glTexSubImage2D

NAME

glTexSubImage2D - 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)

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 n^th 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	The format of the pixel data. The allowable values are GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, GL_RGBA, GL_BGR_EXT, GL_BGRA_EXT, GL_ARGB_I3D, GL_422_EXT, GL_422_REV_EXT, GL_422_AVERAGE_EXT, and GL_422_REV_AVERAGE_EXT.
type	Specifies the data type for pixel data. The allowable values are GL_BITMAP, GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2_EXT, GL_UNSIGNED_BYTE_2_3_3_REV_EXT, GL_UNSIGNED_SHORT_5_6_5_EXT, GL_UNSIGNED_SHORT_5_6_5_REV_EXT, GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT, GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT, GL_UNSIGNED_INT_8_8_8_8_EXT, GL_UNSIGNED_INT_8_8_8_8_REV_EXT, GL_UNSIGNED_INT_10_10_10_2_EXT, and GL_UNSIGNED_INT_2_10_10_10_REV_EXT.
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 and disable two-dimensional texturing, call 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 yoffset + height - 1, inclusive.

If GL_INTERLACE_EXT is enabled, only rows (0,2,4,...) of the texture (where the border is considered part of the texture) are defined. A complete video frame may be assembled in a slice of the texture array by invoking glTexSubImage2D on two consecutive video fields, with yoffset values that differ by one.

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 or height, but such a specification has no effect.

NOTES

glTexSubImage2D 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.

EXTENSIONS

Some routines and constants for this function are part of an extension, not part of the core GL command set. The following extension names must be present in the string returned by glGetString when called with argument GL_EXTENSIONS to use these routines and constants.

GL_EXT_422_pixels: GL_422_EXT, GL_422_REV_EXT, GL_422_AVERAGE_EXT, and GL_422_REV_AVERAGE_EXT are part of the EXT_422_pixels extension.
GL_I3D_argb: GL_ARGB_I3D is part of the I3D_argb extension.
GL_EXT_bgra: GL_BGR_EXT and GL_BGRA_EXT are part of the EXT_bgra extension.
EXT_interlace: GL_INTERLACE_EXT is part of the EXT_interlace extension.
GL_EXT_packed_pixels: GL_UNSIGNED_BYTE_3_3_2_EXT, GL_UNSIGNED_BYTE_2_3_3_REV_EXT, GL_UNSIGNED_SHORT_5_6_5_EXT, GL_UNSIGNED_SHORT_5_6_5_REV_EXT, GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT, GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT, GL_UNSIGNED_INT_8_8_8_8_EXT, GL_UNSIGNED_INT_8_8_8_8_REV_EXT, GL_UNSIGNED_INT_10_10_10_2_EXT, and GL_UNSIGNED_INT_2_10_10_10_REV_EXT are part of the EXT_packed_pixels extension.

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.

GL_INVALID_VALUE may be generated if level is greater than LOG₂(max), where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if xoffset < -b, (xoffset + width) > (w - b), yoffset < -b, or (yoffset + I * height) > (h - b), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, b is the border width of the texture image being modified, and I is 2 if GL_INTERLACE_EXT is enabled and 1 otherwise. 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 constant.

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