fglGetTexParameter(3G)
fglGetTexParameterfv, fglGetTexParameteriv - return texture parameter values
As shipped in IRIX 6.5.30. Last changed in IRIX 6.5.15.
NAME fglGetTexParameterfv, fglGetTexParameteriv - return texture parameter values FORTRAN SPECIFICATION SUBROUTINE fglGetTexParameterfv( INTEGER*4 target, INTEGER*4 pname, CHARACTER*8 params ) SUBROUTINE fglGetTexParameteriv( INTEGER*4 target, INTEGER*4 pname, CHARACTER*8 params ) PARAMETERS target Specifies the symbolic name of the target texture. GL_TEXTURE_1D, GL_TEXTURE_2D, GL_DETAIL_TEXTURE_2D_SGIS, and GL_TEXTURE_3D_EXT are accepted. pname Specifies the symbolic name of a texture parameter. GL_TEXTURE_MAG_FILTER, GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_TEXTURE_BASE_LEVEL, GL_TEXTURE_MAX_LEVEL, GL_TEXTURE_WRAP_S, GL_TEXTURE_WRAP_T, GL_TEXTURE_WRAP_R, GL_TEXTURE_BORDER_COLOR, GL_DETAIL_TEXTURE_LEVEL_SGIS, GL_DETAIL_TEXTURE_MODE_SGIS, GL_DETAIL_TEXTURE_FUNC_POINTS_SGIS, GL_SHARPEN_TEXTURE_FUNC_POINTS_SGIS, GL_POST_TEXTURE_FILTER_BIAS_SGIX, GL_POST_TEXTURE_FILTER_SCALE_SGIX, GL_TEXTURE_PRIORITY, GL_TEXTURE_PRIORITY_EXT, GL_TEXTURE_RESIDENT, GL_TEXTURE_RESIDENT_EXT, GL_TEXTURE_MIN_LOD_SGIS, GL_TEXTURE_MAX_LOD_SGIS, GL_TEXTURE_BASE_LEVEL_SGIS, GL_TEXTURE_MAX_LEVEL_SGIS, GL_TEXTURE_LOD_BIAS_S_SGIX, GL_TEXTURE_LOD_BIAS_T_SGIX, GL_TEXTURE_LOD_BIAS_R_SGIX, GL_TEXTURE_MAX_CLAMP_S_SGIX, GL_TEXTURE_MAX_CLAMP_T_SGIX, GL_TEXTURE_MAX_CLAMP_R_SGIX, GL_DUAL_TEXTURE_SELECT_SGIS, GL_QUAD_TEXTURE_SELECT_SGIS, GL_TEXTURE_FILTER4_SIZE_SGIS, GL_TEXTURE_CLIPMAP_FRAME_SGIX, GL_TEXTURE_CLIPMAP_CENTER_SGIX, GL_TEXTURE_CLIPMAP_OFFSET_SGIX, GL_TEXTURE_CLIPMAP_VIRTUAL_DEPTH_SGIX, GL_TEXTURE_COMPARE_SGIX, GL_TEXTURE_COMPARE_OPERATOR_SGIX, and GL_SHADOW_AMBIENT_SGIX are accepted. params Returns the texture parameters. DESCRIPTION fglGetTexParameter returns in params the value or values of the texture parameter specified as pname. target defines the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, or GL_TEXTURE_3D to specify one-, two-, or three-dimensional texturing. pname accepts the same symbols as fglTexParameter, with the same interpretations: GL_TEXTURE_MAG_FILTER Returns the single-valued texture magnification filter, a symbolic constant. The initial value is GL_LINEAR. GL_TEXTURE_MIN_FILTER Returns the single-valued texture minification filter, a symbolic constant. The initial value is GL_NEAREST_MIPMAP_LINEAR. GL_TEXTURE_MIN_LOD Returns the single-valued texture minimum level-of-detail value. The initial value is -1000. GL_TEXTURE_MAX_LOD Returns the single-valued texture maximum level-of-detail value. The initial value is 1000. GL_TEXTURE_BASE_LEVEL Returns the single-valued base texture mipmap level. The initial value is 0. GL_TEXTURE_MAX_LEVEL Returns the single-valued maximum texture mipmap array level. The initial value is 1000. GL_TEXTURE_WRAP_S Returns the single-valued wrapping function for texture coordinate s, a symbolic constant. The initial value is GL_REPEAT. GL_TEXTURE_WRAP_T Returns the single-valued wrapping function for texture coordinate t, a symbolic constant. The initial value is GL_REPEAT. GL_TEXTURE_WRAP_R Returns the single-valued wrapping function for texture coordinate r, a symbolic constant. The initial value is GL_REPEAT. GL_TEXTURE_BORDER_COLOR Returns four integer or floating-point numbers that comprise the RGBA color of the texture border. Floating-point values are returned in the range [0, 1]. Integer values are returned as a linear mapping of the internal floating-point representation such that 1.0 maps to the most positive representable integer and -1.0 maps to the most negative representable integer. The initial value is (0, 0, 0, 0). GL_DETAIL_TEXTURE_LEVEL_SGIS Returns an integer specifying the number of levels that separate the level zero image of GL_TEXTURE_2D and the image of GL_DETAIL_TEXTURE_2D_SGIS. See fglDetailTexFuncSGIS for more information. GL_DETAIL_TEXTURE_MODE_SGIS Returns a single enumerated value describing the detail texture mode. See fglDetailTexFuncSGIS. GL_DETAIL_TEXTURE_FUNC_POINTS_SGIS Returns the number of points in the specification of the detail texture scaling function. See fglGetDetailTexFuncSGIS. GL_SHARPEN_TEXTURE_FUNC_POINTS_SGIS Returns the number of points in the specification of the sharpen texture scaling function. See fglGetSharpenTexFuncSGIS. GL_TEXTURE_LOD_BIAS_S_SGIX Returns the single-valued bias amount added to the intermediate texture LOD calculated for the s dimension of target. See fglTexParameter for more information. GL_TEXTURE_LOD_BIAS_T_SGIX Returns the single-valued bias amount added to the intermediate texture LOD calculated for the t dimension of target. See fglTexParameter for more information. GL_TEXTURE_LOD_BIAS_R_SGIX Returns the single-valued bias amount added to the intermediate texture LOD calculated for the r dimension of target. See fglTexParameter for more information. GL_TEXTURE_MAX_CLAMP_S_SGIX Returns the single-valued maximum to which the s coordinate of target is clamped when GL_TEXTURE_WRAP_S is set to GL_CLAMP, GL_CLAMP_TO_EDGE, or GL_CLAMP_TO_BORDER_SGIS. The initial value is 1. GL_TEXTURE_MAX_CLAMP_T_SGIX Returns the single-valued maximum to which the t coordinate of target is clamped when GL_TEXTURE_WRAP_T is set to GL_CLAMP, GL_CLAMP_TO_EDGE, or GL_CLAMP_TO_BORDER_SGIS. The initial value is 1. GL_TEXTURE_MAX_CLAMP_R_SGIX Returns the single-valued maximum to which the r coordinate of target is clamped when GL_TEXTURE_WRAP_R is set to GL_CLAMP, GL_CLAMP_TO_EDGE, or GL_CLAMP_TO_BORDER_SGIS. The initial value is 1. GL_POST_TEXTURE_FILTER_BIAS_SGIX Returns four floating-point numbers that comprise the R, G, B and A bias factors for the texture. See fglTexParameterfv and fglTexParameteriv. GL_POST_TEXTURE_FILTER_SCALE_SGIX Returns four floating-point numbers that comprise the R, G, B and A scale factors for the texture. See fglTexParameterfv and fglTexParameteriv. GL_TEXTURE_PRIORITY Returns the residence priority of the target texture (or the named texture bound to it). The initial value is 1. See fglPrioritizeTextures. GL_TEXTURE_PRIORITY_EXT Returns the residence priority of the target texture (or the named texture bound to it). See fglPrioritizeTexturesEXT. GL_TEXTURE_RESIDENT Returns the residence status of the target texture. If the value returned in params is GL_TRUE, the texture is resident in texture memory. See fglAreTexturesResident. GL_TEXTURE_RESIDENT_EXT Returns the residence status of the target texture. If the value returned in params is GL_TRUE, the texture is resident in texture memory. See fglAreTexturesResidentEXT. GL_TEXTURE_MIN_LOD_SGIS Returns the low end of the LOD clamping range. GL_TEXTURE_MAX_LOD_SGIS Returns the high end of the LOD clamping range. GL_TEXTURE_BASE_LEVEL_SGIS Returns the base level of the mipmap set associated with target. GL_TEXTURE_MAX_LEVEL_SGIS Returns the maximum level of the mipmap set associated with target. GL_DUAL_TEXTURE_SELECT_SGIS Returns the currently selected component group for GL_DUAL_ textures. Its value is 0 or 1. See fglTexParameter, fglTexImage1D, fglTexImage2D and fglTexImage3DEXT. GL_QUAD_TEXTURE_SELECT_SGIS, Returns the currently selected component group for GL_QUAD_ textures. Its value is 0, 1, 2 or 3. See fglTexParameter, fglTexImage1D, fglTexImage2D and fglTexImage3DEXT. GL_TEXTURE_FILTER4_SIZE_SGIS Returns the implementation-dependent texture filtering constant Size used by the SGIS_texture_filter4 extension. For an explanation of this constant, see fglTexFilterFuncSGIS. GL_TEXTURE_CLIPMAP_FRAME_SGIX Returns the size of the texture memory area reserved for paging new texels into a clipmap. The size is expressed as a (floating-point) fraction of half the width of a clipped level. See fglTexParameter for more information. GL_TEXTURE_CLIPMAP_CENTER_SGIX Returns the s and t coordinates of the center of a clipmap's region of interest. See fglTexParameter for more information. GL_TEXTURE_CLIPMAP_OFFSET_SGIX Returns the s and t toroidal offsets for a clipmap. See fglTexParameter for more information. GL_TEXTURE_CLIPMAP_VIRTUAL_DEPTH_SGIX Returns the lod offset, depth, and virtual depth, respectively, for a clipmap. See fglTexParameter for more information. GL_TEXTURE_COMPARE_SGIX Returns a single Boolean value indicating whether the texture comparison operation is enabled. See fglTexParameter for more information. GL_TEXTURE_COMPARE_OPERATOR_SGIX Returns the current texture comparison operator. See fglTexParameter for more information. GL_SHADOW_AMBIENT_SGIX Returns the current ambient lighting coefficient for shadows. See fglTexParameter for more information. NOTES GL_TEXTURE_PRIORITY and GL_TEXTURE_RESIDENT are available only if the GL version is 1.1 or greater. GL_TEXTURE_3D, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_TEXTURE_BASE_LEVEL, GL_TEXTURE_MAX_LEVEL, and GL_TEXTURE_WRAP_R are available only if the GL version is 1.2 or greater. If an error is generated, no change is made to the contents of params. GL_TEXTURE_WRAP_R_EXT is part of the EXT_texture3D extension. GL_DETAIL_TEXTURE_LEVEL_SGIS, GL_DETAIL_TEXTURE_MODE_SGIS, and GL_DETAIL_TEXTURE_FUNC_POINTS_SGIS are part of the SGIS_detail_texture extension. GL_SHARPEN_TEXTURE_FUNC_POINTS_SGIS is part of the SGIS_sharpen_texture extension. GL_POST_TEXTURE_FILTER_BIAS_SGIX and GL_POST_TEXTURE_FILTER_SCALE_SGIX are part of the SGIX_texture_scale_bias extension. GL_TEXTURE_PRIORITY_EXT and GL_TEXTURE_RESIDENT_EXT are part of the EXT_texture_object extension. GL_TEXTURE_MIN_LOD_SGIS GL_TEXTURE_MAX_LOD_SGIS, GL_TEXTURE_BASE_LEVEL_SGIS, and GL_TEXTURE_MAX_LEVEL_SGIS are part of the SGIS_texture_lod extension. GL_DUAL_TEXTURE_SELECT_SGIS and GL_QUAD_TEXTURE_SELECT_SGIS are part of the SGIS_texture_select extension. GL_TEXTURE_FILTER4_SIZE_SGIS is part of the SGIS_texture_filter4 extension. GL_TEXTURE_CLIPMAP_FRAME_SGIX, GL_TEXTURE_CLIPMAP_CENTER_SGIX, GL_TEXTURE_CLIPMAP_OFFSET_SGIX, and GL_TEXTURE_CLIPMAP_VIRTUAL_DEPTH_SGIX are part of the SGIX_clipmap extension. GL_TEXTURE_COMPARE_SGIX and GL_TEXTURE_COMPARE_OPERATOR_SGIX are part of the SGIX_shadow extension. GL_SHADOW_AMBIENT_SGIX is part of the SGIX_shadow_ambient extension. GL_TEXTURE_LOD_BIAS_S_SGIX,GL_TEXTURE_LOD_BIAS_T_SGIX, and GL_TEXTURE_LOD_BIAS_R_SGIX are part of the SGIX_texture_lod_bias extension. GL_TEXTURE_MAX_CLAMP_S_SGIX, GL_TEXTURE_MAX_CLAMP_T_SGIX, and GL_TEXTURE_MAX_CLAMP_R_SGIX are part of the SGIX_texture_coordinate_clamp extension. See fglIntro for more information on using extensions. ERRORS GL_INVALID_ENUM is generated if target or pname is not an accepted value. GL_INVALID_ENUM is generated if pname is GL_TEXTURE_FILTER4_SIZE_SGIS and target is not GL_TEXTURE_1D or GL_TEXTURE_2D. GL_INVALID_OPERATION is generated if fglGetTexParameter is executed between the execution of fglBegin and the corresponding execution of fglEnd. MACHINE DEPENDENCIES The SGIX_clipmap extension is supported only on InfiniteReality systems. The following restrictions apply: 1. For best performance, the ``breakpoint'' clipmap level (B) must be loaded before any other level. The implementation derives the size of the clipmap from the size of this level, so loading this level first permits efficient allocation of texture memory. 2. Clipmaps must be square. 3. GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T must be set to GL_CLAMP_TO_EDGE_SGIS. 4. It is more efficient to set clipmap attributes that affect texture memory allocation (such as GL_TEXTURE_CLIPMAP_FRAME_SGIX) before loading the first level of the clipmap, rather than after loading it. 5. Virtual clipmaps (whose GL_TEXTURE_CLIPMAP_VIRTUAL_DEPTH_SGIX parameters have been defined) use texture memory inefficiently. Each level of detail allocates a region of texture memory the same size as that of a clipped level. Any clipmap whose depth is less than GL_MAX_CLIPMAP_DEPTH_SGIX should avoid this by not specifying GL_TEXTURE_CLIPMAP_VIRTUAL_DEPTH_SGIX parameters. An application can not readback the texture levels whose size is smaller than that of the clipped level. 6. The depth of the virtual clipmap given in GL_TEXTURE_CLIPMAP_VIRTUAL_DEPTH_SGIX must be defined before any texture levels are downloaded, and it can not be changed once it has been specified. If the application tries to change the virtual depth, no action is taken. 7. When using virtual clipmaps, an application should not overcommit texture memory. Doing so will result in undefined behavior. RealityEngine, RealityEngine2, and VTX systems do not support GL_DETAIL_TEXTURE_LEVEL_SGIS correctly. The SGIX_texture_lod_bias extension is supported only on Octane2 VPro systems and InfiniteReality systems. On InfiniteReality systems, if the post-texture filter scale and bias values are set to values other than the defaults, they are limited to the range [0.0, 1.0). (note: this range excludes 1.0.) The SGIX_texture_scale_bias extension is not supported on RealityEngine, RealityEngine2, and VTX systems or on High Impact and Maximum Impact systems. The SGIS_texture_select extension is supported only on InfiniteReality systems, High Impact and Maximum Impact on Octane systems, and High Impact and Maximum Impact on Indigo2 systems with the TRAM option card. The SGIS_texture_filter4 extension is supported only on InfiniteReality systems. On InfiniteReality systems, GL_INVALID_VALUE is generated if the value of the argument n to the command fglTexFilterFuncSGIS does not equal the value of the implementation dependent constant Size, which can be determined by calling fglGetTexParameter with argument GL_TEXTURE_FILTER4_SIZE_SGIS. This restriction will be removed in a future release. GL_TEXTURE_MAX_CLAMP_S_SGIX, GL_TEXTURE_MAX_CLAMP_T_SGIX, and GL_TEXTURE_MAX_CLAMP_S_SGIX are only supported on Octane2 VPro systems. SEE ALSO fglAreTexturesResident, fglPrioritizeTextures, fglTexParameter