Initial community commit

Src/Winamp/dpi.cpp

@@ -0,0 +1,106 @@
+#include "main.h"
+#include "dpi.h"
+
+// DPI awareness based on http://msdn.microsoft.com/en-US/library/dd464660.aspx
+// Definition: relative pixel = 1 pixel at 96 DPI and scaled based on actual DPI.
+
+BOOL _fInitialized = FALSE;
+int _dpiX = 96, _dpiY = 96;
+
+void _Init()
+{
+    if (!_fInitialized)
+    {
+        HDC hdc = GetDC(NULL);
+        if (hdc)
+        {
+            _dpiX = GetDeviceCaps(hdc, LOGPIXELSX);
+            _dpiY = GetDeviceCaps(hdc, LOGPIXELSY);
+            ReleaseDC(NULL, hdc);
+        }
+        _fInitialized = TRUE;
+    }
+}
+
+// Get screen DPI.
+int GetDPIX()
+{
+	_Init();
+	return _dpiX;
+}
+
+int GetDPIY()
+{
+	_Init();
+	return _dpiY;
+}
+
+// Convert between raw pixels and relative pixels.
+int ScaleX(int x)
+{
+	_Init();
+	return MulDiv(x, _dpiX, 96);
+}
+
+int ScaleY(int y)
+{
+	_Init();
+	return MulDiv(y, _dpiY, 96);
+}
+
+int UnscaleX(int x)
+{
+	_Init();
+	return MulDiv(x, 96, _dpiX);
+}
+
+int UnscaleY(int y)
+{
+	_Init();
+	return MulDiv(y, 96, _dpiY);
+}
+
+int _ScaledSystemMetricX(int nIndex)
+{
+    _Init();
+    return MulDiv(GetSystemMetrics(nIndex), 96, _dpiX);
+}
+
+int _ScaledSystemMetricY(int nIndex)
+{
+    _Init();
+    return MulDiv(GetSystemMetrics(nIndex), 96, _dpiY);
+}
+
+// Determine the screen dimensions in relative pixels.
+int ScaledScreenWidth()
+{
+	return _ScaledSystemMetricX(SM_CXSCREEN);
+}
+
+int ScaledScreenHeight()
+{
+	return _ScaledSystemMetricY(SM_CYSCREEN);
+}
+
+// Scale rectangle from raw pixels to relative pixels.
+void ScaleRect(__inout RECT *pRect)
+{
+    pRect->left = ScaleX(pRect->left);
+    pRect->right = ScaleX(pRect->right);
+    pRect->top = ScaleY(pRect->top);
+    pRect->bottom = ScaleY(pRect->bottom);
+}
+
+// Determine if screen resolution meets minimum requirements in relative pixels.
+BOOL IsResolutionAtLeast(int cxMin, int cyMin)
+{
+    return (ScaledScreenWidth() >= cxMin) && (ScaledScreenHeight() >= cyMin);
+}
+
+// Convert a point size (1/72 of an inch) to raw pixels.
+int PointsToPixels(int pt)
+{
+	_Init();
+	return MulDiv(pt, _dpiY, 72);
+}