glGet — return the value or values of a selected parameter
void glGetBooleanv( | GLenum | pname, |
GLboolean * | params) ; |
void glGetDoublev( | GLenum | pname, |
GLdouble * | params) ; |
void glGetFloatv( | GLenum | pname, |
GLfloat * | params) ; |
void glGetIntegerv( | GLenum | pname, |
GLint * | params) ; |
void glGetInteger64v( | GLenum | pname, |
GLint64 * | params) ; |
pname
Specifies the parameter value to be returned. The symbolic constants in the list below are accepted.
params
Returns the value or values of the specified parameter.
void glGetBooleani_v( | GLenum | pname, |
GLuint | index, | |
GLboolean * | data) ; |
void glGetIntegeri_v( | GLenum | pname, |
GLuint | index, | |
GLint * | data) ; |
void glGetInteger64i_v( | GLenum | pname, |
GLuint | index, | |
GLint64 * | data) ; |
pname
Specifies the parameter value to be returned. The symbolic constants in the list below are accepted.
index
Specifies the index of the particular element being queried.
data
Returns the value or values of the specified parameter.
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 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 colors and
normals, however, are returned with a linear mapping that maps 1.0 to
the most positive representable integer value
and
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
:
GL_ACTIVE_TEXTURE
params
returns a single value indicating the active multitexture unit.
The initial value is GL_TEXTURE0
.
See glActiveTexture.
GL_ALIASED_LINE_WIDTH_RANGE
params
returns a pair of values indicating the range of
widths supported for aliased lines. See glLineWidth.
GL_SMOOTH_LINE_WIDTH_RANGE
params
returns a pair of values indicating the range of
widths supported for smooth (antialiased) lines. See glLineWidth.
GL_SMOOTH_LINE_WIDTH_GRANULARITY
params
returns a single value indicating the level of
quantization applied to smooth line width parameters.
GL_ARRAY_BUFFER_BINDING
params
returns a single value, the name of the buffer object
currently bound to the target GL_ARRAY_BUFFER
. If no buffer object
is bound to this target, 0 is returned. The initial value is 0.
See glBindBuffer.
GL_BLEND
params
returns a single boolean value indicating whether blending is
enabled. The initial value is GL_FALSE
.
See glBlendFunc.
GL_BLEND_COLOR
params
returns four values,
the red, green, blue, and alpha values which are the components of
the blend color.
See glBlendColor.
GL_BLEND_DST_ALPHA
params
returns one value,
the symbolic constant identifying the alpha destination blend
function. The initial value is GL_ZERO
.
See glBlendFunc and glBlendFuncSeparate.
GL_BLEND_DST_RGB
params
returns one value,
the symbolic constant identifying the RGB destination blend
function. The initial value is GL_ZERO
.
See glBlendFunc and glBlendFuncSeparate.
GL_BLEND_EQUATION_RGB
params
returns one value, a symbolic constant indicating whether
the RGB blend equation is GL_FUNC_ADD
, GL_FUNC_SUBTRACT
,
GL_FUNC_REVERSE_SUBTRACT
, GL_MIN
or GL_MAX
.
See glBlendEquationSeparate.
GL_BLEND_EQUATION_ALPHA
params
returns one value, a symbolic constant indicating whether
the Alpha blend equation is GL_FUNC_ADD
, GL_FUNC_SUBTRACT
,
GL_FUNC_REVERSE_SUBTRACT
, GL_MIN
or GL_MAX
.
See glBlendEquationSeparate.
GL_BLEND_SRC_ALPHA
params
returns one value,
the symbolic constant identifying the alpha source blend function. The initial
value is GL_ONE
.
See glBlendFunc and glBlendFuncSeparate.
GL_BLEND_SRC_RGB
params
returns one value,
the symbolic constant identifying the RGB source blend function. The initial
value is GL_ONE
.
See glBlendFunc and glBlendFuncSeparate.
GL_COLOR_CLEAR_VALUE
params
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
GL_COLOR_LOGIC_OP
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 glLogicOp.
GL_COLOR_WRITEMASK
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.
GL_COMPRESSED_TEXTURE_FORMATS
params
returns a list of symbolic
constants of length GL_NUM_COMPRESSED_TEXTURE_FORMATS
indicating which compressed texture formats are available.
See glCompressedTexImage2D.
GL_CULL_FACE
params
returns a single boolean value indicating whether polygon culling
is enabled. The initial value is GL_FALSE
.
See glCullFace.
GL_CURRENT_PROGRAM
params
returns one value,
the name of the program object that is currently active, or 0 if no program object is active.
See glUseProgram.
GL_DEPTH_CLEAR_VALUE
params
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 representable integer value,
and
GL_DEPTH_FUNC
params
returns one value,
the symbolic constant that indicates the depth comparison
function. The initial value is GL_LESS
.
See glDepthFunc.
GL_DEPTH_RANGE
params
returns two values:
the near and far mapping limits for the depth 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
GL_DEPTH_TEST
params
returns a single boolean value indicating whether depth testing
of fragments is enabled. The initial value is GL_FALSE
.
See glDepthFunc and glDepthRange.
GL_DEPTH_WRITEMASK
params
returns a single boolean value indicating if the depth buffer
is enabled for writing. The initial value is GL_TRUE
.
See glDepthMask.
GL_DITHER
params
returns a single boolean value indicating whether dithering of
fragment colors and indices is enabled. The initial value is GL_TRUE
.
GL_DOUBLEBUFFER
params
returns a single boolean value indicating whether double buffering
is supported.
GL_DRAW_BUFFER
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 buffers, otherwise it is GL_FRONT
.
GL_DRAW_BUFFER
i
params
returns one value,
a symbolic constant indicating which buffers are being drawn to by the corresponding output color.
See glDrawBuffers.
The initial value of GL_DRAW_BUFFER0
is GL_BACK
if there
are back buffers, otherwise it is GL_FRONT
. The
initial values of draw buffers for all other output colors is GL_NONE
.
GL_DRAW_FRAMEBUFFER_BINDING
params
returns one value,
the name of the framebuffer object currently bound to the GL_DRAW_FRAMEBUFFER
target.
If the default framebuffer is bound, this value will be zero. The initial value is zero.
See glBindFramebuffer.
GL_READ_FRAMEBUFFER_BINDING
params
returns one value,
the name of the framebuffer object currently bound to the GL_READ_FRAMEBUFFER
target.
If the default framebuffer is bound, this value will be zero. The initial value is zero.
See glBindFramebuffer.
GL_ELEMENT_ARRAY_BUFFER_BINDING
params
returns a single value, the name of the buffer object
currently bound to the target GL_ELEMENT_ARRAY_BUFFER
. If no buffer object
is bound to this target, 0 is returned. The initial value is 0.
See glBindBuffer.
GL_RENDERBUFFER_BINDING
params
returns a single value, the name of the renderbuffer object
currently bound to the target GL_RENDERBUFFER
. If no renderbuffer object
is bound to this target, 0 is returned. The initial value is 0.
See glBindRenderbuffer.
GL_FRAGMENT_SHADER_DERIVATIVE_HINT
params
returns one value,
a symbolic constant indicating the mode of the derivative accuracy hint
for fragment shaders. The initial value
is GL_DONT_CARE
.
See glHint.
GL_LINE_SMOOTH
params
returns a single boolean value indicating whether antialiasing of
lines is enabled. The initial value is GL_FALSE
.
See glLineWidth.
GL_LINE_SMOOTH_HINT
params
returns one value,
a symbolic constant indicating the mode of the line antialiasing
hint. The initial value is GL_DONT_CARE
.
See glHint.
GL_LINE_WIDTH
params
returns one value,
the line width as specified with glLineWidth. The initial value is
1.
GL_LOGIC_OP_MODE
params
returns one value,
a symbolic constant indicating the selected logic operation
mode. The initial value is GL_COPY
.
See glLogicOp.
GL_MAX_3D_TEXTURE_SIZE
params
returns one value,
a rough estimate of the largest 3D texture that the GL can handle.
The value must be at least 64.
Use GL_PROXY_TEXTURE_3D
to determine if a texture is too large.
See glTexImage3D.
GL_MAX_CLIP_DISTANCES
params
returns one value,
the maximum number of application-defined clipping distances. The value must be at least 8.
GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS
params
returns one value,
the number of words for fragment shader uniform variables in all uniform
blocks (including default). The value must be at least 1.
See glUniform.
GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS
params
returns one value, the maximum supported texture image units that
can be used to access texture maps from the vertex shader and the fragment processor combined.
If both the vertex shader and the fragment processing stage access the same texture image
unit, then that counts as using two texture image units against this limit.
The value must be at least 48.
See glActiveTexture.
GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS
params
returns one value,
the number of words for vertex shader uniform variables in all uniform
blocks (including default). The value must be at least 1.
See glUniform.
GL_MAX_COMBINED_GEOMETRY_UNIFORM_COMPONENTS
params
returns one value,
the number of words for geometry shader uniform variables in all uniform
blocks (including default). The value must be at least 1.
See glUniform.
GL_MAX_VARYING_COMPONENTS
params
returns one value,
the number components for varying variables, which must be at least 60.
GL_MAX_COMBINED_UNIFORM_BLOCKS
params
returns one value,
the maximum number of uniform blocks per program. The value must be at least 36.
See glUniformBlockBinding.
GL_MAX_CUBE_MAP_TEXTURE_SIZE
params
returns one value.
The value gives a rough estimate of the largest cube-map texture that
the GL can handle. The value must be at least 1024.
Use GL_PROXY_TEXTURE_CUBE_MAP
to determine if a texture is too large.
See glTexImage2D.
GL_MAX_DRAW_BUFFERS
params
returns one value, the maximum number
of simultaneous outputs that may be written in a fragment shader.
The value must be at least 8.
See glDrawBuffers.
GL_MAX_DUAL_SOURCE_DRAW_BUFFERS
params
returns one value, the maximum number
of active draw buffers when using dual-source blending. The value must be at least 1.
See glBlendFunc and
glBlendFuncSeparate.
GL_MAX_ELEMENTS_INDICES
params
returns one value,
the recommended maximum number of vertex array indices.
See glDrawRangeElements.
GL_MAX_ELEMENTS_VERTICES
params
returns one value,
the recommended maximum number of vertex array vertices.
See glDrawRangeElements.
GL_MAX_FRAGMENT_UNIFORM_COMPONENTS
params
returns one value,
the maximum number of individual floating-point, integer, or boolean values that can be held
in uniform variable storage for a fragment shader. The value must be at least 1024.
See glUniform.
GL_MAX_FRAGMENT_UNIFORM_BLOCKS
params
returns one value,
the maximum number of uniform blocks per fragment shader. The value must be at least 12.
See glUniformBlockBinding.
GL_MAX_FRAGMENT_INPUT_COMPONENTS
params
returns one value,
the maximum number of components of the inputs read by the fragment shader, which must be at least 128.
GL_MIN_PROGRAM_TEXEL_OFFSET
params
returns one value,
the minimum texel offset allowed in a texture lookup, which must be at most -8.
GL_MAX_PROGRAM_TEXEL_OFFSET
params
returns one value,
the maximum texel offset allowed in a texture lookup, which must be at least 7.
GL_MAX_RECTANGLE_TEXTURE_SIZE
params
returns one value.
The value gives a rough estimate of the largest rectangular texture that
the GL can handle. The value must be at least 1024.
Use GL_PROXY_TEXTURE_RECTANGLE
to determine if a texture is too large.
See glTexImage2D.
GL_MAX_TEXTURE_IMAGE_UNITS
params
returns one value, the maximum supported texture image units that
can be used to access texture maps from the fragment shader.
The value must be at least 16.
See glActiveTexture.
GL_MAX_TEXTURE_LOD_BIAS
params
returns one value,
the maximum, absolute value of the texture level-of-detail bias. The
value must be at least 2.0.
GL_MAX_TEXTURE_SIZE
params
returns one value.
The value gives a rough estimate of the largest texture that
the GL can handle. The value must be at least 1024.
Use a proxy texture target such as GL_PROXY_TEXTURE_1D
or GL_PROXY_TEXTURE_2D
to determine if a texture is too large.
See glTexImage1D and glTexImage2D.
GL_MAX_RENDERBUFFER_SIZE
params
returns one value.
The value indicates the maximum supported size for renderbuffers.
See glFramebufferRenderbuffer.
GL_MAX_ARRAY_TEXTURE_LAYERS
params
returns one value.
The value indicates the maximum number of layers allowed in an array texture, and must be at least 256.
See glTexImage2D.
GL_MAX_TEXTURE_BUFFER_SIZE
params
returns one value.
The value gives the maximum number of texels allowed in the texel array of a texture buffer object.
Value must be at least 65536.
GL_MAX_UNIFORM_BLOCK_SIZE
params
returns one value,
the maximum size in basic machine units of a uniform block.
The value must be at least 16384.
See glUniformBlockBinding.
GL_MAX_VARYING_FLOATS
params
returns one value,
the maximum number of interpolators available for processing varying variables used by
vertex and fragment shaders. This value represents the number of individual floating-point
values that can be interpolated; varying variables declared as vectors, matrices, and arrays
will all consume multiple interpolators. The value must be at least 32.
GL_MAX_VERTEX_ATTRIBS
params
returns one value,
the maximum number of 4-component generic vertex attributes accessible to a vertex shader.
The value must be at least 16.
See glVertexAttrib.
GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS
params
returns one value, the maximum supported texture image units that
can be used to access texture maps from the vertex shader. The value may be at least 16.
See glActiveTexture.
GL_MAX_GEOMETRY_TEXTURE_IMAGE_UNITS
params
returns one value, the maximum supported texture image units that
can be used to access texture maps from the geometry shader. The value must be at least 16.
See glActiveTexture.
GL_MAX_VERTEX_UNIFORM_COMPONENTS
params
returns one value,
the maximum number of individual floating-point, integer, or boolean values that can be held
in uniform variable storage for a vertex shader. The value must be at least 1024.
See glUniform.
GL_MAX_VERTEX_OUTPUT_COMPONENTS
params
returns one value,
the maximum number of components of output written by a vertex shader, which must be at least 64.
GL_MAX_GEOMETRY_UNIFORM_COMPONENTS
params
returns one value,
the maximum number of individual floating-point, integer, or boolean values that can be held
in uniform variable storage for a geometry shader. The value must be at least 1024.
See glUniform.
GL_MAX_SAMPLE_MASK_WORDS
params
returns one value,
the maximum number of sample mask words.
GL_MAX_COLOR_TEXTURE_SAMPLES
params
returns one value,
the maximum number of samples in a color multisample texture.
GL_MAX_DEPTH_TEXTURE_SAMPLES
params
returns one value,
the maximum number of samples in a multisample depth or depth-stencil texture.
GL_MAX_DEPTH_TEXTURE_SAMPLES
params
returns one value,
the maximum number of samples in a multisample depth or depth-stencil texture.
GL_MAX_INTEGER_SAMPLES
params
returns one value,
the maximum number of samples supported in integer format multisample buffers.
GL_MAX_SERVER_WAIT_TIMEOUT
params
returns one value,
the maximum glWaitSync timeout interval.
GL_MAX_UNIFORM_BUFFER_BINDINGS
params
returns one value,
the maximum number of uniform buffer binding points on the context, which must be at least 36.
GL_MAX_UNIFORM_BLOCK_SIZE
params
returns one value,
the maximum size in basic machine units of a uniform block, which must be at least 16384.
GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT
params
returns one value,
the minimum required alignment for uniform buffer sizes and offsets.
GL_MAX_VERTEX_UNIFORM_BLOCKS
params
returns one value,
the maximum number of uniform blocks per vertex shader. The value must be at least 12.
See glUniformBlockBinding.
GL_MAX_GEOMETRY_UNIFORM_BLOCKS
params
returns one value,
the maximum number of uniform blocks per geometry shader. The value must be at least 12.
See glUniformBlockBinding.
GL_MAX_GEOMETRY_INPUT_COMPONENTS
params
returns one value,
the maximum number of components of inputs read by a geometry shader, which must be at least 64.
GL_MAX_GEOMETRY_OUTPUT_COMPONENTS
params
returns one value,
the maximum number of components of outputs written by a geometry shader, which must be at least 128.
GL_MAX_VIEWPORT_DIMS
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.
GL_NUM_COMPRESSED_TEXTURE_FORMATS
params
returns a single integer value indicating the number of available
compressed texture formats. The minimum value is 4.
See glCompressedTexImage2D.
GL_PACK_ALIGNMENT
params
returns one value,
the byte alignment used for writing pixel data to memory. The initial
value is 4.
See glPixelStore.
GL_PACK_IMAGE_HEIGHT
params
returns one value,
the image height used for writing pixel data to memory. The initial
value is 0.
See glPixelStore.
GL_PACK_LSB_FIRST
params
returns a single boolean 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.
GL_PACK_ROW_LENGTH
params
returns one value,
the row length used for writing pixel data to memory. The initial value is
0.
See glPixelStore.
GL_PACK_SKIP_IMAGES
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.
GL_PACK_SKIP_PIXELS
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.
GL_PACK_SKIP_ROWS
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.
GL_PACK_SWAP_BYTES
params
returns a single boolean value indicating whether the bytes of
two-byte and four-byte pixel indices and components are swapped before being
written to memory. The initial value is GL_FALSE
.
See glPixelStore.
GL_PIXEL_PACK_BUFFER_BINDING
params
returns a single value, the name of the buffer object
currently bound to the target GL_PIXEL_PACK_BUFFER
. If no buffer object
is bound to this target, 0 is returned. The initial value is 0.
See glBindBuffer.
GL_PIXEL_UNPACK_BUFFER_BINDING
params
returns a single value, the name of the buffer object
currently bound to the target GL_PIXEL_UNPACK_BUFFER
. If no buffer object
is bound to this target, 0 is returned. The initial value is 0.
See glBindBuffer.
GL_POINT_FADE_THRESHOLD_SIZE
params
returns one value,
the point size threshold for determining the point size.
See glPointParameter.
GL_PRIMITIVE_RESTART_INDEX
params
returns one value,
the current primitive restart index. The initial value is 0.
See glPrimitiveRestartIndex.
GL_PROGRAM_POINT_SIZE
params
returns a single boolean value indicating whether vertex
program point size mode is enabled. If enabled, then the
point size is taken from the shader built-in gl_PointSize
. If disabled,
then the point size is taken from the point state as specified
by glPointSize.
The initial value is GL_FALSE
.
GL_PROVOKING_VERTEX
params
returns one value,
the currently selected provoking vertex convention. The initial value is GL_LAST_VERTEX_CONVENTION
.
See glProvokingVertex.
GL_POINT_SIZE
params
returns one value,
the point size as specified by glPointSize.
The initial value is 1.
GL_POINT_SIZE_GRANULARITY
params
returns one value,
the size difference between adjacent supported sizes for antialiased points.
See glPointSize.
GL_POINT_SIZE_RANGE
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.
GL_POLYGON_OFFSET_FACTOR
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
rasterized. The initial value is 0.
See glPolygonOffset.
GL_POLYGON_OFFSET_UNITS
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.
GL_POLYGON_OFFSET_FILL
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.
GL_POLYGON_OFFSET_LINE
params
returns a single boolean value indicating whether polygon offset
is enabled for polygons in line mode. The initial value is GL_FALSE
.
See glPolygonOffset.
GL_POLYGON_OFFSET_POINT
params
returns a single boolean value indicating whether polygon offset
is enabled for polygons in point mode. The initial value is GL_FALSE
.
See glPolygonOffset.
GL_POLYGON_SMOOTH
params
returns a single boolean value indicating whether antialiasing of
polygons is enabled. The initial value is GL_FALSE
.
See glPolygonMode.
GL_POLYGON_SMOOTH_HINT
params
returns one value,
a symbolic constant indicating the mode of the polygon antialiasing
hint. The initial value is GL_DONT_CARE
.
See glHint.
GL_READ_BUFFER
params
returns one value,
a symbolic 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.
GL_SAMPLE_BUFFERS
params
returns a single integer value indicating the number of sample buffers
associated with the framebuffer.
See glSampleCoverage.
GL_SAMPLE_COVERAGE_VALUE
params
returns a single positive floating-point value indicating the
current sample coverage value.
See glSampleCoverage.
GL_SAMPLE_COVERAGE_INVERT
params
returns a single boolean value indicating if the temporary
coverage value should be inverted.
See glSampleCoverage.
GL_SAMPLER_BINDING
params
returns a single value, the name of the sampler object
currently bound to the active texture unit. The initial value is 0.
See glBindSampler.
GL_SAMPLES
params
returns a single integer value indicating the coverage mask size.
See glSampleCoverage.
GL_SCISSOR_BOX
params
returns four values:
the
GL_SCISSOR_TEST
params
returns a single boolean value indicating whether scissoring is
enabled. The initial value is GL_FALSE
.
See glScissor.
GL_STENCIL_BACK_FAIL
params
returns one value,
a symbolic constant indicating what action is taken for back-facing polygons when the stencil
test fails. The initial value is GL_KEEP
.
See glStencilOpSeparate.
GL_STENCIL_BACK_FUNC
params
returns one value,
a symbolic constant indicating what function is used for back-facing polygons to compare the
stencil reference value with the stencil buffer value. The initial value
is GL_ALWAYS
.
See glStencilFuncSeparate.
GL_STENCIL_BACK_PASS_DEPTH_FAIL
params
returns one value,
a symbolic constant indicating what action is taken for back-facing polygons when the stencil
test passes,
but the depth test fails. The initial value is GL_KEEP
.
See glStencilOpSeparate.
GL_STENCIL_BACK_PASS_DEPTH_PASS
params
returns one value,
a symbolic constant indicating what action is taken for back-facing polygons when the stencil
test passes and the depth test passes. The initial value is GL_KEEP
.
See glStencilOpSeparate.
GL_STENCIL_BACK_REF
params
returns one value,
the reference value that is compared with the contents of the stencil
buffer for back-facing polygons. The initial value is 0.
See glStencilFuncSeparate.
GL_STENCIL_BACK_VALUE_MASK
params
returns one value,
the mask that is used for back-facing polygons to mask both the stencil reference value and the
stencil buffer value before they are compared. The initial value is all 1's.
See glStencilFuncSeparate.
GL_STENCIL_BACK_WRITEMASK
params
returns one value,
the mask that controls writing of the stencil bitplanes for back-facing polygons. The initial value
is all 1's.
See glStencilMaskSeparate.
GL_STENCIL_CLEAR_VALUE
params
returns one value,
the index to which the stencil bitplanes are cleared. The initial value is
0.
See glClearStencil.
GL_STENCIL_FAIL
params
returns one value,
a symbolic constant indicating what action is taken when the stencil
test fails. The initial value is GL_KEEP
.
See glStencilOp.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilOpSeparate.
GL_STENCIL_FUNC
params
returns one value,
a symbolic 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.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilFuncSeparate.
GL_STENCIL_PASS_DEPTH_FAIL
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 glStencilOp.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilOpSeparate.
GL_STENCIL_PASS_DEPTH_PASS
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.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilOpSeparate.
GL_STENCIL_REF
params
returns one value,
the reference value that is compared with the contents of the stencil
buffer. The initial value is 0.
See glStencilFunc.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilFuncSeparate.
GL_STENCIL_TEST
params
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
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 glStencilFunc.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilFuncSeparate.
GL_STENCIL_WRITEMASK
params
returns one value,
the mask that controls writing of the stencil bitplanes. The initial value
is all 1's.
See glStencilMask.
This stencil state only affects non-polygons
and front-facing polygons. Back-facing polygons use separate stencil state.
See glStencilMaskSeparate.
GL_STEREO
params
returns a single boolean value indicating whether stereo buffers
(left and right) are supported.
GL_SUBPIXEL_BITS
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 value must be at least 4.
GL_TEXTURE_BINDING_1D
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.
GL_TEXTURE_BINDING_1D_ARRAY
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_1D_ARRAY
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_BINDING_2D
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.
GL_TEXTURE_BINDING_2D_ARRAY
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_2D_ARRAY
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_BINDING_2D_MULTISAMPLE
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_2D_MULTISAMPLE
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_BINDING_2D_MULTISAMPLE_ARRAY
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_2D_MULTISAMPLE_ARRAY
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_BINDING_3D
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.
GL_TEXTURE_BINDING_BUFFER
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_BUFFER
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_BINDING_CUBE_MAP
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_CUBE_MAP
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_BINDING_RECTANGLE
params
returns a single value, the name of the texture
currently bound to the target GL_TEXTURE_RECTANGLE
. The initial value is 0.
See glBindTexture.
GL_TEXTURE_COMPRESSION_HINT
params
returns a single value indicating the mode of the texture
compression hint. The initial value is GL_DONT_CARE
.
GL_TEXTURE_BINDING_BUFFER
params
returns a single value, the name of the texture buffer object
currently bound. The initial value is 0.
See glBindBuffer.
GL_TIMESTAMP
params
returns a single value, the 64-bit value of the current
GL time.
See glQueryCounter.
GL_TRANSFORM_FEEDBACK_BUFFER_BINDING
When used with non-indexed variants of glGet
(such as glGetIntegerv
),
params
returns a single value, the name of the buffer object
currently bound to the target GL_TRANSFORM_FEEDBACK_BUFFER
. If no buffer object
is bound to this target, 0 is returned.
When used with indexed variants of glGet
(such as glGetIntegeri_v
),
params
returns a single value, the name of the buffer object
bound to the indexed transform feedback attribute stream. The initial value is 0 for all targets.
See glBindBuffer, glBindBufferBase, and
glBindBufferRange.
GL_TRANSFORM_FEEDBACK_BUFFER_START
When used with indexed variants of glGet
(such as glGetInteger64i_v
),
params
returns a single value, the start offset of the binding range for each
transform feedback attribute stream. The initial value is 0 for all streams.
See glBindBufferRange.
GL_TRANSFORM_FEEDBACK_BUFFER_SIZE
When used with indexed variants of glGet
(such as glGetInteger64i_v
),
params
returns a single value, the size of the binding range for each
transform feedback attribute stream. The initial value is 0 for all streams.
See glBindBufferRange.
GL_UNIFORM_BUFFER_BINDING
When used with non-indexed variants of glGet
(such as glGetIntegerv
),
params
returns a single value, the name of the buffer object
currently bound to the target GL_UNIFORM_BUFFER
. If no buffer object
is bound to this target, 0 is returned.
When used with indexed variants of glGet
(such as glGetIntegeri_v
),
params
returns a single value, the name of the buffer object
bound to the indexed uniform buffer binding point. The initial value is 0 for all targets.
See glBindBuffer, glBindBufferBase, and
glBindBufferRange.
GL_UNIFORM_BUFFER_START
When used with indexed variants of glGet
(such as glGetInteger64i_v
),
params
returns a single value, the start offset of the binding range for each
indexed uniform buffer binding. The initial value is 0 for all bindings.
See glBindBufferRange.
GL_UNIFORM_BUFFER_SIZE
When used with indexed variants of glGet
(such as glGetInteger64i_v
),
params
returns a single value, the size of the binding range for each
indexed uniform buffer binding. The initial value is 0 for all bindings.
See glBindBufferRange.
GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT
params
returns a single value, the minimum required alignment
for uniform buffer sizes and offset. The initial value is 1.
See glUniformBlockBinding.
GL_UNPACK_ALIGNMENT
params
returns one value,
the byte alignment used for reading pixel data from memory. The initial
value is 4.
See glPixelStore.
GL_UNPACK_IMAGE_HEIGHT
params
returns one value,
the image height used for reading pixel data from memory. The initial
is 0.
See glPixelStore.
GL_UNPACK_LSB_FIRST
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.
GL_UNPACK_ROW_LENGTH
params
returns one value,
the row length used for reading pixel data from memory. The initial value
is 0.
See glPixelStore.
GL_UNPACK_SKIP_IMAGES
params
returns one value,
the number of pixel images skipped before the first pixel is read
from memory. The initial value is 0.
See glPixelStore.
GL_UNPACK_SKIP_PIXELS
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.
GL_UNPACK_SKIP_ROWS
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.
GL_UNPACK_SWAP_BYTES
params
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_NUM_EXTENSIONS
params
returns one value,
the number of extensions supported by the GL implementation for the current context.
See glGetString.
GL_MAJOR_VERSION
params
returns one value,
the major version number of the OpenGL API supported by the current context.
GL_MINOR_VERSION
params
returns one value,
the minor version number of the OpenGL API supported by the current context.
GL_CONTEXT_FLAGS
params
returns one value,
the flags with which the context was created (such as debugging functionality).
GL_VIEWPORT
params
returns four values:
the
Many of the boolean parameters can also be queried more easily using glIsEnabled.
The following parameters return the associated value for the active texture unit:
GL_TEXTURE_1D
, GL_TEXTURE_BINDING_1D
,
GL_TEXTURE_2D
, GL_TEXTURE_BINDING_2D
,
GL_TEXTURE_3D
and GL_TEXTURE_BINDING_3D
.
GL_MAX_RECTANGLE_TEXTURE_SIZE
, GL_MAX_TEXTURE_BUFFER_SIZE
,
GL_UNIFORM_BUFFER_BINDING
, GL_TEXTURE_BINDING_BUFFER
,
GL_MAX_VERTEX_UNIFORM_BLOCKS
, GL_MAX_FRAGMENT_UNIFORM_BLOCKS
,
GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS
, GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS
GL_MAX_COMBINED_UNIFORM_BLOCKS
, GL_MAX_UNIFORM_BLOCK_SIZE
,
and GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT
are available only if the GL version is 3.1 or greater.
GL_MAX_COMBINED_GEOMETRY_UNIFORM_COMPONENTS
, GL_MAX_GEOMETRY_UNIFORM_BLOCKS
,
GL_MAX_GEOMETRY_INPUT_COMPONENTS
, GL_MAX_GEOMETRY_OUTPUT_COMPONENTS
,
GL_MAX_GEOMETRY_OUTPUT_VERTICES
, GL_MAX_GEOMETRY_TOTAL_OUTPUT_COMPONENTS
and
GL_MAX_GEOMETRY_TEXTURE_IMAGE_UNITS
are available only if the GL version is 3.2 or greater.
glGetInteger64v
and glGetInteger64i_v
are available only if
the GL version is 3.2 or greater.
GL_MAX_DUAL_SOURCE_DRAW_BUFFERS
, GL_SAMPLER_BINDING
, and
GL_TIMESTAMP
are available only if the GL version is 3.3 or greater.
GL_INVALID_ENUM
is generated if pname
is not an accepted value.
GL_INVALID_VALUE
is generated on any of glGetBooleani_v
,
glGetIntegeri_v
, or glGetInteger64i_v
if
index
is outside of the valid range for the indexed state target
.
glGetActiveUniform, glGetAttachedShaders, glGetAttribLocation, glGetBufferParameter, glGetBufferPointerv, glGetBufferSubData, glGetCompressedTexImage, glGetError, glGetProgram, glGetProgramInfoLog, glGetQueryiv, glGetQueryObject, glGetShader, glGetShaderInfoLog, glGetShaderSource, glGetString, glGetTexImage, glGetTexLevelParameter, glGetTexParameter, glGetUniform, glGetUniformLocation, glGetVertexAttrib, glGetVertexAttribPointerv, glIsEnabled
Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.