glTexParameterf

glTexParameter: man2/glTexParameter.xml

Texture mapping is a technique that applies an image onto an object's surface as if the image were a decal or cellophane shrink-wrap. The image is created in texture space, with an ( s, t ) coordinate system. A texture is a one- or two-dimensional image and a set of parameters that determine how samples are derived from the image. glTexParameter assigns the value or values in params to the texture parameter specified as pname. target defines the target texture, either GL_TEXTURE_1D, GL_TEXTURE_2D, or GL_TEXTURE_3D. The following symbols are accepted in pname :

GL_TEXTURE_3D, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_CLAMP_TO_EDGE, GL_TEXTURE_BASE_LEVEL, and GL_TEXTURE_MAX_LEVEL are available only if the GL version is 1.2 or greater. GL_CLAMP_TO_BORDER is available only if the GL version is 1.3 or greater. GL_MIRRORED_REPEAT, GL_TEXTURE_COMPARE_MODE, GL_TEXTURE_COMPARE_FUNC, GL_DEPTH_TEXTURE_MODE, and GL_GENERATE_MIPMAP are available only if the GL version is 1.4 or greater. GL_TEXTURE_COMPARE_FUNC allows the following additional comparison modes only if the GL version is 1.5 or greater: GL_LESS, GL_GREATER, GL_EQUAL, GL_NOTEQUAL, GL_ALWAYS, and GL_NEVER. Suppose that a program has enabled texturing (by calling glEnable with argument GL_TEXTURE_1D, GL_TEXTURE_2D, or GL_TEXTURE_3D ) 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, glTexImage3D, 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. For OpenGL versions 1.3 and greater, or when the ARB_multitexture extension is supported, glTexParameter specifies the texture parameters for the active texture unit, specified by calling glActiveTexture.