From 0de8ffc773c709bf41055f6139524aef7246f944 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miroslav=20=C5=A0ediv=C3=BD?= <sedivy.miro@gmail.com>
Date: Mon, 13 Mar 2023 17:55:41 +0100
Subject: [PATCH] update screen rate set. (#34)

---
 pkg/xorg/xorg.c  | 27 ++-------------------------
 pkg/xorg/xorg.go | 30 ++++++++++++++++++++++--------
 pkg/xorg/xorg.h  |  2 +-
 3 files changed, 25 insertions(+), 34 deletions(-)

diff --git a/pkg/xorg/xorg.c b/pkg/xorg/xorg.c
index 6ef6f8e9..d70e5aaa 100644
--- a/pkg/xorg/xorg.c
+++ b/pkg/xorg/xorg.c
@@ -229,7 +229,7 @@ void XKey(KeySym keysym, int down) {
   XSync(display, 0);
 }
 
-Status XSetScreenConfiguration(int width, int height, short *rate) {
+Status XSetScreenConfiguration(int width, int height, short rate) {
   Display *display = getXDisplay();
   Window root = RootWindow(display, 0);
   XRRScreenConfiguration *conf = XRRGetScreenInfo(display, root);
@@ -251,31 +251,8 @@ Status XSetScreenConfiguration(int width, int height, short *rate) {
     return RRSetConfigFailed;
   }
 
-  short current_rate = 0;
-  if (rate != NULL) {
-    short *rates;
-    int num_rates;
-    rates = XRRConfigRates(conf, size_index, &num_rates);
-
-    // try to find the nearest rate
-    short nearest_rate = 0;
-    float diff = 0;
-    for (int i = 0; i < num_rates; i++) {
-      if (nearest_rate == 0 || abs(rates[i] - *rate) < diff) {
-        nearest_rate = rates[i];
-        diff = abs(rates[i] - *rate);
-      }
-    }
-
-    if (nearest_rate != 0 && diff < 10) {
-      current_rate = nearest_rate;
-    }
-
-    *rate = current_rate;
-  }
-
   Status status;
-  status = XRRSetScreenConfigAndRate(display, conf, root, size_index, RR_Rotate_0, current_rate, CurrentTime);
+  status = XRRSetScreenConfigAndRate(display, conf, root, size_index, RR_Rotate_0, rate, CurrentTime);
 
   XRRFreeScreenConfigInfo(conf);
   return status;
diff --git a/pkg/xorg/xorg.go b/pkg/xorg/xorg.go
index 703aa49d..2be47a66 100644
--- a/pkg/xorg/xorg.go
+++ b/pkg/xorg/xorg.go
@@ -192,23 +192,37 @@ func ChangeScreenSize(width int, height int, rate int16) (int, int, int16, error
 	// round width to 8, because of Xorg
 	width = width - (width % 8)
 
+	// if rate is 0, set it to 60
+	if rate == 0 {
+		rate = 60
+	}
+
 	// convert variables to C types
 	c_width, c_height, c_rate := C.int(width), C.int(height), C.short(rate)
 
 	// if screen configuration already exists, just set it
-	if status := C.XSetScreenConfiguration(c_width, c_height, &c_rate); status == C.RRSetConfigSuccess {
-		return width, height, int16(c_rate), nil
+	status := C.XSetScreenConfiguration(c_width, c_height, c_rate)
+	if status != C.RRSetConfigSuccess {
+		// create new screen configuration
+		C.XCreateScreenMode(c_width, c_height, c_rate)
+
+		// screen configuration should exist now, set it
+		status = C.XSetScreenConfiguration(c_width, c_height, c_rate)
 	}
 
-	// create new screen configuration
-	C.XCreateScreenMode(c_width, c_height, c_rate)
+	var err error
 
-	// screen configuration should exist now, set it
-	if status := C.XSetScreenConfiguration(c_width, c_height, &c_rate); status == C.RRSetConfigSuccess {
-		return width, height, int16(c_rate), nil
+	// if screen configuration was not set successfully, return error
+	if status != C.RRSetConfigSuccess {
+		err = fmt.Errorf("unknown screen configuration %dx%d@%d", width, height, rate)
 	}
 
-	return 0, 0, 0, fmt.Errorf("unknown screen configuration %dx%d@%d", width, height, rate)
+	// if specified rate is not supported a BadValue error is returned
+	if status == C.BadValue {
+		err = fmt.Errorf("unsupported screen rate %d", rate)
+	}
+
+	return width, height, rate, err
 }
 
 func GetScreenSize() types.ScreenSize {
diff --git a/pkg/xorg/xorg.h b/pkg/xorg/xorg.h
index a6e750d7..4bca692c 100644
--- a/pkg/xorg/xorg.h
+++ b/pkg/xorg/xorg.h
@@ -36,7 +36,7 @@ static KeyCode XKeyEntryGet(KeySym keysym);
 static KeyCode XkbKeysymToKeycode(Display *dpy, KeySym keysym);
 void XKey(KeySym keysym, int down);
 
-Status XSetScreenConfiguration(int width, int height, short *rate);
+Status XSetScreenConfiguration(int width, int height, short rate);
 void XGetScreenConfiguration(int *width, int *height, short *rate);
 void XGetScreenConfigurations();
 void XCreateScreenMode(int width, int height, short rate);