GlHint: Difference between revisions

Latest revision as of 01:05, 28 January 2023

The _glHint statement specifies implementation-specific hints.

Syntax

_glHint GLenum target, GLenum mode

Parameters

OpenGL is using its own set of variable types to describe its command parameters.
Use the following table to find the respective QB64 Variable Types.

   Table 2: Relations between the OpenGL variable types vs. C/C++ and QB64.
 ┌──────────────┬────────────────┬──────────────────────────────────────────┐
 │    OpenGL    │     C/C++      │     QB64                                 │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLenum       │ unsigned int   │ _UNSIGNED LONG                           │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLboolean    │ unsigned char  │ _UNSIGNED _BYTE                          │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLbitfield   │ unsigned int   │ _UNSIGNED LONG                           │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLbyte       │ signed char    │ _BYTE                                    │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLshort      │ short          │ INTEGER                                  │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLint        │ int            │ LONG                                     │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLsizei      │ int            │ LONG                                     │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLubyte      │ unsigned char  │ _UNSIGNED _BYTE                          │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLushort     │ unsigned short │ _UNSIGNED INTEGER                        │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLuint       │ unsigned int   │ _UNSIGNED LONG                           │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLfloat      │ float          │ SINGLE                                   │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLclampf     │ float          │ SINGLE                                   │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLdouble     │ double         │ DOUBLE                                   │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLclampd     │ double         │ DOUBLE                                   │
 ├──────────────┼────────────────┼──────────────────────────────────────────┤
 │ GLvoid   (1) │ void           │ _OFFSET(any fixed lenght string or _BYTE │
 │              │                │         array element)                   │
 └──────────────┴────────────────┴──────────────────────────────────────────┘
 Note: If a parameter has an asterisk (*) in front, then it's a pointer to
       the designated OpenGL variable type, rather than a value of that type.
       Those must be passed using the _OFFSET(...) notation.

 E.g.  GLuint *anyParam is actually the offset of a _UNSIGNED LONG (~&)
       variable or array, which must be passed as _OFFSET(anyVar~&) or
       _OFFSET(anyArr~&()) respectively.

  (1)  This type is regularly only used for pointers (with asterisk (*)) to
       any byte sized memory data, hence _BYTE or fixed length strings.

Description

OpenGL's documentation is available in several places, so we won't reproduce it here for another time.
The full description for this command can be found at Microsoft Docs and is also valid for QB64 usage.

@@ Line 1: / Line 1: @@
-'''_glHint:''' specify implementation-specific hints
+{{DISPLAYTITLE:_glHint}}
+The '''_glHint''' statement specifies implementation-specific hints.
 {{PageSyntax}}
+: [[_glHint]] GLenum {{Parameter|target}}, GLenum {{Parameter|mode}}
-  SUB _glHint (BYVAL target AS _UNSIGNED LONG, BYVAL mode AS _UNSIGNED LONG)
-  void '''_glHint'''(GLenum {{Parameter|target}}, GLenum {{Parameter|mode}});
+{{PageParameters}}
-; target
+* OpenGL is using its own set of variable types to describe its command parameters.
-: Specifies a symbolic constant indicating the behavior to be controlled. {{KW|_GL_LINE_SMOOTH_HINT}}, {{KW|_GL_POLYGON_SMOOTH_HINT}}, {{KW|_GL_TEXTURE_COMPRESSION_HINT}}, and {{KW|_GL_FRAGMENT_SHADER_DERIVATIVE_HINT}} are accepted.
+* Use the following table to find the respective QB64 [[Variable Types]].
-; mode
+{{OpenGLTypesPlugin}}
-: Specifies a symbolic constant indicating the desired behavior. {{KW|_GL_FASTEST}}, {{KW|_GL_NICEST}}, and {{KW|_GL_DONT_CARE}} are accepted.
 {{PageDescription}}
+* OpenGL's documentation is available in several places, so we won't reproduce it here for another time.
+* The full description for this command can be found at [https://learn.microsoft.com/en-us/windows/win32/opengl/glhint Microsoft Docs] and is also valid for QB64 usage.
-Certain aspects of GL behavior, when there is room for interpretation, can be controlled with hints. A hint is specified with two arguments. {{Parameter|target}} is a symbolic constant indicating the behavior to be controlled, and {{Parameter|mode}} is another symbolic constant indicating the desired behavior. The initial value for each {{Parameter|target}} is {{KW|_GL_DONT_CARE}}. {{Parameter|mode}} can be one of the following:
-; {{KW|_GL_FASTEST}}
-:
-The most efficient option should be chosen.
-; {{KW|_GL_NICEST}}
-:
-The most correct, or highest quality, option should be chosen.
-; {{KW|_GL_DONT_CARE}}
-:
-No preference.
-Though the implementation aspects that can be hinted are well defined, the interpretation of the hints depends on the implementation. The hint aspects that can be specified with {{Parameter|target}}, along with suggested semantics, are as follows:
-; {{KW|_GL_FRAGMENT_SHADER_DERIVATIVE_HINT}}
-:
-Indicates the accuracy of the derivative calculation for the GL shading language fragment processing built-in functions: {{KW|_dFdx}}, {{KW|_dFdy}}, and {{KW|_fwidth}}.
-; {{KW|_GL_LINE_SMOOTH_HINT}}
-:
-Indicates the sampling quality of antialiased lines. If a larger filter function is applied, hinting {{KW|_GL_NICEST}} can result in more pixel fragments being generated during rasterization.
-; {{KW|_GL_POLYGON_SMOOTH_HINT}}
-:
-Indicates the sampling quality of antialiased polygons. Hinting {{KW|_GL_NICEST}} can result in more pixel fragments being generated during rasterization, if a larger filter function is applied.
-; {{KW|_GL_TEXTURE_COMPRESSION_HINT}}
-:
-Indicates the quality and performance of the compressing texture images. Hinting {{KW|_GL_FASTEST}} indicates that texture images should be compressed as quickly as possible, while {{KW|_GL_NICEST}} indicates that texture images should be compressed with as little image quality loss as possible. {{KW|_GL_NICEST}} should be selected if the texture is to be retrieved by {{KW|_glGetCompressedTexImage}} for reuse.
-{{PageNotes}}
-The interpretation of hints depends on the implementation. Some implementations ignore '''_glHint''' settings.
-{{PageErrors}}
-{{KW|_GL_INVALID_ENUM}} is generated if either {{Parameter|target}} or {{Parameter|mode}} is not an accepted value.
+{{PageSeeAlso}}
+* [[_GL|SUB _GL]]
+* [[_glBegin]], [[_glEnd]]
-{{PageCopyright}}
-Copyright 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see [http://oss.sgi.com/projects/FreeB/ http://oss.sgi.com/projects/FreeB/].
+{{PageNavigation}}

GlHint: Difference between revisions

Latest revision as of 01:05, 28 January 2023

Contents

Syntax

Parameters

Description

See also

Navigation menu

GlHint: Difference between revisions

Latest revision as of 01:05, 28 January 2023

Syntax

Parameters

Description

See also

Navigation menu

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