Add DPI helper #5030

src/lib/synergy/DpiHelper.cpp

@@ -0,0 +1,49 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2015 Synergy Seamless Inc.
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "synergy/DpiHelper.h"
+#include "base/Log.h"
+
+#include <assert.h> 
+
+size_t DpiHelper::s_dpi = kDefaultDpi;
+bool DpiHelper::s_dpiScaled = false;
+size_t DpiHelper::s_resolutionWidth = 0;
+size_t DpiHelper::s_resolutionHeight = 0;
+size_t DpiHelper::s_primaryWidthCenter = 0;
+size_t DpiHelper::s_primaryHeightCenter = 0;
+
+void DpiHelper::calculateDpi(size_t width, size_t height)
+{
+	if (s_resolutionWidth == 0 || s_resolutionHeight == 0) {
+		return;
+	}
+
+	size_t dpiTest1 = s_resolutionWidth * 100 / width;
+	size_t dpiTest2 = s_resolutionHeight * 100 / height;
+
+	assert(dpiTest1 == dpiTest2);
+
+	s_dpi = dpiTest1;
+
+	if (s_dpi != kDefaultDpi) {
+		s_dpiScaled = true;
+
+		LOG((CLOG_DEBUG "DPI: %d%%", s_dpi));
+		LOG((CLOG_DEBUG "physical resolution: %d, %d scaled resolution: %d, %d", s_resolutionWidth, s_resolutionHeight, width, height));
+	}
+}

src/lib/synergy/DpiHelper.h

@@ -0,0 +1,36 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2015 Synergy Seamless Inc.
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+class DpiHelper {
+public:
+	enum EDpi {
+		kDefaultDpi = 100
+	};
+
+	static void calculateDpi(size_t width, size_t height);
+	static float getDpi() { return (float)(s_dpi / 100.0f); }
+
+public:
+	static size_t s_dpi;
+	static bool s_dpiScaled;
+	static size_t s_resolutionWidth;
+	static size_t s_resolutionHeight;
+	static size_t s_primaryWidthCenter;
+	static size_t s_primaryHeightCenter;
+};