glTexSubImage1D(3G) OpenGL Reference glTexSubImage1D(3G)
NAME
glTexSubImage1D - specify a two-dimensional texture subimage
C SPECIFICATION
void glTexSubImage1D( GLenum target,
GLint level,
GLint xoffset,
GLsizei width,
GLenum format,
GLenum type,
const GLvoid *pixels )
PARAMETERS
target Specifies the target texture. Must be GLTEXTURE1D.
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.
width Specifies the width of the texture subimage.
format Specifies the format of the pixel data. The following symbolic
values are accepted: GLCOLORINDEX, GLRED, GLGREEN, GLBLUE,
GLALPHA, GLRGB, GLRGBA, GLLUMINANCE, and GLLUMINANCEALPHA.
type Specifies the data type of the pixel data. The following
symbolic values are accepted: GLUNSIGNEDBYTE, GLBYTE,
GLBITMAP, GLUNSIGNEDSHORT, GLSHORT, GLUNSIGNEDINT, GLINT,
and GLFLOAT.
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. To enable or disable one-
dimensional texturing, call glEnable and glDisable with argument
GLTEXTURE1D.
glTexSubImage1D redefines a contiguous subregion of an existing one-
dimensional texture image. The texels referenced by pixels replace the
portion of the existing texture array with x indices xoffset and
xoffset + width - 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 width of 0, but such a
specification has no effect.
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glTexSubImage1D(3G) OpenGL Reference glTexSubImage1D(3G)
NOTES
glTexSubImage1D is available only if the GL version is 1.1 or greater.
Texturing has no effect in color index mode.
glPixelStore and glPixelTransfer modes affect texture images in exactly
the way they affect glDrawPixels.
ERRORS
GLINVALIDENUM is generated if target is not one of the allowable
values.
GLINVALIDOPERATION is generated if the texture array has not been
defined by a previous glTexImage1D operation.
GLINVALIDVALUE is generated if level is less than 0.
GLINVALIDVALUE may be generated if level is greater than log max, where
2
max is the returned value of GLMAXTEXTURESIZE.
GLINVALIDVALUE is generated if xoffset < -b, or if
(xoffset + width) > (w - b). Where w is the GLTEXTUREWIDTH, and b is
the width of the GLTEXTUREBORDER of the texture image being modified.
Note that w includes twice the border width.
GLINVALIDVALUE is generated if width is less than 0.
GLINVALIDENUM is generated if format is not an accepted format
constant.
GLINVALIDENUM is generated if type is not a type constant.
GLINVALIDENUM is generated if type is GLBITMAP and format is not
GLCOLORINDEX.
GLINVALIDOPERATION is generated if glTexSubImage1D is executed between
the execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GLTEXTURE1D
MACHINE DEPENDENCIES
On InfiniteReality systems, there is a performance benefit when the width
of the image to be transferred to texture memory is a multiple of 8.
Texture borders are not supported on InfiniteReality systems.
Applications should use borderless textures and GLCLAMPTOEDGESGIS
wrap mode.
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glTexSubImage1D(3G) OpenGL Reference glTexSubImage1D(3G)
The EXTpackedpixels extension is not supported on RealityEngine,
RealityEngine2, and VTX systems.
glTexSubImage1D and glTexSubImage1DEXT are not supported on
RealityEngine, RealityEngine2, and VTX systems.
On High Impact and Maximum Impact systems, if the right side of the image
to be transferred to texture memory is not the right side of the texture,
then its index must be a multiple of 32, where index = xoffset+width.
Otherwise it will generate a GLINVALIDVALUE error.
SEE ALSO
glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glDrawPixels, glPixelStore, glPixelTransfer,
glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexParameter,
glTexSubImage2D
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