glCopyTexImage2D — copy pixels into a 2D texture image
void glCopyTexImage2D( | GLenum target, | 
| GLint level, | |
| GLenum internalformat, | |
| GLint x, | |
| GLint y, | |
| GLsizei width, | |
| GLsizei height, | |
GLint border); | 
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.
                
levelSpecifies 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_STENCIL_INDEX8,
                    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, ySpecify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
widthSpecifies the width of the texture image.
heightSpecifies the height of the texture image.
borderMust be 0.
            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 
            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 
            
            Pixel ordering is such that lower 
            
            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.
        
            1, 2, 3, and 4 are not accepted values for internalformat.
        
An image with height or width of 0 indicates a NULL texture.
            GL_STENCIL_INDEX8 is accepted for internalformat only
            if the GL version is 4.4 or higher.
        
            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 
            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 border is not 0.
        
            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.
        
glCopyTexImage1D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexSubImage2D, glTexParameter
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2012-2013 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.