Glcopytexsubimage2D - HP b2600 Reference Manual

C

glCopyTexSubImage2D

glCopyTexSubImage2D
glCopyTexSubImage2D: copy a two-dimensional texture sub image.
C Specification
void glCopyTexSubImage2D(
Parameters
target
level
xoffset
yoffset
x, y
width
height
Description
glCopyTexSubImage2D replaces a rectangular portion of a two-dimensional texture
image with pixels from the current GL_READ_BUFFER (rather than from main
memory, as is the case for glTexSubImage2D).
The screen-aligned pixel rectangle with lower left corner at (x, y) and with width width
and height height, replaces the portion of the texture array with X indices xoffset
through xoffset + width - 1, inclusive, and Y indices yoffset through yoffset + height - 1,
inclusive, at the mipmap level specified by level.
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.
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.
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GLenum target,
GLint level,
GLint xoffset,
GLint yoffset,
GLint x,
GLint y,
GLsizei width,
GLsizei height)
Specifies the target texture. Must be GL_TEXTURE_2D
Specifies the level-of-detail number. Level 0 is the base image level.
Level n is the nth mipmap reduction image.
Specifies a texel offset in the X direction within the texture array.
Specifies a texel offset in the Y direction within the texture array.
Specify the window coordinates of the lower left corner of the
rectangular region of pixels to be copied.
Specifies the width of the texture sub image.
Specifies the height of the texture sub image.
Chapter 3