GLTEXSUBIMAGE3DEXT(3gl)GLTEXSUBIMAGE3DEXT(3gl)NAMEglTexSubImage3DEXT - specify a three-dimensional texture subimage
C SPECIFICATION
void glTexSubImage3DEXT( GLenum target,
GLint level,
GLint xoffset,
GLint yoffset,
GLint zoffset,
GLsizei width,
GLsizei height,
GLsizei depth,
GLenum format,
GLenum type,
const GLvoid* pixels)
PARAMETERS
target Specifies the target texture. Must be GL_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.
xoffset Specifies a texel offset in the x direction within the texture
array.
yoffset Specifies a texel offset in the y direction within the texture
array.
zoffset Specifies a texel offset in the z direction within the texture
array.
width Specifies the width of the texture subimage.
height Specifies the height of the texture subimage.
depth Specifies the depth of the texture subimage.
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_LUMI‐
NANCE_ALPHA.
type Specifies the data type of the pixel data. The following sym‐
bolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BIT‐
MAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, and
GL_FLOAT.
pixels Specifies a pointer to the image data in memory.
DESCRIPTION
Texturing maps a portion of a specified texture image onto each graphi‐
cal primitive for which texturing is enabled. To enable and disable
three-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_3D_EXT.
glTexSubImage3DEXT redefines a contiguous subregion of an existing
three-dimensional texture image. The texels referenced by pixels
replace the portion of the existing texture array with x indices xoff‐
set and xoffset + width - 1, inclusive, and y indices yoffset and yoff‐
set + height - 1, inclusive and z indices zoffset and zoffset + depth -
1 inclusive. This region may not include any texels outside the range
of the texture array as it was originally specified. It is not an
error to specify a subtexture with zero width, height or depth, but
such a specification has no effect.
glTexSubImage3D is called on a existing constant data texture, the call
will always make a copy of the existing texture image before updating
the subimage except when the scenario given below is true.
If a glTexSubImage3D is called with pixel store pname GL_UNPACK_CON‐
STANT_DATA_SUNX set to GL_TRUE on a constant texture, then the address
of the start of the texture image is computed using the specified xoff‐
set, yoffset and zoffset. If this computed address matches the start
address of the currently used constant texture then no action is taken.
If the addresses do not match then a copy is first made of the entire
texture and then the subimage is updated in this copy. A texture is a
"constant texture" if at the time of the specification of the texture
no copy was made. This attribute can be queried using glGetTexLevelPa‐
rameter.
NOTESglTexSubImage3DEXT is part of the GL_EXT_texture3d extension.
Texturing has no effect in color index mode.
glPixelStore and glPixelTransfer modes affect texture images in exactly
the way they affect glDrawPixels. In addition, the extension defines
two additional pixel store modes and one additional wrap mode as
defined in glTexImage3DEXT.
One additional pixel transfer operation and one additional table lookup
to texture processing stage is added as specified by glColorTableSGI.
If GL_UNPACK_CONSTANT_DATA_SUNX is set to GL_TRUE and application
wants to change part of the texture image that has been sent down, the
application should first call glFinishTextureSUNX before a part or all
of this texture image is changed.
ERRORS
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D_EXT.
GL_INVALID_OPERATION is generated if the texture array has not been
defined by a previous glTexImage3DEXT operation.
GL_INVALID_VALUE is generated if level is less than 0.
GL_INVALID_VALUE may be generated if level is greater than log2max,
where max is the returned value of GL_MAX_3D_TEXTURE_SIZE_EXT.
GL_INVALID_VALUE is generated if xoffset < -b, (xoffset + width) > (w -
b), yoffset < - b, or (yoffset + height) > (h - b), zoffset < - b,
(zoffset + depth) > (d - b). Where w is the GL_TEXTURE_WIDTH, h is the
GL_TEXTURE_HEIGHT and d is the GL_TEXTURE_DEPTH_EXT, and b is the bor‐
der width of the texture image being modified. Note that w, h and d
include twice the border width.
GL_INVALID_VALUE is generated if width, height or depth is less than 0.
GL_INVALID_ENUM is generated if format is not an accepted format con‐
stant.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not
GL_COLOR_INDEX.
GL_INVALID_OPERATION is generated if glTexSubImage3DEXT is executed
between the execution of glBegin and the corresponding execution of
glEnd.
GL_INVALID_OPERATION is generated if glTexSubImage3DEXT is executed
within a display list with glPixelStore pname GL_UNPACK_CON‐
TANT_DATA_SUNX set to GL_TRUE.
ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D_EXT
SEE ALSO
glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTex‐
SubImage2D, glDrawPixels, glPixelStore, glPixel Transfer, glTexEnvfP,
glTexGen, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexParameter,
glTexImage3DEXT, glCopyTexSubImage3DEXT, glGetTexLevelParameter, glFin‐
ishTextureSUNX
15 Mar 97 GLTEXSUBIMAGE3DEXT(3gl)