Remove projector resolution copy; use --scale-from instead

Instead of adding random resolutions to outputs that don't
report supporting them in the first place, if using
cloned output, scale the image to the screen's native resolution.

6 files changed, 30 insertions, 111 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 54bf745..c6990d1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -66,7 +66,6 @@ int main(int argc, char *argv[])
     }
 
 	ScreenSetup::inst()->addMissingEdidResolutions();
-	ScreenSetup::inst()->initModes();
 
 	if (CommandLine::center()) {
 		ScreenSetup::inst()->setCenteredClone();
diff --git a/src/widget.cpp b/src/widget.cpp
index c76bde7..491735a 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -91,7 +91,6 @@ Widget::Widget(QWidget *parent) :
 	_ui->tabWidget->setCornerWidget(_ui->btnReload);
 	connect(_ui->btnReload, &QPushButton::clicked, [=](bool) {
 		_ui->btnReload->setStyleSheet(STYLE_RELOAD_BUTTON_NORMAL);
-		ScreenSetup::inst()->initModes();
 		initControls();
 	});
 	setWindowFlags(Qt::Tool | Qt::WindowStaysOnTopHint);
@@ -141,7 +140,6 @@ Widget::Widget(QWidget *parent) :
 				// Nothing seems to have changed. This might happen when another tool changes the screen config. Let's not interfere.
 			} else if (currentCount > _lastScreenCount) { // Screen count increased - auto setup
 				_lastScreenCount = currentCount;
-				ScreenSetup::inst()->initModes();
 				ScreenMode mode;
                 auto ret = ScreenSetup::inst()->setDefaultMode(mode);
 				if (!ret.ok() || !keepResolution()) {
@@ -157,7 +155,6 @@ Widget::Widget(QWidget *parent) :
 		} else {
 			// GUI currently visible -- highlight refresh button
 			if (currentCount > _lastScreenCount) {
-				ScreenSetup::inst()->initModes();
 				initControls();
 			} else {
 				_ui->btnReload->setStyleSheet(STYLE_RELOAD_BUTTON_HOT);
@@ -332,12 +329,15 @@ void Widget::initControls(bool jumpToTab)
 	}
 	auto resolutions = ScreenSetup::inst()->getVirtualResolutions();
 	auto screenMap = ScreenSetup::inst()->getScreenPositions();
-	auto modes = ScreenSetup::inst()->getCommonModes();
+	auto modes = ScreenSetup::inst()->getCommonModes(true);
 	auto screenList = screenMap.values();
 	qSort(screenList.begin(), screenList.end(), dualHeadLess);
 	// Clone
+	// Determine preferred resolution for cloning: If no screen is detected as projector,
+	// use the smallest prefered resolution across all screens
+	// Otherwise, use the prefered resolution of the first projector we encounter
 	QSize preferredClone;
-	for (auto screen : screenList) {
+	for (const auto &screen : screenList) {
 		if (!screen.preferredResolution.isEmpty()) {
 			if (screen.isProjector // Projector always overrides
 					|| preferredClone.isEmpty() // Have no preferred yet
diff --git a/src/xprivate.cpp b/src/xprivate.cpp
index 3aea9b5..37ee5ef 100644
--- a/src/xprivate.cpp
+++ b/src/xprivate.cpp
@@ -518,30 +518,6 @@ void XPrivate::addMissingModesFromDtd(XRRScreenResources *res, RROutput outputId
 }
 
 /**
- * Copy first "num" modes from output to all other outputs if they
- * dont have a suitable mode yet.
- */
-void XPrivate::copyModesToAll(RROutput sourceId, int num)
-{
-        const XRROutputInfo *outputInfo = _outputMap[sourceId]->output;
-        for (int i = 0; i < num; ++i) {
-                if (!_modeMap.contains(outputInfo->modes[i])) {
-                        qDebug() << "BUG: Mode" << outputInfo->modes[i] << "not found in copyModesToAll";
-                        continue;
-                }
-                const XRRModeInfo *mode = _modeMap[outputInfo->modes[i]];
-                for (auto other : _outputMap.keys()) {
-                        if (other == sourceId)
-                                continue;
-                        const XRROutputInfo *otherInfo = _outputMap[other]->output;
-                        if (!getOutputModeForResolution(otherInfo, mode->width, mode->height).isEmpty())
-                                continue;
-                        XRRAddOutputMode(_display, other, outputInfo->modes[i]);
-                }
-        }
-}
-
-/**
  * Get all known modes matching the given resolution.
  * If multiple modes match the given resolution, the function will
  * put the preferred resolution first, then all others sorted by
@@ -704,28 +680,6 @@ QList<QSize> XPrivate::getTotalSize(const QList<OutputInfo*> &projectors, const
 						// Screen supports same resolution as projector
 						modeS = _modeMap[list.first()];
 						qDebug() << "Screen supports same";
-					} else {
-						// Screen does not support same resolution
-						// Usually that should not happen as we add the projector's mode(s) to the
-						// other outputs, but that doesn't work on nvidia cards, so try to use another
-						// suitable resolution there
-						int x = 0, y = 0;
-						if (modeP->width == 1280 && modeP->height == 800) {
-							x = 1280;
-							y = 720;
-						} else if (modeP->width == 1920 && modeP->height == 1200) {
-							x = 1920;
-							y = 1080;
-						}
-						if (x != 0) {
-							auto s = getOutputModeForResolution(screens.at(i)->output, x, y);
-							auto p = getOutputModeForResolution(projectors.at(i)->output, x, y);
-							if (!s.empty() && !p.empty()) {
-								modeP = _modeMap[p.first()];
-								modeS = _modeMap[s.first()];
-								qDebug() << "Falling back to" << modeP->width << "x" << modeP->height << " because of screen incompatibility";
-							}
-						}
 					}
 				}
 				if (modeS == nullptr) {
@@ -749,21 +703,25 @@ QList<QSize> XPrivate::getTotalSize(const QList<OutputInfo*> &projectors, const
         return modes;
 }
 
-XRRModeInfo* XPrivate::setOutputResolution(QStringList &args, OutputInfo *oi, int x, int y, const QSize &size)
+XRRModeInfo* XPrivate::setOutputResolution(QStringList &args, OutputInfo *oi, int x, int y, const QSize &size, const QSize &scaleFrom)
 {
     QList<RRMode> modes = getOutputModeForResolution(oi->output, size);
     if (modes.isEmpty()) {
         qDebug() << "Cannot set" << oi->outputName << "to" << size << " since it's not supported";
-        if (oi->output->nmode == 0)
+        auto *mp = getPreferredMode(oi);
+        if (mp == nullptr)
 			   return nullptr;
-        qDebug() << "falling back to its default mode";
-        modes.append(oi->output->modes[0]);
+		modes.append(mp->id);
+		qDebug() << "falling back to its default mode" << mp->width << "x" << mp->height;
     }
     // modes list is known to be sorted by preferred resolution/rate, then sorted by highest to lowest rate
     // so we just pick the first one for now, as the GUI doesn't offer picking the rate
     XRRModeInfo *best = _modeMap[modes.first()];
     args << "--output" << oi->outputName << "--mode" << best->name << "--rate" << QString::number(toVertRefresh(best), 'f', 2);
     args << "--pos" << QString::asprintf("%dx%d", x, y);
+    if (!scaleFrom.isEmpty() && scaleFrom != QSize(best->width, best->height)) {
+        args << "--scale-from" << QString::asprintf("%dx%d", scaleFrom.width(), scaleFrom.height());
+    }
     if (x == 0 && y == 0 && !args.contains(QLatin1String("--primary"))) {
         args.append("--primary");
     }
diff --git a/src/xprivate.h b/src/xprivate.h
index c10832e..6400ced 100644
--- a/src/xprivate.h
+++ b/src/xprivate.h
@@ -54,9 +54,8 @@ public:
     QList<RRMode> getOutputModeForResolution(const XRROutputInfo *output, unsigned int width, unsigned int height) const;
     QList<RRMode> getOutputModeForResolution(const XRROutputInfo *output, const QSize &resolution) const;
     RRCrtc       getFreeCrtc(const XRROutputInfo* output) const;
-	XRRModeInfo* setOutputResolution(QStringList &args, OutputInfo *oi, int x, int y, const QSize &size);
+    XRRModeInfo* setOutputResolution(QStringList &args, OutputInfo *oi, int x, int y, const QSize &size, const QSize &scaleFrom = {});
     QList<QSize> getTotalSize(const QList<OutputInfo*> &projectors, const QList<OutputInfo*> &screens) const;
-    void         copyModesToAll(RROutput id, int num);
     bool         addResolutionToOutput(OutputInfo *oi, const QSize &res);
 
     Display*            _display;
diff --git a/src/xx.cpp b/src/xx.cpp
index 85f843f..6080316 100644
--- a/src/xx.cpp
+++ b/src/xx.cpp
@@ -250,52 +250,6 @@ QMap<QString, ScreenInfo> ScreenSetup::getScreenPositions() const
 	return ret;
 }
 
-/**
- * Create common modes and add them to all outputs.
- * Make sure every output has some variant of the most commonly
- * used modes.
- */
-void ScreenSetup::initModes()
-{
-	// First copy typical resolutions to all outputs
-#define RES(x,y) (((y) << 16) | (x))
-	QSet<quint32> wanted;
-	wanted << RES(1280, 720) << RES(1280, 800) << RES(1920, 1080);
-	for (XRRModeInfo *mode : a->_modeMap) {
-		if (toVertRefresh(mode) < 55 || toVertRefresh(mode) > 65)
-			continue; // Play it safe and consider only those for copying that are 60Hz
-		if (!wanted.remove(RES(mode->width, mode->height)))
-			continue; // Is not a wanted resolution
-		// Make sure all outputs got it
-		for (OutputInfo *info : a->_outputMap) {
-            if (!a->getOutputModeForResolution(info->output, mode->width, mode->height).isEmpty())
-				continue;
-			XRRAddOutputMode(a->_display, info->id, mode->id);
-			qDebug() << "Adding mode" << mode->width << 'x' << mode->height << "to" << info->outputName;
-		}
-	}
-#undef RES
-	// Create those that no output supported
-	for (auto res : wanted) {
-		unsigned int x = res & 0xffff;
-		unsigned int y = res >> 16;
-		qDebug() << "Creating missing wanted resolution of" << x << "x" << y;
-		createMode(x, y, 60, QString::asprintf("%ux%u", x, y));
-	}
-	if (!wanted.isEmpty()) { // Modes were added, update for final loop below
-		updateScreenResources();
-	}
-	// Finally copy all those the projector supports to other outputs
-	for (auto key : a->_outputMap.keys()) {
-		OutputInfo *oi = a->_outputMap[key];
-		if (oi->outputType == Projector::Yes && oi->output->npreferred > 0) { // Only if has edid
-			qDebug() << "Copying" << oi->output->nmode << "modes to all from" << oi->outputName;
-			a->copyModesToAll(key, oi->output->nmode);
-		}
-	}
-	updateScreenResources();
-}
-
 static QSize getTotalSizeHorz(const QList<QSize> &list)
 {
 	QSize ret(0, 0);
@@ -416,6 +370,8 @@ ConfigBackup ScreenSetup::setDefaultMode(ScreenMode &mode)
         mode = ScreenMode::Advanced; // Dunno lol
         return retval;
     }
+    // We now have a list of projectors and screens.
+    // Make them cloning pairs.
     for (;;) {
         QSize screenSize = getTotalSizeHorz(outputSizes);
         QStringList cmd;
@@ -428,13 +384,13 @@ ConfigBackup ScreenSetup::setDefaultMode(ScreenMode &mode)
             const QSize &size = outputSizes.at(i);
             unsigned int w = 0;
             if (i < projectors.size()) {
-                   auto *mode = a->setOutputResolution(cmd, projectors.at(i), offset, 0, size);
+                   auto *mode = a->setOutputResolution(cmd, projectors.at(i), offset, 0, size, size);
                     if (mode != nullptr && mode->width > w) {
                         w = mode->width;
                     }
             }
             if (i < screens.size()) {
-                   auto *mode = a->setOutputResolution(cmd, screens.at(i), offset, 0, size);
+                   auto *mode = a->setOutputResolution(cmd, screens.at(i), offset, 0, size, size);
                     if (mode != nullptr && mode->width > w) {
                         w = mode->width;
                     }
@@ -584,7 +540,7 @@ ConfigBackup ScreenSetup::setClone(const QSize &resolution)
     QStringList cmd;
     ConfigBackup retval = createCrtcBackup();
 	for (auto oi : a->_outputMap) {
-        a->setOutputResolution(cmd, oi, 0, 0, resolution);
+		a->setOutputResolution(cmd, oi, 0, 0, resolution, resolution);
     }
     retval._ok = runXrandr(cmd);
     return retval;
@@ -658,10 +614,16 @@ static bool modeBiggerThan(const QSize &a, const QSize &b)
 	return a.width() == b.width() && a.height() > b.height();
 }
 
-ResolutionVector ScreenSetup::getCommonModes() const
+ResolutionVector ScreenSetup::getCommonModes(bool projectorsOnly) const
 {
 	QHash<QPair<quint32, quint32>, QSet<RROutput>> matches;
+	int expectedNum = 0;
+	// For all outputs
 	for (auto oi : a->_outputMap) {
+		if (projectorsOnly && oi->outputType == Projector::No)
+			continue;
+		expectedNum++;
+		// Validate all modes, add to match map's set
 		for (int i = 0; i < oi->output->nmode; ++i) {
 			if (!a->_modeMap.contains(oi->output->modes[i]))
 				continue;
@@ -672,7 +634,9 @@ ResolutionVector ScreenSetup::getCommonModes() const
 	}
 	ResolutionVector ret;
 	for (auto it = matches.begin(); it != matches.end(); ++it) {
-		if (it.value().size() == a->_outputMap.size()) {
+		// If a resolution in the map contains all the outputs we expect, it
+		// means it's a common mode
+		if (it.value().size() == expectedNum) {
 			ret.append(QSize(int(it.key().first), int(it.key().second)));
 		}
 	}
diff --git a/src/xx.h b/src/xx.h
index 43cb043..702568c 100644
--- a/src/xx.h
+++ b/src/xx.h
@@ -68,7 +68,6 @@ class ScreenSetup : public QObject
 public:
 	void         addMissingEdidResolutions();
 	void         updateScreenResources();
-	void         initModes();
 	ScreenMode   getCurrentMode();
 	bool         hasScreenWithoutEdid();
 	ConfigBackup setResolutionsFromString(const QString &resolutions, const QString &mapping);
@@ -77,7 +76,7 @@ public:
 	ConfigBackup setCenteredClone();
 	ConfigBackup setClone(const QSize &resolution);
 	ConfigBackup setCustom(const QList<QPair<QSize, QList<QString>>> &list);
-	ResolutionVector getCommonModes() const;
+	ResolutionVector getCommonModes(bool projectorsOnly = false) const;
 	int getOutputCount() const;
 	int queryCurrentOutputCount() const;
 	QMap<QString, ScreenInfo> getScreenPositions() const;