32 lines
1.6 KiB
Racket
32 lines
1.6 KiB
Racket
#lang scribble/doc
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@(require "common.ss")
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@title[#:tag "overview"]{Using OpenGL}
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The @racketmodname[sgl/gl] library provides direct access to the
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C-style OpenGL API, whereas the @racketmodname[sgl] library provides a
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more Racket-like interface. The @racketmodname[sgl/gl] library
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provides a binding for each @tt{#defined} constant and for most
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functions in OpenGL 1.5 and GLU 1.3. The functions perform comparable
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checking to their C-language counterparts; they check the types of
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their arguments, but do not check the length of array arguments. The
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@racketmodname[sgl] library provides wrappers around many of the
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functions in the @racketmodname[sgl/gl] library to present a more
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Racket-friendly interface, including function names that follow Racket
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conventions, and checked, symbolic enumeration arguments, and
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array-length checks.
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@bold{Warning on Safety:} OpenGL programming is inherently unsafe,
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even when using only the @racketmodname[sgl] library. Although
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@racketmodname[sgl] checks the arguments to each function call,
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violation of higher-level assumptions of the system's OpenGL library
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can cause it to crash, bringing the entire Racket system down. For
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example, sending a large number of vertices in a single @tt{glBegin}
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causes at least some GL implementations to crash.
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Some examples are available in the @filepath{examples} directory of
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the @filepath{sgl} collection in the Racket installation. For
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@filepath{alpha.ss}, try choosing the @filepath{sk.jpg} image distritbuted
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with Racket in the @filepath{icons} collection; you may have to
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press the ``t'' key a few times if the spinning cube is blank.
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