HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 36

B gluBuild1DMipmaps gluBuild1DMipmaps gluBuild1DMipmaps: create 1D mipmaps. C Specification GLint gluBuild1DMipmaps( GLenum target, GLint component, GLsizei width, GLenum format, GLenum type, const void *data) Parameters target component width format type data Specifies the target texture. Must be GL_TEXTURE_1D. Specifies the number of color components in the texture. Must be 1, 2, 3, or 4. Specifies the width of the texture image. Specifies the format of the pixel data. Must be one of GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA. Specifies the data type for data. Must be one of GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, or GL_FLOAT. Specifies a pointer to the image data in memory. Description gluBuild1DMipmaps builds a series of pre-filtered 1D texture maps of decreasing resolution. Mipmaps can be used so that textures don't appear aliased. A return value of 0 indicates success. Otherwise a GLU error code is returned (see gluErrorString). gluBuild1DMipmaps first checks whether the width of data is a power of 2. If not, it scales a copy of data (up or down) to the nearest power of two. This copy is used as the base for subsequent mipmapping operations. For example, if width is 57, a copy of data scales up to 64 before mipmapping takes place. (If width is exactly between powers of 2, the copy of data is scaled upward.) If the GL version is 1.1 or greater, gluBuild1DMipmaps uses proxy textures (see glTexImage1D) to determine if the implementation can store the requested texture in texture memory. If there isn't enough room, width is halved (and halved again) until it fits. 36 Chapter 2