<div class="refentry"><a id="glGet"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGet — return the value or values of a selected parameter</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glGetBooleanv</strong>(</code></td><td>GLenum <var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLboolean * <var class="pdparam">params</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glGetFloatv</strong>(</code></td><td>GLenum <var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat * <var class="pdparam">params</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glGetIntegerv</strong>(</code></td><td>GLenum <var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint * <var class="pdparam">params</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>

Specifies the parameter value to be returned.

The symbolic constants in the list below are accepted.

</p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>

Returns the value or values of the specified parameter.

</p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>

These four commands return values for simple state variables in GL.

<em class="parameter"><code>pname</code></em> is a symbolic constant indicating the state variable to be returned,

and <em class="parameter"><code>params</code></em> is a pointer to an array of the indicated type in

which to place the returned data.

</p><p>

Type conversion is performed if <em class="parameter"><code>params</code></em> has a different type than

the state variable value being requested.

If <code class="function">glGetBooleanv</code> is called,

a floating-point (or integer) value is converted to <code class="constant">GL_FALSE</code> if

and only if it is 0.0 (or 0).

Otherwise,

it is converted to <code class="constant">GL_TRUE</code>.

If <code class="function">glGetIntegerv</code> is called, boolean values are returned as

<code class="constant">GL_TRUE</code> or <code class="constant">GL_FALSE</code>, 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

<math overflow="scroll">

<mn>-1.0</mn>

</math>

to the most negative representable integer value.

If <code class="function">glGetFloatv</code> is called,

boolean values are returned as <code class="constant">GL_TRUE</code> or <code class="constant">GL_FALSE</code>,

and integer values are converted to floating-point values.

</p><p>

The following symbolic constants are accepted by <em class="parameter"><code>pname</code></em>:

</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="constant">GL_ACTIVE_TEXTURE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single value indicating the active multitexture unit.

The initial value is <code class="constant">GL_TEXTURE0</code>.

See <a class="citerefentry" href="glActiveTexture"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_ALIASED_LINE_WIDTH_RANGE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns two values,

the smallest and largest supported widths for aliased lines.

The range must include width 1.

</p></dd><dt><span class="term"><code class="constant">GL_ALIASED_POINT_SIZE_RANGE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns two values,

the smallest and largest supported sizes for aliased points.

The range must include size 1.

</p></dd><dt><span class="term"><code class="constant">GL_ALPHA_BITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the number of alpha bitplanes in the color buffer of the

currently bound framebuffer.

</p></dd><dt><span class="term"><code class="constant">GL_ARRAY_BUFFER_BINDING</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single value, the name of the buffer object

currently bound to the target <code class="constant">GL_ARRAY_BUFFER</code>. If no buffer object

is bound to this target, 0 is returned. The initial value is 0.

See <a class="citerefentry" href="glBindBuffer"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether blending is

enabled. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_COLOR</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns four values,

the red, green, blue, and alpha values which are the components of

the blend color.

See <a class="citerefentry" href="glBlendColor"><span class="citerefentry"><span class="refentrytitle">glBlendColor</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_DST_ALPHA</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the symbolic constant identifying the alpha destination blend

function. The initial value is <code class="constant">GL_ZERO</code>.

See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> and <a class="citerefentry" href="glBlendFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_DST_RGB</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the symbolic constant identifying the RGB destination blend

function. The initial value is <code class="constant">GL_ZERO</code>.

See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> and <a class="citerefentry" href="glBlendFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_EQUATION_ALPHA</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value, a symbolic constant indicating whether

the Alpha blend equation is <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, or

<code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>.

See <a class="citerefentry" href="glBlendEquationSeparate"><span class="citerefentry"><span class="refentrytitle">glBlendEquationSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_EQUATION_RGB</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value, a symbolic constant indicating whether

the RGB blend equation is <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, or

<code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>.

See <a class="citerefentry" href="glBlendEquationSeparate"><span class="citerefentry"><span class="refentrytitle">glBlendEquationSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_SRC_ALPHA</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the symbolic constant identifying the alpha source blend function. The initial

value is <code class="constant">GL_ONE</code>.

See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> and <a class="citerefentry" href="glBlendFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLEND_SRC_RGB</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the symbolic constant identifying the RGB source blend function. The initial

value is <code class="constant">GL_ONE</code>.

See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> and <a class="citerefentry" href="glBlendFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_BLUE_BITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the number of blue bitplanes in the color buffer of the

currently bound framebuffer.

</p></dd><dt><span class="term"><code class="constant">GL_COLOR_CLEAR_VALUE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns four values:

the red, green, blue, and alpha values used to clear the color buffers.

Integer values,

if requested,

are linearly mapped from the internal floating-point representation such

that 1.0 returns the most positive representable integer value,

and

<math overflow="scroll">

<mn>-1.0</mn>

</math>

returns the most negative representable integer

value. The initial value is (0, 0, 0, 0).

See <a class="citerefentry" href="glClearColor"><span class="citerefentry"><span class="refentrytitle">glClearColor</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_COLOR_WRITEMASK</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns four boolean values:

the red, green, blue, and alpha write enables for the color

buffers. The initial value is (<code class="constant">GL_TRUE</code>, <code class="constant">GL_TRUE</code>,

<code class="constant">GL_TRUE</code>, <code class="constant">GL_TRUE</code>).

See <a class="citerefentry" href="glColorMask"><span class="citerefentry"><span class="refentrytitle">glColorMask</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_COMPRESSED_TEXTURE_FORMATS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a list of symbolic

constants of length <code class="constant">GL_NUM_COMPRESSED_TEXTURE_FORMATS</code>

indicating which compressed texture formats are available.

See <a class="citerefentry" href="glCompressedTexImage2D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage2D</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_CULL_FACE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether polygon culling

is enabled. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glCullFace"><span class="citerefentry"><span class="refentrytitle">glCullFace</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_CULL_FACE_MODE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

a symbolic constant indicating which polygon faces are to be

culled. The initial value is <code class="constant">GL_BACK</code>.

See <a class="citerefentry" href="glCullFace"><span class="citerefentry"><span class="refentrytitle">glCullFace</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_CURRENT_PROGRAM</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the name of the program object that is currently active, or 0 if no program object is active.

See <a class="citerefentry" href="glUseProgram"><span class="citerefentry"><span class="refentrytitle">glUseProgram</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_DEPTH_BITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the number of bitplanes in the depth buffer of the

currently bound framebuffer.

</p></dd><dt><span class="term"><code class="constant">GL_DEPTH_CLEAR_VALUE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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

<math overflow="scroll">

<mn>-1.0</mn>

</math>

returns the most negative representable integer

value. The initial value is 1.

See <a class="citerefentry" href="glClearDepthf"><span class="citerefentry"><span class="refentrytitle">glClearDepthf</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_DEPTH_FUNC</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the symbolic constant that indicates the depth comparison

function. The initial value is <code class="constant">GL_LESS</code>.

See <a class="citerefentry" href="glDepthFunc"><span class="citerefentry"><span class="refentrytitle">glDepthFunc</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_DEPTH_RANGE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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

<math overflow="scroll">

<mn>-1.0</mn>

</math>

returns the most negative representable integer

value. The initial value is (0, 1).

See <a class="citerefentry" href="glDepthRangef"><span class="citerefentry"><span class="refentrytitle">glDepthRangef</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_DEPTH_TEST</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether depth testing

of fragments is enabled. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glDepthFunc"><span class="citerefentry"><span class="refentrytitle">glDepthFunc</span></span></a> and <a class="citerefentry" href="glDepthRangef"><span class="citerefentry"><span class="refentrytitle">glDepthRangef</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_DEPTH_WRITEMASK</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating if the depth buffer

is enabled for writing. The initial value is <code class="constant">GL_TRUE</code>.

See <a class="citerefentry" href="glDepthMask"><span class="citerefentry"><span class="refentrytitle">glDepthMask</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_DITHER</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether dithering of

fragment colors and indices is enabled. The initial value is <code class="constant">GL_TRUE</code>.

</p></dd><dt><span class="term"><code class="constant">GL_ELEMENT_ARRAY_BUFFER_BINDING</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single value, the name of the buffer object

currently bound to the target <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>. If no buffer object

is bound to this target, 0 is returned. The initial value is 0.

See <a class="citerefentry" href="glBindBuffer"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_FRAMEBUFFER_BINDING</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single value, the name of the currently bound

framebuffer. The initial value is 0, indicating the default framebuffer.

See <a class="citerefentry" href="glBindFramebuffer"><span class="citerefentry"><span class="refentrytitle">glBindFramebuffer</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_FRONT_FACE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

a symbolic constant indicating whether clockwise or counterclockwise

polygon winding is treated as front-facing. The initial value is

<code class="constant">GL_CCW</code>.

See <a class="citerefentry" href="glFrontFace"><span class="citerefentry"><span class="refentrytitle">glFrontFace</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_GENERATE_MIPMAP_HINT</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

a symbolic constant indicating the mode of the mipmap generation filtering

hint. The initial value is <code class="constant">GL_DONT_CARE</code>.

See <a class="citerefentry" href="glHint"><span class="citerefentry"><span class="refentrytitle">glHint</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_GREEN_BITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the number of green bitplanes in the color buffer of the

currently bound framebuffer.

</p></dd><dt><span class="term"><code class="constant">GL_IMPLEMENTATION_COLOR_READ_FORMAT</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value, the format

chosen by the implementation in which pixels may be read from the

color buffer of the currently bound framebuffer in conjunction with

<code class="constant">GL_IMPLEMENTATION_COLOR_READ_TYPE</code>.

In addition

to this implementation-dependent format/type pair, format

<code class="constant">GL_RGBA</code> in conjunction with type

<code class="constant">GL_UNSIGNED_BYTE</code> is always allowed by every

implementation, regardless of the currently bound render surface.

See <a class="citerefentry" href="glReadPixels"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_IMPLEMENTATION_COLOR_READ_TYPE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value, the type

chosen by the implementation with which pixels may be read from the

color buffer of the currently bound framebuffer in conjunction with

<code class="constant">GL_IMPLEMENTATION_COLOR_READ_FORMAT</code>.

In addition

to this implementation-dependent format/type pair, format

<code class="constant">GL_RGBA</code> in conjunction with type

<code class="constant">GL_UNSIGNED_BYTE</code> is always allowed by every

implementation, regardless of the currently bound render surface.

See <a class="citerefentry" href="glReadPixels"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_LINE_WIDTH</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the line width as specified with <a class="citerefentry" href="glLineWidth"><span class="citerefentry"><span class="refentrytitle">glLineWidth</span></span></a>. The initial value is

1.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 8.

See <a class="citerefentry" href="glActiveTexture"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_CUBE_MAP_TEXTURE_SIZE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 16.

See <a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_FRAGMENT_UNIFORM_VECTORS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the maximum number of four-element floating-point, integer, or boolean vectors that can be held

in uniform variable storage for a fragment shader. The value must be at least 16.

See <a class="citerefentry" href="glUniform"><span class="citerefentry"><span class="refentrytitle">glUniform</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_RENDERBUFFER_SIZE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value.

The value indicates the largest renderbuffer width and height

that the GL can handle. The value must be at least 1.

See <a class="citerefentry" href="glRenderbufferStorage"><span class="citerefentry"><span class="refentrytitle">glRenderbufferStorage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_TEXTURE_IMAGE_UNITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 8.

See <a class="citerefentry" href="glActiveTexture"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_TEXTURE_SIZE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value.

The value gives a rough estimate of the largest texture that

the GL can handle. The value must be at least 64.

See <a class="citerefentry" href="glTexImage2D"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_VARYING_VECTORS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the maximum number four-element floating-point vectors available for interpolating varying variables used by

vertex and fragment shaders. Varying variables declared as matrices or arrays

will consume multiple interpolators. The value must be at least 8.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_VERTEX_ATTRIBS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the maximum number of 4-component generic vertex attributes accessible to a vertex shader.

The value must be at least 8.

See <a class="citerefentry" href="glVertexAttrib"><span class="citerefentry"><span class="refentrytitle">glVertexAttrib</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 0.

See <a class="citerefentry" href="glActiveTexture"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_VERTEX_UNIFORM_VECTORS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the maximum number of four-element floating-point, integer, or boolean vectors that can be held

in uniform variable storage for a vertex shader. The value must be at least 128.

See <a class="citerefentry" href="glUniform"><span class="citerefentry"><span class="refentrytitle">glUniform</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_MAX_VIEWPORT_DIMS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 <a class="citerefentry" href="glViewport"><span class="citerefentry"><span class="refentrytitle">glViewport</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_NUM_COMPRESSED_TEXTURE_FORMATS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single integer value indicating the number of available

compressed texture formats. The minimum value is 0.

See <a class="citerefentry" href="glCompressedTexImage2D"><span class="citerefentry"><span class="refentrytitle">glCompressedTexImage2D</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_NUM_SHADER_BINARY_FORMATS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single integer value indicating the number of available

shader binary formats. The minimum value is 0.

See <a class="citerefentry" href="glShaderBinary"><span class="citerefentry"><span class="refentrytitle">glShaderBinary</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_PACK_ALIGNMENT</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the byte alignment used for writing pixel data to memory. The initial

value is 4.

See <a class="citerefentry" href="glPixelStorei"><span class="citerefentry"><span class="refentrytitle">glPixelStorei</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_POLYGON_OFFSET_FACTOR</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 <a class="citerefentry" href="glPolygonOffset"><span class="citerefentry"><span class="refentrytitle">glPolygonOffset</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_POLYGON_OFFSET_FILL</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether polygon offset

is enabled for polygons in fill mode. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glPolygonOffset"><span class="citerefentry"><span class="refentrytitle">glPolygonOffset</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_POLYGON_OFFSET_UNITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 <a class="citerefentry" href="glPolygonOffset"><span class="citerefentry"><span class="refentrytitle">glPolygonOffset</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_RED_BITS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

the number of red bitplanes in the color buffer of the

currently bound framebuffer.

</p></dd><dt><span class="term"><code class="constant">GL_RENDERBUFFER_BINDING</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single value, the name of the currently bound

renderbuffer. The initial value is 0, indicating no renderbuffer is bound.

See <a class="citerefentry" href="glBindRenderbuffer"><span class="citerefentry"><span class="refentrytitle">glBindRenderbuffer</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SAMPLE_ALPHA_TO_COVERAGE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating if the

fragment coverage value should be ANDed with a temporary coverage value based

on the fragment's alpha value. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SAMPLE_BUFFERS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single integer value indicating the number of sample buffers

associated with the currently bound framebuffer.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SAMPLE_COVERAGE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating if the

fragment coverage value should be ANDed with a temporary coverage value based

on the current sample coverage value. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SAMPLE_COVERAGE_INVERT</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating if the temporary

coverage value should be inverted.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SAMPLE_COVERAGE_VALUE</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single positive floating-point value indicating the

current sample coverage value.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SAMPLES</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single integer value

indicating the coverage mask size of the currently bound framebuffer.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SCISSOR_BOX</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns four values:

the

<math overflow="scroll"><mi mathvariant="italic">x</mi></math>

and

<math overflow="scroll"><mi mathvariant="italic">y</mi></math>

window coordinates of the scissor box,

followed by its width and height.

Initially the

<math overflow="scroll"><mi mathvariant="italic">x</mi></math>

and

<math overflow="scroll"><mi mathvariant="italic">y</mi></math>

window coordinates are both 0 and the

width and height are set to the size of the window.

See <a class="citerefentry" href="glScissor"><span class="citerefentry"><span class="refentrytitle">glScissor</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SCISSOR_TEST</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether scissoring is

enabled. The initial value is <code class="constant">GL_FALSE</code>.

See <a class="citerefentry" href="glScissor"><span class="citerefentry"><span class="refentrytitle">glScissor</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SHADER_BINARY_FORMATS</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a list of symbolic

constants of length <code class="constant">GL_NUM_SHADER_BINARY_FORMATS</code>

indicating which shader binary formats are available.

See <a class="citerefentry" href="glShaderBinary"><span class="citerefentry"><span class="refentrytitle">glShaderBinary</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_SHADER_COMPILER</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns a single boolean value indicating whether a shader compiler

is supported. <code class="constant">GL_FALSE</code> indicates that any call to

<a class="citerefentry" href="glShaderSource"><span class="citerefentry"><span class="refentrytitle">glShaderSource</span></span></a>,

<a class="citerefentry" href="glCompileShader"><span class="citerefentry"><span class="refentrytitle">glCompileShader</span></span></a>, or

<a class="citerefentry" href="glReleaseShaderCompiler"><span class="citerefentry"><span class="refentrytitle">glReleaseShaderCompiler</span></span></a> will result in a

<code class="constant">GL_INVALID_OPERATION</code> error being generated.

</p></dd><dt><span class="term"><code class="constant">GL_STENCIL_BACK_FAIL</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> returns one value,

a symbolic constant indicating what action is taken for back-facing polygons when the stencil

test fails. The initial value is <code class="constant">GL_KEEP</code>.

See <a class="citerefentry" href="glStencilOpSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilOpSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_STENCIL_BACK_FUNC</code></span></dt><dd><p>

<em class="parameter"><code>params</code></em> 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 <code class="constant">GL_ALWAYS</code>.

See <a class="citerefentry" href="glStencilFuncSeparate"><span class="citerefentry"><span class="refentrytitle">glStencilFuncSeparate</span></span></a>.

</p></dd><dt><span class="term"><code class="constant">GL_STENCIL_BACK_PASS_DEPTH_FAIL</code></span></dt><dd><p>