1GLHINT(3G)                       OpenGL Manual                      GLHINT(3G)
2
3
4

NAME

6       glHint - specify implementation-specific hints
7

C SPECIFICATION

9       void glHint(GLenum target, GLenum mode);
10

PARAMETERS

12       target
13           Specifies a symbolic constant indicating the behavior to be
14           controlled.  GL_LINE_SMOOTH_HINT, GL_POLYGON_SMOOTH_HINT,
15           GL_TEXTURE_COMPRESSION_HINT, and GL_FRAGMENT_SHADER_DERIVATIVE_HINT
16           are accepted.
17
18       mode
19           Specifies a symbolic constant indicating the desired behavior.
20           GL_FASTEST, GL_NICEST, and GL_DONT_CARE are accepted.
21

DESCRIPTION

23       Certain aspects of GL behavior, when there is room for interpretation,
24       can be controlled with hints. A hint is specified with two arguments.
25       target is a symbolic constant indicating the behavior to be controlled,
26       and mode is another symbolic constant indicating the desired behavior.
27       The initial value for each target is GL_DONT_CARE.  mode can be one of
28       the following:
29
30       GL_FASTEST
31
32           The most efficient option should be chosen.
33
34       GL_NICEST
35
36           The most correct, or highest quality, option should be chosen.
37
38       GL_DONT_CARE
39
40           No preference.
41
42       Though the implementation aspects that can be hinted are well defined,
43       the interpretation of the hints depends on the implementation. The hint
44       aspects that can be specified with target, along with suggested
45       semantics, are as follows:
46
47       GL_FRAGMENT_SHADER_DERIVATIVE_HINT
48
49           Indicates the accuracy of the derivative calculation for the GL
50           shading language fragment processing built-in functions: dFdx,
51           dFdy, and fwidth.
52
53       GL_LINE_SMOOTH_HINT
54
55           Indicates the sampling quality of antialiased lines. If a larger
56           filter function is applied, hinting GL_NICEST can result in more
57           pixel fragments being generated during rasterization.
58
59       GL_POLYGON_SMOOTH_HINT
60
61           Indicates the sampling quality of antialiased polygons. Hinting
62           GL_NICEST can result in more pixel fragments being generated during
63           rasterization, if a larger filter function is applied.
64
65       GL_TEXTURE_COMPRESSION_HINT
66
67           Indicates the quality and performance of the compressing texture
68           images. Hinting GL_FASTEST indicates that texture images should be
69           compressed as quickly as possible, while GL_NICEST indicates that
70           texture images should be compressed with as little image quality
71           loss as possible.  GL_NICEST should be selected if the texture is
72           to be retrieved by glGetCompressedTexImage() for reuse.
73

NOTES

75       The interpretation of hints depends on the implementation. Some
76       implementations ignore glHint settings.
77

ERRORS

79       GL_INVALID_ENUM is generated if either target or mode is not an
80       accepted value.
81

83       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
84       under the SGI Free Software B License. For details, see
85       http://oss.sgi.com/projects/FreeB/.
86

AUTHORS

88       opengl.org
89
90
91
92opengl.org                        06/10/2014                        GLHINT(3G)
Impressum