
-			else {
-				// Flashing cell, decide if phase in this cycle is on or off
-				bool phaseOn;
-
-				if (m_decoder->cellFlashRatePhase(r, c) == 0)
-					phaseOn = (ph < 3) ^ (m_decoder->cellFlashMode(r, c) == 2);
-				else
-					phaseOn = ((ph == m_decoder->cellFlash2HzPhaseNumber(r, c)-1) || (ph == m_decoder->cellFlash2HzPhaseNumber(r, c)+2)) ^ (m_decoder->cellFlashMode(r, c) == 2);
-
-				// If flashing to adjacent CLUT select the appropriate foreground colour
-				if (m_decoder->cellFlashMode(r, c) == 3 && !phaseOn)
-					m_foregroundQColor = m_decoder->cellFlashForegroundQColor(r, c);
-				else
 					m_foregroundQColor = m_decoder->cellForegroundQColor(r, c);
+				else {
+					// Flashing cell, decide if phase in this cycle is on or off
+					bool phaseOn;
 
-				// If flashing mode is Normal or Invert, draw a space instead of a character on phase
+					if (m_decoder->cellFlashRatePhase(r, c) == 0)
-				if ((m_decoder->cellFlashMode(r, c) == 1 || m_decoder->cellFlashMode(r, c) == 2) && !phaseOn) {
+						phaseOn = (ph < 3) ^ (m_decoder->cellFlashMode(r, c) == 2);
-					// Character 0x00 draws space without underline
+					else
-					characterCode = 0x00;
+						phaseOn = ((ph == m_decoder->cellFlash2HzPhaseNumber(r, c)-1) || (ph == m_decoder->cellFlash2HzPhaseNumber(r, c)+2)) ^ (m_decoder->cellFlashMode(r, c) == 2);
-					characterSet = 0;
+
-					characterDiacritical = 0;
+					// If flashing to adjacent CLUT select the appropriate foreground colour
+					if (m_decoder->cellFlashMode(r, c) == 3 && !phaseOn)
+						m_foregroundQColor = m_decoder->cellFlashForegroundQColor(r, c);
+					else
+						m_foregroundQColor = m_decoder->cellForegroundQColor(r, c);
+
+					// If flashing mode is Normal or Invert, draw a space instead of a character on phase
+					if ((m_decoder->cellFlashMode(r, c) == 1 || m_decoder->cellFlashMode(r, c) == 2) && !phaseOn) {
+						// Character 0x00 draws space without underline
+						characterCode = 0x00;
+						characterSet = 0;
+						characterDiacritical = 0;
+					}
 				}
-			}
 
-			if (!m_mix || m_decoder->cellBoxed(r, c))
+				if (m_renderMode != RenderMix || m_decoder->cellBoxed(r, c))
-				m_backgroundQColor = m_decoder->cellBackgroundQColor(r, c);
+					m_backgroundQColor = m_decoder->cellBackgroundQColor(r, c);
-			else
+				else
-				m_backgroundQColor = Qt::transparent;
+					m_backgroundQColor = Qt::transparent;
+			}
 
 			drawCharacter(painter, r, c, characterCode, characterSet, characterDiacritical, m_decoder->cellCharacterFragment(r, c));
 
@@ -439,17 +450,16 @@ void TeletextPageRender::setReveal(bool reveal)
 				m_decoder->setRefresh(r, c, true);
 }
 
-void TeletextPageRender::setMix(bool mix)
+void TeletextPageRender::setRenderMode(RenderMode renderMode)
 {
-	if (mix  == m_mix)
+	if (renderMode == m_renderMode)
 		return;
 
-	m_mix = mix;
+	m_renderMode = renderMode;
 
 	for (int r=0; r<25; r++)
 		for (int c=0; c<72; c++)
-			if (!m_decoder->cellBoxed(r, c))
+			m_decoder->setRefresh(r, c, true);
-				m_decoder->setRefresh(r, c, true);
 }
 
 

src/qteletextdecoder/render.h

@@ -49,11 +49,13 @@ class TeletextPageRender : public QObject
 	Q_OBJECT
 
 public:
+	enum RenderMode { RenderNormal, RenderMix, RenderWhiteOnBlack, RenderBlackOnWhite };
+
 	TeletextPageRender();
 	~TeletextPageRender();
 
 	QImage* image(int i) const { return m_pageImage[i]; };
-	bool mix() const { return m_mix; };
+	RenderMode renderMode() const { return m_renderMode; };
 	void setDecoder(TeletextPageDecode *decoder);
 	void renderPage(bool force=false);
 	bool showControlCodes() const { return m_showControlCodes; };
@@ -61,7 +63,7 @@ public:
 public slots:
 	void colourChanged(int index);
 	void setReveal(bool reveal);
-	void setMix(bool mix);
+	void setRenderMode(RenderMode renderMode);
 	void setShowControlCodes(bool showControlCodes);
 
 signals:
@@ -71,7 +73,8 @@ protected:
 	TeletextFontBitmap m_fontBitmap;
 	QImage* m_pageImage[6];
 	unsigned char m_controlCodeCache[25][40];
-	bool m_reveal, m_mix, m_showControlCodes;
+	RenderMode m_renderMode;
+	bool m_reveal, m_showControlCodes;
 	int m_flashBuffersHz;
 	int m_flashingRow[25];
 

src/qteletextmaker/mainwidget.cpp

@@ -161,18 +161,18 @@ void TeletextWidget::setReveal(bool reveal)
 	update();
 }
 
-void TeletextWidget::setMix(bool mix)
-{
-	m_pageRender.setMix(mix);
-	update();
-}
-
 void TeletextWidget::setShowControlCodes(bool showControlCodes)
 {
 	m_pageRender.setShowControlCodes(showControlCodes);
 	update();
 }
 
+void TeletextWidget::setRenderMode(TeletextPageRender::RenderMode renderMode)
+{
+	m_pageRender.setRenderMode(renderMode);
+	update();
+}
+
 void TeletextWidget::setControlBit(int bitNumber, bool active)
 {
 	m_levelOnePage->setControlBit(bitNumber, active);
@@ -705,19 +705,34 @@ void LevelOneScene::updateSelection()
 	m_selectionRectItem->setVisible(true);
 }
 
-void LevelOneScene::setMix(bool mix)
+void LevelOneScene::setRenderMode(TeletextPageRender::RenderMode renderMode)
 {
-	if (mix) {
+	static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->setRenderMode(renderMode);
-		m_fullScreenTopRectItem->setBrush(Qt::transparent);
+
-		m_fullScreenBottomRectItem->setBrush(Qt::transparent);
+	QColor fullColour;
-		for (int r=0; r<25; r++) {
+
-			m_fullRowLeftRectItem[r]->setBrush(Qt::transparent);
+	switch (renderMode) {
-			m_fullRowRightRectItem[r]->setBrush(Qt::transparent);
+		case TeletextPageRender::RenderNormal:
-		}
+			setFullScreenColour(static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageDecode()->fullScreenQColor());
-	} else {
+			for (int r=0; r<25; r++)
-		setFullScreenColour(static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageDecode()->fullScreenQColor());
+				setFullRowColour(r, static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageDecode()->fullRowQColor(r));
-		for (int r=0; r<25; r++)
+			return;
-			setFullRowColour(r, static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageDecode()->fullRowQColor(r));
+		case TeletextPageRender::RenderMix:
+			fullColour = Qt::transparent;
+			break;
+		case TeletextPageRender::RenderWhiteOnBlack:
+			fullColour = Qt::black;
+			break;
+		case TeletextPageRender::RenderBlackOnWhite:
+			fullColour = Qt::white;
+			break;
+	}
+
+	m_fullScreenTopRectItem->setBrush(fullColour);
+	m_fullScreenBottomRectItem->setBrush(fullColour);
+	for (int r=0; r<25; r++) {
+		m_fullRowLeftRectItem[r]->setBrush(fullColour);
+		m_fullRowRightRectItem[r]->setBrush(fullColour);
 	}
 }
 
@@ -782,7 +797,7 @@ void LevelOneScene::keyReleaseEvent(QKeyEvent *keyEvent)
 
 void LevelOneScene::setFullScreenColour(const QColor &newColor)
 {
-	if (!static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageRender()->mix()) {
+	if (static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageRender()->renderMode() == TeletextPageRender::RenderNormal) {
 		m_fullScreenTopRectItem->setBrush(newColor);
 		m_fullScreenBottomRectItem->setBrush(newColor);
 	}
@@ -790,7 +805,7 @@ void LevelOneScene::setFullScreenColour(const QColor &newColor)
 
 void LevelOneScene::setFullRowColour(int row, const QColor &newColor)
 {
-	if (!static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageRender()->mix()) {
+	if (static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->pageRender()->renderMode() == TeletextPageRender::RenderNormal) {
 		m_fullRowLeftRectItem[row]->setBrush(newColor);
 		m_fullRowRightRectItem[row]->setBrush(newColor);
 	}

src/qteletextmaker/mainwidget.h

@@ -65,8 +65,8 @@ public slots:
 	void subPageSelected();
 	void refreshPage();
 	void setReveal(bool reveal);
-	void setMix(bool mix);
 	void setShowControlCodes(bool showControlCodes);
+	void setRenderMode(TeletextPageRender::RenderMode renderMode);
 	void updateFlashTimer(int newFlashTimer);
 	void pauseFlash(bool pauseNow);
 
@@ -120,7 +120,7 @@ public:
 public slots:
 	void updateCursor();
 	void updateSelection();
-	void setMix(bool mix);
+	void setRenderMode(TeletextPageRender::RenderMode renderMode);
 	void toggleGrid(bool gridOn);
 	void hideGUIElements(bool hidden);
 	void setFullScreenColour(const QColor &newColor);

src/qteletextmaker/mainwindow.cpp

@@ -189,11 +189,9 @@ void MainWindow::exportPNG()
 	m_textWidget->pauseFlash(true);
 	m_textScene->hideGUIElements(true);
 	// Disable exporting in Mix mode as it corrupts the background
-	bool reMix = m_textWidget->pageRender()->mix();
+	bool reMix = m_textWidget->pageRender()->renderMode() == TeletextPageRender::RenderMix;
-	if (reMix) {
+	if (reMix)
-		m_textWidget->setMix(false);
+		m_textScene->setRenderMode(TeletextPageRender::RenderNormal);
-		m_textScene->setMix(false);
-	}
 
 	// Extract the image from the scene
 	QImage interImage = QImage(m_textScene->sceneRect().size().toSize(), QImage::Format_RGB32);
@@ -205,10 +203,8 @@ void MainWindow::exportPNG()
 
 	// Now we've extracted the image we can put the GUI things back
 	m_textScene->hideGUIElements(false);
-	if (reMix) {
+	if (reMix)
-		m_textWidget->setMix(true);
+		m_textScene->setRenderMode(TeletextPageRender::RenderMix);
-		m_textScene->setMix(true);
-	}
 	m_textWidget->pauseFlash(false);
 
 	// Now scale the extracted image to the selected aspect ratio
@@ -503,13 +499,6 @@ void MainWindow::createActions()
 	revealAct->setStatusTip(tr("Toggle reveal"));
 	connect(revealAct, &QAction::toggled, m_textWidget, &TeletextWidget::setReveal);
 
-	QAction *mixAct = viewMenu->addAction(tr("&Mix"));
-	mixAct->setCheckable(true);
-	mixAct->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_M));
-	mixAct->setStatusTip(tr("Toggle mix"));
-	connect(mixAct, &QAction::toggled, m_textWidget, &TeletextWidget::setMix);
-	connect(mixAct, &QAction::toggled, m_textScene, &LevelOneScene::setMix);
-
 	QAction *gridAct = viewMenu->addAction(tr("&Grid"));
 	gridAct->setCheckable(true);
 	gridAct->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_G));
@@ -524,6 +513,17 @@ void MainWindow::createActions()
 
 	viewMenu->addSeparator();
 
+	QMenu *renderModeSubMenu = viewMenu->addMenu(tr("Render mode"));
+	QAction *renderModeActs[4];
+	renderModeActs[0] = renderModeSubMenu->addAction(tr("Normal"));
+	renderModeActs[0]->setStatusTip(tr("Render page normally"));
+	renderModeActs[1] = renderModeSubMenu->addAction(tr("Mix"));
+	renderModeActs[1]->setStatusTip(tr("Render page in mix mode"));
+	renderModeActs[2] = renderModeSubMenu->addAction(tr("White on black"));
+	renderModeActs[2]->setStatusTip(tr("Render page with white foreground on black background"));
+	renderModeActs[3] = renderModeSubMenu->addAction(tr("Black on white"));
+	renderModeActs[3]->setStatusTip(tr("Render page with black foreground on white background"));
+
 	QMenu *borderSubMenu = viewMenu->addMenu(tr("Border"));
 	m_borderActs[0] = borderSubMenu->addAction(tr("None"));
 	m_borderActs[0]->setStatusTip(tr("View with no border"));
@@ -542,18 +542,26 @@ void MainWindow::createActions()
 	m_aspectRatioActs[3] = aspectRatioSubMenu->addAction(tr("Pixel 1:2"));
 	m_aspectRatioActs[3]->setStatusTip(tr("View with 1:2 pixel mapping"));
 
+	QActionGroup *renderModeGroup = new QActionGroup(this);
 	QActionGroup *borderGroup = new QActionGroup(this);
 	QActionGroup *aspectRatioGroup = new QActionGroup(this);
 	for (int i=0; i<=3; i++) {
+		renderModeActs[i]->setCheckable(true);
+		connect(renderModeActs[i], &QAction::triggered, [=]() { m_textScene->setRenderMode(static_cast<TeletextPageRender::RenderMode>(i)); });
+		renderModeGroup->addAction(renderModeActs[i]);
+
 		m_aspectRatioActs[i]->setCheckable(true);
 		connect(m_aspectRatioActs[i], &QAction::triggered, [=]() { setAspectRatio(i); });
 		aspectRatioGroup->addAction(m_aspectRatioActs[i]);
+
 		if (i == 3)
 			break;
+
 		m_borderActs[i]->setCheckable(true);
 		connect(m_borderActs[i], &QAction::triggered, [=]() { setBorder(i); });
 		borderGroup->addAction(m_borderActs[i]);
 	}
+	renderModeActs[0]->setChecked(true);
 
 	viewMenu->addSeparator();