gistfile1.txt

float getDisplayDensity()
{
	const char* current_display = getenv("DISPLAY");
	if (current_display == 0)
		return g_settings->getFloat("screen_dpi")/96.0;

	Display * x11display = XOpenDisplay(current_display);

	float dpi_height = floor(DisplayHeight(x11display, 0) / (DisplayHeightMM(x11display, 0) * 0.039370) + 0.5);
	float dpi_width = floor(DisplayWidth(x11display, 0) / (DisplayWidthMM(x11display, 0) * 0.039370) +0.5);

XCloseDisplay(x11display);

	errorstream << "DPIH: " << dpi_height << " DPIW: " << dpi_width << std::endl;

	return (std::max(dpi_height,dpi_width) / 96.0);
}