39 lines
1.3 KiB
Racket
39 lines
1.3 KiB
Racket
#lang scribble/doc
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@(require "common.ss"
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(for-label mrlib/image-core))
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@title{Image Core}
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@defmodule[mrlib/image-core]
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This library is the core part of the @racketmodname[2htdp/image] library that DrRacket
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links into the namespace of all languages that it runs. This ensures that minimal
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support for these images are the same in all languages, specifically including
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support for printing the images and constructing the core data structures making
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up an image.
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@defproc[(render-image [image image?]
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[dc (is-a?/c dc<%>)]
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[dx number?]
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[dy number?])
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void?]{
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Draws @racket[image] in @racket[dc] at the position (@racket[dx],@racket[dy]).
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}
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@defproc[(image? [v any/c]) boolean?]{
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Recognizes the images that library handles.
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}
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@defproc[(un/cache-image [image image?] [b any/c]) image?]{
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Returns an image that either caches its drawing in the
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snip @method[snip% draw] method or doesn't, depending on @racket[b].
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}
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@defproc[(compute-image-cache [image image?]) void?]{
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When the image has a bitmap-cache (which it does by default,
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although @racket[un/cache-image] can disable it), this function
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fills in the bitmap, doing the work to draw image into the bitmap.
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Ordinarily, the image's bitmap cache is computed the first time
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the image is actually rendered.
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} |