📄 gettexlevelparameter.html
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<STRONG>NAME</STRONG>
<STRONG>glGetTexLevelParameterfv,</STRONG> <STRONG>glGetTexLevelParameteriv</STRONG> - return
texture parameter values for a specific level of detail
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetTexLevelParameterfv</STRONG>( GLenum <EM>target</EM>,
GLint <EM>level</EM>,
GLenum <EM>pname</EM>,
GLfloat *<EM>params</EM> )
void <STRONG>glGetTexLevelParameteriv</STRONG>( GLenum <EM>target</EM>,
GLint <EM>level</EM>,
GLenum <EM>pname</EM>,
GLint *<EM>params</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>target</EM> Specifies the symbolic name of the target texture,
either <STRONG>GL_TEXTURE_1D</STRONG>, <STRONG>GL_TEXTURE_2D</STRONG>,
<STRONG>GL_PROXY_TEXTURE_1D</STRONG>, or <STRONG>GL_PROXY_TEXTURE_2D</STRONG>.
<EM>level</EM> Specifies the level-of-detail number of the desired
image. Level 0 is the base image level. Level n is
the nth mipmap reduction image.
<EM>pname</EM> Specifies the symbolic name of a texture parameter.
<STRONG>GL_TEXTURE_WIDTH</STRONG>, <STRONG>GL_TEXTURE_HEIGHT</STRONG>,
<STRONG>GL_TEXTURE_INTERNAL_FORMAT</STRONG>, <STRONG>GL_TEXTURE_BORDER</STRONG>,
<STRONG>GL_TEXTURE_RED_SIZE</STRONG>, <STRONG>GL_TEXTURE_GREEN_SIZE</STRONG>,
<STRONG>GL_TEXTURE_BLUE_SIZE</STRONG>, <STRONG>GL_TEXTURE_ALPHA_SIZE</STRONG>,
<STRONG>GL_TEXTURE_LUMINANCE_SIZE</STRONG>, and
<STRONG>GL_TEXTURE_INTENSITY_SIZE</STRONG> are accepted.
<EM>params</EM> Returns the requested data.
<STRONG>DESCRIPTION</STRONG>
<STRONG>glGetTexLevelParameter</STRONG> returns in <EM>params</EM> texture parameter
values for a specific level-of-detail value, specified as
<EM>level</EM>. <EM>target</EM> defines the target texture, either
<STRONG>GL_TEXTURE_1D</STRONG>, <STRONG>GL_TEXTURE_2D</STRONG>, <STRONG>GL_PROXY_TEXTURE_1D</STRONG>, or
<STRONG>GL_PROXY_TEXTURE_2D</STRONG>.
<STRONG>GL_MAX_TEXTURE_SIZE</STRONG> is not really descriptive enough. It
has to report the largest square texture image that can be
accommodated with mipmaps and borders, but a long skinny
texture, or a texture without mipmaps and borders, may
easily fit in texture memory. The proxy targets allow the
user to more accurately query whether the GL can accommodate
a texture of a given configuration. If the texture cannot
be accommodated, the texture state variables, which may be
queried with <STRONG>glGetTexLevelParameter</STRONG>, are set to 0. If the
texture can be accommodated, the texture state values will
be set as they would be set for a non-proxy target.
<EM>pname</EM> specifies the texture parameter whose value or values
will be returned.
The accepted parameter names are as follows:
<STRONG>GL_TEXTURE_WIDTH</STRONG>
<EM>params</EM> returns a single value, the width of the
texture image. This value includes the border of
the texture image. The initial value is 0.
<STRONG>GL_TEXTURE_HEIGHT</STRONG>
<EM>params</EM> returns a single value, the height of the
texture image. This value includes the border of
the texture image. The initial value is 0.
<STRONG>GL_TEXTURE_INTERNAL_FORMAT</STRONG>
<EM>params</EM> returns a single value, the internal format
of the texture image.
<STRONG>GL_TEXTURE_BORDER</STRONG>
<EM>params</EM> returns a single value, the width in pixels
of the border of the texture image. The initial
value is 0.
<STRONG>GL_TEXTURE_RED_SIZE</STRONG>,
<STRONG>GL_TEXTURE_GREEN_SIZE</STRONG>,
<STRONG>GL_TEXTURE_BLUE_SIZE</STRONG>,
<STRONG>GL_TEXTURE_ALPHA_SIZE</STRONG>,
<STRONG>GL_TEXTURE_LUMINANCE_SIZE</STRONG>,
<STRONG>GL_TEXTURE_INTENSITY_SIZE</STRONG>
The internal storage resolution of an individual
component. The resolution chosen by the GL will
be a close match for the resolution requested by
the user with the component argument of
<STRONG>glTexImage1D</STRONG> or <STRONG>glTexImage2D</STRONG>. The initial value is
0.
<STRONG>NOTES</STRONG>
If an error is generated, no change is made to the contents
of <EM>params</EM>.
<STRONG>GL_TEXTURE_INTERNAL_FORMAT</STRONG> is only available if the GL
version is 1.1 or greater. In version 1.0, use
<STRONG>GL_TEXTURE_COMPONENTS</STRONG> instead.
<STRONG>GL_PROXY_TEXTURE_1D</STRONG> and <STRONG>GL_PROXY_TEXTURE_2D</STRONG> are only
available if the GL version is 1.1 or greater.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_ENUM</STRONG> is generated if <EM>target</EM> or <EM>pname</EM> is not an
accepted value.
<STRONG>GL_INVALID_VALUE</STRONG> is generated if <EM>level</EM> is less than 0.
<STRONG>GL_INVALID_VALUE</STRONG> may be generated if <EM>level</EM> is greater than
log <EM>max</EM>, where <EM>max</EM> is the returned value of
<STRONG>GL_MAX_TEXTURE_SIZE</STRONG>.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glGetTexLevelParameter</STRONG>
is executed between the execution of <STRONG>glBegin</STRONG> and the
corresponding execution of <STRONG>glEnd</STRONG>.
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glGetTexParameter</STRONG>, <STRONG>glCopyTexImage1D</STRONG>, <STRONG>glCopyTexImage2D</STRONG>,
<STRONG>glCopyTexSubImage1D</STRONG>, <STRONG>glCopyTexSubImage2D</STRONG>, <STRONG>glTexEnv</STRONG>,
<STRONG>glTexGen</STRONG>, <STRONG>glTexImage1D</STRONG>, <STRONG>glTexImage2D</STRONG>, <STRONG>glTexSubImage1D</STRONG>,
<STRONG>glTexSubImage2D</STRONG>,
<STRONG>glTexParameter</STRONG>
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