glTexImage3DEXT

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.; Specifies the number of color components in the texture. 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_R3_G3_B2, GL_RGB, 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. Additionally, if the extension GL_EXT_shadow is supported, may be one of the symbolic constants GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16_EXT, GL_DEPTH_COMPONENT24_EXT, or GL_DEPTH_COMPONENT32_EXT.
width: Specifies the width of the texture image. Must be 2ⁿ + 2border for some integer n.
height: Specifies the height of the texture image. Must be 2^m + 2 border for some integer m.
depth: Specifies the depth of the texture image. Must be 2^l + 2border 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_LUMINANCE, and GL_LUMINANCE_ALPHA. If the extension GL_EXT_shadow is supported, the symbolic value GL_DEPTH_COMPONENT is also accepted.
type: Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, and GL_FLOAT.
pixels: Specifies a pointer to the image data in memory.

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), 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.

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.

Each element of pixels is converted to an RGBA element according to

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.

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.

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 log₂max, where max is the returned value of GL_MAX_3D_TEXTURE_SIZE_EXT.
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, height, or depth cannot be represented as 2^k + 2border for some integer k,
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_TEXTURE_TOO_LARGE_EXT is generated if the implementation cannot accomodate a texture of the size requested.

Associated Gets

glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D_EXT