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<STRONG>NAME</STRONG>
<STRONG>glGetBooleanv,</STRONG> <STRONG>glGetDoublev,</STRONG> <STRONG>glGetFloatv,</STRONG> <STRONG>glGetIntegerv</STRONG> -
return the value or values of a selected parameter
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetBooleanv</STRONG>( GLenum <EM>pname</EM>,
GLboolean *<EM>params</EM> )
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetDoublev</STRONG>( GLenum <EM>pname</EM>,
GLdouble *<EM>params</EM> )
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetFloatv</STRONG>( GLenum <EM>pname</EM>,
GLfloat *<EM>params</EM> )
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetIntegerv</STRONG>( GLenum <EM>pname</EM>,
GLint *<EM>params</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>pname</EM> Specifies the parameter value to be returned. The
symbolic constants in the list below are accepted.
<EM>params</EM> Returns the value or values of the specified
parameter.
<STRONG>DESCRIPTION</STRONG>
These four commands return values for simple state variables
in GL. <EM>pname</EM> is a symbolic constant indicating the state
variable to be returned, and <EM>params</EM> is a pointer to an array
of the indicated type in which to place the returned data.
Type conversion is performed if <EM>params</EM> has a different type
than the state variable value being requested. If
<STRONG>glGetBooleanv</STRONG> is called, a floating-point (or integer) value
is converted to <STRONG>GL_FALSE</STRONG> if and only if it is 0.0 (or 0).
Otherwise, it is converted to <STRONG>GL_TRUE</STRONG>. If <STRONG>glGetIntegerv</STRONG> is
called, boolean values are returned as <STRONG>GL_TRUE</STRONG> or <STRONG>GL_FALSE</STRONG>,
and most floating-point values are rounded to the nearest
integer value. Floating-point colors and normals, however,
are returned with a linear mapping that maps 1.0 to the most
positive representable integer value, and -1.0 to the most
negative representable integer value. If <STRONG>glGetFloatv</STRONG> or
<STRONG>glGetDoublev</STRONG> is called, boolean values are returned as
<STRONG>GL_TRUE</STRONG> or <STRONG>GL_FALSE</STRONG>, and integer values are converted to
floating-point values.
The following symbolic constants are accepted by <EM>pname</EM>:
<STRONG>GL_ACCUM_ALPHA_BITS</STRONG> <EM>params</EM> returns one value, the
number of alpha bitplanes in the
accumulation buffer.
<STRONG>GL_ACCUM_BLUE_BITS</STRONG> <EM>params</EM> returns one value, the
number of blue bitplanes in the
accumulation buffer.
<STRONG>GL_ACCUM_CLEAR_VALUE</STRONG> <EM>params</EM> returns four values: the
red, green, blue, and alpha values
used to clear the accumulation
buffer. Integer values, if
requested, are linearly mapped from
the internal floating-point
representation such that 1.0
returns the most positive
representable integer value, and
-1.0 returns the most negative
representable integer value. The
initial value is (0, 0, 0, 0). See
<STRONG>glClearAccum</STRONG>.
<STRONG>GL_ACCUM_GREEN_BITS</STRONG> <EM>params</EM> returns one value, the
number of green bitplanes in the
accumulation buffer.
<STRONG>GL_ACCUM_RED_BITS</STRONG> <EM>params</EM> returns one value, the
number of red bitplanes in the
accumulation buffer.
<STRONG>GL_ALPHA_BIAS</STRONG> <EM>params</EM> returns one value, the alpha
bias factor used during pixel
transfers. The initial value is 0.
See <STRONG>glPixelTransfer</STRONG>.
<STRONG>GL_ALPHA_BITS</STRONG> <EM>params</EM> returns one value, the
number of alpha bitplanes in each
color buffer.
<STRONG>GL_ALPHA_SCALE</STRONG> <EM>params</EM> returns one value, the alpha
scale factor used during pixel
transfers. The initial value is 1.
See <STRONG>glPixelTransfer</STRONG>.
<STRONG>GL_ALPHA_TEST</STRONG> <EM>params</EM> returns a single boolean
value indicating whether alpha
testing of fragments is enabled.
The initial value is <STRONG>GL_FALSE</STRONG>. See
<STRONG>glAlphaFunc</STRONG>.
<STRONG>GL_ALPHA_TEST_FUNC</STRONG> <EM>params</EM> returns one value, the
symbolic name of the alpha test
function. The initial value is
<STRONG>GL_ALWAYS</STRONG>. See <STRONG>glAlphaFunc</STRONG>.
<STRONG>GL_ALPHA_TEST_REF</STRONG> <EM>params</EM> returns one value, the
reference value for the alpha test.
The initial value is 0. See
<STRONG>glAlphaFunc</STRONG>. An integer value, if
requested, is linearly mapped from
the internal floating-point
representation such that 1.0
returns the most positive
representable integer value, and
-1.0 returns the most negative
representable integer value.
<STRONG>GL_ATTRIB_STACK_DEPTH</STRONG> <EM>params</EM> returns one value, the depth
of the attribute stack. If the
stack is empty, 0 is returned. The
initial value is 0. See
<STRONG>glPushAttrib</STRONG>.
<STRONG>GL_AUTO_NORMAL</STRONG> <EM>params</EM> returns a single boolean
value indicating whether 2D map
evaluation automatically generates
surface normals. The initial value
is <STRONG>GL_FALSE</STRONG>. See <STRONG>glMap2</STRONG>.
<STRONG>GL_AUX_BUFFERS</STRONG> <EM>params</EM> returns one value, the
number of auxiliary color buffers.
The initial value is 0.
<STRONG>GL_BLEND</STRONG> <EM>params</EM> returns a single boolean
value indicating whether blending
is enabled. The initial value is
<STRONG>GL_FALSE</STRONG>. See <STRONG>glBlendFunc</STRONG>.
<STRONG>GL_BLEND_COLOR_EXT</STRONG> <EM>params</EM> returns four values, the
red, green, blue, and alpha values
which are the components of the
blend color. See <STRONG>glBlendColorEXT</STRONG>.
<STRONG>GL_BLEND_DST</STRONG> <EM>params</EM> returns one value, the
symbolic constant identifying the
destination blend function. The
initial value is <STRONG>GL_ZERO</STRONG>. See
<STRONG>glBlendFunc</STRONG>.
<STRONG>GL_BLEND_EQUATION_EXT</STRONG> <EM>params</EM> returns one value, a
symbolic constant indicating
whether the blend equation is
<STRONG>GL_FUNC_ADD_EXT</STRONG>, <STRONG>GL_MIN_EXT</STRONG> or
<STRONG>GL_MAX_EXT</STRONG>. See <STRONG>glBlendEquationEXT</STRONG>.
<STRONG>GL_BLEND_SRC</STRONG> <EM>params</EM> returns one value, the
symbolic constant identifying the
source blend function. The initial
value is <STRONG>GL_ONE</STRONG>. See <STRONG>glBlendFunc</STRONG>.
<STRONG>GL_BLUE_BIAS</STRONG> <EM>params</EM> returns one value, the blue
bias factor used during pixel
transfers. The initial value is 0.
See <STRONG>glPixelTransfer</STRONG>.
<STRONG>GL_BLUE_BITS</STRONG> <EM>params</EM> returns one value, the
number of blue bitplanes in each
color buffer.
<STRONG>GL_BLUE_SCALE</STRONG> <EM>params</EM> returns one value, the blue
scale factor used during pixel
transfers. The initial value is 1.
See <STRONG>glPixelTransfer</STRONG>.
<STRONG>GL_CLIENT_ATTRIB_STACK_DEPTH</STRONG>
<EM>params</EM> returns one value indicating
the depth of the attribute stack.
The initial value is 0. See
<STRONG>glPushClientAttrib</STRONG>.
<STRONG>GL_CLIP_PLANE</STRONG><EM>i</EM> <EM>params</EM> returns a single boolean
value indicating whether the
specified clipping plane is
enabled. The initial value is
<STRONG>GL_FALSE</STRONG>. See <STRONG>glClipPlane</STRONG>.
<STRONG>GL_COLOR_ARRAY</STRONG> <EM>params</EM> returns a single boolean
value indicating whether the color
array is enabled. The initial value
is <STRONG>GL_FALSE</STRONG>. See <STRONG>glColorPointer</STRONG>.
<STRONG>GL_COLOR_ARRAY_SIZE</STRONG> <EM>params</EM> returns one value, the
number of components per color in
the color array. The initial value
is 4. See <STRONG>glColorPointer</STRONG>.
<STRONG>GL_COLOR_ARRAY_STRIDE</STRONG> <EM>params</EM> returns one value, the byte
offset between consecutive colors
in the color array. The initial
value is 0. See <STRONG>glColorPointer</STRONG>.
<STRONG>GL_COLOR_ARRAY_TYPE</STRONG> <EM>params</EM> returns one value, the data
type of each component in the color
array. The initial value is
<STRONG>GL_FLOAT</STRONG>. See <STRONG>glColorPointer</STRONG>.
<STRONG>GL_COLOR_CLEAR_VALUE</STRONG> <EM>params</EM> returns four values: the
red, green, blue, and alpha values
used to clear the color buffers.
Integer values, if requested, are
linearly mapped from the internal
floating-point representation such
that 1.0 returns the most positive
representable integer value, and
-1.0 returns the most negative
representable integer value. The
initial value is (0, 0, 0, 0). See
<STRONG>glClearColor</STRONG>.
<STRONG>GL_COLOR_LOGIC_OP</STRONG> <EM>params</EM> returns a single boolean
value indicating whether a
fragment's RGBA color values are
merged into the framebuffer using a
logical operation. The initial
value is <STRONG>GL_FALSE</STRONG>. See <STRONG>glLogicOp</STRONG>.
<STRONG>GL_COLOR_MATERIAL</STRONG> <EM>params</EM> returns a single boolean
value indicating whether one or
more material parameters are
tracking the current color. The
initial value is <STRONG>GL_FALSE</STRONG>. See
<STRONG>glColorMaterial</STRONG>.
<STRONG>GL_COLOR_MATERIAL_FACE</STRONG> <EM>params</EM> returns one value, a
symbolic constant indicating which
materials have a parameter that is
tracking the current color. The
initial value is <STRONG>GL_FRONT_AND_BACK</STRONG>.
See <STRONG>glColorMaterial</STRONG>.
<STRONG>GL_COLOR_MATERIAL_PARAMETER</STRONG>
<EM>params</EM> returns one value, a
symbolic constant indicating which
material parameters are tracking
the current color. The initial
value is <STRONG>GL_AMBIENT_AND_DIFFUSE</STRONG>.
See <STRONG>glColorMaterial</STRONG>.
<STRONG>GL_COLOR_WRITEMASK</STRONG> <EM>params</EM> returns four boolean values:
the red, green, blue, and alpha
write enables for the color
buffers. The initial value is
(<STRONG>GL_TRUE</STRONG>, <STRONG>GL_TRUE</STRONG>, <STRONG>GL_TRUE</STRONG>,
<STRONG>GL_TRUE</STRONG>). See <STRONG>glColorMask</STRONG>.
<STRONG>GL_CULL_FACE</STRONG> <EM>params</EM> returns a single boolean
value indicating whether polygon
culling is enabled. The initial
value is <STRONG>GL_FALSE</STRONG>. See <STRONG>glCullFace</STRONG>.
<STRONG>GL_CULL_FACE_MODE</STRONG> <EM>params</EM> returns one value, a
symbolic constant indicating which
polygon faces are to be culled. The
initial value is <STRONG>GL_BACK</STRONG>. See
<STRONG>glCullFace</STRONG>.
<STRONG>GL_CURRENT_COLOR</STRONG> <EM>params</EM> returns four values: the
red, green, blue, and alpha values
of the current color. Integer
values, if requested, are linearly
mapped from the internal floating-
point representation such that 1.0
returns the most positive
representable integer value, and
-1.0 returns the most negative
representable integer value. See
<STRONG>glColor</STRONG>. The initial value is (1,
1, 1, 1).
<STRONG>GL_CURRENT_INDEX</STRONG> <EM>params</EM> returns one value, the
current color index. The initial
value is 1. See <STRONG>glIndex</STRONG>.
<STRONG>GL_CURRENT_NORMAL</STRONG> <EM>params</EM> returns three values: the
<EM>x</EM>, <EM>y</EM>, and <EM>z</EM> values of the current
normal. Integer values, if
requested, are linearly mapped from
the internal floating-point
representation such that 1.0
returns the most positive
representable integer value, and
-1.0 returns the most negative
representable integer value. The
initial value is (0, 0, 1). See
<STRONG>glNormal</STRONG>.
<STRONG>GL_CURRENT_RASTER_COLOR</STRONG> <EM>params</EM> returns four values: the
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