HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 38

B gluBuild2DMipmaps gluBuild2DMipmaps gluBuild2DMipmaps: create 2D mipmaps. C Specification GLint gluBuild2DMipmaps( GLenum target, GLint component, GLsizei width, GLsizei height, GLenum format, GLenum type, const void *data) Parameters target component target width, height format type data Specifies the target texture. Must be GL_TEXTURE_2D. Specifies the number of color components in the texture. Must be 1, 2, 3, or 4. Specifies the target texture. Must be GL_TEXTURE_2D. Specifies the width and height, respectively, 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 gluBuild2DMipmaps builds a series of pre-filtered 2D 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). gluBuild2DMipmaps first check whether width and height of data are both powers of 2. If not, gluBuild2DMipmaps scales a copy of data up or down to the nearest power of 2. This copy is then used as the base for subsequent mipmapping operations. For example, if width is 57 and height is 23, then a copy of data scales up to 64 and down to 16, respectively, before mipmapping takes place. (If width or height is exactly between powers of 2, the copy of data is scaled upward.) 38 Chapter 2