glGetBooleanv, glGetDoublev, glGetFloatv, glGetIntegerv
These functions 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);
Parameters
pname
The parameter value to be returned. The following symbolic constants are accepted:Constant Description GL_ACCUM_ALPHA_BITS The params parameter returns one value: the number of alpha bitplanes in the accumulation buffer. GL_ACCUM_BLUE_BITS The params parameter returns one value: the number of blue bitplanes in the accumulation buffer. GL_ACCUM_CLEAR_VALUE The params parameter 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. See glClearAccum. GL_ACCUM_GREEN_BITS The params parameter returns one value: the number of green bitplanes in the accumulation buffer. GL_ACCUM_RED_BITS The params parameter returns one value: the number of red bitplanes in the accumulation buffer. GL_ALPHA_BIAS The params parameter returns one value: the alpha bias factor used during pixel transfers. See glPixelTransfer. GL_ALPHA_BITS The params parameter returns one value: the number of alpha bitplanes in each color buffer. GL_ALPHA_SCALE The params parameter returns one value: the alpha scale factor used during pixel transfers. See glPixelTransfer. GL_ALPHA_TEST The params parameter returns a single Boolean value indicating whether alpha testing of fragments is enabled. See glAlphaFunc. GL_ALPHA_TEST_FUNC The params parameter returns one value: the symbolic name of the alpha test function. See glAlphaFunc. GL_ALPHA_TEST_REF The params parameter returns one value: the reference value for the alpha test. 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 The params parameter returns one value: the depth of the attribute stack. If the stack is empty, zero is returned. See glPushAttrib. GL_AUTO_NORMAL The params parameter returns a single Boolean value indicating whether 2-D map evaluation automatically generates surface normals. See glMap2. GL_AUX_BUFFERS The params parameter returns one value: the number of auxiliary color buffers. GL_BLEND The params parameter returns a single Boolean value indicating whether blending is enabled. See glBlendFunc. GL_BLEND_DST The params parameter returns one value: the symbolic constant identifying the destination blend function. See glBlendFunc. GL_BLEND_SRC The params parameter returns one value: the symbolic constant identifying the source blend function. See glBlendFunc. GL_BLUE_BIAS The params parameter returns one value: the blue bias factor used during pixel transfers. See glPixelTransfer. GL_BLUE_BITS The params parameter returns one value: the number of blue bitplanes in each color buffer. GL_BLUE_SCALE The params parameter returns one value: the blue scale factor used during pixel transfers. See glPixelTransfer. GL_CLIENT_ATTRIB_STACK_DEPTH The params parameter returns one value indicating the depth of the attribute stack. The initial value is zero. See glPushClientAttrib. GL_CLIP_PLANEi The params parameter returns a single Boolean value indicating whether the specified clipping plane is enabled. See glClipPlane. GL_COLOR_ARRAY The params parameter returns a single Boolean value indicating whether the specified clipping plane is enabled. See glClipPlane. GL_COLOR_ARRAY_SIZE The params parameter returns one value, the number of components per color in the color array. See glColorPointer. GL_COLOR_ARRAY_STRIDE The params parameter returns one value, the byte offset between consecutive colors in the color array. See glColorPointer. GL_COLOR_ARRAY_TYPE The params parameter returns one value, the data type of each component in the color array. See glColorPointer. GL_COLOR_CLEAR_VALUE The params parameter 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. See glClearColor. GL_COLOR_LOGIC_OP The params parameter returns a single Boolean value indicating whether a fragment's RGBA color values are merged into the framebuffer using a logical operation. See glLogicOp. GL_COLOR_MATERIAL The params parameter returns a single Boolean value indicating whether one or more material parameters are tracking the current color. See glColorMaterial. GL_COLOR_MATERIAL_FACE The params parameter returns one value: a symbolic constant indicating which materials have a parameter that is tracking the current color. See glColorMaterial. GL_COLOR_MATERIAL_PARAMETER The params parameter returns one value: a symbolic constant indicating which material parameters are tracking the current color. See glColorMaterial. GL_COLOR_WRITEMASK The params parameter returns four Boolean values: the red, green, blue, and alpha write enables for the color buffers. See glColorMask. GL_CULL_FACE The params parameter returns a single Boolean value indicating whether polygon culling is enabled. See glCullFace. GL_CULL_FACE_MODE The params parameter returns one value: a symbolic constant indicating which polygon faces are to be culled. See glCullFace. GL_CURRENT_COLOR The params parameter 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. GL_CURRENT_INDEX The params parameter returns one value: the current color index. See glIndex. GL_CURRENT_NORMAL The params parameter 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. See glNormal. GL_CURRENT_RASTER_COLOR The params parameter 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. See glRasterPos. GL_CURRENT_RASTER_DISTANCE The params parameter returns one value: the distance from the eye to the current raster position. See glRasterPos. GL_CURRENT_RASTER_INDEX The params parameter returns one value: the color index of the current raster position. See glRasterPos. GL_CURRENT_RASTER_POSITION The params parameter returns four values: the x, y, z, and w components of the current raster position. The x, y, and z components are in window coordinates, and w is in clip coordinates. See glRasterPos. GL_CURRENT_RASTER_POSITION_VALID The params parameter returns a single Boolean value indicating whether the current raster position is valid. See glRasterPos. GL_CURRENT_RASTER_TEXTURE_COORDS The params parameter returns four values: the s, t, r, and q current raster texture coordinates. See glRasterPos and glTexCoord. GL_CURRENT_TEXTURE_COORDS The params parameter returns four values: the s, t, r, and q current texture coordinates. See glTexCoord. GL_DEPTH_BIAS The params parameter returns one value: the depth bias factor used during pixel transfers. See glPixelTransfer. GL_DEPTH_BITS The params parameter returns one value: the number of bitplanes in the depth buffer. GL_DEPTH_CLEAR_VALUE The params parameter 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. See glClearDepth. GL_DEPTH_FUNC The params parameter returns one value: the symbolic constant that indicates the depth comparison function. See glDepthFunc. GL_DEPTH_RANGE The params parameter 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. See glDepthRange. GL_DEPTH_SCALE The params parameter returns one value: the depth scale factor used during pixel transfers. See glPixelTransfer. GL_DEPTH_TEST The params parameter returns a single Boolean value indicating whether depth testing of fragments is enabled. See glDepthFunc and glDepthRange. GL_DEPTH_WRITEMASK The params parameter returns a single Boolean value indicating if the depth buffer is enabled for writing. See glDepthMask. GL_DITHER The params parameter returns a single Boolean value indicating whether dithering of fragment colors and indexes is enabled. GL_DOUBLEBUFFER The params parameter returns a single Boolean value indicating whether double buffering is supported. GL_DRAW_BUFFER The params parameter returns one value: a symbolic constant indicating which buffers are being drawn to. See glDrawBuffer. GL_EDGE_FLAG The params parameter returns a single Boolean value indicating whether the current edge flag is true or false. See glEdgeFlag. GL_EDGE_FLAG_ARRAY The params parameter returns a single Boolean value indicating whether the edge flag array is enabled. See glEdgeFlagPointer. GL_EDGE_FLAG_ARRAY_STRIDE The params parameter returns one value, the byte offset between consecutive edge flags in the edge flag array. See glEdgeFlagPointer. GL_FOG The params parameter returns a single Boolean value indicating whether fogging is enabled. See glFog. GL_FOG_COLOR The params parameter 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. See glFog. GL_FOG_DENSITY The params parameter returns one value: the fog density parameter. See glFog. GL_FOG_END The params parameter returns one value: the end factor for the linear fog equation. See glFog. GL_FOG_HINT The params parameter returns one value: a symbolic constant indicating the mode of the fog hint. See glHint. GL_FOG_INDEX The params parameter returns one value: the fog color index. See glFog. GL_FOG_MODE The params parameter returns one value: a symbolic constant indicating which fog equation is selected. See glFog. GL_FOG_START The params parameter returns one value: the start factor for the linear fog equation. See glFog. GL_FRONT_FACE The params parameter returns one value: a symbolic constant indicating whether clockwise or counterclockwise polygon winding is treated as front-facing. See glFrontFace. GL_GREEN_BIAS The params parameter returns one value: the green bias factor used during pixel transfers. GL_GREEN_BITS The params parameter returns one value: the number of green bitplanes in each color buffer. GL_GREEN_SCALE The params parameter returns one value: the green scale factor used during pixel transfers. See glPixelTransfer. GL_INDEX_ARRAY The params parameter returns a single Boolean value indicating whether the color index array is enabled. See glIndexPointer. GL_INDEX_ARRAY_STRIDE The params parameter returns one value, the byte offset between consecutive color indexes in the color index array. See glIndexPointer. GL_INDEX_ARRAY_TYPE The params parameter returns one value, the data type of indexes in the color index array. The initial value is GL_FLOAT. See glIndexPointer. GL_INDEX_BITS The params parameter returns one value: the number of bitplanes in each color-index buffer. GL_INDEX_CLEAR_VALUE The params parameter returns one value: the color index used to clear the color-index buffers. See glClearIndex. GL_INDEX_LOGIC_OP The params parameter returns a single Boolean value indicating whether a fragment's index values are merged into the framebuffer using a logical operation. See glLogicOp. GL_INDEX_MODE The params parameter returns a single Boolean value indicating whether OpenGL is in color-index mode (TRUE) or RGBA mode (FALSE). GL_INDEX_OFFSET The params parameter returns one value: the offset added to color and stencil indexes during pixel transfers. See glPixelTransfer. GL_INDEX_SHIFT The params parameter returns one value: the amount that color and stencil indexes are shifted during pixel transfers. See glPixelTransfer. GL_INDEX_WRITEMASK The params parameter returns one value: a mask indicating which bitplanes of each color-index buffer can be written. See glIndexMask. GL_LIGHTi The params parameter returns a single Boolean value indicating whether the specified light is enabled. See glLight and glLightModel. GL_LIGHTING The params parameter returns a single Boolean value indicating whether lighting is enabled. See glLightModel. GL_LIGHT_MODEL_AMBIENT The params parameter 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. See glLightModel. GL_LIGHT_MODEL_LOCAL_VIEWER The params parameter returns a single Boolean value indicating whether specular reflection calculations treat the viewer as being local to the scene. See glLightModel. GL_LIGHT_MODEL_TWO_SIDE The params parameter returns a single Boolean value indicating whether separate materials are used to compute lighting for front- and back-facing polygons. See glLightModel. GL_LINE_SMOOTH The params parameter returns a single Boolean value indicating whether antialiasing of lines is enabled. See glLineWidth. GL_LINE_SMOOTH_HINT The params parameter returns one value: a symbolic constant indicating the mode of the line antialiasing hint. See glHint. GL_LINE_STIPPLE The params parameter returns a single Boolean value indicating whether stippling of lines is enabled. See glLineStipple. GL_LINE_STIPPLE_PATTERN The params parameter returns one value: the 16-bit line stipple pattern. See glLineStipple. GL_LINE_STIPPLE_REPEAT The params parameter returns one value: the line stipple repeat factor. See glLineStipple. GL_LINE_WIDTH The params parameter returns one value: the line width as specified with glLineWidth. GL_LINE_WIDTH_GRANULARITY The params parameter returns one value: the width difference between adjacent supported widths for antialiased lines. See glLineWidth. GL_LINE_WIDTH_RANGE The params parameter returns two values: the smallest and largest supported widths for antialiased lines. See glLineWidth. GL_LIST_BASE The params parameter returns one value: the base offset added to all names in arrays presented to glCallLists. See glListBase. GL_LIST_INDEX The params parameter returns one value: the name of the display list currently under construction. Zero is returned if no display list is currently under construction. See glNewList. GL_LIST_MODE The params parameter returns one value: a symbolic constant indicating the construction mode of the display list currently being constructed. See glNewList. GL_LOGIC_OP The params parameter returns a single Boolean value indicating whether fragment indexes are merged into the framebuffer using a logical operation. See glLogicOp. GL_LOGIC_OP_MODE The params parameter returns one value: a symbolic constant indicating the selected logic operational mode. See glLogicOp. GL_MAP1_COLOR_4 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates colors. See glMap1. GL_MAP1_GRID_DOMAIN The params parameter returns two values: the endpoints of the 1-D maps grid domain. See glMapGrid. GL_MAP1_GRID_SEGMENTS The params parameter returns one value: the number of partitions in the 1-D maps grid domain. See glMapGrid. GL_MAP1_INDEX The params parameter returns a single Boolean value indicating whether 1-D evaluation generates color indexes. See glMap1. GL_MAP1_NORMAL The params parameter returns a single Boolean value indicating whether 1-D evaluation generates normals. See glMap1. GL_MAP1_TEXTURE_COORD_1 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates 1-D texture coordinates. See glMap1. GL_MAP1_TEXTURE_COORD_2 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates 2-D texture coordinates. See glMap1. GL_MAP1_TEXTURE_COORD_3 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates 3-D texture coordinates. See glMap1. GL_MAP1_TEXTURE_COORD_4 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates 4-D texture coordinates. See glMap1. GL_MAP1_VERTEX_3 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates 3-D vertex coordinates. See glMap1. GL_MAP1_VERTEX_4 The params parameter returns a single Boolean value indicating whether 1-D evaluation generates 4-D vertex coordinates. See glMap1. GL_MAP2_COLOR_4 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates colors. See glMap2. GL_MAP2_GRID_DOMAIN The params parameter returns four values: the endpoints of the 2-D maps i and j grid domains. See glMapGrid. GL_MAP2_GRID_SEGMENTS The params parameter returns two values: the number of partitions in the 2-D maps i and j grid domains. See glMapGrid. GL_MAP2_INDEX The params parameter returns a single Boolean value indicating whether 2-D evaluation generates color indexes. See glMap2. GL_MAP2_NORMAL The params parameter returns a single Boolean value indicating whether 2-D evaluation generates normals. See glMap2. GL_MAP2_TEXTURE_COORD_1 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates 1-D texture coordinates. See glMap2. GL_MAP2_TEXTURE_COORD_2 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates 2-D texture coordinates. See glMap2. GL_MAP2_TEXTURE_COORD_3 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates 3-D texture coordinates. See glMap2. GL_MAP2_TEXTURE_COORD_4 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates 4-D texture coordinates. See glMap2. GL_MAP2_VERTEX_3 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates 3-D vertex coordinates. See glMap2. GL_MAP2_VERTEX_4 The params parameter returns a single Boolean value indicating whether 2-D evaluation generates 4-D vertex coordinates. See glMap2. GL_MAP_COLOR The params parameter returns a single Boolean value indicating whether colors and color indexes are to be replaced by table lookup during pixel transfers. See glPixelTransfer. GL_MAP_STENCIL The params parameter returns a single Boolean value indicating whether stencil indexes are to be replaced by table lookup during pixel transfers. See glPixelTransfer. GL_MATRIX_MODE The params parameter returns one value: a symbolic constant indicating which matrix stack is currently the target of all matrix operations. See glMatrixMode. GL_MAX_CLIENT_ATTRIB_STACK_DEPTH The params parameter returns one value indicating the maximum supported depth of the client attribute stack. See glPushClientAttrib. GL_MAX_ATTRIB_STACK_DEPTH The params parameter returns one value: the maximum supported depth of the attribute stack. See glPushAttrib. GL_MAX_CLIP_PLANES The params parameter returns one value: the maximum number of application-defined clipping planes. See glClipPlane. GL_MAX_EVAL_ORDER The params parameter returns one value: the maximum equation order supported by 1-D and 2-D evaluators. See glMap1 and glMap2. GL_MAX_LIGHTS The params parameter returns one value: the maximum number of lights. See glLight. GL_MAX_LIST_NESTING The params parameter returns one value: the maximum recursion depth allowed during display-list traversal. See glCallList. GL_MAX_MODELVIEW_STACK_DEPTH The params parameter returns one value: the maximum supported depth of the modelview matrix stack. See glPushMatrix. GL_MAX_NAME_STACK_DEPTH The params parameter returns one value: the maximum supported depth of the selection name stack. See glPushName. GL_MAX_PIXEL_MAP_TABLE The params parameter returns one value: the maximum supported size of a glPixelMap lookup table. See glPixelMap. GL_MAX_PROJECTION_STACK_DEPTH The params parameter returns one value: the maximum supported depth of the projection matrix stack. See glPushMatrix. GL_MAX_TEXTURE_SIZE The params parameter returns one value: the maximum width or height of any texture image (without borders). See glTexImage1D and glTexImage2D. GL_MAX_TEXTURE_STACK_DEPTH The params parameter returns one value: the maximum supported depth of the texture matrix stack. See glPushMatrix. GL_MAX_VIEWPORT_DIMS The params parameter returns two values: the maximum supported width and height of the viewport. See glViewport. GL_MODELVIEW_MATRIX The params parameter returns 16 values: the modelview matrix on the top of the modelview matrix stack. See glPushMatrix. GL_MODELVIEW_STACK_DEPTH The params parameter returns one value: the number of matrices on the modelview matrix stack. See glPushMatrix. GL_NAME_STACK_DEPTH The params parameter returns one value: the number of names on the selection name stack. See glPushName. GL_NORMAL_ARRAY The params parameter returns a single Boolean value, indicating whether the normal array is enabled. See glNormalPointer. GL_NORMAL_ARRAY_STRIDE The params parameter returns one value, the byte offset between consecutive normals in the normal array. See glNormalPointer. GL_NORMAL_ARRAY_TYPE The params parameter returns one value, the data type of each coordinate in the normal array. See glNormalPointer. GL_NORMALIZE The params parameter returns a single Boolean value indicating whether normals are automatically scaled to unit length after they have been transformed to eye coordinates. See glNormal. GL_PACK_ALIGNMENT The params parameter returns one value: the byte alignment used for writing pixel data to memory. See glPixelStore. GL_PACK_LSB_FIRST The params parameter 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. See glPixelStore. GL_PACK_ROW_LENGTH The params parameter returns one value: the row length used for writing pixel data to memory. See glPixelStore. GL_PACK_SKIP_PIXELS The params parameter returns one value: the number of pixel locations skipped before the first pixel is written into memory. See glPixelStore. GL_PACK_SKIP_ROWS The params parameter returns one value: the number of rows of pixel locations skipped before the first pixel is written into memory. See glPixelStore. GL_PACK_SWAP_BYTES The params parameter returns a single Boolean value indicating whether the bytes of 2-byte and 4-byte pixel indexes and components are swapped before being written to memory. See glPixelStore. GL_PERSPECTIVE_CORRECTION_HINT The params parameter returns one value: a symbolic constant indicating the mode of the perspective correction hint. See glHint. GL_PIXEL_MAP_A_TO_A_SIZE The params parameter returns one value: the size of the alpha-to-alpha pixel-translation table. See glPixelMap. GL_PIXEL_MAP_B_TO_B_SIZE The params parameter returns one value: the size of the blue-to-blue pixel-translation table. See glPixelMap. GL_PIXEL_MAP_G_TO_G_SIZE The params parameter returns one value: the size of the green-to-green pixel-translation table. See glPixelMap. GL_PIXEL_MAP_I_TO_A_SIZE The params parameter returns one value: the size of the index-to-alpha pixel translation table. See glPixelMap. GL_PIXEL_MAP_I_TO_B_SIZE The params parameter returns one value: the size of the index-to-blue pixel translation table. See glPixelMap. GL_PIXEL_MAP_I_TO_G_SIZE The params parameter returns one value: the size of the index-to-green pixel-translation table. See glPixelMap. GL_PIXEL_MAP_I_TO_I_SIZE The params parameter returns one value: the size of the index-to-index pixel-translation table. See glPixelMap. GL_PIXEL_MAP_I_TO_R_SIZE The params parameter returns one value: the size of the index-to-red pixel-translation table. See glPixelMap. GL_PIXEL_MAP_R_TO_R_SIZE The params parameter returns one value: the size of the red-to-red pixel-translation table. See glPixelMap. GL_PIXEL_MAP_S_TO_S_SIZE The params parameter returns one value: the size of the stencil-to-stencil pixel translation table. See glPixelMap. GL_POINT_SIZE The params parameter returns one value: the point size as specified by glPointSize. GL_POINT_SIZE_GRANULARITY The params parameter returns one value: the size difference between adjacent supported sizes for antialiased points. See glPointSize. GL_POINT_SIZE_RANGE The params parameter returns two values: the smallest and largest supported sizes for antialiased points. See glPointSize. GL_POINT_SMOOTH The params parameter returns a single Boolean value indicating whether antialiasing of points is enabled. See glPointSize. GL_POINT_SMOOTH_HINT The params parameter returns one value: a symbolic constant indicating the mode of the point antialiasing hint. See glHint. GL_POLYGON_MODE The params parameter returns two values: symbolic constants indicating whether front-facing and back-facing polygons are rasterized as points, lines, or filled polygons. See glPolygonMode. GL_POLYGON_OFFSET_FACTOR The params parameter 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. See glPolygonOffset. GL_POLYGON_OFFSET_UNITS The params parameter 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. See glPolygonOffset. GL_POLYGON_OFFSET_FILL The params parameter returns a single Boolean value indicating whether polygon offset is enabled for polygons in fill mode. See glPolygonOffset. GL_POLYGON_OFFSET_LINE The params parameter returns a single Boolean value indicating whether polygon offset is enabled for polygons in line mode. See glPolygonOffset. GL_POLYGON_OFFSET_POINT The params parameter returns a single Boolean value indicating whether polygon offset is enabled for polygons in point mode. See glPolygonOffset. GL_POLYGON_SMOOTH The params parameter returns a single Boolean value indicating whether antialiasing of polygons is enabled. See glPolygonMode. GL_POLYGON_SMOOTH_HINT The params parameter returns one value: a symbolic constant indicating the mode of the polygon antialiasing hint. See glHint. GL_POLYGON_STIPPLE The params parameter returns a single Boolean value indicating whether stippling of polygons is enabled. See glPolygonStipple. GL_PROJECTION_MATRIX The params parameter returns 16 values: the projection matrix on the top of the projection matrix stack. See glPushMatrix. GL_PROJECTION_STACK_DEPTH The params parameter returns one value: the number of matrices on the projection matrix stack. See glPushMatrix. GL_READ_BUFFER The params parameter returns one value: a symbolic constant indicating which color buffer is selected for reading. See glReadPixels and glAccum. GL_RED_BIAS The params parameter returns one value: the red bias factor used during pixel transfers. See glPixelTransfer. GL_RED_BITS The params parameter returns one value: the number of red bitplanes in each color buffer. GL_RED_SCALE The params parameter returns one value: the red scale factor used during pixel transfers. See glPixelTransfer. GL_RENDER_MODE The params parameter returns one value: a symbolic constant indicating whether OpenGL is in render, select, or feedback mode. See glRenderMode. GL_RGBA_MODE The params parameter returns a single Boolean value indicating whether OpenGL is in RGBA mode (TRUE) or color-index mode (FALSE). See glColor. GL_SCISSOR_BOX The params parameter returns four values: the x and y window coordinates of the scissor box, followed by its width and height. See glScissor. GL_SCISSOR_TEST The params parameter returns a single Boolean value indicating whether scissoring is enabled. See glScissor. GL_SHADE_MODEL The params parameter returns one value: a symbolic constant indicating whether the shading mode is flat or smooth. See glShadeModel. GL_STENCIL_BITS The params parameter returns one value: the number of bitplanes in the stencil buffer. GL_STENCIL_CLEAR_VALUE The params parameter returns one value: the index to which the stencil bitplanes are cleared. See glClearStencil. GL_STENCIL_FAIL The params parameter returns one value: a symbolic constant indicating what action is taken when the stencil test fails. See glStencilOp. GL_STENCIL_FUNC The params parameter returns one value: a symbolic constant indicating what function is used to compare the stencil reference value with the stencil buffer value. See glStencilFunc. GL_STENCIL_PASS_DEPTH_FAIL The params parameter returns one value: a symbolic constant indicating what action is taken when the stencil test passes, but the depth test fails. See glStencilOp. GL_STENCIL_PASS_DEPTH_PASS The params parameter returns one value: a symbolic constant indicating what action is taken when the stencil test passes and the depth test passes. See glStencilOp. GL_STENCIL_REF The params parameter returns one value: the reference value that is compared with the contents of the stencil buffer. See glStencilFunc. GL_STENCIL_TEST The params parameter returns a single Boolean value indicating whether stencil testing of fragments is enabled. See glStencilFunc and glStencilOp. GL_STENCIL_VALUE_MASK The params parameter returns one value: the mask that is used to mask both the stencil reference value and the stencil buffer value before they are compared. See glStencilFunc. GL_STENCIL_WRITEMASK The params parameter returns one value: the mask that controls writing of the stencil bitplanes. See glStencilMask. GL_STEREO The params parameter returns a single Boolean value indicating whether stereo buffers (left and right) are supported. GL_SUBPIXEL_BITS The params parameter returns one value: an estimate of the number of bits of subpixel resolution that are used to position rasterized geometry in window coordinates. GL_TEXTURE_1D The params parameter returns a single Boolean value indicating whether 1-D texture mapping is enabled. See glTexImage1D. GL_TEXTURE_2D The params parameter returns a single Boolean value indicating whether 2-D texture mapping is enabled. See glTexImage2D. GL_TEXTURE_COORD_ARRAY The params parameter returns a single Boolean value indicating whether the texture coordinate array is enabled. See glTexCoordPointer. GL_TEXTURE_COORD_ARRAY_SIZE The params parameter returns one value, the number of coordinates per element in the texture coordinate array. See glTexCoordPointer. GL_TEXTURE_COORD_ARRAY_STRIDE The params parameter returns one value, the byte offset between consecutive elements in the texture coordinate array. See glTexCoordPointer. GL_TEXTURE_COORD_ARRAY_TYPE The params parameter params returns one value, the data type of the coordinates in the texture coordinate array. See glTexCoordPointer. GL_TEXTURE_ENV_COLOR The params parameter returns four values: the red, green, blue, and alpha values of the texture environment 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 glTexEnv. GL_TEXTURE_ENV_MODE The params parameter returns one value: a symbolic constant indicating which texture environment function is currently selected. See glTexEnv. GL_TEXTURE_GEN_Q The params parameter returns a single Boolean value indicating whether automatic generation of the Q texture coordinate is enabled. See glTexGen. GL_TEXTURE_GEN_R The params parameter returns a single Boolean value indicating whether automatic generation of the R texture coordinate is enabled. See glTexGen. GL_TEXTURE_GEN_S The params parameter returns a single Boolean value indicating whether automatic generation of the S texture coordinate is enabled. See glTexGen. GL_TEXTURE_GEN_T The params parameter returns a single Boolean value indicating whether automatic generation of the T texture coordinate is enabled. See glTexGen. GL_TEXTURE_MATRIX The params parameter returns 16 values: the texture matrix on the top of the texture matrix stack. See glPushMatrix. GL_TEXTURE_STACK_DEPTH The params parameter returns one value: the number of matrices on the texture matrix stack. See glPushMatrix. GL_UNPACK_ALIGNMENT The params parameter returns one value: the byte alignment used for reading pixel data from memory. See glPixelStore. GL_UNPACK_LSB_FIRST The params parameter 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. See glPixelStore. GL_UNPACK_ROW_LENGTH The params parameter returns one value: the row length used for reading pixel data from memory. See glPixelStore. GL_UNPACK_SKIP_PIXELS The params parameter returns one value: the number of pixel locations skipped before the first pixel is read from memory. See glPixelStore. GL_UNPACK_SKIP_ROWS The params parameter returns one value: the number of rows of pixel locations skipped before the first pixel is read from memory. See glPixelStore. GL_UNPACK_SWAP_BYTES The params parameter returns a single Boolean value indicating whether the bytes of 2-byte and 4-byte pixel indexes and components are swapped after being read from memory. See glPixelStore. GL_VERTEX_ARRAY The params parameter returns a single Boolean value indicating whether the vertex array is enabled. See glVertexPointer. GL_VERTEX_ARRAY_SIZE The params parameter returns one value, the number of coordinates per vertex in the vertex array. See glVertexPointer. GL_VERTEX_ARRAY_STRIDE The params parameter returns one value, the byte offset between consecutive vertexes in the vertex array. See glVertexPointer. GL_VERTEX_ARRAY_TYPE The params parameter returns one value, the data type of each coordinate in the vertex array. See glVertexPointer. GL_VIEWPORT The params parameter returns four values: the x and y window coordinates of the viewport, followed by its width and height. See glViewport. GL_ZOOM_X The params parameter returns one value: the x pixel zoom factor. See glPixelZoom. GL_ZOOM_Y The params parameter returns one value: the y pixel zoom factor. See glPixelZoom. params
Returns the value or values of the specified parameter.
Remarks
These four functions return values for simple state variables in OpenGL. The pname parameter 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 from the state variable value being requested. If you call glGetBooleanv, a floating-point or integer value is converted to GL_FALSE if and only if it is zero. Otherwise, it is converted to GL_TRUE.
If you call glGetIntegerv, 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 you call glGetFloatv or glGetDoublev, Boolean values are returned as GL_TRUE or GL_FALSE, and integer values are converted to floating-point values.
You can query many of the Boolean parameters more easily with glIsEnabled.
Error Codes
The following are the error codes generated and their conditions.
| Error code | Condition |
|---|---|
| GL_INVALID_ENUM | pname was not an accepted value. |
| GL_INVALID_OPERATION | glGet was called between a call to glBegin and the corresponding call to glEnd. |
Requirements
** Windows NT/2000:** Requires Windows NT 3.5 or later.
** Windows 95/98:** Requires Windows 95 or later. Available as a redistributable for Windows 95.
** Header:** Declared in Gl.h.
** Library:** Use Opengl32.lib.
See Also
glAccum, glAlphaFunc, glBegin, glBlendFunc, glCallList, glClearAccum, glClearColor, glClearDepth, glClearIndex, glClearStencil, glClipPlane, glColor, glColorMask, glColorMaterial, glCullFace, glDepthFunc, glDepthMask, glDepthRange, glDrawBuffer, glEdgeFlag, glEnd, glFog, glFrontFace, glGetClipPlane, glGetError, glGetLight, glGetMap, glGetMaterial, glGetPixelMap, glGetPolygonStipple, glGetString, glGetTexEnv, glGetTexGen, glGetTexImage, glGetTexLevelParameter, glGetTexParameter, glHint, glIndex, glIndexMask, glIsEnabled, glLight, glLightModel, glLineStipple, glLineWidth, glListBase, glLogicOp, glMap1, glMap2, glMapGrid, glMatrixMode, glNewList, glNormal, glPixelMap, glPixelStore, glPixelTransfer, glPixelZoom, glPointSize, glPolygonMode, glPolygonStipple, glPushAttrib, glPushMatrix, glPushName, glRasterPos, glReadPixels, glScissor, glShadeModel, glStencilFunc, glStencilMask, glStencilOp, glTexCoord, glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glViewport