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| author | Russ Cox <rsc@swtch.com> | 2012-11-25 22:15:57 -0500 |
|---|---|---|
| committer | Russ Cox <rsc@swtch.com> | 2012-11-25 22:15:57 -0500 |
| commit | 9f3851871ed6edb544dfe5b518bff0121d6c020b (patch) | |
| tree | 086485c69525c1923fc55f65a93605bd14e85f38 | |
| parent | 323e7d0193999a22e605786d06fcff76cb780e38 (diff) | |
| download | plan9port-9f3851871ed6edb544dfe5b518bff0121d6c020b.tar.gz plan9port-9f3851871ed6edb544dfe5b518bff0121d6c020b.tar.bz2 plan9port-9f3851871ed6edb544dfe5b518bff0121d6c020b.zip | |
libdraw: add scalesize
R=rsc
http://codereview.appspot.com/6855092
| -rw-r--r-- | include/draw.h | 1 | ||||
| -rw-r--r-- | man/man3/graphics.3 | 16 | ||||
| -rw-r--r-- | src/libdraw/init.c | 7 |
3 files changed, 24 insertions, 0 deletions
diff --git a/include/draw.h b/include/draw.h index 9bf5ce12..fe059aca 100644 --- a/include/draw.h +++ b/include/draw.h @@ -351,6 +351,7 @@ extern Image* namedimage(Display*, char*); extern int nameimage(Image*, char*, int); extern Image* allocimagemix(Display*, u32int, u32int); extern int drawsetlabel(char*); +extern int scalesize(Display*, int); /* * Colors diff --git a/man/man3/graphics.3 b/man/man3/graphics.3 index 4b39332d..d07c269a 100644 --- a/man/man3/graphics.3 +++ b/man/man3/graphics.3 @@ -62,6 +62,9 @@ int gengetwindow(Display *d, char *winname, Image **ip, Screen **sp, int ref) .PP .B +int scalesize(Display *d, int n) +.PP +.B void cursorswitch(Cursor *curs) .PP .B @@ -502,6 +505,19 @@ and .B Screen variables for the new window. .PP +Historically, Plan 9 graphics programs have used fixed-size graphics features that assume a narrow range of display densities, around 100 dpi: pixels (or dots) per inch. +The new field +.B display->dpi +contains the display's actual density if known, or else +.B DefaultDPI +(100). +.I Scalesize +scales the fixed pixel count +.I n +by +.BR display->dpi / DefaultDPI , +rounding appropriately. +.PP The mouse cursor is always displayed. The initial cursor is an arrow. .I Cursorswitch diff --git a/src/libdraw/init.c b/src/libdraw/init.c index c698ec68..b2df7fd7 100644 --- a/src/libdraw/init.c +++ b/src/libdraw/init.c @@ -428,3 +428,10 @@ bufimage(Display *d, int n) return p; } +int +scalesize(Display *d, int n) +{ + if(d == nil || d->dpi <= DefaultDPI) + return n; + return (n*d->dpi+DefaultDPI/2)/DefaultDPI; +} |