diff options
Diffstat (limited to 'doc/photo.n')
| -rw-r--r-- | doc/photo.n | 27 |
1 files changed, 12 insertions, 15 deletions
diff --git a/doc/photo.n b/doc/photo.n index 7f03fe7..c14abe3 100644 --- a/doc/photo.n +++ b/doc/photo.n @@ -30,10 +30,8 @@ C code through a procedural interface. At present, only GIF and PPM/PGM formats are supported, but an interface exists to allow additional image file formats to be added easily. A photo image is transparent in regions where no image data has been supplied -.VS 8.4 or where it has been set transparent by the \fBtransparency set\fR subcommand. -.VE 8.4 .SH "CREATING PHOTOS" .PP Like all images, photos are created using the \fBimage create\fR @@ -188,7 +186,6 @@ about the Y or X axes, respectively. If \fIy\fR is not given, the default value is the same as \fIx\fR. .TP \fB\-compositingrule \fIrule\fR -.VS 8.4 Specifies how transparent pixels in the source image are combined with the destination image. When a compositing rule of \fIoverlay\fR is set, the old contents of the destination image are visible, as if the @@ -197,7 +194,6 @@ over the top of the destination. When a compositing rule of \fIset\fR is set, the old contents of the destination image are discarded and the source image is used as-is. The default compositing rule is \fIoverlay\fR. -.VE 8.4 .RE .TP \fIimageName \fBdata ?\fIoption value(s) ...\fR? @@ -214,9 +210,14 @@ the specified color. Specifies the name of the image file format handler to be used. Specifically, this subcommand searches for the first handler whose name matches an initial substring of -\fIformat-name\fR and which has the capability to read this image data. -If this option is not given, this subcommand uses the first -handler that has the capability to read the image data. +\fIformat-name\fR and which has the capability to write a string +containing this image data. +If this option is not given, this subcommand uses a format that +consists of a list (one element per row) of lists (one element per +pixel/column) of colors in +.QW \fB#\fIrrggbb\fR +format (where \fIrr\fR is a pair of hexadecimal digits for the red +channel, \fIgg\fR for green, and \fIbb\fR for blue). .TP \fB\-from \fIx1 y1 x2 y2\fR Specifies a rectangular region of \fIimageName\fR to be returned. @@ -259,8 +260,8 @@ format handler to read the data. .TP \fB\-to \fIx1 y1\fR ?\fIx2 y2\fR? Specifies the coordinates of the top-left corner (\fIx1\fR,\fIy1\fR) -of the region of \fIimageName\fR into which data from \fIfilename\fR -are to be read. The default is (0,0). If \fIx2\fR,\fIy2\fR is given +of the region of \fIimageName\fR into which the image data will be +copied. The default position is (0,0). If \fIx2\fR,\fIy2\fR is given and \fIdata\fR is not large enough to cover the rectangle specified by this option, the image data extracted will be tiled so it covers the entire destination rectangle. Note that if \fIdata\fR specifies a @@ -316,7 +317,6 @@ recalculate the dithered image in each window where the image is displayed. .TP \fIimageName \fBtransparency \fIsubcommand ?arg arg ...?\fR -.VS 8.4 Allows examination and manipulation of the transparency information in the photo image. Several subcommands are available: .RS @@ -329,7 +329,6 @@ transparent. Makes the pixel at (\fIx\fR,\fIy\fR) transparent if \fIboolean\fR is true, and makes that pixel opaque otherwise. .RE -.VE 8.4 .TP \fIimageName \fBwrite \fIfilename\fR ?\fIoption value(s) ...\fR? Writes image data from \fIimageName\fR to a file named \fIfilename\fR. @@ -374,7 +373,7 @@ When reading an image file or processing string data specified with the \fB\-data\fR configuration option, the photo image code invokes each handler in turn until one is found that claims to be able to read the data in the file or string. -Usually this will find the correct handler, but if it doesn't, the +Usually this will find the correct handler, but if it does not, the user may give a format name with the \fB\-format\fR option to specify which handler to use. In fact the photo image code will try those handlers whose names begin with the string specified for the @@ -390,10 +389,8 @@ for the \fB\-format\fR option must begin with the complete name of the requested handler, and may contain additional information following that, which the handler can use, for example, to specify which variant to use of the formats supported by the handler. -.VS 8.4 Note that not all image handlers may support writing transparency data to a file, even where the target image format does. -.VE 8.4 .SH "COLOR ALLOCATION" .PP When a photo image is displayed in a window, the photo image code @@ -433,7 +430,7 @@ Load an image from a file and tile it to the size of a window, which is useful for producing a tiled background: .CS # These lines should be called once -\fBimage create photo\fR untiled -file "theFile.ppm" +\fBimage create photo\fR untiled \-file "theFile.ppm" \fBimage create photo\fR tiled # These lines should be called whenever .someWidget changes |