tderandr: workaround for tde/75fix/tde-75

Some videocards' drivers (most notably propryetary nvidia) report
incorrect screen refresh rate via XRRRates(). Use
XRRGetScreenResources() + some math borrowed from xrandr instead.

Bug: https://mirror.git.trinitydesktop.org/gitea/TDE/tde/issues/75
Signed-off-by: Alexander Golubev <fatzer2@gmail.com>

2 files changed, 121 insertions, 36 deletions

diff --git a/tderandr/randr.cpp b/tderandr/randr.cpp
index 6a3d0381e..e050852df 100644
--- a/tderandr/randr.cpp
+++ b/tderandr/randr.cpp
@@ -40,6 +40,10 @@
 #undef INT32
 #include <X11/extensions/Xrandr.h>
 
+static int refreshRateForModeInfo (const XRRModeInfo *mode_info);
+static int refreshRateIndexToXRR(int screen, int size, int index);
+static int refreshRateXRRToIndex(int screen, int size, int hz);
+
 HotPlugRule::HotPlugRule()
 {
 	//
@@ -169,7 +173,8 @@ KDE_EXPORT void RandRScreen::loadSettings()
 	}
 
 	if (d->config) {
-		m_currentRefreshRate = m_proposedRefreshRate = refreshRateHzToIndex(m_currentSize, XRRConfigCurrentRate(d->config));
+		m_currentRefreshRate = m_proposedRefreshRate =
+			refreshRateXRRToIndex(m_screen, m_currentSize, XRRConfigCurrentRate(d->config));
 	}
 	else {
 		m_currentRefreshRate = m_proposedRefreshRate = 0;
@@ -185,8 +190,12 @@ KDE_EXPORT void RandRScreen::setOriginal()
 
 KDE_EXPORT bool RandRScreen::applyProposed()
 {
-	//kdDebug() << k_funcinfo << " size " << (SizeID)proposedSize() << ", rotation " << proposedRotation() << ", refresh " << refreshRateIndexToHz(proposedSize(), proposedRefreshRate()) << endl;
-
+#if 0
+	kdDebug() << k_funcinfo << " size " << (SizeID)proposedSize() <<
+		", rotation " << proposedRotation() <<
+		", refresh " << refreshRateIndexToHz(proposedSize(), proposedRefreshRate())
+			<< " (" << refreshRateIndexToXRR(m_screen, proposedSize(), proposedRefreshRate()) << ")" << endl;
+#endif
 	Status status;
 
 	if (!d->config) {
@@ -198,10 +207,11 @@ KDE_EXPORT bool RandRScreen::applyProposed()
 		if (proposedRefreshRate() < 0)
 			status = XRRSetScreenConfig(tqt_xdisplay(), d->config, DefaultRootWindow(tqt_xdisplay()), (SizeID)proposedSize(), (Rotation)proposedRotation(), CurrentTime);
 		else {
-			if( refreshRateIndexToHz(proposedSize(), proposedRefreshRate()) <= 0 ) {
+			int hz = refreshRateIndexToXRR(m_screen, proposedSize(), proposedRefreshRate());
+			if( hz <= 0 ) {
 				m_proposedRefreshRate = 0;
 			}
-			status = XRRSetScreenConfigAndRate(tqt_xdisplay(), d->config, DefaultRootWindow(tqt_xdisplay()), (SizeID)proposedSize(), (Rotation)proposedRotation(), refreshRateIndexToHz(proposedSize(), proposedRefreshRate()), CurrentTime);
+			status = XRRSetScreenConfigAndRate(tqt_xdisplay(), d->config, DefaultRootWindow(tqt_xdisplay()), (SizeID)proposedSize(), (Rotation)proposedRotation(), hz, CurrentTime);
 		}
 	}
 	else {
@@ -487,26 +497,22 @@ KDE_EXPORT int RandRScreen::currentMMHeight() const
 	return m_pixelSizes[m_currentSize].height();
 }
 
-KDE_EXPORT TQStringList RandRScreen::refreshRates(int size) const
+KDE_EXPORT TQValueVector<int> RandRScreen::refreshRatesValues(int size) const
 {
-	int nrates;
-	TQStringList ret;
+	ScreenInfo *screeninfo = internal_read_screen_info(tqt_xdisplay());
+	int numSizes = screeninfo->res->nmode;
+	TQValueVector<int> ret;
 
-	if (d->config) {
-		short* rates = XRRRates(tqt_xdisplay(), m_screen, (SizeID)size, &nrates);
-
-		for (int i = 0; i < nrates; i++)
-			ret << refreshRateDirectDescription(rates[i]);
+	if (size > numSizes-1) { // out of range
+		return ret;
 	}
-	else {
-		// Great, now we have to go after the information manually.  Ughh.
-		ScreenInfo *screeninfo = internal_read_screen_info(tqt_xdisplay());
-		int numSizes = screeninfo->res->nmode;
-		for (int i = 0; i < numSizes; i++) {
-			int refresh_rate = ((screeninfo->res->modes[i].dotClock*1.0)/((screeninfo->res->modes[i].hTotal)*(screeninfo->res->modes[i].vTotal)*1.0));
-			TQString newRate = refreshRateDirectDescription(refresh_rate);
-			if (!ret.contains(newRate)) {
-				ret.append(newRate);
+
+	char * currentModeName = screeninfo->res->modes[size].name;
+	for (int i = 0; i < numSizes; i++) {
+		if (strcmp(currentModeName, screeninfo->res->modes[i].name) == 0) {
+			int rate = refreshRateForModeInfo(&screeninfo->res->modes[i]);
+			if (rate!=0) {
+				ret.append(rate);
 			}
 		}
 	}
@@ -514,6 +520,17 @@ KDE_EXPORT TQStringList RandRScreen::refreshRates(int size) const
 	return ret;
 }
 
+KDE_EXPORT TQStringList RandRScreen::refreshRates(int size) const
+{
+	TQStringList ret;
+
+	for (int rate: refreshRatesValues(size)) {
+		ret.append(refreshRateDirectDescription(rate));
+	}
+
+	return ret;
+}
+
 KDE_EXPORT TQString RandRScreen::refreshRateDirectDescription(int rate) const
 {
 	return i18n("Refresh rate in Hertz (Hz)", "%1 Hz").arg(rate);
@@ -521,7 +538,7 @@ KDE_EXPORT TQString RandRScreen::refreshRateDirectDescription(int rate) const
 
 KDE_EXPORT TQString RandRScreen::refreshRateIndirectDescription(int size, int index) const
 {
-	return i18n("Refresh rate in Hertz (Hz)", "%1 Hz").arg(refreshRateIndexToHz(size, index));
+	return refreshRateDirectDescription(refreshRateIndexToHz(size, index));
 }
 
 KDE_EXPORT TQString RandRScreen::refreshRateDescription(int size, int index) const
@@ -556,30 +573,28 @@ KDE_EXPORT int RandRScreen::proposedRefreshRate() const
 
 KDE_EXPORT int RandRScreen::refreshRateHzToIndex(int size, int hz) const
 {
-	int nrates;
-	short* rates = XRRRates(tqt_xdisplay(), m_screen, (SizeID)size, &nrates);
-
-	for (int i = 0; i < nrates; i++)
-		if (hz == rates[i])
+	TQValueVector<int> rates = refreshRatesValues(size);
+	for (size_t i=0; i<rates.size(); i++) {
+		if ( (int) (rates[i] + 0.5) == hz) {
 			return i;
+		}
+	}
 
-	if (nrates != 0)
+	if (rates.size() != 0)
 		// Wrong input Hz!
 		Q_ASSERT(false);
 
 	return -1;
 }
 
-KDE_EXPORT int RandRScreen::refreshRateIndexToHz(int size, int index) const
-{
-	int nrates;
-	short* rates = XRRRates(tqt_xdisplay(), m_screen, (SizeID)size, &nrates);
+KDE_EXPORT int RandRScreen::refreshRateIndexToHz(int size, int index) const {
+	TQValueVector<int> rates = refreshRatesValues(size);
 
-	if (nrates == 0 || index < 0)
+	if (rates.size() == 0 || index < 0)
 		return 0;
 
-	// Wrong input Hz!
-	if(index >= nrates)
+	// Wrong input index!
+	if(index >= (ssize_t)rates.size())
 		return 0;
 
 	return rates[index];
@@ -880,4 +895,72 @@ KDE_EXPORT int RandRScreen::pixelCount( int index ) const
 	return sz.width() * sz.height();
 }
 
+// Calculates refresh rate for modeinfo
+// snatch from xrandr-1.5
+static int refreshRateForModeInfo(const XRRModeInfo *mode_info)
+{
+	double rate;
+	double vTotal = mode_info->vTotal;
+
+	if (mode_info->modeFlags & RR_DoubleScan) {
+		/* doublescan doubles the number of lines */
+		vTotal *= 2;
+	}
+
+	if (mode_info->modeFlags & RR_Interlace) {
+		/* interlace splits the frame into two fields */
+		/* the field rate is what is typically reported by monitors */
+		vTotal /= 2;
+	}
+
+	if (mode_info->hTotal && vTotal)
+		rate = ((double) mode_info->dotClock /
+				((double) mode_info->hTotal * (double) vTotal));
+	else
+		rate = 0;
+	return (int) (rate+0.5);
+}
+
+// On some video drivers (e.g. proprietary nvidia) XRandR returns incorrect
+// readings for refresh rate[1], when read via XRRRates(), so for display
+// purposes we will use data from XRRGetScreenResources() and some fancy
+// calculations (see internal_read_screen_info() and  refreshRateForModeInfo()).
+// Unfortunately, other XRandR functions (like XRRConfigCurrentRate() and
+// XRRSetScreenConfigAndRate()) expect the data reported by XRRRates(). So,
+// in order to be able to correctly set a refresh rate we have to request
+// it via XRRRates() anyway.
+//
+// [1]: see https://mirror.git.trinitydesktop.org/gitea/TDE/tde/issues/75
+
+static int refreshRateXRRToIndex(int screen, int size, int hz)
+{
+	int nrates;
+	short* rates = XRRRates(tqt_xdisplay(), screen, (SizeID)size, &nrates);
+
+	for (int i = 0; i < nrates; i++)
+		if (hz == rates[i])
+			return i;
+
+	if (nrates != 0)
+		// Wrong input Hz!
+		Q_ASSERT(false);
+
+	return -1;
+}
+
+static int refreshRateIndexToXRR(int screen, int size, int index)
+{
+	int nrates;
+	short* rates = XRRRates(tqt_xdisplay(), screen, (SizeID)size, &nrates);
+
+	if (nrates == 0 || index < 0)
+		return 0;
+
+	// Wrong input Hz!
+	if(index >= nrates)
+		return 0;
+
+	return rates[index];
+}
+
 #include "randr.moc"
diff --git a/tderandr/randr.h b/tderandr/randr.h
index 36e87badd..36cdd0088 100644
--- a/tderandr/randr.h
+++ b/tderandr/randr.h
@@ -21,6 +21,7 @@
 
 #include <tqobject.h>
 #include <tqstringlist.h>
+#include <tqvaluevector.h>
 #include <tqptrlist.h>
 
 #include <tdecmodule.h>
@@ -152,6 +153,7 @@ public:
 	/**
 	 * Refresh rate functions.
 	 */
+	TQValueVector<int> refreshRatesValues(int size) const;
 	TQStringList refreshRates(int size) const;
 
 	TQString		refreshRateDirectDescription(int rate) const;