- return the value or values of a selected parameter
C SPECIFICATION
C SPECIFICATION
C SPECIFICATION
C SPECIFICATION
PARAMETERS
_param1 Specifies the parameter value to be returned.
The symbolic constants in the list below are
accepted.
_param2 Returns the value or values of the specified
parameter.
DESCRIPTION
These four commands return values for simple state vari-
ables in GL. _param1 is a symbolic constant indicating
the state variable to be returned, and _param2 is a
pointer to an array of the indicated type in which to
place the returned data.
Type conversion is performed if _param2 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
glGetIntegerv 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 col-
ors and normals, however, are returned with a linear map-
ping 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 _param1:
GL_ACCUM_ALPHA_BITS _param2 returns one value, the
number of alpha bitplanes in the
accumulation buffer.
GL_ACCUM_BLUE_BITS _param2 returns one value, the
number of blue bitplanes in the
accumulation buffer.
GL_ACCUM_CLEAR_VALUE _param2 returns four values: the
red, green, blue, and alpha val-
ues used to clear the accumula-
tion buffer. Integer values, if
requested, are linearly mapped
number of red bitplanes in the
accumulation buffer.
GL_ACTIVE_TEXTURE_ARB _param2 returns a single value
indicating the active multitex-
ture unit. The initial value is
GL_TEXTURE0_ARB. See
glActiveTextureARB.
GL_ALIASED_POINT_SIZE_RANGE
_param2 returns two values, the
smallest and largest supported
sizes for aliased points.
GL_ALIASED_LINE_WIDTH_RANGE
_param2 returns two values, the
smallest and largest supported
widths for aliased lines.
GL_ALPHA_BIAS _param2 returns one value, the
alpha bias factor used during
pixel transfers. The initial
value is 0. See glPixelTransfer.
GL_ALPHA_BITS _param2 returns one value, the
number of alpha bitplanes in each
color buffer.
GL_ALPHA_SCALE _param2 returns one value, the
alpha scale factor used during
pixel transfers. The initial
value is 1. See glPixelTransfer.
GL_ALPHA_TEST _param2 returns a single boolean
value indicating whether alpha
testing of fragments is enabled.
The initial value is GL_FALSE.
See glAlphaFunc.
GL_ALPHA_TEST_FUNC _param2 returns one value, the
symbolic name of the alpha test
function. The initial value is
GL_ALWAYS. See glAlphaFunc.
GL_ALPHA_TEST_REF _param2 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 float-
ing-point representation such
that 1.0 returns the most posi-
value is GL_FALSE. See glMap2.
GL_AUX_BUFFERS _param2 returns one value, the
number of auxiliary color
buffers. The initial value is 0.
GL_BLEND _param2 returns a single boolean
value indicating whether blending
is enabled. The initial value is
GL_FALSE. See glBlendFunc.
GL_BLEND_COLOR _param2 returns four values, the
red, green, blue, and alpha val-
ues which are the components of
the blend color. See
glBlendColor.
GL_BLEND_DST _param2 returns one value, the
symbolic constant identifying the
destination blend function. The
initial value is GL_ZERO. See
glBlendFunc.
GL_BLEND_EQUATION _param2 returns one value, a sym-
bolic constant indicating whether
the blend equation is
GL_FUNC_ADD, GL_MIN or GL_MAX.
See glBlendEquation.
GL_BLEND_SRC _param2 returns one value, the
symbolic constant identifying the
source blend function. The ini-
tial value is GL_ONE. See
glBlendFunc.
GL_BLUE_BIAS _param2 returns one value, the
blue bias factor used during
pixel transfers. The initial
value is 0. See glPixelTransfer.
GL_BLUE_BITS _param2 returns one value, the
number of blue bitplanes in each
color buffer.
GL_BLUE_SCALE _param2 returns one value, the
blue scale factor used during
pixel transfers. The initial
value is 1. See glPixelTransfer.
GL_CLIENT_ACTIVE_TEXTURE_ARB
_param2 returns a single integer
value indicating the current
specified clipping plane is
enabled. The initial value is
GL_FALSE. See glClipPlane.
GL_COLOR_ARRAY _param2 returns a single boolean
value indicating whether the
color array is enabled. The ini-
tial value is GL_FALSE. See
glColorPointer.
GL_COLOR_ARRAY_SIZE _param2 returns one value, the
number of components per color in
the color array. The initial
value is 4. See glColorPointer.
GL_COLOR_ARRAY_STRIDE _param2 returns one value, the
byte offset between consecutive
colors in the color array. The
initial value is 0. See
glColorPointer.
GL_COLOR_ARRAY_TYPE _param2 returns one value, the
data type of each component in
the color array. The initial
value is GL_FLOAT. See
glColorPointer.
GL_COLOR_CLEAR_VALUE _param2 returns four values: the
red, green, blue, and alpha val-
ues 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 repre-
sentable integer value, and -1.0
returns the most negative repre-
sentable integer value. The ini-
tial value is (0, 0, 0, 0). See
glClearColor.
GL_COLOR_LOGIC_OP _param2 returns a single boolean
value indicating whether a frag-
ment's RGBA color values are
merged into the framebuffer using
a logical operation. The initial
value is GL_FALSE. See
glLogicOp.
GL_COLOR_MATERIAL _param2 returns a single boolean
value indicating whether one or
more material parameters are
bolic constant indicating which
material parameters are tracking
the current color. The initial
value is GL_AMBIENT_AND_DIFFUSE.
See glColorMaterial.
GL_COLOR_MATRIX _param2 returns sixteen values:
the color matrix on the top of
the color matrix stack. Initially
this matrix is the identity
matrix. See glPushMatrix.
GL_COLOR_MATRIX_STACK_DEPTH
_param2 returns one value, the
maximum supported depth of the
projection matrix stack. The
value must be at least 2. See
glPushMatrix.
GL_COLOR_TABLE _param2 returns a single boolean
value indicating whether the
color table lookup is enabled.
See glColorTable.
GL_COLOR_WRITEMASK _param2 returns four boolean val-
ues: 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.
GL_CONVOLUTION_1D _param2 returns a single boolean
value indicating whether 1D con-
volution is enabled. The initial
value is GL_FALSE. See
glConvolutionFilter1D.
GL_CONVOLUTION_2D _param2 returns a single boolean
value indicating whether 2D con-
volution is enabled. The initial
value is GL_FALSE. See
glConvolutionFilter2D.
GL_CULL_FACE _param2 returns a single boolean
value indicating whether polygon
culling is enabled. The initial
value is GL_FALSE. See
glCullFace.
GL_CULL_FACE_MODE _param2 returns one value, a sym-
bolic constant indicating which
polygon faces are to be culled.
value is (1, 1, 1, 1).
GL_CURRENT_INDEX _param2 returns one value, the
current color index. The initial
value is 1. See glIndex.
GL_CURRENT_NORMAL _param2 returns three values: the
x, y, and z 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 repre-
sentable integer value, and -1.0
returns the most negative repre-
sentable integer value. The ini-
tial value is (0, 0, 1). See
glNormal.
GL_CURRENT_RASTER_COLOR _param2 returns four values: the
red, green, blue, and alpha val-
ues of the current raster posi-
tion. Integer values, if
requested, are linearly mapped
from the internal floating-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 ini-
tial value is (1, 1, 1, 1). See
glRasterPos.
GL_CURRENT_RASTER_DISTANCE
_param2 returns one value, the
distance from the eye to the cur-
rent raster position. The initial
value is 0. See glRasterPos.
GL_CURRENT_RASTER_INDEX _param2 returns one value, the
color index of the current raster
position. The initial value is 1.
See glRasterPos.
GL_CURRENT_RASTER_POSITION
_param2 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.
GL_CURRENT_TEXTURE_COORDS
_param2 returns four values: the
s, t, r, and q current texture
coordinates. The initial value is
(0, 0, 0, 1). See glTexCoord.
GL_DEPTH_BIAS _param2 returns one value, the
depth bias factor used during
pixel transfers. The initial
value is 0. See glPixelTransfer.
GL_DEPTH_BITS _param2 returns one value, the
number of bitplanes in the depth
buffer.
GL_DEPTH_CLEAR_VALUE _param2 returns one value, the
value that is used to clear the
depth buffer. Integer values, if
requested, are linearly mapped
from the internal floating-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 ini-
tial value is 1. See
glClearDepth.
GL_DEPTH_FUNC _param2 returns one value, the
symbolic constant that indicates
the depth comparison function.
The initial value is GL_LESS.
See glDepthFunc.
GL_DEPTH_RANGE _param2 returns two values: the
near and far mapping limits for
the depth buffer. Integer val-
ues, if requested, are linearly
mapped from the internal float-
ing-point representation such
that 1.0 returns the most posi-
tive representable integer value,
and -1.0 returns the most nega-
tive representable integer value.
The initial value is (0, 1). See
glDepthRange.
GL_DEPTH_SCALE _param2 returns one value, the
depth scale factor used during
pixel transfers. The initial
value is 1. See glPixelTransfer.
value indicating whether dither-
ing of fragment colors and
indices is enabled. The initial
value is GL_TRUE.
GL_DOUBLEBUFFER _param2 returns a single boolean
value indicating whether double
buffering is supported.
GL_DRAW_BUFFER _param2 returns one value, a sym-
bolic constant indicating which
buffers are being drawn to. See
glDrawBuffer. The initial value
is GL_BACK if there are back
buffers, otherwise it is
GL_FRONT.
GL_EDGE_FLAG _param2 returns a single boolean
value indicating whether the cur-
rent edge flag is GL_TRUE or
GL_FALSE. The initial value is
GL_TRUE. See glEdgeFlag.
GL_EDGE_FLAG_ARRAY _param2 returns a single boolean
value indicating whether the edge
flag array is enabled. The ini-
tial value is GL_FALSE. See
glEdgeFlagPointer.
GL_EDGE_FLAG_ARRAY_STRIDE
_param2 returns one value, the
byte offset between consecutive
edge flags in the edge flag
array. The initial value is 0.
See glEdgeFlagPointer.
GL_FEEDBACK_BUFFER_SIZE _param2 returns one value, the
size of the feedback buffer. See
glFeedbackBuffer.
GL_FEEDBACK_BUFFER_TYPE _param2 returns one value, the
type of the feedback buffer. See
glFeedbackBuffer.
GL_FOG _param2 returns a single boolean
value indicating whether fogging
is enabled. The initial value is
GL_FALSE. See glFog.
GL_FOG_COLOR _param2 returns four values: the
red, green, blue, and alpha com-
ponents of the fog color. Inte-
GL_FOG_END _param2 returns one value, the
end factor for the linear fog
equation. The initial value is 1.
See glFog.
GL_FOG_HINT _param2 returns one value, a sym-
bolic constant indicating the
mode of the fog hint. The initial
value is GL_DONT_CARE. See
glHint.
GL_FOG_INDEX _param2 returns one value, the
fog color index. The initial
value is 0. See glFog.
GL_FOG_MODE _param2 returns one value, a sym-
bolic constant indicating which
fog equation is selected. The
initial value is GL_EXP. See
glFog.
GL_FOG_START _param2 returns one value, the
start factor for the linear fog
equation. The initial value is 0.
See glFog.
GL_FRONT_FACE _param2 returns one value, a sym-
bolic constant indicating whether
clockwise or counterclockwise
polygon winding is treated as
front-facing. The initial value
is GL_CCW. See glFrontFace.
GL_GREEN_BIAS _param2 returns one value, the
green bias factor used during
pixel transfers. The initial
value is 0.
GL_GREEN_BITS _param2 returns one value, the
number of green bitplanes in each
color buffer.
GL_GREEN_SCALE _param2 returns one value, the
green scale factor used during
pixel transfers. The initial
value is 1. See glPixelTransfer.
GL_HISTOGRAM _param2 returns a single boolean
value indicating whether his-
togram is enabled. The initial
value is GL_FALSE. See
glHistogram.
data type of indexes in the color
index array. The initial value is
GL_FLOAT. See glIndexPointer.
GL_INDEX_BITS _param2 returns one value, the
number of bitplanes in each color
index buffer.
GL_INDEX_CLEAR_VALUE _param2 returns one value, the
color index used to clear the
color index buffers. The initial
value is 0. See glClearIndex.
GL_INDEX_LOGIC_OP _param2 returns a single boolean
value indicating whether a frag-
ment's index values are merged
into the framebuffer using a log-
ical operation. The initial value
is GL_FALSE. See glLogicOp.
GL_INDEX_MODE _param2 returns a single boolean
value indicating whether the GL
is in color index mode (GL_TRUE)
or RGBA mode (GL_FALSE).
GL_INDEX_OFFSET _param2 returns one value, the
offset added to color and stencil
indices during pixel transfers.
The initial value is 0. See
glPixelTransfer.
GL_INDEX_SHIFT _param2 returns one value, the
amount that color and stencil
indices are shifted during pixel
transfers. The initial value is
0. See glPixelTransfer.
GL_INDEX_WRITEMASK _param2 returns one value, a mask
indicating which bitplanes of
each color index buffer can be
written. The initial value is all
1's. See glIndexMask.
GL_LIGHTi _param2 returns a single boolean
value indicating whether the
specified light is enabled. The
initial value is GL_FALSE. See
glLight and glLightModel.
GL_LIGHTING _param2 returns a single boolean
value indicating whether lighting
is enabled. The initial value is
0.2, 0.2, 1.0). See
glLightModel.
GL_LIGHT_MODEL_COLOR_CONTROL
_param2 returns single enumerated
value indicating whether specular
reflection calculations are sepa-
rated from normal lighting compu-
tations. The initial value is
GL_SINGLE_COLOR.
GL_LIGHT_MODEL_LOCAL_VIEWER
_param2 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 glLightModel.
GL_LIGHT_MODEL_TWO_SIDE _param2 returns a single boolean
value indicating whether separate
materials are used to compute
lighting for front- and back-fac-
ing polygons. The initial value
is GL_FALSE. See glLightModel.
GL_LINE_SMOOTH _param2 returns a single boolean
value indicating whether
antialiasing of lines is enabled.
The initial value is GL_FALSE.
See glLineWidth.
GL_LINE_SMOOTH_HINT _param2 returns one value, a sym-
bolic constant indicating the
mode of the line antialiasing
hint. The initial value is
GL_DONT_CARE. See glHint.
GL_LINE_STIPPLE _param2 returns a single boolean
value indicating whether stip-
pling of lines is enabled. The
initial value is GL_FALSE. See
glLineStipple.
GL_LINE_STIPPLE_PATTERN _param2 returns one value, the
16-bit line stipple pattern. The
initial value is all 1's. See
glLineStipple.
GL_LINE_STIPPLE_REPEAT _param2 returns one value, the
line stipple repeat factor. The
initial value is 1. See
smallest and largest supported
widths for antialiased lines.
See glLineWidth.
GL_LIST_BASE _param2 returns one value, the
base offset added to all names in
arrays presented to glCallLists.
The initial value is 0. See
glListBase.
GL_LIST_INDEX _param2 returns one value, the
name of the display list cur-
rently under construction. 0 is
returned if no display list is
currently under construction. The
initial value is 0. See
glNewList.
GL_LIST_MODE _param2 returns one value, a sym-
bolic constant indicating the
construction mode of the display
list currently under construc-
tion. The initial value is 0.
See glNewList.
GL_LOGIC_OP_MODE _param2 returns one value, a sym-
bolic constant indicating the
selected logic operation mode.
The initial value is GL_COPY.
See glLogicOp.
GL_MAP1_COLOR_4 _param2 returns a single boolean
value indicating whether 1D eval-
uation generates colors. The ini-
tial value is GL_FALSE. See
glMap1.
GL_MAP1_GRID_DOMAIN _param2 returns two values: the
endpoints of the 1D map's grid
domain. The initial value is (0,
1). See glMapGrid.
GL_MAP1_GRID_SEGMENTS _param2 returns one value, the
number of partitions in the 1D
map's grid domain. The initial
value is 1. See glMapGrid.
GL_MAP1_INDEX _param2 returns a single boolean
value indicating whether 1D eval-
uation generates color indices.
The initial value is GL_FALSE.
See glMap1.
value indicating whether 1D eval-
uation generates 2D texture coor-
dinates. The initial value is
GL_FALSE. See glMap1.
GL_MAP1_TEXTURE_COORD_3 _param2 returns a single boolean
value indicating whether 1D eval-
uation generates 3D texture coor-
dinates. The initial value is
GL_FALSE. See glMap1.
GL_MAP1_TEXTURE_COORD_4 _param2 returns a single boolean
value indicating whether 1D eval-
uation generates 4D texture coor-
dinates. The initial value is
GL_FALSE. See glMap1.
GL_MAP1_VERTEX_3 _param2 returns a single boolean
value indicating whether 1D eval-
uation generates 3D vertex coor-
dinates. The initial value is
GL_FALSE. See glMap1.
GL_MAP1_VERTEX_4 _param2 returns a single boolean
value indicating whether 1D eval-
uation generates 4D vertex coor-
dinates. The initial value is
GL_FALSE. See glMap1.
GL_MAP2_COLOR_4 _param2 returns a single boolean
value indicating whether 2D eval-
uation generates colors. The ini-
tial value is GL_FALSE. See
glMap2.
GL_MAP2_GRID_DOMAIN _param2 returns four values: the
endpoints of the 2D map's i and j
grid domains. The initial value
is (0,1; 0,1). See glMapGrid.
GL_MAP2_GRID_SEGMENTS _param2 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.
GL_MAP2_INDEX _param2 returns a single boolean
value indicating whether 2D eval-
uation generates color indices.
The initial value is GL_FALSE.
See glMap2.
uation generates 2D texture coor-
dinates. The initial value is
GL_FALSE. See glMap2.
GL_MAP2_TEXTURE_COORD_3 _param2 returns a single boolean
value indicating whether 2D eval-
uation generates 3D texture coor-
dinates. The initial value is
GL_FALSE. See glMap2.
GL_MAP2_TEXTURE_COORD_4 _param2 returns a single boolean
value indicating whether 2D eval-
uation generates 4D texture coor-
dinates. The initial value is
GL_FALSE. See glMap2.
GL_MAP2_VERTEX_3 _param2 returns a single boolean
value indicating whether 2D eval-
uation generates 3D vertex coor-
dinates. The initial value is
GL_FALSE. See glMap2.
GL_MAP2_VERTEX_4 _param2 returns a single boolean
value indicating whether 2D eval-
uation generates 4D vertex coor-
dinates. The initial value is
GL_FALSE. See glMap2.
GL_MAP_COLOR _param2 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.
GL_MAP_STENCIL _param2 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.
GL_MATRIX_MODE _param2 returns one value, a sym-
bolic constant indicating which
matrix stack is currently the
target of all matrix operations.
The initial value is
GL_MODELVIEW. See glMatrixMode.
GL_MAX_3D_TEXTURE_SIZE _param2 returns one value, a
rough estimate of the largest 3D
texture that the GL can handle.
attribute stack. The value must
be at least 16. See
glPushAttrib.
GL_MAX_CLIP_PLANES _param2 returns one value, the
maximum number of application-
defined clipping planes. The
value must be at least 6. See
glClipPlane.
GL_MAX_COLOR_MATRIX_STACK_DEPTH
_param2 returns one value, the
maximum supported depth of the
color matrix stack. The value
must be at least 2. See
glPushMatrix.
GL_MAX_ELEMENTS_INDICES _param2 returns one value, the
recommended maximum number of
vertex array indices. See
glDrawRangeElements.
GL_MAX_ELEMENTS_VERTICES _param2 returns one value, the
recommended maximum number of
vertex array vertices. See
glDrawRangeElements.
GL_MAX_EVAL_ORDER _param2 returns one value, the
maximum equation order supported
by 1D and 2D evaluators. The
value must be at least 8. See
glMap1 and glMap2.
GL_MAX_LIGHTS _param2 returns one value, the
maximum number of lights. The
value must be at least 8. See
glLight.
GL_MAX_LIST_NESTING _param2 returns one value, the
maximum recursion depth allowed
during display-list traversal.
The value must be at least 64.
See glCallList.
GL_MAX_MODELVIEW_STACK_DEPTH
_param2 returns one value, the
maximum supported depth of the
modelview matrix stack. The value
must be at least 32. See
glPushMatrix.
GL_MAX_NAME_STACK_DEPTH _param2 returns one value, the
projection matrix stack. The
value must be at least 2. See
glPushMatrix.
GL_MAX_TEXTURE_SIZE _param2 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_TEXTURE_1D or
GL_PROXY_TEXTURE_2D to determine
if a texture is too large. See
glTexImage1D and glTexImage2D.
GL_MAX_TEXTURE_STACK_DEPTH
_param2 returns one value, the
maximum supported depth of the
texture matrix stack. The value
must be at least 2. See
glPushMatrix.
GL_MAX_TEXTURE_UNITS_ARB _param2 returns a single value
indicating the number of texture
units supported. The value must
be at least 1. See
glActiveTextureARB.
GL_MAX_VIEWPORT_DIMS _param2 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.
GL_MINMAX _param2 returns a single boolean
value indicating whether pixel
minmax values are computed. The
initial value is GL_FALSE. See
glMinmax.
GL_MODELVIEW_MATRIX _param2 returns sixteen values:
the modelview matrix on the top
of the modelview matrix stack.
Initially this matrix is the
identity matrix. See
glPushMatrix.
GL_MODELVIEW_STACK_DEPTH _param2 returns one value, the
number of matrices on the mod-
elview matrix stack. The initial
value is 1. See glPushMatrix.
normals in the normal array. The
initial value is 0. See
glNormalPointer.
GL_NORMAL_ARRAY_TYPE _param2 returns one value, the
data type of each coordinate in
the normal array. The initial
value is GL_FLOAT. See
glNormalPointer.
GL_NORMALIZE _param2 returns a single boolean
value indicating whether normals
are automatically scaled to unit
length after they have been
transformed to eye coordinates.
The initial value is GL_FALSE.
See glNormal.
GL_PACK_ALIGNMENT _param2 returns one value, the
byte alignment used for writing
pixel data to memory. The initial
value is 4. See glPixelStore.
GL_PACK_IMAGE_HEIGHT _param2 returns one value, the
image height used for writing
pixel data to memory. The ini-
tial value is 0. See
glPixelStore.
GL_PACK_LSB_FIRST _param2 returns a single boolean
value indicating whether single-
bit pixels being written to mem-
ory are written first to the
least significant bit of each
unsigned byte. The initial value
is GL_FALSE. See glPixelStore.
GL_PACK_ROW_LENGTH _param2 returns one value, the
row length used for writing pixel
data to memory. The initial value
is 0. See glPixelStore.
GL_PACK_SKIP_IMAGES _param2 returns one value, the
number of pixel images skipped
before the first pixel is written
into memory. The initial value is
0. See glPixelStore.
GL_PACK_SKIP_PIXELS _param2 returns one value, the
number of pixel locations skipped
before the first pixel is written
into memory. The initial value is
GL_FALSE. See glPixelStore.
GL_PERSPECTIVE_CORRECTION_HINT
_param2 returns one value, a sym-
bolic constant indicating the
mode of the perspective correc-
tion hint. The initial value is
GL_DONT_CARE. See glHint.
GL_PIXEL_MAP_A_TO_A_SIZE _param2 returns one value, the
size of the alpha-to-alpha pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_B_TO_B_SIZE _param2 returns one value, the
size of the blue-to-blue pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_G_TO_G_SIZE _param2 returns one value, the
size of the green-to-green pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_A_SIZE _param2 returns one value, the
size of the index-to-alpha pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_B_SIZE _param2 returns one value, the
size of the index-to-blue pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_G_SIZE _param2 returns one value, the
size of the index-to-green pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_I_SIZE _param2 returns one value, the
size of the index-to-index pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_I_TO_R_SIZE _param2 returns one value, the
size of the index-to-red pixel
translation table. The initial
value is 1. See glPixelMap.
GL_PIXEL_MAP_R_TO_R_SIZE _param2 returns one value, the
size of the red-to-red pixel
translation table. The initial
_param2 returns one value, the
size difference between adjacent
supported sizes for antialiased
points. See glPointSize.
GL_POINT_SIZE_RANGE _param2 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.
GL_POINT_SMOOTH _param2 returns a single boolean
value indicating whether
antialiasing of points is
enabled. The initial value is
GL_FALSE. See glPointSize.
GL_POINT_SMOOTH_HINT _param2 returns one value, a sym-
bolic constant indicating the
mode of the point antialiasing
hint. The initial value is
GL_DONT_CARE. See glHint.
GL_POLYGON_MODE _param2 returns two values: sym-
bolic constants indicating
whether front-facing and back-
facing polygons are rasterized as
points, lines, or filled poly-
gons. The initial value is
GL_FILL. See glPolygonMode.
GL_POLYGON_OFFSET_FACTOR _param2 returns one value, the
scaling factor used to determine
the variable offset that is added
to the depth value of each frag-
ment generated when a polygon is
rasterized. The initial value is
0. See glPolygonOffset.
GL_POLYGON_OFFSET_UNITS _param2 returns one value. This
value is multiplied by an imple-
mentation-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.
GL_POLYGON_OFFSET_FILL _param2 returns a single boolean
value indicating whether polygon
offset is enabled for polygons in
fill mode. The initial value is
GL_POLYGON_SMOOTH _param2 returns a single boolean
value indicating whether
antialiasing of polygons is
enabled. The initial value is
GL_FALSE. See glPolygonMode.
GL_POLYGON_SMOOTH_HINT _param2 returns one value, a sym-
bolic constant indicating the
mode of the polygon antialiasing
hint. The initial value is
GL_DONT_CARE. See glHint.
GL_POLYGON_STIPPLE _param2 returns a single boolean
value indicating whether polygon
stippling is enabled. The initial
value is GL_FALSE. See
glPolygonStipple.
GL_POST_COLOR_MATRIX_COLOR_TABLE
_param2 returns a single boolean
value indicating whether post
color matrix transformation
lookup is enabled. The initial
value is GL_FALSE. See
glColorTable.
GL_POST_COLOR_MATRIX_RED_BIAS
_param2 returns one value, the
red bias factor applied to RGBA
fragments after color matrix
transformations. The initial
value is 0. See glPixelTransfer.
GL_POST_COLOR_MATRIX_GREEN_BIAS
_param2 returns one value, the
green bias factor applied to RGBA
fragments after color matrix
transformations. The initial
value is 0. See glPixelTransfer
GL_POST_COLOR_MATRIX_BLUE_BIAS
_param2 returns one value, the
blue bias factor applied to RGBA
fragments after color matrix
transformations. The initial
value is 0. See glPixelTransfer.
GL_POST_COLOR_MATRIX_ALPHA_BIAS
_param2 returns one value, the
alpha bias factor applied to RGBA
fragments after color matrix
transformations. The initial
value is 1. See glPixelTransfer.
GL_POST_COLOR_MATRIX_BLUE_SCALE
_param2 returns one value, the
blue scale factor applied to RGBA
fragments after color matrix
transformations. The initial
value is 1. See glPixelTransfer.
GL_POST_COLOR_MATRIX_ALPHA_SCALE
_param2 returns one value, the
alpha scale factor applied to
RGBA fragments after color matrix
transformations. The initial
value is 1. See glPixelTransfer.
GL_POST_CONVOLUTION_COLOR_TABLE
_param2 returns a single boolean
value indicating whether post
convolution lookup is enabled.
The initial value is GL_FALSE.
See glColorTable.
GL_POST_CONVOLUTION_RED_BIAS
_param2 returns one value, the
red bias factor applied to RGBA
fragments after convolution. The
initial value is 0. See
glPixelTransfer.
GL_POST_CONVOLUTION_GREEN_BIAS
_param2 returns one value, the
green bias factor applied to RGBA
fragments after convolution. The
initial value is 0. See
glPixelTransfer.
GL_POST_CONVOLUTION_BLUE_BIAS
_param2 returns one value, the
blue bias factor applied to RGBA
fragments after convolution. The
initial value is 0. See
glPixelTransfer.
GL_POST_CONVOLUTION_ALPHA_BIAS
_param2 returns one value, the
alpha bias factor applied to RGBA
fragments after convolution. The
initial value is 0. See
glPixelTransfer.
GL_POST_CONVOLUTION_RED_SCALE
GL_POST_CONVOLUTION_BLUE_SCALE
_param2 returns one value, the
blue scale factor applied to RGBA
fragments after convolution. The
initial value is 1. See
glPixelTransfer.
GL_POST_CONVOLUTION_ALPHA_SCALE
_param2 returns one value, the
alpha scale factor applied to
RGBA fragments after convolution.
The initial value is 1. See
glPixelTransfer.
GL_PROJECTION_MATRIX _param2 returns sixteen values:
the projection matrix on the top
of the projection matrix stack.
Initially this matrix is the
identity matrix. See
glPushMatrix.
GL_PROJECTION_STACK_DEPTH
_param2 returns one value, the
number of matrices on the projec-
tion matrix stack. The initial
value is 1. See glPushMatrix.
GL_READ_BUFFER _param2 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.
GL_RED_BIAS _param2 returns one value, the
red bias factor used during pixel
transfers. The initial value is
0.
GL_RED_BITS _param2 returns one value, the
number of red bitplanes in each
color buffer.
GL_RED_SCALE _param2 returns one value, the
red scale factor used during
pixel transfers. The initial
value is 1. See glPixelTransfer.
GL_RENDER_MODE _param2 returns one value, a sym-
bolic constant indicating whether
the GL is in render, select, or
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 win-
dow. See glScissor.
GL_SCISSOR_TEST _param2 returns a single boolean
value indicating whether scissor-
ing is enabled. The initial value
is GL_FALSE. See glScissor.
GL_SELECTION_BUFFER_SIZE _param2 return one value, the
size of the selection buffer.
See glSelectBuffer.
GL_SEPARABLE_2D _param2 returns a single boolean
value indicating whether 2D sepa-
rable convolution is enabled. The
initial value is GL_FALSE. See
glSeparableFilter2D.
GL_SHADE_MODEL _param2 returns one value, a sym-
bolic constant indicating whether
the shading mode is flat or
smooth. The initial value is
GL_SMOOTH. See glShadeModel.
GL_SMOOTH_LINE_WIDTH_RANGE
_param2 returns two values, the
smallest and largest supported
widths for antialiased lines.
See glLineWidth.
GL_SMOOTH_LINE_WIDTH_GRANULARITY
_param2 returns one value, the
granularity of widths for
antialiased lines. See
glLineWidth.
GL_SMOOTH_POINT_SIZE_RANGE
_param2 returns two values, the
smallest and largest supported
widths for antialiased points.
See glPointSize.
GL_SMOOTH_POINT_SIZE_GRANULARITY
_param2 returns one value, the
granularity of sizes for
antialiased points. See
glPointSize.
test fails. The initial value is
GL_KEEP. See glStencilOp.
GL_STENCIL_FUNC _param2 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.
GL_STENCIL_PASS_DEPTH_FAIL
_param2 returns one value, a sym-
bolic constant indicating what
action is taken when the stencil
test passes, but the depth test
fails. The initial value is
GL_KEEP. See glStencilOp.
GL_STENCIL_PASS_DEPTH_PASS
_param2 returns one value, a sym-
bolic constant indicating what
action is taken when the stencil
test passes and the depth test
passes. The initial value is
GL_KEEP. See glStencilOp.
GL_STENCIL_REF _param2 returns one value, the
reference value that is compared
with the contents of the stencil
buffer. The initial value is 0.
See glStencilFunc.
GL_STENCIL_TEST _param2 returns a single boolean
value indicating whether stencil
testing of fragments is enabled.
The initial value is GL_FALSE.
See glStencilFunc and
glStencilOp.
GL_STENCIL_VALUE_MASK _param2 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
glStencilFunc.
GL_STENCIL_WRITEMASK _param2 returns one value, the
mask that controls writing of the
stencil bitplanes. The initial
value is all 1's. See
GL_TEXTURE_1D _param2 returns a single boolean
value indicating whether 1D tex-
ture mapping is enabled. The ini-
tial value is GL_FALSE. See
glTexImage1D.
GL_TEXTURE_BINDING_1D _param2 returns a single value,
the name of the texture currently
bound to the target
GL_TEXTURE_1D. The initial value
is 0. See glBindTexture.
GL_TEXTURE_2D _param2 returns a single boolean
value indicating whether 2D tex-
ture mapping is enabled. The ini-
tial value is GL_FALSE. See
glTexImage2D.
GL_TEXTURE_BINDING_2D _param2 returns a single value,
the name of the texture currently
bound to the target
GL_TEXTURE_2D. The initial value
is 0. See glBindTexture.
GL_TEXTURE_3D _param2 returns a single boolean
value indicating whether 3D tex-
ture mapping is enabled. The ini-
tial value is GL_FALSE. See
glTexImage3D.
GL_TEXTURE_BINDING_3D _param2 returns a single value,
the name of the texture currently
bound to the target
GL_TEXTURE_3D. The initial value
is 0. See glBindTexture.
GL_TEXTURE_COORD_ARRAY _param2 returns a single boolean
value indicating whether the tex-
ture coordinate array is enabled.
The initial value is GL_FALSE.
See glTexCoordPointer.
GL_TEXTURE_COORD_ARRAY_SIZE
_param2 returns one value, the
number of coordinates per element
in the texture coordinate array.
The initial value is 4. See
glTexCoordPointer.
GL_TEXTURE_COORD_ARRAY_STRIDE
_param2 returns one value, the
matic generation of the q texture
coordinate is enabled. The ini-
tial value is GL_FALSE. See
glTexGen.
GL_TEXTURE_GEN_R _param2 returns a single boolean
value indicating whether auto-
matic generation of the r texture
coordinate is enabled. The ini-
tial value is GL_FALSE. See
glTexGen.
GL_TEXTURE_GEN_S _param2 returns a single boolean
value indicating whether auto-
matic generation of the S texture
coordinate is enabled. The ini-
tial value is GL_FALSE. See
glTexGen.
GL_TEXTURE_GEN_T _param2 returns a single boolean
value indicating whether auto-
matic generation of the T texture
coordinate is enabled. The ini-
tial value is GL_FALSE. See
glTexGen.
GL_TEXTURE_MATRIX _param2 returns sixteen values:
the texture matrix on the top of
the texture matrix stack. Ini-
tially this matrix is the iden-
tity matrix. See glPushMatrix.
GL_TEXTURE_STACK_DEPTH _param2 returns one value, the
number of matrices on the texture
matrix stack. The initial value
is 1. See glPushMatrix.
GL_UNPACK_ALIGNMENT _param2 returns one value, the
byte alignment used for reading
pixel data from memory. The ini-
tial value is 4. See
glPixelStore.
GL_UNPACK_IMAGE_HEIGHT _param2 returns one value, the
image height used for reading
pixel data from memory. The ini-
tial is 0. See glPixelStore.
GL_UNPACK_LSB_FIRST _param2 returns a single boolean
value indicating whether single-
bit pixels being read from memory
are read first from the least
GL_UNPACK_SKIP_PIXELS _param2 returns one value, the
number of pixel locations skipped
before the first pixel is read
from memory. The initial value is
0. See glPixelStore.
GL_UNPACK_SKIP_ROWS _param2 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.
GL_UNPACK_SWAP_BYTES _param2 returns a single boolean
value indicating whether the
bytes of two-byte and four-byte
pixel indices and components are
swapped after being read from
memory. The initial value is
GL_FALSE. See glPixelStore.
GL_VERTEX_ARRAY _param2 returns a single boolean
value indicating whether the ver-
tex array is enabled. The initial
value is GL_FALSE. See
glVertexPointer.
GL_VERTEX_ARRAY_SIZE _param2 returns one value, the
number of coordinates per vertex
in the vertex array. The initial
value is 4. See glVertexPointer.
GL_VERTEX_ARRAY_STRIDE _param2 returns one value, the
byte offset between consecutive
vertexes in the vertex array. The
initial value is 0. See
glVertexPointer.
GL_VERTEX_ARRAY_TYPE _param2 returns one value, the
data type of each coordinate in
the vertex array. The initial
value is GL_FLOAT. See
glVertexPointer.
GL_VIEWPORT _param2 returns four values: the
x and y window coordinates of the
viewport, followed by its width
and height. Initially 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
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_NORMAL_ARRAY_STRIDE, GL_NORMAL_ARRAY_TYPE,
GL_POLYGON_OFFSET_UNITS, GL_POLYGON_OFFSET_FACTOR,
GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFFSET_LINE,
GL_POLYGON_OFFSET_POINT, GL_TEXTURE_COORD_ARRAY,
GL_TEXTURE_COORD_ARRAY_SIZE,
GL_TEXTURE_COORD_ARRAY_STRIDE,
GL_TEXTURE_COORD_ARRAY_TYPE, GL_VERTEX_ARRAY,
GL_VERTEX_ARRAY_SIZE, GL_VERTEX_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_AMBIENT, GL_LIGHT_MODEL_COLOR_CONTROL,
GL_MAX_3D_TEXTURE_SIZE, GL_MAX_ELEMENTS_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_TEXTURE_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 functionality was replaced by
GL_SMOOTH_LINE_WIDTH_GRANULARITY.
GL_LINE_WIDTH_RANGE was deprecated in GL version 1.2. Its
functionality was replaced by GL_SMOOTH_LINE_WIDTH_RANGE.
GL_POINT_SIZE_GRANULARITY was deprecated in GL version
1.2. Its functionality was replaced by
GL_SMOOTH_POINT_SIZE_GRANULARITY.
GL_POINT_SIZE_RANGE was deprecated in GL version 1.2. Its
functionality 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_CONVOLUTION_2D, GL_HISTOGRAM,
GL_MAX_COLOR_MATRIX_STACK_DEPTH, GL_MINMAX,
GL_POST_COLOR_MATRIX_COLOR_TABLE,
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_TEXTURE_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_BINDING_3D, GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T,
GL_TEXTURE_GEN_R, GL_TEXTURE_GEN_Q, GL_TEXTURE_MATRIX, and
GL_TEXTURE_STACK_DEPTH. Likewise, the following parame-
ters return the associated value for the active client
texture unit: GL_TEXTURE_COORD_ARRAY,
GL_TEXTURE_COORD_ARRAY_SIZE,
GL_TEXTURE_COORD_ARRAY_STRIDE,
GL_TEXTURE_COORD_ARRAY_TYPE.
ERRORS
GL_INVALID_ENUM is generated if _param1 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 ALSO
glGetClipPlane, glGetColorTable, glGetColorTableParameter,
glGetConvolutionFilter, glGetConvolutionParameter,
glGetError, glGetHistogram, glGetHistogramParameter,
glGetLight, glGetMap, glGetMaterial, glGetMinmax,
glGetMinmaxParameter, glGetPixelMap, glGetPointerv,
glGetPolygonStipple, glGetSeparableFilter, glGetString,
glGetTexEnv, glGetTexGen, glGetTexImage,
glGetTexLevelParameter, glGetTexParameter, glIsEnabled
1