Index for Section 3G

Alphabetical listing for G

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glGetTexLevelParameter(3G)
NAME
  glGetTexLevelParameter, glGetTexLevelParameterfv, glGetTexLevelParameteriv
  - return texture parameter values for a specific level of detail

SYNOPSIS
  void glGetTexLevelParameterfv(
	  GLenum target,
	  GLint level,
	  GLenum pname,
	  GLfloat *params );

  void glGetTexLevelParameteriv(
	  GLenum target,
	  GLint level,
	  GLenum pname,
	  GLint *params );

PARAMETERS
  target
      Specifies the symbolic name of the target texture, either
      GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_PROXY_TEXTURE_1D,
      GL_PROXY_TEXTURE_2D, or GL_PROXY_TEXTURE_3D.

  level
      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.

  pname
      Specifies the symbolic name of a texture parameter.  GL_TEXTURE_WIDTH,
      GL_TEXTURE_HEIGHT, GL_TEXTURE_DEPTH, GL_TEXTURE_INTERNAL_FORMAT,
      GL_TEXTURE_BORDER, GL_TEXTURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE,
      GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE, GL_TEXTURE_LUMINANCE_SIZE,
      and GL_TEXTURE_INTENSITY_SIZE are accepted.

  params
      Returns the requested data.

DESCRIPTION
  glGetTexLevelParameter() returns in params texture parameter values for a
  specific level-of-detail value, specified as level.  target defines the
  target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D,
  GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_2D, or GL_PROXY_TEXTURE_3D.

  GL_MAX_TEXTURE_SIZE, and GL_MAX_3D_TEXTURE_SIZE are 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
  glGetTexLevelParameter(), 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.

  pname specifies the texture parameter whose value or values will be
  returned.

  The accepted parameter names are as follows:

  GL_TEXTURE_WIDTH
      params returns a single value, the width of the texture image.  This
      value includes the border of the texture image. The initial value is 0.

  GL_TEXTURE_HEIGHT
      params returns a single value, the height of the texture image.  This
      value includes the border of the texture image. The initial value is 0.

  GL_TEXTURE_DEPTH
      params returns a single value, the depth of the texture image.  This
      value includes the border of the texture image. The initial value is 0.

  GL_TEXTURE_INTERNAL_FORMAT
      params returns a single value, the internal  of the texture image.

  GL_TEXTURE_BORDER
      params returns a single value, the width in pixels of the border of the
      texture image. The initial value is 0.

       GL_TEXTURE_RED_SIZE
       GL_TEXTURE_GREEN_SIZE
       GL_TEXTURE_BLUE_SIZE
       GL_TEXTURE_ALPHA_SIZE
       GL_TEXTURE_LUMINANCE_SIZE

  GL_TEXTURE_INTENSITY_SIZE
	  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
	  glTexImage1D(), glTexImage2D(), glTexImage3D(), glCopyTexImage1D(),
	  and glCopyTexImage2D(). The initial value is 0.

NOTES
  If an error is generated, no change is made to the contents of params.

  GL_TEXTURE_INTERNAL_FORMAT is available only if the GL version is 1.1 or
  greater. In version 1.0, use GL_TEXTURE_COMPONENTS instead.

  GL_PROXY_TEXTURE_1D and GL_PROXY_TEXTURE_2D are available only if the GL
  version is 1.1 or greater.

  GL_TEXTURE_3D, GL_PROXY_TEXTURE_3D, and GL_TEXTURE_DEPTH are available only
  if the GL version is 1.2 or greater.

  When the GL_ARB_multitexture extension is supported,
  glGetTexLevelParameter() returns the texture level parameters for the
  active texture unit.

ERRORS
  GL_INVALID_ENUM is generated if target or pname is not an accepted value.

  GL_INVALID_VALUE is generated if level is less than 0.

  GL_INVALID_VALUE may be generated if level is greater than  log sub 2 max,
  where max is the returned value of GL_MAX_TEXTURE_SIZE.

  GL_INVALID_OPERATION is generated if glGetTexLevelParameter() is executed
  between the execution of glBegin() and the corresponding execution of
  glEnd().

SEE ALSO
  glActiveTextureARB(3), glGetTexParameter(3), glCopyTexImage1D(3),
  glCopyTexImage2D(3), glCopyTexSubImage1D(3), glCopyTexSubImage2D(3),
  glCopyTexSubImage3D(3), glTexEnv(3), glTexGen(3), glTexImage1D(3),
  glTexImage2D(3), glTexImage3D(3), glTexSubImage1D(3), glTexSubImage2D(3),
  glTexSubImage3D(3), glTexParameter(3)

Index for Section 3G

Alphabetical listing for G

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