Index for Section 3G

Alphabetical listing for G

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glGetMaterial(3G)
NAME
  glGetMaterial, glGetMaterialfv, glGetMaterialiv - return material
  parameters

SYNOPSIS
  void glGetMaterialfv(
	  GLenum face,
	  GLenum pname,
	  GLfloat *params );

  void glGetMaterialiv(
	  GLenum face,
	  GLenum pname,
	  GLint *params );

PARAMETERS
  face
      Specifies which of the two materials is being queried.  GL_FRONT or
      GL_BACK are accepted, representing the front and back materials,
      respectively.

  pname
      Specifies the material parameter to return.  GL_AMBIENT, GL_DIFFUSE,
      GL_SPECULAR, GL_EMISSION, GL_SHININESS, and GL_COLOR_INDEXES are
      accepted.

  params
      Returns the requested data.

DESCRIPTION
  glGetMaterial() returns in params the value or values of parameter pname of
  material face. Six parameters are defined:

  GL_AMBIENT
      params returns four integer or floating-point values representing the
      ambient reflectance of the material. Integer values, when requested,
      are linearly mapped from the internal floating-point representation
      such that 1.0 maps to the most positive representable integer value,
      and -1.0 maps to the most negative representable integer value. If the
      internal value is outside the range [-1, 1], the corresponding integer
      return value is undefined. The initial value is (0.2, 0.2, 0.2, 1.0)

  GL_DIFFUSE
      params returns four integer or floating-point values representing the
      diffuse reflectance of the material. Integer values, when requested,
      are linearly mapped from the internal floating-point representation
      such that 1.0 maps to the most positive representable integer value,
      and -1.0 maps to the most negative representable integer value. If the
      internal value is outside the range [-1, 1], the corresponding integer
      return value is undefined. The initial value is (0.8, 0.8, 0.8, 1.0).

  GL_SPECULAR
      params returns four integer or floating-point values representing the
      specular reflectance of the material. Integer values, when requested,
      are linearly mapped from the internal floating-point representation
      such that 1.0 maps to the most positive representable integer value,
      and -1.0 maps to the most negative representable integer value. If the
      internal value is outside the range [-1, 1], the corresponding integer
      return value is undefined. The initial value is (0, 0, 0, 1).

  GL_EMISSION
      params returns four integer or floating-point values representing the
      emitted light intensity of the material. Integer values, when
      requested, are linearly mapped from the internal floating-point
      representation such that 1.0 maps to the most positive representable
      integer value, and -1.0 maps to the most negative representable integer
      value. If the internal value is outside the range [-1, 1.0], the
      corresponding integer return value is undefined. The initial value is
      (0, 0, 0, 1).

  GL_SHININESS
      params returns one integer or floating-point value representing the
      specular exponent of the material. Integer values, when requested, are
      computed by rounding the internal floating-point value to the nearest
      integer value. The initial value is 0.

  GL_COLOR_INDEXES
      params returns three integer or floating-point values representing the
      ambient, diffuse, and specular indices of the material. These indices
      are used only for color index lighting. (All the other parameters are
      used only for RGBA lighting.) Integer values, when requested, are
      computed by rounding the internal floating-point values to the nearest
      integer values.

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

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

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

SEE ALSO
  glMaterial(3)

Index for Section 3G

Alphabetical listing for G

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