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GLCOPYTEXIMAGE2D(3G)                                                                    GLCOPYTEXIMAGE2D(3G)



NAME
       glCopyTexImage2D - copy pixels into a 2D texture image


C SPECIFICATION
       void glCopyTexImage2D( GLenum target,
                              GLint level,
                              GLenum internalformat,
                              GLint x,
                              GLint y,
                              GLsizei width,
                              GLsizei height,
                              GLint border )


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.

       internalformat  Specifies the internal  of the texture.  Must be one of the following  symbolic  con-stants: constants:
                       stants:   GL_ALPHA,   GL_ALPHA4,  GL_ALPHA8,  GL_ALPHA12,  GL_ALPHA16,  GL_LUMINANCE,
                       GL_LUMINANCE4,  GL_LUMINANCE8,  GL_LUMINANCE12,  GL_LUMINANCE16,  GL_LUMINANCE_ALPHA,
                       GL_LUMINANCE4_ALPHA4,           GL_LUMINANCE6_ALPHA2,           GL_LUMINANCE8_ALPHA8,
                       GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16,  GL_INTENSITY,
                       GL_INTENSITY4,  GL_INTENSITY8,  GL_INTENSITY12,  GL_INTENSITY16, GL_RGB, GL_R3_G3_B2,
                       GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4,
                       GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.

       x, y            Specify  the window coordinates of the lower left corner of the rectangular region of
                       pixels to be copied.

       width           Specifies the width of the texture image.  Must be 0 or (2^n)  +  2*border  for  some
                       integer n.

       height          Specifies  the  height  of the texture image.  Must be 0 or (2^m) + 2*border for some
                       integer m.

       border          Specifies the width of the border.  Must be either 0 or 1.

DESCRIPTION
       glCopyTexImage2D defines a two-dimensional texture image with pixels from the current GL_READ_BUFFER.

       The  screen-aligned pixel rectangle with lower left corner at (x, y) and with a width of width+2*bor-der width+2*border
       der and a height of height+2*border defines the texture array at the mipmap level specified by level.
       internalformat specifies the internal  of the texture array.

       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  for storage in the texel array.

       Pixel  ordering  is  such  that  lower x and y screen coordinates correspond to lower s and t texture
       coordinates.

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


NOTES
       glCopyTexImage2D is available only if the GL version is 1.1 or greater.

       Texturing has no effect in color index mode.

       1, 2, 3, and 4 are not accepted values for internalformat.

       An image with height or width of 0 indicates a NULL texture.

       When the GL_ARB_imaging extension is supported, the RGBA components read from the framebuffer may  be
       processed by the imaging pipeline.  See glTexImage1D for specific details.

ERRORS
       GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.

       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 width or height is less than 0, greater than  2+GL_MAX_TEXTURE_SIZE,
       or if width or height cannot be represented as (2^k) + 2*border for some integer k.

       GL_INVALID_VALUE is generated if border is not 0 or 1.

       GL_INVALID_ENUM is generated if internalformat is not one of the allowable values.

       GL_INVALID_OPERATION  is  generated  if glCopyTexImage2D is executed between the execution of glBegin
       and the corresponding execution of glEnd.

ASSOCIATED GETS
       glGetTexImage
       glIsEnabled with argument GL_TEXTURE_2D

SEE ALSO
       glCopyPixels(3G),    glCopyTexImage1D(3G),    glCopyTexSubImage1D(3G),     glCopyTexSubImage2D(3G),     glPixelStore(3G),
       glPixelTransfer(3G), glTexEnv(3G), glTexGen(3G), glTexImage1D(3G), glTexImage2D(3G), glTexSubImage1D(3G), glTexSubImage2D(3G),
       glTexParameter(3G)






                                                                                        GLCOPYTEXIMAGE2D(3G)