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GLCOPYTEXIMAGE2D(3G)                             OpenGL 3.3                             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, 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.

       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 format of the texture. Must be one of the following symbolic constants:
           GL_COMPRESSED_RED, GL_COMPRESSED_RG, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA.  GL_COMPRESSED_SRGB,
           GL_COMPRESSED_SRGB_ALPHA.  GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24,
           GL_DEPTH_COMPONENT32, GL_RED, GL_RG, 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,
           GL_RGBA16, GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, or GL_SRGB8_ALPHA8.

       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, or cube-map 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 ^,
       border and a height of height + 2 ^, border defines the texture array at the mipmap level specified
       by level.  internalformat specifies the internal format of the texture array.

       The pixels in the rectangle are processed exactly as if glReadPixels() 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.

       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.

       When internalformat is one of the sRGB types, the GL does not automatically convert the source pixels
       to the sRGB color space. In this case, the glPixelMap function can be used to accomplish the
       conversion.

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

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

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_VALUE is generated if level is less than 0.


       GL_INVALID_VALUE may be generated if level is greater than log 2 ^/ max, where max is the returned
       value of GL_MAX_TEXTURE_SIZE.


       GL_INVALID_VALUE is generated if width is less than 0 or greater than GL_MAX_TEXTURE_SIZE.


       GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width or depth
       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_VALUE is generated if internalformat is not an accepted format.


       GL_INVALID_OPERATION is generated if internalformat is GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16,
       GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT32 and there is no depth buffer.

ASSOCIATED GETS
       glGetTexImage()

SEE ALSO
       glCopyTexImage1D(), glCopyTexSubImage1D(), glCopyTexSubImage2D(), glPixelStore(), glTexImage1D(),
       glTexImage2D(), glTexSubImage1D(), glTexSubImage2D(), glTexParameter()


COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software
       B License. For details, see http://oss.sgi.com/projects/FreeB/.



OpenGL 3.3                                       03/08/2011                             GLCOPYTEXIMAGE2D(3G)