C SPECIFICATION

void glTexImage3D(GLenum target, GLint level, GLint internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const GLvoid * data);

PARAMETERS

target

Specifies the target texture. Must be one of GL_TEXTURE_3D, GL_PROXY_TEXTURE_3D, GL_TEXTURE_2D_ARRAY or GL_PROXY_TEXTURE_2D_ARRAY.

level

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

internalFormat

Specifies the number of color components in the texture. Must be one of base internal formats given in Table 1, one of the sized internal formats given in Table 2, or one of the compressed internal formats given in Table 3, below.

width

Specifies the width of the texture image. All implementations support 3D texture images that are at least 16 texels wide.

height

Specifies the height of the texture image. All implementations support 3D texture images that are at least 256 texels high.

depth

Specifies the depth of the texture image, or the number of layers in a texture array. All implementations support 3D texture images that are at least 256 texels deep, and texture arrays that are at least 256 layers deep.

border

This value must be 0.

format

Specifies the format of the pixel data. The following symbolic values are accepted: GL_RED, GL_RG, GL_RGB, GL_BGR, GL_RGBA, and GL_BGRA.

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, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV.

data

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. To enable and disable three-dimensional texturing, call glEnable() and glDisable() with argument GL_TEXTURE_3D.

To define texture images, call glTexImage3D. 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 number of color components provided. The last three arguments describe how the image is represented in memory.

If target is GL_PROXY_TEXTURE_3D, no data is read from data, 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 sets all of the image state to 0, but does not generate an error (see glGetError()). To query for an entire mipmap array, use an image array level greater than or equal to 1.

If target is GL_TEXTURE_3D, data is read from data 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. Each data byte is treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see glPixelStore()).

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer()) while a texture image is specified, data is treated as a byte offset into the buffer object's data store.

The first element corresponds to the lower left corner of the texture image. Subsequent elements progress left-to-right through the remaining texels in the lowest row of the texture image, and then in successively higher rows of the texture image. The final element corresponds to the upper right corner of the texture image.

format determines the composition of each element in data. It can assume one of these symbolic values:

GL_RED

Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1].

GL_RG

Each element is a red and green pair. The GL converts each to floating point and assembles it into an RGBA element by attaching 0 for blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1].

GL_RGB

GL_BGR

Each element is an RGB triple. The GL converts it to floating point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1].

GL_RGBA

GL_BGRA

Each element contains all four components. 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].

If an application wants to store the texture at a certain resolution or in a certain format, it can request the resolution and format with internalFormat. The GL will choose an internal representation that closely approximates that requested by internalFormat, but it may not match exactly. (The representations specified by GL_RED, GL_RG, GL_RGB, and GL_RGBA must match exactly.)

internalFormat may be one of the base internal formats shown in Table 1, below

Table 1. Base Internal Formats

internalFormat may also be one of the sized internal formats shown in Table 2, below

Table 2. Sized Internal Formats

Finally, internalFormat may also be one of the generic or compressed compressed texture formats shown in Table 3 below

Table 3. Compressed Internal Formats

If the internalFormat parameter is one of the generic compressed formats, GL_COMPRESSED_RED, GL_COMPRESSED_RG, GL_COMPRESSED_RGB, or GL_COMPRESSED_RGBA, the GL will replace the internal format with the symbolic constant for a specific internal format and compress the texture before storage. If no corresponding internal format is available, or the GL can not compress that image for any reason, the internal format is instead replaced with a corresponding base internal format.

If the internalFormat parameter is GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8, the texture is treated as if the red, green, blue, or luminance components are encoded in the sRGB color space. Any alpha component is left unchanged. The conversion from the sRGB encoded component c s to a linear component c l is:

c l = { c s 12.92 if c s ≤ 0.04045 ( c s + 0.055 1.055 ) 2.4 if c s > 0.04045

Assume c s is the sRGB component in the range [0,1].

Use the GL_PROXY_TEXTURE_3D target to try out a resolution and format. The implementation will update and recompute its best match for the requested storage resolution and format. To then query this state, call glGetTexLevelParameter(). If the texture cannot be accommodated, texture state is set to 0.

A one-component texture image uses only the red component of the RGBA color extracted from data. 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.

NOTES

The glPixelStore() mode affects texture images.

data may be a null pointer. In this case texture memory is allocated to accommodate a texture of width width, height height, and depth depth. You can then download subtextures to initialize this texture memory. The image is undefined if the user tries to apply an uninitialized portion of the texture image to a primitive.

glTexImage3D specifies the three-dimensional texture for the current texture unit, specified with glActiveTexture().

ASSOCIATED GETS

glGetTexImage()

glGet() with argument GL_PIXEL_UNPACK_BUFFER_BINDING

COPYRIGHT

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2011 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see m[blue]http://oss.sgi.com/projects/FreeB/m[].