38 lines
1.3 KiB
C
38 lines
1.3 KiB
C
/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3 - an improved dynamic tiling window manager
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* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
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*
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*/
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#include "libi3.h"
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#include <math.h>
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extern xcb_screen_t *root_screen;
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/*
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* Convert a logical amount of pixels (e.g. 2 pixels on a “standard” 96 DPI
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* screen) to a corresponding amount of physical pixels on a standard or retina
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* screen, e.g. 5 pixels on a 227 DPI MacBook Pro 13" Retina screen.
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*
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*/
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int logical_px(const int logical) {
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if (root_screen == NULL) {
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/* Dpi info may not be available when parsing a config without an X
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* server, such as for config file validation. */
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return logical;
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}
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const int dpi = (double)root_screen->height_in_pixels * 25.4 /
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(double)root_screen->height_in_millimeters;
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/* There are many misconfigurations out there, i.e. systems with screens
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* whose dpi is in fact higher than 96 dpi, but not significantly higher,
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* so software was never adapted. We could tell people to reconfigure their
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* systems to 96 dpi in order to get the behavior they expect/are used to,
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* but since we can easily detect this case in code, let’s do it for them.
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*/
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if ((dpi / 96.0) < 1.25)
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return logical;
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return ceil((dpi / 96.0) * logical);
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}
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