HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 453

Chapter 18 T glTexParameter Notes Suppose that a program has enabled texturing (by calling glEnable with argument GL_TEXTURE_1D or GL_TEXTURE_2D) and has set GL_TEXTURE_MIN_FILTER to one of the functions that requires a mipmap. If either the dimensions of the texture images currently defined (with previous calls to glTexImage1D, glTexImage2D, glCopyTexImage1D, or glCopyTexImage2D) do not follow the proper sequence for mipmaps (described above), or there are fewer texture images defined than are needed, or the set of texture images have differing numbers of texture components, then it is as if texture mapping were disabled. Linear filtering accesses the four nearest texture elements only in 2D textures. In 1D textures, linear filtering accesses the two nearest texture elements. In 3D textures, linear filtering accesses the eight nearest texture elements. The GL_CLAMP_TO_BORDER_EXT param to GL_WRAP_S, GL_WRAP_T, and GL_WRAP_R_EXT is only supported if the extension GL_EXT_texture_border_clamp is supported. The GL_CLAMP_TO_EDGE_EXT param to GL_WRAP_S, GL_WRAP_T, and GL_WRAP_R_EXT is only supported if the extension GL_EXT_texture_edge_clamp is supported. GL_TEXTURE_WRAP_R_EXT and the target GL_TEXTURE_3D_EXT are only supported if the extension GL_EXT_texture3D is supported. GL_GENERATE_MIPMAP_EXTis only supported if the extension GL_EXT_generate_mipmap is supported. GL_TEXTURE_COMPARE_EXT and GL_TEXTURE_COMPARE_OPERATOR_EXT are only supported if the extension GL_EXT_shadow is supported. Errors • GL_INVALID_ENUM is generated if target or pname is not one of the accepted defined values. • GL_INVALID_ENUM is generated if params should have a defined constant value (based on the value of pname) and does not. • GL_INVALID_OPERATION is generated if glTexParameter is executed between the execution of glBegin and the corresponding execution of glEnd. Associated Gets glGetTexParameter glGetTexLevelParameter See Also glBindTexture, glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, 453