Parameters

Description

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is active. Texturing is active when the current fragment shader or vertex shader makes use of built-in texture lookup functions.

glTexSubImage2D redefines a contiguous subregion of an existing two-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and $\mathit{xoffset}+\mathit{width}-1$, inclusive, and y indices yoffset and $\mathit{yoffset}+\mathit{height}-1$, 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 or height, but such a specification has no effect.

Notes

Storage parameter GL_UNPACK_ALIGNMENT, set by glPixelStorei, affects the way that data is read out of client memory. See glPixelStorei for a description.

glTexSubImage2D specifies a two-dimensional or cube-map subtexture for the current texture unit, specified with glActiveTexture.

Errors

GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.

GL_INVALID_ENUM is generated if format or type is not an accepted value.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than ${\mathit{log}}_2$ max, where max is the returned value of GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if $\mathit{xoffset}<0$, $\left(\mathit{xoffset}+\mathit{width}\right)>\mathit{w}$, $\mathit{yoffset}<0$, or $\left(\mathit{yoffset}+\mathit{height}\right)>\mathit{h}$, where $\mathit{w}$ is the width and $\mathit{h}$ is the height of the texture image being modified.

GL_INVALID_VALUE is generated if width or height is less than 0.

GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D or glCopyTexImage2D operation whose internalformat matches the format of glTexSubImage2D.

GL_INVALID_OPERATION is generated if type is GL_UNSIGNED_SHORT_5_6_5 and format is not GL_RGB.

GL_INVALID_OPERATION is generated if type is GL_UNSIGNED_SHORT_4_4_4_4 or GL_UNSIGNED_SHORT_5_5_5_1 and format is not GL_RGBA.

Associated Gets

glGet with argument GL_MAX_TEXTURE_SIZE or GL_MAX_CUBE_MAP_TEXTURE_SIZE

Tutorials

Songho - OpenGL Pixel Buffer Object (PBO)

See Also

glActiveTexture, glCompressedTexImage2D, glCompressedTexSubImage2D, glCopyTexImage2D, glCopyTexSubImage2D, glPixelStorei, glTexImage2D, glTexParameter