This is the skippy Reference Manual, version 1.3.12, generated automatically by Declt version 4.0 beta 2 "William Riker" on Sun Jun 15 07:26:27 2025 GMT+0.
skippy/skippy.asdskippy/package.lispskippy/conditions.lispskippy/types.lispskippy/bitstream.lispskippy/lzw.lispskippy/color-table.lispskippy/canvas.lispskippy/data-stream.lispskippy/image.lispskippy/gif89a.lispskippy/load-gif.lispThe main system appears first, followed by any subsystem dependency.
skippyRead and write GIF files
Zachary Beane <xach@xach.com>
BSD
1.3.12
package.lisp (file).
conditions.lisp (file).
types.lisp (file).
bitstream.lisp (file).
lzw.lisp (file).
color-table.lisp (file).
canvas.lisp (file).
data-stream.lisp (file).
image.lisp (file).
gif89a.lisp (file).
load-gif.lisp (file).
Files are sorted by type and then listed depth-first from the systems components trees.
skippy/skippy.asdskippy/package.lispskippy/conditions.lispskippy/types.lispskippy/bitstream.lispskippy/lzw.lispskippy/color-table.lispskippy/canvas.lispskippy/data-stream.lispskippy/image.lispskippy/gif89a.lispskippy/load-gif.lispskippy/conditions.lisppackage.lisp (file).
skippy (system).
color-table-full (condition).
lzw-error (condition).
missing-color-table (condition).
signature-error (condition).
skippy-error (condition).
skippy-warning (condition).
unexpected-value (condition).
color-table-full-color-table (reader method).
invalid-image-dimension-height (reader method).
invalid-image-dimension-width (reader method).
invalid-image-dimensions (condition).
lzw-error-description (reader method).
missing-color-table-image (reader method).
short-signature (condition).
signature-error-position (reader method).
signature-error-source (reader method).
signature-mismatch (condition).
skippy-warn (function).
unexpected-value-actual-value (reader method).
unexpected-value-description (reader method).
unexpected-value-expected-value (reader method).
unexpected-value-source (reader method).
unexpected-value-source-position (reader method).
skippy/types.lisppackage.lisp (file).
skippy (system).
bitstream-buffer (type).
buffer-offset (type).
image-dimension (type).
octet (type).
skippy/bitstream.lisppackage.lisp (file).
types.lisp (file).
skippy (system).
%make-bitstream (function).
*bitstream-slot-attributes* (special variable).
bitstream (structure).
bitstream-bits-left (reader).
(setf bitstream-bits-left) (writer).
bitstream-buffer (reader).
(setf bitstream-buffer) (writer).
bitstream-count (reader).
(setf bitstream-count) (writer).
bitstream-octet (reader).
(setf bitstream-octet) (writer).
bitstream-offset (reader).
(setf bitstream-offset) (writer).
bitstream-p (function).
bitstream-stream (reader).
(setf bitstream-stream) (writer).
copy-bitstream (function).
finish-input (function).
make-bitstream (function).
make-input-bitstream (function).
read-bits (function).
reset-stream (function).
with-bitstream-slots (macro).
write-bits (function).
skippy/lzw.lisppackage.lisp (file).
conditions.lisp (file).
bitstream.lisp (file).
skippy (system).
compression-context (class).
decompression-context (class).
entries (reader method).
lzw-compress (function).
lzw-decompress (function).
preds (reader method).
string-table-entry (type).
string-table-vector (type).
table (reader method).
skippy/color-table.lisppackage.lisp (file).
conditions.lisp (file).
skippy (system).
add-color (function).
color-rgb (function).
color-table (class).
color-table-entry (function).
(setf color-table-entry) (function).
color-table-entry (type).
color-table-size (function).
copy-color-table (function).
ensure-color (function).
find-color (function).
make-color-table (function).
print-object (method).
rgb-color (function).
+max-color-table-size+ (constant).
color-table-code-size (function).
entries (reader method).
skippy/canvas.lisppackage.lisp (file).
color-table.lisp (file).
skippy (system).
clip-canvas (function).
clone (method).
composite (function).
fill-area (method).
fill-canvas (function).
flip-horizontal (method).
flip-vertical (method).
height (reader method).
image-data (reader method).
(setf image-data) (writer method).
initialize-instance (method).
load-canvas (function).
make-canvas (function).
make-image-data (function).
pixel-ref (method).
(setf pixel-ref) (method).
print-object (method).
read-canvas (function).
rotate-180 (method).
save-canvas (function).
scale (method).
width (reader method).
write-canvas (function).
*canvas-magic* (special variable).
*file-format-version* (special variable).
canvas (class).
canvas-data (type).
canvas-index (type).
clip (function).
deinterlaced-image-data (function).
interlaced-image-data (function).
palette-index (type).
read-u32 (function).
write-u32 (function).
skippy/data-stream.lisppackage.lisp (file).
skippy (system).
add-delay (function).
add-image (function).
color-table (reader method).
(setf color-table) (writer method).
comment (reader method).
(setf comment) (writer method).
height (reader method).
images (reader method).
initialize-instance (method).
last-image (function).
loopingp (reader method).
(setf loopingp) (writer method).
make-data-stream (function).
print-object (method).
width (reader method).
check-dimensions (function).
data-stream (class).
skippy/image.lispdata-stream.lisp (file).
color-table.lisp (file).
canvas.lisp (file).
skippy (system).
*default-delay-time* (special variable).
canvas-image (function).
clone (method).
color-table (reader method).
(setf color-table) (writer method).
delay-time (reader method).
(setf delay-time) (writer method).
disposal-method (reader method).
(setf disposal-method) (writer method).
height (reader method).
(setf height) (writer method).
image-data (reader method).
(setf image-data) (writer method).
initialize-instance (method).
left-position (reader method).
(setf left-position) (writer method).
make-image (function).
print-object (method).
top-position (reader method).
(setf top-position) (writer method).
transparency-index (reader method).
(setf transparency-index) (writer method).
width (reader method).
(setf width) (writer method).
check-image-dimensions (function).
data-stream (reader method).
(setf data-stream) (method).
(setf data-stream) (writer method).
image (class).
interlacedp (reader method).
(setf interlacedp) (writer method).
transparentp (generic function).
wrap-image (method).
skippy/gif89a.lisppackage.lisp (file).
conditions.lisp (file).
types.lisp (file).
lzw.lisp (file).
data-stream.lisp (file).
image.lisp (file).
skippy (system).
output-data-stream (function).
write-data-stream (function).
*disposal-methods* (special variable).
*gif-signature* (special variable).
*netscape-signature* (special variable).
+gif-trailer-code+ (constant).
+image-separator-code+ (constant).
+pixel-aspect-ratio+ (constant).
boolean-bit (function).
compression-code-size (function).
disposal-method-value (function).
effective-color-table (function).
write-block-terminator (function).
write-color-table (function).
write-comment (function).
write-data-stream-header (function).
write-end-code (function).
write-graphic-control-block (function).
write-image (function).
write-netscape-looping-block (function).
write-uint16 (function).
skippy/load-gif.lisppackage.lisp (file).
conditions.lisp (file).
types.lisp (file).
lzw.lisp (file).
data-stream.lisp (file).
image.lisp (file).
gif89a.lisp (file).
skippy (system).
delay-time (reader method).
disposal-method (reader method).
load-data-stream (function).
read-data-stream (function).
transparency-index (reader method).
*effective-graphic-control* (special variable).
*gif87a-signature* (special variable).
*gif89a-signature* (special variable).
+application-label+ (constant).
+comment-label+ (constant).
+extension-introducer+ (constant).
+graphic-control-label+ (constant).
+plain-text-label+ (constant).
advance-stream-position (function).
bind-bits (macro).
check-gif-signature (function).
disposal-method-keyword (function).
graphic-control-extension (class).
merge-graphic-control (function).
process-objects (function).
read-application-extension (function).
read-color (function).
read-color-table (function).
read-comment-extension (function).
read-extension-object (function).
read-graphic-control-extension (function).
read-image (function).
read-uint16 (function).
skip-data-blocks (function).
stream-position (function).
Packages are listed by definition order.
skippycommon-lisp.
*default-delay-time* (special variable).
add-color (function).
add-delay (function).
add-image (function).
canvas-image (function).
clip-canvas (function).
clone (generic function).
color-rgb (function).
color-table (generic reader).
(setf color-table) (generic writer).
color-table (class).
color-table-entry (function).
(setf color-table-entry) (function).
color-table-entry (type).
color-table-full (condition).
color-table-size (function).
comment (generic reader).
(setf comment) (generic writer).
composite (function).
copy-color-table (function).
delay-time (generic reader).
(setf delay-time) (generic writer).
disposal-method (generic reader).
(setf disposal-method) (generic writer).
ensure-color (function).
fill-area (generic function).
fill-canvas (function).
find-color (function).
flip-horizontal (generic function).
flip-vertical (generic function).
height (generic reader).
(setf height) (generic writer).
image-data (generic reader).
(setf image-data) (generic writer).
images (generic reader).
last-image (function).
left-position (generic reader).
(setf left-position) (generic writer).
load-canvas (function).
load-data-stream (function).
loopingp (generic reader).
(setf loopingp) (generic writer).
lzw-error (condition).
make-canvas (function).
make-color-table (function).
make-data-stream (function).
make-image (function).
make-image-data (function).
missing-color-table (condition).
output-data-stream (function).
pixel-ref (generic function).
(setf pixel-ref) (generic function).
read-canvas (function).
read-data-stream (function).
rgb-color (function).
rotate-180 (generic function).
save-canvas (function).
scale (generic function).
signature-error (condition).
skippy-error (condition).
skippy-warning (condition).
top-position (generic reader).
(setf top-position) (generic writer).
transparency-index (generic reader).
(setf transparency-index) (generic writer).
unexpected-value (condition).
width (generic reader).
(setf width) (generic writer).
write-canvas (function).
write-data-stream (function).
%make-bitstream (function).
*bitstream-slot-attributes* (special variable).
*canvas-magic* (special variable).
*disposal-methods* (special variable).
*effective-graphic-control* (special variable).
*file-format-version* (special variable).
*gif-signature* (special variable).
*gif87a-signature* (special variable).
*gif89a-signature* (special variable).
*netscape-signature* (special variable).
+application-label+ (constant).
+comment-label+ (constant).
+extension-introducer+ (constant).
+gif-trailer-code+ (constant).
+graphic-control-label+ (constant).
+image-separator-code+ (constant).
+max-color-table-size+ (constant).
+pixel-aspect-ratio+ (constant).
+plain-text-label+ (constant).
advance-stream-position (function).
bind-bits (macro).
bitstream (structure).
bitstream-bits-left (reader).
(setf bitstream-bits-left) (writer).
bitstream-buffer (reader).
(setf bitstream-buffer) (writer).
bitstream-buffer (type).
bitstream-count (reader).
(setf bitstream-count) (writer).
bitstream-octet (reader).
(setf bitstream-octet) (writer).
bitstream-offset (reader).
(setf bitstream-offset) (writer).
bitstream-p (function).
bitstream-stream (reader).
(setf bitstream-stream) (writer).
boolean-bit (function).
buffer-offset (type).
canvas (class).
canvas-data (type).
canvas-index (type).
check-dimensions (function).
check-gif-signature (function).
check-image-dimensions (function).
clip (function).
color-table-code-size (function).
color-table-full-color-table (generic reader).
compression-code-size (function).
compression-context (class).
copy-bitstream (function).
data-stream (generic reader).
(setf data-stream) (generic function).
data-stream (class).
decompression-context (class).
deinterlaced-image-data (function).
disposal-method-keyword (function).
disposal-method-value (function).
effective-color-table (function).
entries (generic reader).
finish-input (function).
graphic-control-extension (class).
image (class).
image-dimension (type).
interlaced-image-data (function).
interlacedp (generic reader).
(setf interlacedp) (generic writer).
invalid-image-dimension-height (generic reader).
invalid-image-dimension-width (generic reader).
invalid-image-dimensions (condition).
lzw-compress (function).
lzw-decompress (function).
lzw-error-description (generic reader).
make-bitstream (function).
make-input-bitstream (function).
merge-graphic-control (function).
missing-color-table-image (generic reader).
octet (type).
palette-index (type).
preds (generic reader).
process-objects (function).
read-application-extension (function).
read-bits (function).
read-color (function).
read-color-table (function).
read-comment-extension (function).
read-extension-object (function).
read-graphic-control-extension (function).
read-image (function).
read-u32 (function).
read-uint16 (function).
reset-stream (function).
short-signature (condition).
signature-error-position (generic reader).
signature-error-source (generic reader).
signature-mismatch (condition).
skip-data-blocks (function).
skippy-warn (function).
stream-position (function).
string-table-entry (type).
string-table-vector (type).
table (generic reader).
transparentp (generic function).
unexpected-value-actual-value (generic reader).
unexpected-value-description (generic reader).
unexpected-value-expected-value (generic reader).
unexpected-value-source (generic reader).
unexpected-value-source-position (generic reader).
with-bitstream-slots (macro).
wrap-image (generic function).
write-bits (function).
write-block-terminator (function).
write-color-table (function).
write-comment (function).
write-data-stream-header (function).
write-end-code (function).
write-graphic-control-block (function).
write-image (function).
write-netscape-looping-block (function).
write-u32 (function).
write-uint16 (function).
Definitions are sorted by export status, category, package, and then by lexicographic order.
Return new dx,dy and sx,sy and width,height values to use when clipping SOURCE to fit within the bounds of DEST.
image)) ¶image)) ¶The local color table of the image, if any.
data-stream)) ¶data-stream)) ¶The global color table for the data stream (optional)
data-stream)) ¶automatically generated reader method
data-stream)) ¶automatically generated writer method
image)) ¶image)) ¶The time, in hundredths of a second, to wait after this image before displaying the next image
graphic-control-extension)) ¶automatically generated reader method
graphic-control-extension)) ¶automatically generated reader method
Horizontally mirror the image data of CANVAS.
Vertically mirror the image data of CANVAS.
data-stream)) ¶The height of the logical screen
data-stream)) ¶A vector of the images in the data stream
data-stream)) ¶automatically generated reader method
data-stream)) ¶automatically generated writer method
Does a 180-degree rotation of the image data of CANVAS.
image)) ¶image)) ¶The color table index of the transparent color for this image. If null, the image has no transparent color.
graphic-control-extension)) ¶automatically generated reader method
data-stream)) ¶The width of the logical screen
image) &key data-stream height width image-data color-table &allow-other-keys) ¶data-stream) &key color-table &allow-other-keys) ¶color-table) stream) ¶data-stream) stream) ¶:color-table
This slot is read-only.
:description
This slot is read-only.
:image
This slot is read-only.
error.
simple-warning.
(quote nil)
:description
This slot is read-only.
:actual-value
This slot is read-only.
(quote nil)
:expected-value
This slot is read-only.
(quote nil)
:source
This slot is read-only.
(quote nil)
:source-position
This slot is read-only.
The end-of-GIF marker.
Color tables are restricted by the GIF89a specification to 256 entries.
Pixel aspect ratios are not set.
The graphic control extension in effect for the current image.
The ASCII codes for the characters of the string "GIF89a".
The ASCII codes for the characters of the string "NETSCAPE2.0".
Skip past COUNT bytes of input in STREAM.
Check that STREAM starts with the ASCII string "GIF89a" or "GIF87a".
The number of bits needed to store the largest index in the color table. The spec-imposed minimum is 2.
Return the number of bits needed to represent the largest index in the effective color table of INDEX.
Return the color table in effect when writing out IMAGE, or signal an error if no color table is available.
Decompress the GIF LZW data from STREAM into VECTOR.
FILE-POSITION may return NIL or may signal an error (for e.g. Gray streams); wrap it.
Write COMMENT to the GIF. Since the characters must be ASCII, replace any out-of-range character codes with #\Space.
color-table-full)) ¶data-stream)) ¶color-table)) ¶automatically generated reader method
decompression-context)) ¶automatically generated reader method
invalid-image-dimensions)) ¶invalid-image-dimensions)) ¶missing-color-table)) ¶decompression-context)) ¶automatically generated reader method
signature-error)) ¶signature-error)) ¶compression-context)) ¶automatically generated reader method
unexpected-value)) ¶unexpected-value)) ¶unexpected-value)) ¶unexpected-value)) ¶unexpected-value)) ¶Return a data stream of the appropriate size that contains IMAGE.
structure-object.
skippy::bitstream-buffer
(make-array 255 :element-type (quote skippy::octet))
skippy::octet
0
common-lisp.
skippy::octet
0
skippy::octet
0
(mod 9)
8
common-lisp.
| Initarg | Value |
|---|---|
:height | (error ~s required height) |
:width | (error ~s required width) |
:image-data
Store data structures that may be re-used when writing out multiple images in a GIF animation.
A DATA-STREAM instance represents a container for GIF image data. It defines the logical dimensions of the overall image. It may contain a color table, which is used if an individual image does not provide its own color table.
| Initarg | Value |
|---|---|
:height | (error ~a initarg is required height) |
:width | (error ~a initarg is required width) |
:color-table | nil |
:loopingp | nil |
:comment | nil |
:images | (make-array 10 adjustable t fill-pointer 0) |
The height of the logical screen
:height
This slot is read-only.
The width of the logical screen
:width
This slot is read-only.
The global color table for the data stream (optional)
:color-table
:loopingp
:comment
A decompression context is used to hold data structures that may be re-used for repeated calls to lzw-decompress, so they don’t have to be allocated fresh each time.
(make-array 4096 :element-type (quote skippy::string-table-entry) :initial-element -1)
This slot is read-only.
:delay-time
This slot is read-only.
:disposal-method
This slot is read-only.
:transparency-index
This slot is read-only.
An IMAGE instance represents a graphic within a GIF data stream. There may be multiple images in the data stream.
clone.
(setf color-table).
color-table.
(setf data-stream).
data-stream.
(setf delay-time).
delay-time.
(setf disposal-method).
disposal-method.
(setf height).
height.
(setf image-data).
image-data.
initialize-instance.
(setf interlacedp).
interlacedp.
(setf left-position).
left-position.
print-object.
(setf top-position).
top-position.
(setf transparency-index).
transparency-index.
(setf width).
width.
| Initarg | Value |
|---|---|
:top-position | 0 |
:left-position | 0 |
:color-table | nil |
:interlacedp | nil |
:height | nil |
:width | nil |
:disposal-method | unspecified |
:delay-time | *default-delay-time* |
:transparency-index | nil |
The data stream in which this image occurs.
:data-stream
:height
:width
:image-data
The position of the image relative to the top of the logical screen
:top-position
The position of the image relative to the left of the logical screen
:left-position
The local color table of the image, if any.
:color-table
Is the image interlaced?
:interlacedp
:disposal-method
The time, in hundredths of a second, to wait after this image before displaying the next image
:delay-time
The color table index of the transparent color for this image. If null, the image has no transparent color.
:transparency-index
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