GLTEXSUBIMAGE2D()GLTEXSUBIMAGE2D()NAMEglTexSubImage2D - specify a two-dimensional texture subimage
C SPECIFICATION
void glTexSubImage2D( GLenum target,
GLint level,
GLint xoffset,
GLint yoffset,
GLsizei width,
GLsizei height,
GLenum format,
GLenum type,
const GLvoid *pixels )
delim $$
PARAMETERS
target Specifies the target texture. Must be GL_TEXTURE_2D.
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.
width Specifies the width of the texture subimage.
height Specifies the height of the texture subimage.
format Specifies the format of the pixel data. The following sym‐
bolic 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
two-dimensional texturing, call glEnable and glDisable with argument
GL_TEXTURE_2D.
glTexSubImage2D redefines a contiguous subregion of an existing two-
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, and y indices yoffset and $"yoff‐
set"~+~"height"~-~1$, inclusive. This region may not include any tex‐
els outside the range of the texture array as it was originally speci‐
fied. It is not an error to specify a subtexture with zero width or
height, but such a specification has no effect.
NOTESglTexSubImage2D 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
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.
GL_INVALID_OPERATION is generated if the texture array has not been
defined by a previous glTexImage2D operation.
GL_INVALID_VALUE is generated if level is less than 0.
P GL_INVALID_VALUE may be generated if level is greater than $log sub
2$max, where max is the returned value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if $"xoffset" ~<~ ~-b$, $("xoff‐
set"~+~"width") ~>~ (w~-~b)$, $"yoffset" ~<~ ~-b$, or $("yoffset" ~+~
"height") ~>~ (h~-~b)$. Where $w$ is the GL_TEXTURE_WIDTH, $h$ is the
GL_TEXTURE_HEIGHT, and $b$ is the border width of the texture image
being modified. Note that $w$ and $h$ include twice the border width.
GL_INVALID_VALUE is generated if width or height 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 glTexSubImage2D is executed
between the execution of glBegin and the corresponding execution of
glEnd.
ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GL_TEXTURE_2D
SEE ALSO
glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTex‐
SubImage2D, glDrawPixels, glPixelStore, glPixelTransfer, glTexEnv,
glTexGen, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexParameter
GLTEXSUBIMAGE2D()
