NAME glGetBooleanv, glGetDoublev, glGetFloatv, glGetIntegerv - return the value or values of a selected parameter C SPECIFICATION void glGetBooleanv( GLenum pname, GLboolean *params ) C SPECIFICATION void glGetDoublev( GLenum pname, GLdouble *params ) C SPECIFICATION void glGetFloatv( GLenum pname, GLfloat *params ) C SPECIFICATION void glGetIntegerv( GLenum pname, GLint *params ) PARAMETERS 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. DESCRIPTION These four commands return values for simple state variables in GL. pname is a symbolic constant indicating the state variable to be returned, and params is a pointer to an array of the indicated type in which to place the returned data. Type conversion is performed if params has a different type than the state variable value being requested. If glGetBooleanv is called, a floating-point (or integer) value is converted to GL_FALSE if and only if it is 0.0 (or 0). Otherwise, it is converted to GL_TRUE. If 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 -1.0 to the most negative representable integer value. If glGetFloatv or glGetDoublev is called, boolean values are returned as GL_TRUE or GL_FALSE, and integer values are converted to floating-point values. The following symbolic constants are accepted by pname: GL_ACCUM_ALPHA_BITS params returns one value, the number of alpha bitplanes in the accumulation buffer. GL_ACCUM_BLUE_BITS params returns one value, the number of blue bitplanes in the accumulation buffer. GL_ACCUM_CLEAR_VALUE params returns four values: the red, green, blue, and alpha values used to clear the accumulation buffer. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glClearAccum. GL_ACCUM_GREEN_BITS params returns one value, the number of green bitplanes in the accumulation buffer. GL_ACCUM_RED_BITS params returns one value, the number of red bitplanes in the accumulation buffer. GL_ALPHA_BIAS params returns one value, the alpha bias factor used during pixel transfers. The initial value is 0. See glPixelTransfer. GL_ALPHA_BITS params returns one value, the number of alpha bitplanes in each color buffer. GL_ALPHA_SCALE params returns one value, the alpha scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer. GL_ALPHA_TEST params 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 params returns one value, the symbolic name of the alpha test function. The initial value is GL_ALWAYS. See glAlphaFunc. GL_ALPHA_TEST_REF params returns one value, the reference value for the alpha test. The initial value is 0. See glAlphaFunc. An integer value, if requested, is linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. GL_ATTRIB_STACK_DEPTH params returns one value, the depth of the attribute stack. If the stack is empty, 0 is returned. The initial value is 0. See glPushAttrib. GL_AUTO_NORMAL params returns a single boolean value indicating whether 2D map evaluation automatically generates surface normals. The initial value is GL_FALSE. See glMap2. GL_AUX_BUFFERS params returns one value, the number of auxiliary color buffers. The initial value is 0. GL_BLEND params returns a single boolean value indicating whether blending is enabled. The initial value is GL_FALSE. See glBlendFunc. GL_BLEND_COLOR_EXT params returns four values, the red, green, blue, and alpha values which are the components of the blend color. See glBlendColorEXT. GL_BLEND_DST params returns one value, the symbolic constant identifying the destination blend function. The initial value is GL_ZERO. See glBlendFunc. GL_BLEND_EQUATION_EXT params returns one value, a symbolic constant indicating whether the blend equation is GL_FUNC_ADD_EXT, GL_MIN_EXT or GL_MAX_EXT. See glBlendEquationEXT. GL_BLEND_SRC params returns one value, the symbolic constant identifying the source blend function. The initial value is GL_ONE. See glBlendFunc. GL_BLUE_BIAS params returns one value, the blue bias factor used during pixel transfers. The initial value is 0. See glPixelTransfer. GL_BLUE_BITS params returns one value, the number of blue bitplanes in each color buffer. GL_BLUE_SCALE params returns one value, the blue scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer. GL_CLIENT_ATTRIB_STACK_DEPTH params returns one value indicating the depth of the attribute stack. The initial value is 0. See glPushClientAttrib. GL_CLIP_PLANEi params returns a single boolean value indicating whether the specified clipping plane is enabled. The initial value is GL_FALSE. See glClipPlane. GL_COLOR_ARRAY params returns a single boolean value indicating whether the color array is enabled. The initial value is GL_FALSE. See glColorPointer. GL_COLOR_ARRAY_SIZE params returns one value, the number of components per color in the color array. The initial value is 4. See glColorPointer. GL_COLOR_ARRAY_STRIDE params returns one value, the byte offset between consecutive colors in the color array. The initial value is 0. See glColorPointer. GL_COLOR_ARRAY_TYPE params 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 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 -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glClearColor. 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_MATERIAL params returns a single boolean value indicating whether one or more material parameters are tracking the current color. The initial value is GL_FALSE. See glColorMaterial. GL_COLOR_MATERIAL_FACE params returns one value, a symbolic constant indicating which materials have a parameter that is tracking the current color. The initial value is GL_FRONT_AND_BACK. See glColorMaterial. GL_COLOR_MATERIAL_PARAMETER params returns one value, a symbolic constant indicating which material parameters are tracking the current color. The initial value is GL_AMBIENT_AND_DIFFUSE. See glColorMaterial. 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_CULL_FACE params returns a single boolean value indicating whether polygon culling is enabled. The initial value is GL_FALSE. See glCullFace. GL_CULL_FACE_MODE params returns one value, a symbolic constant indicating which polygon faces are to be culled. The initial value is GL_BACK. See glCullFace. GL_CURRENT_COLOR params returns four values: the red, green, blue, and alpha values of the current color. Integer values, if requested, are linearly mapped from the internal floating- point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. See glColor. The initial value is (1, 1, 1, 1). GL_CURRENT_INDEX params returns one value, the current color index. The initial value is 1. See glIndex. GL_CURRENT_NORMAL params 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 representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 1). See glNormal. GL_CURRENT_RASTER_COLOR params returns four values: the red, green, blue, and alpha values of the current raster position. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (1, 1, 1, 1). See glRasterPos. GL_CURRENT_RASTER_DISTANCE params returns one value, the distance from the eye to the current raster position. The initial value is 0. See glRasterPos. GL_CURRENT_RASTER_INDEX params returns one value, the color index of the current raster position. The initial value is 1. See glRasterPos. GL_CURRENT_RASTER_POSITION params returns four values: the x, y, z, and w components of the current raster position. x, y, and z are in window coordinates, and w is in clip coordinates. The initial value is (0, 0, 0, 1). See glRasterPos. GL_CURRENT_RASTER_POSITION_VALID params returns a single boolean value indicating whether the current raster position is valid. The initial value is GL_TRUE. See glRasterPos. GL_CURRENT_RASTER_TEXTURE_COORDS params returns four values: the s, t, r, and q current raster texture coordinates. The initial value is (0, 0, 0, 1). See glRasterPos and glTexCoord. GL_CURRENT_TEXTURE_COORDS params 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 params returns one value, the depth bias factor used during pixel transfers. The initial value is 0. See glPixelTransfer. GL_DEPTH_BITS params returns one value, the number of bitplanes in the depth buffer. 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 -1.0 returns the most negative representable integer value. The initial value is 1. See glClearDepth. 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 -1.0 returns the most negative representable integer value. The initial value is (0, 1). See glDepthRange. GL_DEPTH_SCALE params returns one value, the depth scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer. 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_EDGE_FLAG params returns a single boolean value indicating whether the current edge flag is GL_TRUE or GL_FALSE. The initial value is GL_TRUE. See glEdgeFlag. GL_EDGE_FLAG_ARRAY params returns a single boolean value indicating whether the edge flag array is enabled. The initial value is GL_FALSE. See glEdgeFlagPointer. GL_EDGE_FLAG_ARRAY_STRIDE params returns one value, the byte offset between consecutive edge flags in the edge flag array. The initial value is 0. See glEdgeFlagPointer. GL_FOG params returns a single boolean value indicating whether fogging is enabled. The initial value is GL_FALSE. See glFog. GL_FOG_COLOR params returns four values: the red, green, blue, and alpha components of the fog color. Integer values, if requested, are linearly mapped from the internal floating-point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0, 0, 0, 0). See glFog. GL_FOG_DENSITY params returns one value, the fog density parameter. The initial value is 1. See glFog. GL_FOG_END params returns one value, the end factor for the linear fog equation. The initial value is 1. See glFog. GL_FOG_HINT params returns one value, a symbolic constant indicating the mode of the fog hint. The initial value is GL_DONT_CARE. See glHint. GL_FOG_INDEX params returns one value, the fog color index. The initial value is 0. See glFog. GL_FOG_MODE params returns one value, a symbolic constant indicating which fog equation is selected. The initial value is GL_EXP. See glFog. GL_FOG_START params returns one value, the start factor for the linear fog equation. The initial value is 0. See glFog. GL_FRONT_FACE params returns one value, a symbolic constant indicating whether clockwise or counterclockwise polygon winding is treated as front-facing. The initial value is GL_CCW. See glFrontFace. GL_GREEN_BIAS params returns one value, the green bias factor used during pixel transfers. The initial value is 0. GL_GREEN_BITS params returns one value, the number of green bitplanes in each color buffer. GL_GREEN_SCALE params returns one value, the green scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer. GL_INDEX_ARRAY params returns a single boolean value indicating whether the color index array is enabled. The initial value is GL_FALSE. See glIndexPointer. GL_INDEX_ARRAY_STRIDE params returns one value, the byte offset between consecutive color indexes in the color index array. The initial value is 0. See glIndexPointer. GL_INDEX_ARRAY_TYPE params returns one value, the data type of indexes in the color index array. The initial value is GL_FLOAT. See glIndexPointer. GL_INDEX_BITS params returns one value, the number of bitplanes in each color index buffer. GL_INDEX_CLEAR_VALUE params returns one value, the color index used to clear the color index buffers. The initial value is 0. See glClearIndex. GL_INDEX_LOGIC_OP params returns a single boolean value indicating whether a fragment's index values are merged into the framebuffer using a logical operation. The initial value is GL_FALSE. See glLogicOp. GL_INDEX_MODE params returns a single boolean value indicating whether the GL is in color index mode (GL_TRUE) or RGBA mode (GL_FALSE). GL_INDEX_OFFSET params returns one value, the offset added to color and stencil indices during pixel transfers. The initial value is 0. See glPixelTransfer. GL_INDEX_SHIFT params 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 params 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 params returns a single boolean value indicating whether the specified light is enabled. The initial value is GL_FALSE. See glLight and glLightModel. GL_LIGHTING params returns a single boolean value indicating whether lighting is enabled. The initial value is GL_FALSE. See glLightModel. GL_LIGHT_MODEL_AMBIENT params returns four values: the red, green, blue, and alpha components of the ambient intensity of the entire scene. Integer values, if requested, are linearly mapped from the internal floating- point representation such that 1.0 returns the most positive representable integer value, and -1.0 returns the most negative representable integer value. The initial value is (0.2, 0.2, 0.2, 1.0). See glLightModel. GL_LIGHT_MODEL_LOCAL_VIEWER params returns a single boolean value indicating whether specular reflection calculations treat the viewer as being local to the scene. The initial value is GL_FALSE. See glLightModel. GL_LIGHT_MODEL_TWO_SIDE params returns a single boolean value indicating whether separate materials are used to compute lighting for front- and back-facing polygons. The initial value is GL_FALSE. See glLightModel. 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_STIPPLE params returns a single boolean value indicating whether stippling of lines is enabled. The initial value is GL_FALSE. See glLineStipple. GL_LINE_STIPPLE_PATTERN params returns one value, the 16- bit line stipple pattern. The initial value is all 1's. See glLineStipple. GL_LINE_STIPPLE_REPEAT params returns one value, the line stipple repeat factor. The initial value is 1. See glLineStipple. GL_LINE_WIDTH params returns one value, the line width as specified with glLineWidth. The initial value is 1. GL_LINE_WIDTH_GRANULARITY params returns one value, the width difference between adjacent supported widths for antialiased lines. See glLineWidth. GL_LINE_WIDTH_RANGE params returns two values: the smallest and largest supported widths for antialiased lines. See glLineWidth. GL_LIST_BASE params 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 params returns one value, the name of the display list currently under construction. 0 is returned if no display list is currently under construction. The initial value is 0. See glNewList. GL_LIST_MODE params returns one value, a symbolic constant indicating the construction mode of the display list currently under construction. The initial value is 0. See glNewList. 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_MAP1_COLOR_4 params returns a single boolean value indicating whether 1D evaluation generates colors. The initial value is GL_FALSE. See glMap1. GL_MAP1_GRID_DOMAIN params returns two values: the endpoints of the 1D map's grid domain. The initial value is (0, 1). See glMapGrid. GL_MAP1_GRID_SEGMENTS params returns one value, the number of partitions in the 1D map's grid domain. The initial value is 1. See glMapGrid. GL_MAP1_INDEX params returns a single boolean value indicating whether 1D evaluation generates color indices. The initial value is GL_FALSE. See glMap1. GL_MAP1_NORMAL params returns a single boolean value indicating whether 1D evaluation generates normals. The initial value is GL_FALSE. See glMap1. GL_MAP1_TEXTURE_COORD_1 params returns a single boolean value indicating whether 1D evaluation generates 1D texture coordinates. The initial value is GL_FALSE. See glMap1. GL_MAP1_TEXTURE_COORD_2 params returns a single boolean value indicating whether 1D evaluation generates 2D texture coordinates. The initial value is GL_FALSE. See glMap1. GL_MAP1_TEXTURE_COORD_3 params returns a single boolean value indicating whether 1D evaluation generates 3D texture coordinates. The initial value is GL_FALSE. See glMap1. GL_MAP1_TEXTURE_COORD_4 params returns a single boolean value indicating whether 1D evaluation generates 4D texture coordinates. The initial value is GL_FALSE. See glMap1. GL_MAP1_VERTEX_3 params returns a single boolean value indicating whether 1D evaluation generates 3D vertex coordinates. The initial value is GL_FALSE. See glMap1. GL_MAP1_VERTEX_4 params returns a single boolean value indicating whether 1D evaluation generates 4D vertex coordinates. The initial value is GL_FALSE. See glMap1. GL_MAP2_COLOR_4 params returns a single boolean value indicating whether 2D evaluation generates colors. The initial value is GL_FALSE. See glMap2. GL_MAP2_GRID_DOMAIN params 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 params returns two values: the number of partitions in the 2D map's i and j grid domains. The initial value is (1,1). See glMapGrid. GL_MAP2_INDEX params returns a single boolean value indicating whether 2D evaluation generates color indices. The initial value is GL_FALSE. See glMap2. GL_MAP2_NORMAL params returns a single boolean value indicating whether 2D evaluation generates normals. The initial value is GL_FALSE. See glMap2. GL_MAP2_TEXTURE_COORD_1 params returns a single boolean value indicating whether 2D evaluation generates 1D texture coordinates. The initial value is GL_FALSE. See glMap2. GL_MAP2_TEXTURE_COORD_2 params returns a single boolean value indicating whether 2D evaluation generates 2D texture coordinates. The initial value is GL_FALSE. See glMap2. GL_MAP2_TEXTURE_COORD_3 params returns a single boolean value indicating whether 2D evaluation generates 3D texture coordinates. The initial value is GL_FALSE. See glMap2. GL_MAP2_TEXTURE_COORD_4 params returns a single boolean value indicating whether 2D evaluation generates 4D texture coordinates. The initial value is GL_FALSE. See glMap2. GL_MAP2_VERTEX_3 params returns a single boolean value indicating whether 2D evaluation generates 3D vertex coordinates. The initial value is GL_FALSE. See glMap2. GL_MAP2_VERTEX_4 params returns a single boolean value indicating whether 2D evaluation generates 4D vertex coordinates. The initial value is GL_FALSE. See glMap2. GL_MAP_COLOR params returns a single boolean value indicating if colors and color indices are to be replaced by table lookup during pixel transfers. The initial value is GL_FALSE. See glPixelTransfer. GL_MAP_STENCIL params returns a single boolean value indicating if stencil indices are to be replaced by table lookup during pixel transfers. The initial value is GL_FALSE. See glPixelTransfer. GL_MATRIX_MODE params returns one value, a symbolic constant indicating which matrix stack is currently the target of all matrix operations. The initial value is GL_MODELVIEW. See glMatrixMode. GL_MAX_CLIENT_ATTRIB_STACK_DEPTH params returns one value indicating the maximum supported depth of the client attribute stack. See glPushClientAttrib. GL_MAX_ATTRIB_STACK_DEPTH params returns one value, the maximum supported depth of the attribute stack. The value must be at least 16. See glPushAttrib. GL_MAX_CLIP_PLANES params returns one value, the maximum number of application- defined clipping planes. The value must be at least 6. See glClipPlane. GL_MAX_EVAL_ORDER params returns one value, the maximum equation order supported by 1D and 2D evaluators. The value must be at least 8. See glMap1 and glMap2. GL_MAX_LIGHTS params returns one value, the maximum number of lights. The value must be at least 8. See glLight. GL_MAX_LIST_NESTING params 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 params 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 params returns one value, the maximum supported depth of the selection name stack. The value must be at least 64. See glPushName. GL_MAX_PIXEL_MAP_TABLE params returns one value, the maximum supported size of a glPixelMap lookup table. The value must be at least 32. See glPixelMap. GL_MAX_PROJECTION_STACK_DEPTH params returns one value, the maximum supported depth of the projection matrix stack. The value must be at least 2. See glPushMatrix. GL_MAX_TEXTURE_SIZE params returns one value. The value gives a rough estimate of the largest texture that the GL can handle. If the GL version is 1.1 or greater, use GL_PROXY_TEXTURE_1D or GL_PROXY_TEXTURE_2D to determine if a texture is too large. See glTexImage1D and glTexImage2D. GL_MAX_TEXTURE_STACK_DEPTH params returns one value, the maximum supported depth of the texture matrix stack. The value must be at least 2. See glPushMatrix. 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_MODELVIEW_MATRIX params 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 params returns one value, the number of matrices on the modelview matrix stack. The initial value is 1. See glPushMatrix. GL_NAME_STACK_DEPTH params returns one value, the number of names on the selection name stack. The initial value is 0. See glPushName. GL_NORMAL_ARRAY params returns a single boolean value, indicating whether the normal array is enabled. The initial value is GL_FALSE. See glNormalPointer. GL_NORMAL_ARRAY_STRIDE params returns one value, the byte offset between consecutive normals in the normal array. The initial value is 0. See glNormalPointer. GL_NORMAL_ARRAY_TYPE params returns one value, the data type of each coordinate in the normal array. The initial value is GL_FLOAT. See glNormalPointer. GL_NORMALIZE params 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 params returns one value, the byte alignment used for writing pixel data to memory. The initial value is 4. 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_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_PERSPECTIVE_CORRECTION_HINT params returns one value, a symbolic constant indicating the mode of the perspective correction hint. The initial value is GL_DONT_CARE. See glHint. GL_PIXEL_MAP_A_TO_A_SIZE params 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 params 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 params 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 params 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 params 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 params 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 params 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 params 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 params returns one value, the size of the red-to-red pixel translation table. The initial value is 1. See glPixelMap. GL_PIXEL_MAP_S_TO_S_SIZE params returns one value, the size of the stencil-to-stencil pixel translation table. The initial value is 1. See glPixelMap. 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_POINT_SMOOTH params returns a single boolean value indicating whether antialiasing of points is enabled. The initial value is GL_FALSE. See glPointSize. GL_POINT_SMOOTH_HINT params returns one value, a symbolic constant indicating the mode of the point antialiasing hint. The initial value is GL_DONT_CARE. See glHint. GL_POLYGON_MODE params returns two values: symbolic constants indicating whether front-facing and back- facing polygons are rasterized as points, lines, or filled polygons. The initial value is GL_FILL. See glPolygonMode. 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_POLYGON_STIPPLE params returns a single boolean value indicating whether polygon stippling is enabled. The initial value is GL_FALSE. See glPolygonStipple. GL_PROJECTION_MATRIX params 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 params returns one value, the number of matrices on the projection matrix stack. The initial value is 1. See glPushMatrix. 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 and glAccum. GL_RED_BIAS params returns one value, the red bias factor used during pixel transfers. The initial value is 0. GL_RED_BITS params returns one value, the number of red bitplanes in each color buffer. GL_RED_SCALE params returns one value, the red scale factor used during pixel transfers. The initial value is 1. See glPixelTransfer. GL_RENDER_MODE params returns one value, a symbolic constant indicating whether the GL is in render, select, or feedback mode. The initial value is GL_RENDER. See glRenderMode. GL_RGBA_MODE params returns a single boolean value indicating whether the GL is in RGBA mode (true) or color index mode (false). See glColor. GL_SCISSOR_BOX params returns four values: the x and y window coordinates of the scissor box, followed by its width and height. Initially the x and y window coordinates are both 0 and the width and height are set to the size of the window. See glScissor. GL_SCISSOR_TEST params returns a single boolean value indicating whether scissoring is enabled. The initial value is GL_FALSE. See glScissor. GL_SHADE_MODEL params returns one value, a symbolic constant indicating whether the shading mode is flat or smooth. The initial value is GL_SMOOTH. See glShadeModel. GL_STENCIL_BITS params returns one value, the number of bitplanes in the stencil buffer. 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. 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. 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. 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. 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. 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. 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. 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 initial value is 4. GL_TEXTURE_1D params returns a single boolean value indicating whether 1D texture mapping is enabled. The initial value is GL_FALSE. See glTexImage1D. GL_TEXTURE_1D_BINDING 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_2D params returns a single boolean value indicating whether 2D texture mapping is enabled. The initial value is GL_FALSE. See glTexImage2D. GL_TEXTURE_2D_BINDING 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_COORD_ARRAY params returns a single boolean value indicating whether the texture coordinate array is enabled. The initial value is GL_FALSE. See glTexCoordPointer. GL_TEXTURE_COORD_ARRAY_SIZE params 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 params returns one value, the byte offset between consecutive elements in the texture coordinate array. The initial value is 0. See glTexCoordPointer. GL_TEXTURE_COORD_ARRAY_TYPE params returns one value, the data type of the coordinates in the texture coordinate array. The initial value is GL_FLOAT. See glTexCoordPointer. GL_TEXTURE_GEN_Q params returns a single boolean value indicating whether automatic generation of the q texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen. GL_TEXTURE_GEN_R params returns a single boolean value indicating whether automatic generation of the r texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen. GL_TEXTURE_GEN_S params returns a single boolean value indicating whether automatic generation of the S texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen. GL_TEXTURE_GEN_T params returns a single boolean value indicating whether automatic generation of the T texture coordinate is enabled. The initial value is GL_FALSE. See glTexGen. GL_TEXTURE_MATRIX params returns sixteen values: the texture matrix on the top of the texture matrix stack. Initially this matrix is the identity matrix. See glPushMatrix. GL_TEXTURE_STACK_DEPTH params returns one value, the number of matrices on the texture matrix stack. The initial value is 1. See glPushMatrix. 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_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_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_VERTEX_ARRAY params returns a single boolean value indicating whether the vertex array is enabled. The initial value is GL_FALSE. See glVertexPointer. GL_VERTEX_ARRAY_SIZE params returns one value, the number of coordinates per vertex in the vertex array. The initial value is 4. See glVertexPointer. GL_VERTEX_ARRAY_STRIDE params returns one value, the byte offset between consecutive vertexes in the vertex array. The initial value is 0. See glVertexPointer. GL_VERTEX_ARRAY_TYPE params returns one value, the data type of each coordinate in the vertex array. The initial value is GL_FLOAT. See glVertexPointer. GL_VIEWPORT params 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 will do its rendering. See glViewport. GL_ZOOM_X params returns one value, the x pixel zoom factor. The initial value is 1. See glPixelZoom. GL_ZOOM_Y params returns one value, the y pixel zoom factor. The initial value is 1. See glPixelZoom. Many of the boolean parameters can also be queried more easily using glIsEnabled. NOTES GL_COLOR_LOGIC_OP, GL_COLOR_ARRAY, GL_COLOR_ARRAY_SIZE, GL_COLOR_ARRAY_STRIDE, GL_COLOR_ARRAY_TYPE, GL_EDGE_FLAG_ARRAY, GL_EDGE_FLAG_ARRAY_STRIDE, GL_INDEX_ARRAY, GL_INDEX_ARRAY_STRIDE, GL_INDEX_ARRAY_TYPE, GL_INDEX_LOGIC_OP, GL_NORMAL_ARRAY, GL_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. ERRORS GL_INVALID_ENUM is generated if pname is not an accepted value. GL_INVALID_OPERATION is generated if glGet is executed between the execution of glBegin and the corresponding execution of glEnd. SEE ALSO glGetClipPlane, glGetError, glGetLight, glGetMap, glGetMaterial, glGetPixelMap, glGetPointerv, glGetPolygonStipple, glGetString, glGetTexEnv, glGetTexGen, glGetTexImage, glGetTexLevelParameter, glGetTexParameter, glIsEnabled