glCopyTexSubImage3DEXT

glCopyTexSubImage3DEXT: copy pixels into a 3D texture subimage.

C Specification

void glCopyTexSubImage3DEXT(
    GLenum   target,
    GLint    level,
    GLint    xoffset,
    GLint    yoffset,
    GLint    zoffset,
    GLint    x,
    GLint    y,
    GLsizei  width,
    GLsizei  height)

Parameters

target: The target texture. Must be GL_TEXTURE_3D_EXT.
level: The level-of-detail number. Level 0 is the base image level, and level n is the nth mipmap reduction image.
xoffset: Texel offset in the X direction within the texture array.
yoffset: Texel offset in the Y direction within the texture array.
zoffset: Texel offset in the Z direction within the texture array.
x: The X coordinate of the lower-left corner of the pixel rectangle to be transferred to the texture array.
y: The Y coordinate of the lower-left corner of the pixel rectangle to be transferred to the texture array.
width: The width of the texture subimage.
height: The height of the texture subimage.

glCopyTexSubImage3DEXT replaces a rectangular portion of a three-dimensional texture image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage3DEXT).

The screen-aligned pixel rectangle with lower-left corner at (x, y) having width width and height height replaces the rectangular area of the S-T slice located at zoffset with X indices xoffset through xoffset + width 1, inclusive, and Y indices yoffset through yoffset + height 1, inclusive.

The destination rectangle in the texture array may not include any texels outside 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.

The pixels in the rectangle are processed exactly as if glCopyPixels had been called, but the process stops just before final conversion. At this point all pixel component values are clamped to the range [0, 1] and then converted to the texture's internal format for storage in the texel array.

If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the read window associated with the current rendering context, then the values obtained for those pixels are undefined.

Notes

glCopyTexSubImage3DEXT is part of the EXT_copy_texture extension.

Errors

GL_INVALID_ENUM is generated when target is not one of the allowable values.
GL_INVALID_VALUE is generated if level is less than zero or greater than log₂max, where max is the returned value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if xoffset < TEXTURE_BORDER, (xoffset + width) > (TEXTURE_WIDTH TEXTURE_BORDER), yoffset < TEXTURE_BORDER, or if zoffset < TEXTURE_BORDER, where TEXTURE_WIDTH, TEXTURE_HEIGHT, and TEXTURE_BORDER are the state values of the texture image being modified, and interlace is 1 if GL_INTERLACE_SGIX is disabled, and 2 otherwise. Note that TEXTURE_WIDTH and TEXTURE_HEIGHT include twice the border width.
GL_INVALID_VALUE is generated if width or height is negative.
GL_INVALID_OPERATION is generated when the texture array has not been defined by a previous glTexImage3D (or equivalent) operation.
GL_INVALID_OPERATION is generated if glCopyTexSubImage3DEXT is executed between the execution of glBegin and the corresponding execution of glEnd.

Associated Gets

glGetTexImage