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gluBuild1DMipmaps()
NAME
  gluBuild1DMipmaps - builds a 1-D mipmap

SYNOPSIS
  GLint gluBuild1DMipmaps(
	  GLenum target,
	  GLint internalFormat,
	  GLsizei width,
	  GLenum format,
	  GLenum type,
	  const void *data );

PARAMETERS
  target
      Specifies the target texture. Must be GL_TEXTURE_1D.

  internalFormat
      Requests the internal storage format of the texture image. Must be 1,
      2, 3, or 4 or one of the following symbolic constants: GL_ALPHA,
      GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE,
      GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
      GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
      GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12,
      GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8,
      GL_INTENSITY12, GL_INTENSITY16, GL_RGB, GL_R3_G3_B2, GL_RGB4, GL_RGB5,
      GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4,
      GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12 or GL_RGBA16.

  width
      Specifies the width, in pixels, of the texture image.

  format
      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.

  type
      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.

  data
      Specifies a pointer to the image data in memory.

DESCRIPTION
  gluBuild1DMipmaps() builds a series of prefiltered 1-D texture maps of
  decreasing resolutions called a mipmap. This is used for the antialiasing
  of texture mapped primitives.

  A return value of 0 indicates success, otherwise a GLU error code is
  returned (see gluErrorString()).

  Initially, the width of data is checked to see if it is a power of two. If
  not, a copy of data (not data) is scaled up or down to the nearest power of
  two. This copy will be used for subsequent mipmapping operations described
  below. (If width is exactly between powers of 2, then the copy of data will
  scale upwards.) For example, if width is 57 then a copy of data will scale
  up to 64 before mipmapping takes place.

  Then, proxy textures (see glTexImage1D()) are used to determine if the
  implementation can fit the requested texture. If not, width is continually
  halved until it fits.

  Next, a series of mipmap levels is built by decimating a copy of data in
  half until size 1 is reached. At each level, each texel in the halved
  mipmap level is an average of the corresponding two texels in the larger
  mipmap level.

  glTexImage1D() is called to load each of these mipmap levels. Level 0 is a
  copy of data. The highest level is log[2](width). For example, if width is
  64 and the implementation can store a texture of this size, the following
  mipmap levels are built: 64x1, 32x1, 16x1, 8x1, 4x1, 2x1 and 1x1. These
  correspond to levels 0 through 6, respectively.

  See the glTexImage1D() reference page for a description of the acceptable
  values for type. See the glDrawPixels() reference page for a description of
  the acceptable values for data.

NOTES
  Note that there is no direct way of querying the maximum level. This can be
  derived indirectly via glGetTexLevelParameter().  First, query for the
  width actually used at level 0. (The width may not be equal to width since
  proxy textures might have scaled it to fit the implementation.) Then the
  maximum level can be derived from the formula log2(width).

ERRORS
  GLU_INVALID_VALUE is returned if width is < 1.

  GLU_INVALID_ENUM is returned if internalFormat, format or type are not
  legal.

SEE ALSO
  glDrawPixels(3), glTexImage1D(3), , glTexImage2D(3), gluBuild2DMipmaps(3),
  gluErrorString(3), gluScaleImage(3),

Index for Section 3

Alphabetical listing for G

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