glTexImage3DEXT(3G)

glTexImage3DEXT - specify a three-dimensional texture image

As shipped in IRIX 6.5.22. Last changed in IRIX 6.5.15.

NAME
     glTexImage3DEXT - specify a three-dimensional texture image


C SPECIFICATION
     void glTexImage3DEXT( GLenum target,
                           GLint level,
                           GLenum internalformat,
                           GLsizei width,
                           GLsizei height,
                           GLsizei depth,
                           GLint border,
                           GLenum format,
                           GLenum type,
                           const GLvoid *pixels )


PARAMETERS
     target          Specifies the target texture.  Must be GL_TEXTURE_3D_EXT
                     or GL_PROXY_TEXTURE_3D_EXT.

     level           Specifies the level-of-detail number.  Level 0 is the
                     base image level.  Level n is the nth mipmap reduction
                     image.

     internalformat  Specifies the internal storage format of the texture
                     image.  it must be one of the following symbolic
                     constants:  GL_ALPHA, GL_ALPHA4_EXT, GL_ALPHA8_EXT,
                     GL_ALPHA12_EXT, GL_ALPHA16_EXT, GL_LUMINANCE,
                     GL_LUMINANCE4_EXT, GL_LUMINANCE8_EXT, GL_LUMINANCE12_EXT,
                     GL_LUMINANCE16_EXT, GL_LUMINANCE_ALPHA,
                     GL_LUMINANCE4_ALPHA4_EXT, GL_LUMINANCE6_ALPHA2_EXT,
                     GL_LUMINANCE8_ALPHA8_EXT, GL_LUMINANCE12_ALPHA4_EXT,
                     GL_LUMINANCE12_ALPHA12_EXT, GL_LUMINANCE16_ALPHA16_EXT,
                     GL_INTENSITY_EXT, GL_INTENSITY4_EXT, GL_INTENSITY8_EXT,
                     GL_INTENSITY12_EXT, GL_INTENSITY16_EXT, GL_RGB,
                     GL_RGB2_EXT, GL_RGB4_EXT, GL_RGB5_EXT, GL_RGB8_EXT,
                     GL_RGB10_EXT, GL_RGB12_EXT, GL_RGB16_EXT, GL_RGBA,
                     GL_RGBA2_EXT, GL_RGBA4_EXT, GL_RGB5_A1_EXT, GL_RGBA8_EXT,
                     GL_RGB10_A2_EXT, GL_RGBA12_EXT, GL_RGBA16_EXT,
                     GL_DUAL_ALPHA4_SGIS, GL_DUAL_ALPHA8_SGIS,
                     GL_DUAL_ALPHA12_SGIS, GL_DUAL_ALPHA16_SGIS,
                     GL_DUAL_LUMINANCE4_SGIS, GL_DUAL_LUMINANCE8_SGIS,
                     GL_DUAL_LUMINANCE12_SGIS, GL_DUAL_LUMINANCE16_SGIS,
                     GL_DUAL_INTENSITY4_SGIS, GL_DUAL_INTENSITY8_SGIS,
                     GL_DUAL_INTENSITY12_SGIS, GL_DUAL_INTENSITY16_SGIS,
                     GL_DUAL_LUMINANCE_ALPHA4_SGIS,
                     GL_DUAL_LUMINANCE_ALPHA8_SGIS, GL_QUAD_ALPHA4_SGIS,
                     GL_QUAD_ALPHA8_SGIS, GL_QUAD_LUMINANCE4_SGIS,
                     GL_QUAD_LUMINANCE8_SGIS, GL_QUAD_INTENSITY4_SGIS, or
                     GL_QUAD_INTENSITY8_SGIS.

     width           Specifies the width of the texture image.  Must be
                     2**n+2*border for some integer n.

     height          Specifies the height of the texture image.  Must be
                     2**m+I*border for some integer m, where I is 2 when
                     GL_INTERLACE_SGIX is disabled, and 1 otherwise.

     depth           Specifies the depth of the texture image.  Must be
                     2**l+2*border for some integer l.

     border          Specifies the width of the border.  Must be either 0 or
                     1.

     format          Specifies the format of the pixel data.  The following
                     symbolic values are accepted:  GL_COLOR_INDEX, GL_RED,
                     GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA,
                     GL_ABGR_EXT, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.

     type            Specifies the data type of the pixel data.  The following
                     symbolic values are accepted:  GL_UNSIGNED_BYTE, GL_BYTE,
                     GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
                     GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2_EXT,
                     GL_UNSIGNED_SHORT_4_4_4_4_EXT,
                     GL_UNSIGNED_SHORT_5_5_5_1_EXT,
                     GL_UNSIGNED_INT_8_8_8_8_EXT, and
                     GL_UNSIGNED_INT_10_10_10_2_EXT.

     pixels          Specifies a pointer to the image data in memory.


DESCRIPTION
     Texturing maps a portion of a specified texture image onto each graphical
     primitive for which texturing is enabled.  Three-dimensional texturing is
     enabled and disabled using glEnable and glDisable with argument
     GL_TEXTURE_3D_EXT.

     Texture images are defined with glTexImage3DEXT. The arguments describe
     the parameters of the texture image, such as height, width, depth, width
     of the border, level-of-detail number (see glTexParameter), and the
     internal resolution and format used to store the image.  The last three
     arguments describe the way the image is represented in memory, and they
     are identical to the pixel formats used for glDrawPixels.

     If target is GL_PROXY_TEXTURE_3D_EXT no data is read from pixels,  but
     all of the texture image state is recalculated, checked for consistency,
     and checked against the implementation's capabilities.  If the
     implementation cannot handle a texture of the requested texture size, it
     will set all of the texture image state to 0 (GL_TEXTURE_WIDTH,
     GL_TEXTURE_HEIGHT, GL_TEXTURE_BORDER, GL_TEXTURE_COMPONENTS,
     GL_TEXTURE_RED_SIZE_EXT, GL_TEXTURE_GREEN_SIZE_EXT,
     GL_TEXTURE_BLUE_SIZE_EXT, GL_TEXTURE_ALPHA_SIZE_EXT,
     GL_TEXTURE_LUMINANCE_SIZE_EXT, and GL_TEXTURE_INTENSITY_SIZE_EXT), but no
     error will be generated.

     If target is GL_TEXTURE_3D_EXT, data is read from pixels as a sequence of
     signed or unsigned bytes, shorts, or longs, or single-precision
     floating-point values, depending on type. These values are grouped into
     sets of one, two, three, or four values, depending on format, to form
     elements.  (Note that if type is set to GL_UNSIGNED_BYTE_3_3_2_EXT,
     GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT,
     GL_UNSIGNED_INT_8_8_8_8_EXT, or GL_UNSIGNED_INT_10_10_10_2_EXT then it is
     a special case in which all the elements of each group are packed into a
     single unsigned byte, unsigned short, or unsigned int. This is described
     in glDrawPixels.)

     The first element corresponds to the lower-left-rear corner of the
     texture volume.  Subsequent elements progress left-to-right through the
     remaining texels in the lowest-rear row of the texture volume, then in
     successively higher rows of the rear 2D slice of the texture volume, then
     in successively closer 2D slices of the texture volume.  The final
     element corresponds to the upper-right-front corner of the texture
     volume.

     When GL_INTERLACE_SGIX is enabled, only rows (0,2,4,...) of each S-T
     slice (where the border is considered part of the slice) are defined.
     Rows (1,3,5,...) are left undefined and can only be defined using
     glTexSubImage3DEXT or glCopyTexSubImage3DEXT.  Note, that when
     GL_INTERLACE_SGIX is enabled the total height (i.e., the height of
     interior texture image plus twice the border) of the defined texture is
     2*height.

     Each element of pixels is converted to an RGBA element according to
     format, as detailed below.  Except for GL_COLOR_INDEX, after the
     conversion to RGBA, each component is multiplied by the signed scale
     factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the
     range [0,1], where c is RED, GREEN, BLUE, or ALPHA, respectively (see
     glPixelTransfer).

     According to format, the conversion to RGBA is as follows:

     GL_COLOR_INDEX
               Each element is a single value, a color index. It is converted
               to fixed point (with an unspecified number of zero bits to the
               right of the binary point), shifted left or right depending on
               the value and sign of GL_INDEX_SHIFT, and added to
               GL_INDEX_OFFSET (see glPixelTransfer). The resulting index is
               converted to a set of color components using the
               GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B,
               and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].

     GL_RED    Each element is a single red component. It is converted to
               floating point and assembled into an RGBA element by attaching
               0.0 for green and blue, and 1.0 for alpha.

     GL_GREEN  Each element is a single green component. It is converted to
               floating point and assembled into an RGBA element by attaching
               0.0 for red and blue, and 1.0 for alpha.

     GL_BLUE   Each element is a single blue component. It is converted to
               floating point and assembled into an RGBA element by attaching
               0.0 for red and green, and 1.0 for alpha.

     GL_ALPHA  Each element is a single alpha component. It is converted to
               floating point and assembled into an RGBA element by attaching
               0.0 for red, green, and blue.

     GL_RGB    Each element is an RGB triple.  It is converted to floating
               point and assembled into an RGBA element by attaching 1.0 for
               alpha.  (see  glPixelTransfer).

     GL_RGBA,

     GL_ABGR_EXT
               Each element contains all four components; for GL_RGBA, the red
               component is first, followed by green, then blue, and then
               alpha; for GL_ABGR_EXT the order is alpha, blue, green, and
               then red.

     GL_LUMINANCE
               Each element is a single luminance value.  It is converted to
               floating point, then assembled into an RGBA element by
               replicating the luminance value three times for red, green, and
               blue and attaching 1.0 for alpha.

     GL_LUMINANCE_ALPHA
               Each element is a luminance/alpha pair.  It is converted to
               floating point, then assembled into an RGBA element by
               replicating the luminance value three times for red, green, and
               blue.

     Please refer to the glDrawPixels reference page for a description of the
     acceptable values for the type parameter.

     An application may desire that the texture be stored at a certain
     resolution, or that it be stored in a certain format. This resolution and
     format can be requested by internalformat, but the implementation may not
     support that resolution (The formats of GL_LUMINANCE, GL_LUMINANCE_ALPHA,
     GL_RGB, and GL_RGBA must be supported.)  When a resolution and storage
     format is specified, the implementation will update the texture state to
     provide the best match to the requested resolution. The
     GL_PROXY_TEXTURE_3D_EXT target can be used to try a resolution and
     format.  The implementation will compute its best match for the requested
     storage resolution and format; this state can then be queried using
     glGetTexLevelParameter.

     A one-component texture image uses only the red component of the RGBA
     color extracted from pixels. A two-component image uses the R and A
     values.  A three-component image uses the R, G, and B values.  A four-
     component image uses all of the RGBA components.

     The mapping of components from the canonical RGBA to the internal storage
     formats that begin with GL_DUAL_ and GL_QUAD_ needs to be clarified.
     There are three cases.  The first case is for the GL_DUAL_ formats that
     are groups of GL_ALPHA, GL_LUMINANCE, and GL_INTENSITY.  The R value goes
     to the first group while the A value goes to the second group.  The
     second case is for the GL_DUAL_ formats that are groups of
     GL_LUMINANCE_ALPHA.  The R and G values go to the first group while the B
     and A values go to the second group.  The third case is for the GL_QUAD_
     formats.  The R value goes to the first group, the G value to the second
     group, the B value to the third group, and the A value to the fourth
     group.

NOTES
     Texturing has no effect in color index mode.

     The texture image can be represented by the same data formats and types
     as the pixels in a glDrawPixels command, except that formats
     GL_STENCIL_INDEX and GL_DEPTH_COMPONENT cannot be used, and type
     GL_BITMAP cannot be used.  glPixelStore and glPixelTransfer modes affect
     texture images in exactly the way they affect glDrawPixels.

     A texture image with zero height, width, or depth indicates the null
     texture.  If the null texture is specified for level-of-detail 0, it is
     as if texturing were disabled.

     glTexImage3DEXT is part of the EXT_texture3d extension.

     If type is set to GL_UNSIGNED_BYTE_3_3_2_EXT,
     GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT,
     GL_UNSIGNED_INT_8_8_8_8_EXT, or GL_UNSIGNED_INT_10_10_10_2_EXT and the
     EXT_packed_pixels extension is not supported then a GL_INVALID_ENUM error
     is generated.

     See glIntro for more information on using extensions.

ERRORS
     GL_INVALID_ENUM is generated when target is not an accepted value.

     GL_INVALID_ENUM is generated when format is not an accepted value.

     GL_INVALID_ENUM is generated when type is not an accepted value.

     GL_INVALID_VALUE is generated if level is less than zero or greater than
     log (max), where max is the returned value of GL_MAX_3D_TEXTURE_SIZE_EXT.
        2

     GL_INVALID_VALUE is generated if internalformat is not an accepted value.

     GL_INVALID_VALUE is generated if width, height, or depth is less than
     zero or greater than GL_MAX_3D_TEXTURE_SIZE_EXT, when width, or depth
     cannot be represented as 2**k+2*border for some integer k, or when height
     cannot be represented as 2**k+I*border, where I is 2 when
     GL_INTERLACE_SGIX is disabled and 1 otherwise.

     GL_INVALID_VALUE is generated if border is not 0 or 1.

     GL_INVALID_OPERATION is generated if glTexImage3DEXT is executed between
     the execution of glBegin and the corresponding execution of glEnd.

     GL_INVALID_VALUE is generated if the implementation cannot accomodate a
     texture of the size requested.

ASSOCIATED GETS
     glGetTexImage
     glIsEnabled with argument GL_TEXTURE_3D_EXT
     glGetTexLevelParameter with a first argument of GL_PROXY_TEXTURE_3D_EXT
     and a third argument of GL_TEXTURE_RED_SIZE_EXT,
     GL_TEXTURE_GREEN_SIZE_EXT, GL_TEXTURE_BLUE_SIZE_EXT,
     GL_TEXTURE_ALPHA_SIZE_EXT, GL_TEXTURE_LUMINANCE_SIZE_EXT,
     GL_TEXTURE_INTENSITY_SIZE_EXT, GL_TEXTURE_WIDTH, GL_TEXTURE_HEIGHT,
     GL_TEXTURE_DEPTH_EXT, GL_TEXTURE_BORDER, or GL_TEXTURE_COMPONENTS.



MACHINE DEPENDENCIES
     RealityEngine, RealityEngine2, and VTX systems do not support color
     matrix transformations on images as they are loaded to or read back from
     texture memory.

     RealityEngine, RealityEngine2, and VTX systems do not support convolving
     images as they are loaded into texture memory.

     RealityEngine, RealityEngine2, and VTX systems do not support histogram
     or minmax operations on images as they are being loaded into texture
     memory.

     The SGIX_interlace extension is supported only on InfiniteReality
     systems, on RealityEngine, RealityEngine2, and VTX systems, on Octane2
     VPro systems, and on O2 systems.

     The EXT_packed_pixels extension is not supported on RealityEngine,
     RealityEngine2, and VTX systems.

     On High Impact and Maximum Impact systems the number of bits per
     component, represented internally, is the same for all components and
     will be 4, 8, or 12 bits per component. All specified internal formats
     will receive an equal or greater representation in this scheme, up to the
     12-bit limit.  High Impact and Maximum Impact on Indigo2 systems do not
     support texture internal formats of the type GL_INTENSITY or GL_ALPHA,
     although High Impact and Maximum Impact on Octane systems do support
     these types.

     High Impact and Maximum Impact on Indigo2 systems without the TRAM option
     card support 4 bits per component for GL_RGB and GL_RGBA, 4/8 bits per
     component for GL_LUMINANCE_ALPHA, and 4/8/12 bits per component for
     GL_LUMINANCE.

     On RealityEngine, RealityEngine2, and VTX systems, the following
     restrictions apply to 3D texturing:

          1.  The texture environment must be defined and texturing must be
              enabled before loading a texture.

          2.  Texture formats composed only of alpha are not supported.

          3.  Borders are not supported; hence the border width must be 0.

          4.  Proxy textures are not supported.

          5.  3D mipmaps are not supported. Hence, the minifying function must
              be set to GL_NEAREST or GL_LINEAR (see glTexParameter).

          6   3D texturing when rendering to pixmaps is not supported.

          7.  GL_INTERLACE_SGIX is not supported (see glEnable).

     On High Impact and Maximum Impact systems, the following restrictions
     apply to 3D texturing:

          1.  Perspective views are not supported.

          2.  Borders are not supported; hence the border width must be 0.

          3.  3D mipmaps are not supported. Hence, the minifying function must
              be set to GL_NEAREST or GL_LINEAR (see glTexParameter), and the
              level parameter must be 0.

          4.  Textures that have a width of 16 or less will not render
              correctly at the wrap_s boundary.
     On Octane2 VPro systems, 3D mipmapping is not supported.  However, all
     OpenGL state related to the GL_TEXTURE_3D target is correctly error-
     checked and queryable.  For example, an incomplete mipmap stack results
     in disabling 3D texturing, just as if 3D mipmapping were supported.  The
     only restriction is that, during rasterization, only the base level of
     the texture is sampled.  (The GL_TEXTURE_BASE_LEVEL parameter may be used
     to establish the base level of the texture; it need not be level 0.)  For
     3D texturing at rasterization time, the mipmapping forms of the
     GL_TEXTURE_MIN_FILTER parameter are synonymous with the equivalent non-
     mipmapping form.

     Texture borders are not supported on InfiniteReality systems, so the
     border width should always be zero.  Applications should use the texture
     wrap mode GL_CLAMP_TO_EDGE_SGIS to obtain behavior similar to that of
     borders.

     The SGIS_texture_select extension is supported only on InfiniteReality
     systems, High Impact and Maximum Impact on Octane systems, and High
     Impact and Maximum Impact on Indigo2 systems with the TRAM option card.

     On InfiniteReality, RealityEngine, RealityEngine2, and VTX systems, High
     Impact and Maximum Impact systems, and Octane2 VPro systems, texture
     objects (see glBindTextureEXT) are significantly faster than display-
     listed textures, and therefore are recommended for managing texture
     memory.


SEE ALSO
     glDrawPixels, glFog, glPixelStore, glPixelTransfer, glTexEnv, glTexGen,
     glTexImage1D, glTexImage2D, glTexParameter,