Platform/Unix/UnixMisc.cpp: implement display mode lookups using xrandr extension.

source/Platform/Unix/UnixMisc.cpp

@@ -1,15 +1,115 @@
 
+#include <Spectre/System/Log.h>
 #include <Platform/PlatformMisc.h>
+#include "X11SharedDisplay.h"
+#include <X11/Xlib.h>
+#include <X11/extensions/Xrandr.h>
+#include <algorithm>
 
 namespace sp {
 
+// Code "borrowed" from SFML :)
+// see: https://github.com/SFML/SFML/blob/master/src/SFML/Window/Unix/VideoModeImpl.cpp
+
 void PlatformMisc::GetDisplayModes(std::vector<DisplayMode>& modes)
 {
+	::Display *disp = XGetDisplay();
+
+	if (disp) {
+		int scr = DefaultScreen(disp);
+
+		// Check for XRandR.
+		int ver;
+		if (XQueryExtension(disp, "RANDR", &ver, &ver, &ver)) {
+
+			XRRScreenConfiguration* config = ::XRRGetScreenInfo(disp, RootWindow(disp, scr));
+			if (config) {
+				int nbSizes;
+                XRRScreenSize* sizes = ::XRRConfigSizes(config, &nbSizes);
+				if (sizes && nbSizes > 0) {
+					int nbDepths = 0;
+					int* depths = XListDepths(disp, scr, &nbDepths);
+					if (depths && nbDepths > 0) {
+
+						for(int i = 0; i < nbDepths; i++) {
+							for(int j = 0; j < nbSizes; j++) {
+								DisplayMode mode(sizes[j].width, sizes[j].height, depths[i]);
+
+								::Rotation rot;
+								XRRConfigRotations(config, &rot);
+
+								if (rot == RR_Rotate_90 || rot == RR_Rotate_270) {
+									std::swap(mode.width, mode.height);
+								}
+
+								if (std::find(modes.begin(), modes.end(), mode) == modes.end()) {
+									modes.push_back(mode);
+								}
+							}
+						}
+
+						XFree(depths);
+					}
+				}
+			} else {
+				Log::error("Failed to get screen configuration while trying to get display modes.");
+			}
+
+			XRRFreeScreenConfigInfo(config);
+		} else {
+			Log::error("Failed to use XRandR extension while trying to get display modes.");
+		}
+
+		XReleaseDisplay();
+	} else {
+		Log::error("Failed to connect to the X server while trying to get display modes.");
+	}
 }
 
 DisplayMode PlatformMisc::GetDesktopMode()
 {
-	return DisplayMode();
+	DisplayMode mode;
+
+	::Display *disp = XGetDisplay();
+
+	if (disp) {
+		int scr = DefaultScreen(disp);
+
+		// Check for XRandR.
+		int ver;
+		if (XQueryExtension(disp, "RANDR", &ver, &ver, &ver)) {
+
+			XRRScreenConfiguration* config = ::XRRGetScreenInfo(disp, RootWindow(disp, scr));
+			if (config) {
+				int nbSizes;
+				::Rotation rot;
+				int current = XRRConfigCurrentConfiguration(config, &rot);
+
+                XRRScreenSize* sizes = ::XRRConfigSizes(config, &nbSizes);
+				if (sizes && nbSizes > 0) {
+
+					mode = DisplayMode(sizes[current].width, sizes[current].height, DefaultDepth(disp, scr));
+
+					XRRConfigRotations(config, &rot);
+					if (rot == RR_Rotate_90 || rot == RR_Rotate_270) {
+						std::swap(mode.width, mode.height);
+					}
+				}
+			} else {
+				Log::error("Failed to get screen configuration while trying to get desktop display mode.");
+			}
+
+			XRRFreeScreenConfigInfo(config);
+		} else {
+			Log::error("Failed to use XRandR extension while trying to get desktop display mode.");
+		}
+
+		XReleaseDisplay();
+	} else {
+		Log::error("Failed to connect to the X server while trying to get desktop display mode.");
+	}
+
+	return mode;
 }
 
 } // namespace sp