1GLHINT(3G) GLHINT(3G)
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6 glHint - specify implementation-specific hints
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10 void glHint( GLenum target,
11 GLenum mode )
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15 target Specifies a symbolic constant indicating the behavior to be
16 controlled. GL_FOG_HINT, GL_LINE_SMOOTH_HINT,
17 GL_PERSPECTIVE_CORRECTION_HINT, GL_POINT_SMOOTH_HINT, and
18 GL_POLYGON_SMOOTH_HINT are accepted.
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20 mode Specifies a symbolic constant indicating the desired behavior.
21 GL_FASTEST, GL_NICEST, and GL_DONT_CARE are accepted.
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24 Certain aspects of GL behavior, when there is room for interpretation,
25 can be controlled with hints. A hint is specified with two arguments.
26 target is a symbolic constant indicating the behavior to be controlled,
27 and mode is another symbolic constant indicating the desired behavior.
28 The initial value for each target is GL_DONT_CARE. mode can be one of
29 the following:
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31 GL_FASTEST The most efficient option should be chosen.
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33 GL_NICEST The most correct, or highest quality, option should
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36 GL_DONT_CARE No preference.
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38 Though the implementation aspects that can be hinted are well defined,
39 the interpretation of the hints depends on the implementation. The
40 hint aspects that can be specified with target, along with suggested
41 semantics, are as follows:
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43 GL_FOG_HINT Indicates the accuracy of fog calculation. If per-
44 pixel fog calculation is not efficiently supported
45 by the GL implementation, hinting GL_DONT_CARE or
46 GL_FASTEST can result in per-vertex calculation of
47 fog effects.
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49 GL_LINE_SMOOTH_HINT Indicates the sampling quality of antialiased
50 lines. If a larger filter function is applied,
51 hinting GL_NICEST can result in more pixel frag‐
52 ments being generated during rasterization,
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54 GL_PERSPECTIVE_CORRECTION_HINT
55 Indicates the quality of color and texture coordi‐
56 nate interpolation. If perspective-corrected
57 parameter interpolation is not efficiently sup‐
58 ported by the GL implementation, hinting
59 GL_DONT_CARE or GL_FASTEST can result in simple
60 linear interpolation of colors and/or texture coor‐
61 dinates.
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63 GL_POINT_SMOOTH_HINT
64 Indicates the sampling quality of antialiased
65 points. If a larger filter function is applied,
66 hinting GL_NICEST can result in more pixel frag‐
67 ments being generated during rasterization,
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69 GL_POLYGON_SMOOTH_HINT
70 Indicates the sampling quality of antialiased poly‐
71 gons. Hinting GL_NICEST can result in more pixel
72 fragments being generated during rasterization, if
73 a larger filter function is applied.
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76 The interpretation of hints depends on the implementation. Some imple‐
77 mentations ignore glHint settings.
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80 GL_INVALID_ENUM is generated if either target or mode is not an
81 accepted value.
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83 GL_INVALID_OPERATION is generated if glHint is executed between the
84 execution of glBegin and the corresponding execution of glEnd.
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88 GLHINT(3G)