glGet(3G)glGet(3G)NAME
glGet, glGetBooleanv, glGetDoublev, glGetFloatv, glGetIntegerv - return
the value or values of a selected parameter
SYNOPSIS
void glGetBooleanv(
GLenum pname,
GLboolean *params ); void glGetDoublev(
GLenum pname,
GLdouble *params ); void glGetFloatv(
GLenum pname,
GLfloat *params ); void glGetIntegerv(
GLenum pname,
GLint *params );
PARAMETERS
Specifies the parameter value to be returned. The symbolic constants in
the list below are accepted. Returns the value or values of the speci‐
fied parameter.
DESCRIPTION
These four commands return values for simple state variables in GL.
pname is a symbolic constant indicating the state variable to be
returned, and params is a pointer to an array of the indicated type in
which to place the returned data.
Type conversion is performed if params has a different type than the
state variable value being requested. If glGetBooleanv() is called, a
floating-point (or integer) value is converted to GL_FALSE if and only
if it is 0.0 (or 0). Otherwise, it is converted to GL_TRUE. If glGet‐
Integerv() is called, boolean values are returned as GL_TRUE or
GL_FALSE, 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 glGetFloatv() or glGetDoublev() is called, boolean values
are returned as GL_TRUE or GL_FALSE, and integer values are converted
to floating-point values.
The following symbolic constants are accepted by pname: params returns
one value, the number of alpha bitplanes in the accumulation buffer.
params returns one value, the number of blue bitplanes in the accumula‐
tion buffer. params 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 repre‐
sentation 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 glClearAccum(). params returns
one value, the number of green bitplanes in the accumulation buffer.
params returns one value, the number of red bitplanes in the accumula‐
tion buffer. params returns a single value indicating the active mul‐
titexture unit. The initial value is GL_TEXTURE0_ARB. See glActiveTex‐
tureARB(). params returns two values, the smallest and largest sup‐
ported sizes for aliased points. params returns two values, the small‐
est and largest supported widths for aliased lines. params returns one
value, the alpha bias factor used during pixel transfers. The initial
value is 0. See glPixelTransfer(). params returns one value, the num‐
ber of alpha bitplanes in each color buffer. params returns one value,
the alpha scale factor used during pixel transfers. The initial value
is 1. See glPixelTransfer(). params returns a single boolean value
indicating whether alpha testing of fragments is enabled. The initial
value is GL_FALSE. See glAlphaFunc(). params returns one value, the
symbolic name of the alpha test function. The initial value is
GL_ALWAYS. See glAlphaFunc(). params returns one value, the reference
value for the alpha test. The initial value is 0. See glAlphaFunc(). 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 repre‐
sentable integer value. params returns one value, the depth of the
attribute stack. If the stack is empty, 0 is returned. The initial
value is 0. See glPushAttrib(). params returns a single boolean value
indicating whether 2D map evaluation automatically generates surface
normals. The initial value is GL_FALSE. See glMap2(). params returns
one value, the number of auxiliary color buffers. The initial value is
0. params returns a single boolean value indicating whether blending
is enabled. The initial value is GL_FALSE. See glBlendFunc(). params
returns four values, the red, green, blue, and alpha values which are
the components of the blend color. See glBlendColor(). params returns
one value, the symbolic constant identifying the destination blend
function. The initial value is GL_ZERO. See glBlendFunc(). params
returns one value, a symbolic constant indicating whether the blend
equation is GL_FUNC_ADD, GL_MIN or GL_MAX. See glBlendEquation().
params returns one value, the symbolic constant identifying the source
blend function. The initial value is GL_ONE. See glBlendFunc().
params returns one value, the blue bias factor used during pixel trans‐
fers. The initial value is 0. See glPixelTransfer(). params returns
one value, the number of blue bitplanes in each color buffer. params
returns one value, the blue scale factor used during pixel transfers.
The initial value is 1. See glPixelTransfer(). params returns a single
integer value indicating the current client active multitexture unit.
The initial value is GL_TEXTURE0_ARB. See glClientActiveTextureARB().
params returns one value indicating the depth of the attribute stack.
The initial value is 0. See glPushClientAttrib(). params returns a
single boolean value indicating whether the specified clipping plane is
enabled. The initial value is GL_FALSE. See glClipPlane(). params
returns a single boolean value indicating whether the color array is
enabled. The initial value is GL_FALSE. See glColorPointer(). params
returns one value, the number of components per color in the color
array. The initial value is 4. See glColorPointer(). params returns
one value, the byte offset between consecutive colors in the color
array. The initial value is 0. See glColorPointer(). params returns
one value, the data type of each component in the color array. The ini‐
tial value is GL_FLOAT. See glColorPointer(). params returns four val‐
ues: 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 nega‐
tive representable integer value. The initial value is (0, 0, 0, 0).
See glClearColor(). params 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 GL_FALSE. See glLogi‐
cOp(). params returns a single boolean value indicating whether one or
more material parameters are tracking the current color. The initial
value is GL_FALSE. See glColorMaterial(). params returns one value, a
symbolic constant indicating which materials have a parameter that is
tracking the current color. The initial value is GL_FRONT_AND_BACK. See
glColorMaterial(). params returns one value, a symbolic constant indi‐
cating which material parameters are tracking the current color. The
initial value is GL_AMBIENT_AND_DIFFUSE. See glColorMaterial(). params
returns sixteen values: the color matrix on the top of the color matrix
stack. Initially this matrix is the identity matrix. See glPushMa‐
trix(). params returns one value, the maximum supported depth of the
projection matrix stack. The value must be at least 2. See glPushMa‐
trix(). params returns a single boolean value indicating whether the
color table lookup is enabled. See glColorTable(). params returns four
boolean values: the red, green, blue, and alpha write enables for the
color buffers. The initial value is (GL_TRUE, GL_TRUE, GL_TRUE,
GL_TRUE). See glColorMask(). params returns a single boolean value
indicating whether 1D convolution is enabled. The initial value is
GL_FALSE. See glConvolutionFilter1D(). params returns a single bool‐
ean value indicating whether 2D convolution is enabled. The initial
value is GL_FALSE. See glConvolutionFilter2D(). params returns a sin‐
gle boolean value indicating whether polygon culling is enabled. The
initial value is GL_FALSE. See glCullFace(). params returns one value,
a symbolic constant indicating which polygon faces are to be culled.
The initial value is GL_BACK. See glCullFace(). params 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 repre‐
sentable integer value. See glColor(). The initial value is (1, 1, 1,
1). params returns one value, the current color index. The initial
value is 1. See glIndex(). params returns three values: the x, y, and
z values of the current normal. Integer values, if requested, are lin‐
early 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 glNormal(). params returns four values: the
red, green, blue, and alpha values of the current raster position.
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 repre‐
sentable integer value. The initial value is (1, 1, 1, 1). See
glRasterPos(). params returns one value, the distance from the eye to
the current raster position. The initial value is 0. See glRasterPos().
params returns one value, the color index of the current raster posi‐
tion. The initial value is 1. See glRasterPos(). params returns four
values: the x, y, z, and w components of the current raster position.
x, y, and z are in window coordinates, and w is in clip coordinates.
The initial value is (0, 0, 0, 1). See glRasterPos(). params returns a
single boolean value indicating whether the current raster position is
valid. The initial value is GL_TRUE. See glRasterPos(). params returns
four values: the s, t, r, and q current raster texture coordinates. The
initial value is (0, 0, 0, 1). See glRasterPos() and glTexCoord().
params returns four values: the s, t, r, and q current texture coordi‐
nates. The initial value is (0, 0, 0, 1). See glTexCoord(). params
returns one value, the depth bias factor used during pixel transfers.
The initial value is 0. See glPixelTransfer(). params returns one
value, the number of bitplanes in the depth buffer. params returns one
value, the value that is used to clear the depth buffer. Integer val‐
ues, 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 1. See glClearDepth(). params returns one
value, the symbolic constant that indicates the depth comparison func‐
tion. The initial value is GL_LESS. See glDepthFunc(). params returns
two values: the near and far mapping limits for the depth buffer. Inte‐
ger values, if requested, are linearly mapped from the internal float‐
ing-point representation such that 1.0 returns the most positive repre‐
sentable integer value, and -1.0 returns the most negative repre‐
sentable integer value. The initial value is (0, 1). See
glDepthRange(). params returns one value, the depth scale factor used
during pixel transfers. The initial value is 1. See glPixelTransfer().
params returns a single boolean value indicating whether depth testing
of fragments is enabled. The initial value is GL_FALSE. See glDepth‐
Func() and glDepthRange(). params returns a single boolean value indi‐
cating if the depth buffer is enabled for writing. The initial value is
GL_TRUE. See glDepthMask(). params returns a single boolean value
indicating whether dithering of fragment colors and indices is enabled.
The initial value is GL_TRUE. params returns a single boolean value
indicating whether double buffering is supported. params returns one
value, a symbolic constant indicating which buffers are being drawn to.
See glDrawBuffer(). The initial value is GL_BACK if there are back buf‐
fers, otherwise it is GL_FRONT. params returns a single boolean value
indicating whether the current edge option is GL_TRUE or GL_FALSE. The
initial value is GL_TRUE. See glEdgeFlag(). params returns a single
boolean value indicating whether the edge option array is enabled. The
initial value is GL_FALSE. See glEdgeFlagPointer(). params returns
one value, the byte offset between consecutive edge options in the edge
option array. The initial value is 0. See glEdgeFlagPointer(). params
returns one value, the size of the feedback buffer. See glFeedback‐
Buffer(). params returns one value, the type of the feedback buffer.
See glFeedbackBuffer(). params returns a single boolean value indicat‐
ing whether fogging is enabled. The initial value is GL_FALSE. See
glFog(). params returns four values: the red, green, blue, and alpha
components of the fog 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. The initial value is (0,
0, 0, 0). See glFog(). params returns one value, the fog density
parameter. The initial value is 1. See glFog(). params returns one
value, the end factor for the linear fog equation. The initial value
is 1. See glFog(). params returns one value, a symbolic constant indi‐
cating the mode of the fog hint. The initial value is GL_DONT_CARE. See
glHint(). params returns one value, the fog color index. The initial
value is 0. See glFog(). params returns one value, a symbolic constant
indicating which fog equation is selected. The initial value is GL_EXP.
See glFog(). params returns one value, the start factor for the linear
fog equation. The initial value is 0. See glFog(). params returns one
value, a symbolic constant indicating whether clockwise or counter‐
clockwise polygon winding is treated as front-facing. The initial
value is GL_CCW. See glFrontFace(). params returns one value, the
green bias factor used during pixel transfers. The initial value is 0.
params returns one value, the number of green bitplanes in each color
buffer. params returns one value, the green scale factor used during
pixel transfers. The initial value is 1. See glPixelTransfer(). params
returns a single boolean value indicating whether histogram is enabled.
The initial value is GL_FALSE. See glHistogram(). params returns a
single boolean value indicating whether the color index array is
enabled. The initial value is GL_FALSE. See glIndexPointer(). params
returns one value, the byte offset between consecutive color indexes in
the color index array. The initial value is 0. See glIndexPointer().
params returns one value, the data type of indexes in the color index
array. The initial value is GL_FLOAT. See glIndexPointer(). params
returns one value, the number of bitplanes in each color index buffer.
params returns one value, the color index used to clear the color index
buffers. The initial value is 0. See glClearIndex(). params returns a
single boolean value indicating whether a fragment's index values are
merged into the framebuffer using a logical operation. The initial
value is GL_FALSE. See glLogicOp(). params returns a single boolean
value indicating whether the GL is in color index mode (GL_TRUE) or
RGBA mode (GL_FALSE). params returns one value, the offset added to
color and stencil indices during pixel transfers. The initial value is
0. See glPixelTransfer(). params returns one value, the amount that
color and stencil indices are shifted during pixel transfers. The ini‐
tial value is 0. See glPixelTransfer(). params returns one value, a
mask indicating which bitplanes of each color index buffer can be writ‐
ten. The initial value is all 1's. See glIndexMask(). params returns a
single boolean value indicating whether the specified light is enabled.
The initial value is GL_FALSE. See glLight() and glLightModel().
params returns a single boolean value indicating whether lighting is
enabled. The initial value is GL_FALSE. See glLightModel(). params
returns four values: the red, green, blue, and alpha components of the
ambient intensity of the entire scene. 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 (0.2, 0.2, 0.2, 1.0). See glLightModel(). params
returns single enumerated value indicating whether specular reflection
calculations are separated from normal lighting computations. The ini‐
tial value is GL_SINGLE_COLOR. params returns a single boolean value
indicating whether specular reflection calculations treat the viewer as
being local to the scene. The initial value is GL_FALSE. See glLight‐
Model(). params returns a single boolean value indicating whether sep‐
arate materials are used to compute lighting for front- and back-facing
polygons. The initial value is GL_FALSE. See glLightModel(). params
returns a single boolean value indicating whether antialiasing of lines
is enabled. The initial value is GL_FALSE. See glLineWidth(). params
returns one value, a symbolic constant indicating the mode of the line
antialiasing hint. The initial value is GL_DONT_CARE. See glHint().
params returns a single boolean value indicating whether stippling of
lines is enabled. The initial value is GL_FALSE. See glLineStipple().
params returns one value, the 16-bit line stipple pattern. The initial
value is all 1's. See glLineStipple(). params returns one value, the
line stipple repeat factor. The initial value is 1. See glLineStip‐
ple(). params returns one value, the line width as specified with
glLineWidth(). The initial value is 1. params returns one value, the
width difference between adjacent supported widths for antialiased
lines. See glLineWidth(). params returns two values: the smallest and
largest supported widths for antialiased lines. See glLineWidth().
params returns one value, the base offset added to all names in arrays
presented to glCallLists(). The initial value is 0. See glListBase().
params returns one value, the name of the display list currently under
construction. 0 is returned if no display list is currently under con‐
struction. The initial value is 0. See glNewList(). params returns
one value, a symbolic constant indicating the construction mode of the
display list currently under construction. The initial value is 0. See
glNewList(). params returns one value, a symbolic constant indicating
the selected logic operation mode. The initial value is GL_COPY. See
glLogicOp(). params returns a single boolean value indicating whether
1D evaluation generates colors. The initial value is GL_FALSE. See
glMap1(). params returns two values: the endpoints of the 1D map's
grid domain. The initial value is (0, 1). See glMapGrid(). params
returns one value, the number of partitions in the 1D map's grid
domain. The initial value is 1. See glMapGrid(). params returns a sin‐
gle boolean value indicating whether 1D evaluation generates color
indices. The initial value is GL_FALSE. See glMap1(). params returns a
single boolean value indicating whether 1D evaluation generates nor‐
mals. The initial value is GL_FALSE. See glMap1(). params returns a
single boolean value indicating whether 1D evaluation generates 1D tex‐
ture coordinates. The initial value is GL_FALSE. See glMap1(). params
returns a single boolean value indicating whether 1D evaluation gener‐
ates 2D texture coordinates. The initial value is GL_FALSE. See
glMap1(). params returns a single boolean value indicating whether 1D
evaluation generates 3D texture coordinates. The initial value is
GL_FALSE. See glMap1(). params returns a single boolean value indicat‐
ing whether 1D evaluation generates 4D texture coordinates. The initial
value is GL_FALSE. See glMap1(). params returns a single boolean value
indicating whether 1D evaluation generates 3D vertex coordinates. The
initial value is GL_FALSE. See glMap1(). params returns a single bool‐
ean value indicating whether 1D evaluation generates 4D vertex coordi‐
nates. The initial value is GL_FALSE. See glMap1(). params returns a
single boolean value indicating whether 2D evaluation generates colors.
The initial value is GL_FALSE. See glMap2(). params returns four val‐
ues: the endpoints of the 2D map's i and j grid domains. The initial
value is (0,1; 0,1). See glMapGrid(). params returns two values: the
number of partitions in the 2D map's i and j grid domains. The initial
value is (1,1). See glMapGrid(). params returns a single boolean value
indicating whether 2D evaluation generates color indices. The initial
value is GL_FALSE. See glMap2(). params returns a single boolean value
indicating whether 2D evaluation generates normals. The initial value
is GL_FALSE. See glMap2(). params returns a single boolean value
indicating whether 2D evaluation generates 1D texture coordinates. The
initial value is GL_FALSE. See glMap2(). params returns a single bool‐
ean value indicating whether 2D evaluation generates 2D texture coordi‐
nates. The initial value is GL_FALSE. See glMap2(). params returns a
single boolean value indicating whether 2D evaluation generates 3D tex‐
ture coordinates. The initial value is GL_FALSE. See glMap2(). params
returns a single boolean value indicating whether 2D evaluation gener‐
ates 4D texture coordinates. The initial value is GL_FALSE. See
glMap2(). params returns a single boolean value indicating whether 2D
evaluation generates 3D vertex coordinates. The initial value is
GL_FALSE. See glMap2(). params returns a single boolean value indicat‐
ing whether 2D evaluation generates 4D vertex coordinates. The initial
value is GL_FALSE. See glMap2(). params returns a single boolean value
indicating if colors and color indices are to be replaced by table
lookup during pixel transfers. The initial value is GL_FALSE. See
glPixelTransfer(). params returns a single boolean value indicating if
stencil indices are to be replaced by table lookup during pixel trans‐
fers. The initial value is GL_FALSE. See glPixelTransfer(). params
returns one value, a symbolic constant indicating which matrix stack is
currently the target of all matrix operations. The initial value is
GL_MODELVIEW. See glMatrixMode(). params returns one value, a rough
estimate of the largest 3D texture that the GL can handle. If the GL
version is 1.2 or greater, use GL_PROXY_TEXTURE_3D to determine if a
texture is too large. See glTexImage3D(). params returns one value
indicating the maximum supported depth of the client attribute stack.
See glPushClientAttrib(). params returns one value, the maximum sup‐
ported depth of the attribute stack. The value must be at least 16. See
glPushAttrib(). params returns one value, the maximum number of appli‐
cation-defined clipping planes. The value must be at least 6. See
glClipPlane(). params returns one value, the maximum supported depth
of the color matrix stack. The value must be at least 2. See glPushMa‐
trix(). params returns one value, the recommended maximum number of
vertex array indices. See glDrawRangeElements(). params returns one
value, the recommended maximum number of vertex array vertices. See
glDrawRangeElements(). params returns one value, the maximum equation
order supported by 1D and 2D evaluators. The value must be at least 8.
See glMap1() and glMap2(). params returns one value, the maximum num‐
ber of lights. The value must be at least 8. See glLight(). params
returns one value, the maximum recursion depth allowed during display-
list traversal. The value must be at least 64. See glCallList().
params returns one value, the maximum supported depth of the modelview
matrix stack. The value must be at least 32. See glPushMatrix().
params returns one value, the maximum supported depth of the selection
name stack. The value must be at least 64. See glPushName(). params
returns one value, the maximum supported size of a glPixelMap() lookup
table. The value must be at least 32. See glPixelMap(). params returns
one value, the maximum supported depth of the projection matrix stack.
The value must be at least 2. See glPushMatrix(). params returns one
value. The value gives a rough estimate of the largest texture that the
GL can handle. If the GL version is 1.1 or greater, use GL_PROXY_TEX‐
TURE_1D or GL_PROXY_TEXTURE_2D to determine if a texture is too large.
See glTexImage1D() and glTexImage2D(). params returns one value, the
maximum supported depth of the texture matrix stack. The value must be
at least 2. See glPushMatrix(). params returns a single value indicat‐
ing the number of texture units supported. The value must be at least
1. See glActiveTextureARB(). params returns two values: the maximum
supported width and height of the viewport. These must be at least as
large as the visible dimensions of the display being rendered to. See
glViewport(). params returns a single boolean value indicating whether
pixel minmax values are computed. The initial value is GL_FALSE. See
glMinmax(). params returns sixteen values: the modelview matrix on the
top of the modelview matrix stack. Initially this matrix is the iden‐
tity matrix. See glPushMatrix(). params returns one value, the number
of matrices on the modelview matrix stack. The initial value is 1. See
glPushMatrix(). params returns one value, the number of names on the
selection name stack. The initial value is 0. See glPushName(). params
returns a single boolean value, indicating whether the normal array is
enabled. The initial value is GL_FALSE. See glNormalPointer(). params
returns one value, the byte offset between consecutive normals in the
normal array. The initial value is 0. See glNormalPointer(). params
returns one value, the data type of each coordinate in the normal
array. The initial value is GL_FLOAT. See glNormalPointer(). params
returns a single boolean value indicating whether normals are automati‐
cally scaled to unit length after they have been transformed to eye
coordinates. The initial value is GL_FALSE. See glNormal(). params
returns one value, the byte alignment used for writing pixel data to
memory. The initial value is 4. See glPixelStore(). params returns one
value, the image height used for writing pixel data to memory. The
initial value is 0. See glPixelStore(). params returns a single bool‐
ean value indicating whether single-bit pixels being written to memory
are written first to the least significant bit of each unsigned byte.
The initial value is GL_FALSE. See glPixelStore(). params returns one
value, the row length used for writing pixel data to memory. The ini‐
tial value is 0. See glPixelStore(). params returns one value, the
number of pixel images skipped before the first pixel is written into
memory. The initial value is 0. See glPixelStore(). params returns one
value, the number of pixel locations skipped before the first pixel is
written into memory. The initial value is 0. See glPixelStore().
params returns one value, the number of rows of pixel locations skipped
before the first pixel is written into memory. The initial value is 0.
See glPixelStore(). params returns a single boolean value indicating
whether the bytes of two-byte and four-byte pixel indices and compo‐
nents are swapped before being written to memory. The initial value is
GL_FALSE. See glPixelStore(). params returns one value, a symbolic
constant indicating the mode of the perspective correction hint. The
initial value is GL_DONT_CARE. See glHint(). params returns one value,
the size of the alpha-to-alpha pixel translation table. The initial
value is 1. See glPixelMap(). params returns one value, the size of
the blue-to-blue pixel translation table. The initial value is 1. See
glPixelMap(). params returns one value, the size of the green-to-green
pixel translation table. The initial value is 1. See glPixelMap().
params returns one value, the size of the index-to-alpha pixel transla‐
tion table. The initial value is 1. See glPixelMap(). params returns
one value, the size of the index-to-blue pixel translation table. The
initial value is 1. See glPixelMap(). params returns one value, the
size of the index-to-green pixel translation table. The initial value
is 1. See glPixelMap(). params returns one value, the size of the
index-to-index pixel translation table. The initial value is 1. See
glPixelMap(). params returns one value, the size of the index-to-red
pixel translation table. The initial value is 1. See glPixelMap().
params returns one value, the size of the red-to-red pixel translation
table. The initial value is 1. See glPixelMap(). params returns one
value, the size of the stencil-to-stencil pixel translation table. The
initial value is 1. See glPixelMap(). params returns one value, the
point size as specified by glPointSize(). The initial value is 1.
params returns one value, the size difference between adjacent sup‐
ported sizes for antialiased points. See glPointSize(). params returns
two values: the smallest and largest supported sizes for antialiased
points. The smallest size must be at most 1, and the largest size must
be at least 1. See glPointSize(). params returns a single boolean
value indicating whether antialiasing of points is enabled. The initial
value is GL_FALSE. See glPointSize(). params returns one value, a sym‐
bolic constant indicating the mode of the point antialiasing hint. The
initial value is GL_DONT_CARE. See glHint(). params returns two val‐
ues: symbolic constants indicating whether front-facing and back-facing
polygons are rasterized as points, lines, or filled polygons. The ini‐
tial value is GL_FILL. See glPolygonMode(). params returns one value,
the scaling factor used to determine the variable offset that is added
to the depth value of each fragment generated when a polygon is raster‐
ized. The initial value is 0. See glPolygonOffset(). params returns
one value. This value is multiplied by an implementation-specific value
and then added to the depth value of each fragment generated when a
polygon is rasterized. The initial value is 0. See glPolygonOffset().
params returns a single boolean value indicating whether polygon offset
is enabled for polygons in fill mode. The initial value is GL_FALSE.
See glPolygonOffset(). params returns a single boolean value indicat‐
ing whether polygon offset is enabled for polygons in line mode. The
initial value is GL_FALSE. See glPolygonOffset(). params returns a
single boolean value indicating whether polygon offset is enabled for
polygons in point mode. The initial value is GL_FALSE. See glPoly‐
gonOffset(). params returns a single boolean value indicating whether
antialiasing of polygons is enabled. The initial value is GL_FALSE.
See glPolygonMode(). params returns one value, a symbolic constant
indicating the mode of the polygon antialiasing hint. The initial value
is GL_DONT_CARE. See glHint(). params returns a single boolean value
indicating whether polygon stippling is enabled. The initial value is
GL_FALSE. See glPolygonStipple(). params returns a single boolean
value indicating whether post color matrix transformation lookup is
enabled. The initial value is GL_FALSE. See glColorTable(). params
returns one value, the red bias factor applied to RGBA fragments after
color matrix transformations. The initial value is 0. See glPixelTrans‐
fer(). params returns one value, the green bias factor applied to RGBA
fragments after color matrix transformations. The initial value is 0.
See glPixelTransfer() params returns one value, the blue bias factor
applied to RGBA fragments after color matrix transformations. The ini‐
tial value is 0. See glPixelTransfer(). params returns one value, the
alpha bias factor applied to RGBA fragments after color matrix trans‐
formations. The initial value is 0. See glPixelTransfer(). params
returns one value, the red scale factor applied to RGBA fragments after
color matrix transformations. The initial value is 1. See glPixelTrans‐
fer(). params returns one value, the green scale factor applied to
RGBA fragments after color matrix transformations. The initial value is
1. See glPixelTransfer(). params returns one value, the blue scale
factor applied to RGBA fragments after color matrix transformations.
The initial value is 1. See glPixelTransfer(). params returns one
value, the alpha scale factor applied to RGBA fragments after color
matrix transformations. The initial value is 1. See glPixelTransfer().
params returns a single boolean value indicating whether post convolu‐
tion lookup is enabled. The initial value is GL_FALSE. See glCol‐
orTable(). params returns one value, the red bias factor applied to
RGBA fragments after convolution. The initial value is 0. See glPixel‐
Transfer(). params returns one value, the green bias factor applied to
RGBA fragments after convolution. The initial value is 0. See glPixel‐
Transfer(). params returns one value, the blue bias factor applied to
RGBA fragments after convolution. The initial value is 0. See glPixel‐
Transfer(). params returns one value, the alpha bias factor applied to
RGBA fragments after convolution. The initial value is 0. See glPixel‐
Transfer(). params returns one value, the red scale factor applied to
RGBA fragments after convolution. The initial value is 1. See glPixel‐
Transfer(). params returns one value, the green scale factor applied
to RGBA fragments after convolution. The initial value is 1. See
glPixelTransfer(). params returns one value, the blue scale factor
applied to RGBA fragments after convolution. The initial value is 1.
See glPixelTransfer(). params returns one value, the alpha scale fac‐
tor applied to RGBA fragments after convolution. The initial value is
1. See glPixelTransfer(). params returns sixteen values: the projec‐
tion matrix on the top of the projection matrix stack. Initially this
matrix is the identity matrix. See glPushMatrix(). params returns one
value, the number of matrices on the projection matrix stack. The ini‐
tial value is 1. See glPushMatrix(). params returns one value, a sym‐
bolic constant indicating which color buffer is selected for reading.
The initial value is GL_BACK if there is a back buffer, otherwise it is
GL_FRONT. See glReadPixels() and glAccum(). params returns one value,
the red bias factor used during pixel transfers. The initial value is
0. params returns one value, the number of red bitplanes in each color
buffer. params returns one value, the red scale factor used during
pixel transfers. The initial value is 1. See glPixelTransfer(). params
returns one value, a symbolic constant indicating whether the GL is in
render, select, or feedback mode. The initial value is GL_RENDER. See
glRenderMode(). params returns single boolean value indicating whether
normal rescaling is enabled. See glEnable(). params returns a single
boolean value indicating whether the GL is in RGBA mode (true) or color
index mode (false). See glColor(). params returns four values: the x
and y window coordinates of the scissor box, followed by its width and
height. Initially the x and y window coordinates are both 0 and the
width and height are set to the size of the window. See glScissor().
params returns a single boolean value indicating whether scissoring is
enabled. The initial value is GL_FALSE. See glScissor(). params return
one value, the size of the selection buffer. See glSelectBuffer().
params returns a single boolean value indicating whether 2D separable
convolution is enabled. The initial value is GL_FALSE. See glSepara‐
bleFilter2D(). params returns one value, a symbolic constant indicat‐
ing whether the shading mode is flat or smooth. The initial value is
GL_SMOOTH. See glShadeModel(). params returns two values, the smallest
and largest supported widths for antialiased lines. See glLineWidth().
params returns one value, the granularity of widths for antialiased
lines. See glLineWidth(). params returns two values, the smallest and
largest supported widths for antialiased points. See glPointSize().
params returns one value, the granularity of sizes for antialiased
points. See glPointSize(). params returns one value, the number of
bitplanes in the stencil buffer. params returns one value, the index
to which the stencil bitplanes are cleared. The initial value is 0. See
glClearStencil(). params returns one value, a symbolic constant indi‐
cating what action is taken when the stencil test fails. The initial
value is GL_KEEP. See glStencilOp(). params returns one value, a sym‐
bolic constant indicating what function is used to compare the stencil
reference value with the stencil buffer value. The initial value is
GL_ALWAYS. See glStencilFunc(). params returns one value, a symbolic
constant indicating what action is taken when the stencil test passes,
but the depth test fails. The initial value is GL_KEEP. See glSten‐
cilOp(). params returns one value, a symbolic constant indicating what
action is taken when the stencil test passes and the depth test passes.
The initial value is GL_KEEP. See glStencilOp(). params returns one
value, the reference value that is compared with the contents of the
stencil buffer. The initial value is 0. See glStencilFunc(). params
returns a single boolean value indicating whether stencil testing of
fragments is enabled. The initial value is GL_FALSE. See glStencil‐
Func() and glStencilOp(). params returns one value, the mask that is
used to mask both the stencil reference value and the stencil buffer
value before they are compared. The initial value is all 1's. See glS‐
tencilFunc(). params returns one value, the mask that controls writing
of the stencil bitplanes. The initial value is all 1's. See glStencil‐
Mask(). params returns a single boolean value indicating whether
stereo buffers (left and right) are supported. params returns one
value, an estimate of the number of bits of subpixel resolution that
are used to position rasterized geometry in window coordinates. The
initial value is 4. params returns a single boolean value indicating
whether 1D texture mapping is enabled. The initial value is GL_FALSE.
See glTexImage1D(). params returns a single value, the name of the
texture currently bound to the target GL_TEXTURE_1D. The initial value
is 0. See glBindTexture(). params returns a single boolean value indi‐
cating whether 2D texture mapping is enabled. The initial value is
GL_FALSE. See glTexImage2D(). params returns a single value, the name
of the texture currently bound to the target GL_TEXTURE_2D. The initial
value is 0. See glBindTexture(). params returns a single boolean value
indicating whether 3D texture mapping is enabled. The initial value is
GL_FALSE. See glTexImage3D(). params returns a single value, the name
of the texture currently bound to the target GL_TEXTURE_3D. The initial
value is 0. See glBindTexture(). params returns a single boolean value
indicating whether the texture coordinate array is enabled. The initial
value is GL_FALSE. See glTexCoordPointer(). params returns one value,
the number of coordinates per element in the texture coordinate array.
The initial value is 4. See glTexCoordPointer(). params returns one
value, the byte offset between consecutive elements in the texture
coordinate array. The initial value is 0. See glTexCoordPointer().
params returns one value, the data type of the coordinates in the tex‐
ture coordinate array. The initial value is GL_FLOAT. See glTexCoord‐
Pointer(). params returns a single boolean value indicating whether
automatic generation of the q texture coordinate is enabled. The ini‐
tial value is GL_FALSE. See glTexGen(). params returns a single bool‐
ean value indicating whether automatic generation of the r texture
coordinate is enabled. The initial value is GL_FALSE. See glTexGen().
params returns a single boolean value indicating whether automatic gen‐
eration of the S texture coordinate is enabled. The initial value is
GL_FALSE. See glTexGen(). params returns a single boolean value indi‐
cating whether automatic generation of the T texture coordinate is
enabled. The initial value is GL_FALSE. See glTexGen(). params returns
sixteen values: the texture matrix on the top of the texture matrix
stack. Initially this matrix is the identity matrix. See glPushMa‐
trix(). params returns one value, the number of matrices on the tex‐
ture matrix stack. The initial value is 1. See glPushMatrix(). params
returns one value, the byte alignment used for reading pixel data from
memory. The initial value is 4. See glPixelStore(). params returns one
value, the image height used for reading pixel data from memory. The
initial is 0. See glPixelStore(). params returns a single boolean
value indicating whether single-bit pixels being read from memory are
read first from the least significant bit of each unsigned byte. The
initial value is GL_FALSE. See glPixelStore(). params returns one
value, the row length used for reading pixel data from memory. The ini‐
tial value is 0. See glPixelStore(). params returns one value, the
number of pixel images skipped before the first pixel is read from mem‐
ory. The initial value is 0. See glPixelStore(). params returns one
value, the number of pixel locations skipped before the first pixel is
read from memory. The initial value is 0. See glPixelStore(). params
returns one value, the number of rows of pixel locations skipped before
the first pixel is read from memory. The initial value is 0. See
glPixelStore(). params returns a single boolean value indicating
whether the bytes of two-byte and four-byte pixel indices and compo‐
nents are swapped after being read from memory. The initial value is
GL_FALSE. See glPixelStore(). params returns a single boolean value
indicating whether the vertex array is enabled. The initial value is
GL_FALSE. See glVertexPointer(). params returns one value, the number
of coordinates per vertex in the vertex array. The initial value is 4.
See glVertexPointer(). params returns one value, the byte offset
between consecutive vertexes in the vertex array. The initial value is
0. See glVertexPointer(). params returns one value, the data type of
each coordinate in the vertex array. The initial value is GL_FLOAT. See
glVertexPointer(). params returns four values: the x and y window
coordinates of the viewport, followed by its width and height. Ini‐
tially the x and y window coordinates are both set to 0, and the width
and height are set to the width and height of the window into which the
GL will do its rendering. See glViewport(). params returns one value,
the x pixel zoom factor. The initial value is 1. See glPixelZoom().
params returns one value, the y pixel zoom factor. The initial value is
1. See glPixelZoom().
Many of the boolean parameters can also be queried more easily using
glIsEnabled().
NOTES
GL_COLOR_LOGIC_OP, GL_COLOR_ARRAY, GL_COLOR_ARRAY_SIZE,
GL_COLOR_ARRAY_STRIDE, GL_COLOR_ARRAY_TYPE, GL_EDGE_FLAG_ARRAY,
GL_EDGE_FLAG_ARRAY_STRIDE, GL_INDEX_ARRAY, GL_INDEX_ARRAY_STRIDE,
GL_INDEX_ARRAY_TYPE, GL_INDEX_LOGIC_OP, GL_NORMAL_ARRAY, GL_NOR‐
MAL_ARRAY_STRIDE, GL_NORMAL_ARRAY_TYPE, GL_POLYGON_OFFSET_UNITS,
GL_POLYGON_OFFSET_FACTOR, GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFF‐
SET_LINE, GL_POLYGON_OFFSET_POINT, GL_TEXTURE_COORD_ARRAY, GL_TEX‐
TURE_COORD_ARRAY_SIZE, GL_TEXTURE_COORD_ARRAY_STRIDE, GL_TEX‐
TURE_COORD_ARRAY_TYPE, GL_VERTEX_ARRAY, GL_VERTEX_ARRAY_SIZE, GL_VER‐
TEX_ARRAY_STRIDE, and GL_VERTEX_ARRAY_TYPE are available only if the GL
version is 1.1 or greater.
GL_ALIASED_POINT_SIZE_RANGE, GL_ALIASED_POINT_SIZE_GRANULARITY,
GL_FEEDBACK_BUFFER_SIZE, GL_FEEDBACK_BUFFER_TYPE, GL_LIGHT_MODEL_AMBI‐
ENT, GL_LIGHT_MODEL_COLOR_CONTROL, GL_MAX_3D_TEXTURE_SIZE, GL_MAX_ELE‐
MENTS_INDICES, GL_MAX_ELEMENTS_VERTICES, GL_PACK_IMAGE_HEIGHT,
GL_PACK_SKIP_IMAGES, GL_RESCALE_NORMAL, GL_SELECTION_BUFFER_SIZE,
GL_SMOOTH_LINE_WIDTH_GRANULARITY, GL_SMOOTH_LINE_WIDTH_RANGE,
GL_SMOOTH_POINT_SIZE_GRANULARITY, GL_SMOOTH_POINT_SIZE_RANGE, GL_TEX‐
TURE_3D, GL_TEXTURE_BINDING_3D, GL_UNPACK_IMAGE_HEIGHT, and
GL_UNPACK_SKIP_IMAGES are available only if the GL version is 1.2 or
greater.
GL_LINE_WIDTH_GRANULARITY was deprecated in GL version 1.2. Its func‐
tionality was replaced by GL_SMOOTH_LINE_WIDTH_GRANULARITY.
GL_LINE_WIDTH_RANGE was deprecated in GL version 1.2. Its functional‐
ity was replaced by GL_SMOOTH_LINE_WIDTH_RANGE.
GL_POINT_SIZE_GRANULARITY was deprecated in GL version 1.2. Its func‐
tionality was replaced by GL_SMOOTH_POINT_SIZE_GRANULARITY.
GL_POINT_SIZE_RANGE was deprecated in GL version 1.2. Its functional‐
ity was replaced by GL_SMOOTH_POINT_SIZE_RANGE.
GL_BLEND_COLOR, GL_BLEND_EQUATION, GL_COLOR_MATRIX,
GL_COLOR_MATRIX_STACK_DEPTH, GL_COLOR_TABLE, GL_CONVOLUTION_1D, GL_CON‐
VOLUTION_2D, GL_HISTOGRAM, GL_MAX_COLOR_MATRIX_STACK_DEPTH, GL_MINMAX,
GL_POST_COLOR_MATRIX_COLOR_TABLE, GL_POST_COLOR_MATRIX_RED_BIAS,
GL_POST_COLOR_MATRIX_GREEN_BIAS, GL_POST_COLOR_MATRIX_BLUE_BIAS,
GL_POST_COLOR_MATRIX_ALPHA_BIAS, GL_POST_COLOR_MATRIX_RED_SCALE,
GL_POST_COLOR_MATRIX_GREEN_SCALE, GL_POST_COLOR_MATRIX_BLUE_SCALE,
GL_POST_COLOR_MATRIX_ALPHA_SCALE, GL_POST_CONVOLUTION_COLOR_TABLE,
GL_POST_CONVOLUTION_RED_BIAS, GL_POST_CONVOLUTION_GREEN_BIAS,
GL_POST_CONVOLUTION_BLUE_BIAS, GL_POST_CONVOLUTION_ALPHA_BIAS,
GL_POST_CONVOLUTION_RED_SCALE, GL_POST_CONVOLUTION_GREEN_SCALE,
GL_POST_CONVOLUTION_BLUE_SCALE, GL_POST_CONVOLUTION_ALPHA_SCALE, and
GL_SEPARABLE_2D are available only if GL_ARB_imaging is returned from
glGet() when called with the argument GL_EXTENSIONS.
GL_ACTIVE_TEXTURE_ARB, GL_CLIENT_ACTIVE_TEXTURE_ARB, and GL_MAX_TEX‐
TURE_UNITS_ARB are available only if GL_ARB_multitexture is returned
from glGet() when called with the argument GL_EXTENSIONS.
When the GL_ARB_multitexture extension is supported, the following
parameters return the associated value for the active texture unit:
GL_CURRENT_RASTER_TEXTURE_COORDS, GL_TEXTURE_1D, GL_TEXTURE_BINDING_1D,
GL_TEXTURE_2D, GL_TEXTURE_BINDING_2D, GL_TEXTURE_3D, GL_TEXTURE_BIND‐
ING_3D, GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, GL_TEX‐
TURE_GEN_Q, GL_TEXTURE_MATRIX, and GL_TEXTURE_STACK_DEPTH. Likewise,
the following parameters return the associated value for the active
client texture unit: GL_TEXTURE_COORD_ARRAY, GL_TEX‐
TURE_COORD_ARRAY_SIZE, GL_TEXTURE_COORD_ARRAY_STRIDE, GL_TEX‐
TURE_COORD_ARRAY_TYPE.
ERRORS
GL_INVALID_ENUM is generated if pname is not an accepted value.
GL_INVALID_OPERATION is generated if glGet() is executed between the
execution of glBegin() and the corresponding execution of glEnd().
SEE ALSOglGetClipPlane(3), glGetColorTable(3), glGetColorTableParameter(3),
glGetConvolutionFilter(3), glGetConvolutionParameter(3), glGetError(3),
glGetHistogram(3), glGetHistogramParameter(3), glGetLight(3),
glGetMap(3), glGetMaterial(3), glGetMinmax(3), glGetMinmaxParameter(3),
glGetPixelMap(3), glGetPointerv(3), glGetPolygonStipple(3), glGetSepa‐
rableFilter(3), glGetString(3), glGetTexEnv(3), glGetTexGen(3), glGet‐
TexImage(3), glGetTexLevelParameter(3), glGetTexParameter(3), glIsEn‐
abled(3)glGet(3G)