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52 lines
2.3 KiB
Plaintext
52 lines
2.3 KiB
Plaintext
#
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# $Id: README.Raster,v 1.3 2001/03/04 15:01:12 ltoetsch Exp $
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#
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This is the README file for the Raster display driver for lcd4linux
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This driver is intended to create various raster formats, at the moment
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there is support for binary PPM (portable pixmap) and PNG.
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The driver creates the output file(s) specified with the -o switch. The
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parameter is used as a format string for sprintf(), if you specify '%d'
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in the output file, files with a sequence number will be created.
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The output file is first created with a '.tmp' extension, this temporary
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file will be written and closed, and finally (atomically) renamed. This way
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you can be shure that you will always get a complete file, but its contents
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changes every 'tick' milliseconds.
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Configuration:
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The driver needs/supports the following entries in lcd4linux.conf:
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Display: must be either "PPM" or "PNG"
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size: [columns]x[rows], e.g. "20x4"
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font: [xrex]x[yres], at the moment only "5x8" and "6x8" supported.
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pixel: [pixelsize]+[pixelgap], e.g. "5+1"
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gap: [row gap]x[column gap], e.g. "3x3"
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border: border width
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foreground: color of an active LCD Pixel, must be #rrggbb
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halfground: color of an inactive LCD Pixel, must be #rrggbb
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background: backlight color, must be #rrggbb
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This may look weird, but it is weird. Let's explain this a bit further:
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The raster driver tries to emulate a real LC display. A real LCD has a
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size of columns*rows characters. Each character consists of xres*yres
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LCD cells. One single cell will be represented by a rectangle of
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pixelsize*pixelsize pixels. If you want to, you can emulate the gap
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between this lcd cells by specifying a pixelgap greater than zero.
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Sometimes there's a gap between characters, too. You can specify this
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gap (in pixels again) horizontally and vertically. Usually this gap
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is the same size as a cell (which is pixelsize+pixelgap). If you specify
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either the row gap or the column gap as -1, this cell size will be used
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instead.
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If you use a font of 5x8, some characters may use the first and the last
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pixel. So you should specify a column gap, otherwise the caracters may
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touch. On the other hand, the 6x8 font never uses the first pixel. So you
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can omit the column gap, and will get the same text layout, but
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uninterupted bars!
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After all: don't try to understand this unless you have tried it out!
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