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GLBITMAP(3G)                                                                                    GLBITMAP(3G)



NAME
       glBitmap - draw a bitmap


C SPECIFICATION
       void glBitmap( GLsizei width,
                      GLsizei height,
                      GLfloat xorig,
                      GLfloat yorig,
                      GLfloat xmove,
                      GLfloat ymove,
                      const GLubyte *bitmap )


PARAMETERS
       width, height Specify the pixel width and height of the bitmap image.

       xorig, yorig  Specify  the  location  of the origin in the bitmap image.  The origin is measured from
                     the lower left corner of the bitmap, with right and up being the positive axes.

       xmove, ymove  Specify the x and y offsets to be added to the current raster position after the bitmap
                     is drawn.

       bitmap        Specifies the address of the bitmap image.

DESCRIPTION
       A  bitmap  is  a  binary  image.  When drawn, the bitmap is positioned relative to the current raster
       position, and frame buffer pixels corresponding to 1's in the bitmap are written  using  the  current
       raster color or index.  Frame buffer pixels corresponding to 0's in the bitmap are not modified.

       glBitmap  takes  seven arguments.  The first pair specifies the width and height of the bitmap image.
       The second pair specifies the location of the bitmap origin relative to the lower left corner of  the
       bitmap  image.   The  third  pair  of  arguments specifies x and y offsets to be added to the current
       raster position after the bitmap has been drawn.  The final argument is a pointer to the bitmap image
       itself.

       The  bitmap  image is interpreted like image data for the glDrawPixels command, with width and height
       corresponding to the width and height arguments of that command, and with type set to  GL_BITMAP  and
       format set to GL_COLOR_INDEX.  Modes specified using glPixelStore affect the interpretation of bitmap
       image data; modes specified using glPixelTransfer do not.

       If the current raster position is invalid, glBitmap is ignored.  Otherwise, the lower left corner  of
       the bitmap image is positioned at the window coordinates

                                                   xw = xr - xo

                                                   yw = yr - yo

       where  (  xr  , yr ) is the raster position and ( xo , yo ) is the bitmap origin.  Fragments are then
       generated for each pixel corresponding to a 1 (one) in the bitmap image.  These fragments are  gener-ated generated
       ated  using the current raster z coordinate, color or color index, and current raster texture coordi-nates. coordinates.
       nates.  They are then treated just as if they had been  generated  by  a  point,  line,  or  polygon,
       including texture mapping,
       fogging, and all per-fragment operations such as alpha and depth testing.

       After the bitmap has been drawn, the x and y coordinates of the current raster position are offset by
       xmove and ymove.  No change is made to the z coordinate of the current raster  position,  or  to  the
       current raster color, texture coordinates, or index.

NOTES
       To  set  a  valid  raster position outside the viewport, first set a valid raster position inside the
       viewport, then call glBitmap with NULL as the bitmap parameter and with xmove and ymove  set  to  the
       offsets  of  the new raster position. This technique is useful when panning an image around the view-port. viewport.
       port.

ERRORS
       GL_INVALID_VALUE is generated if width or height is negative.

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

ASSOCIATED GETS
       glGet with argument GL_CURRENT_RASTER_POSITION
       glGet with argument GL_CURRENT_RASTER_COLOR
       glGet with argument GL_CURRENT_RASTER_DISTANCE
       glGet with argument GL_CURRENT_RASTER_INDEX
       glGet with argument GL_CURRENT_RASTER_TEXTURE_COORDS
       glGet with argument GL_CURRENT_RASTER_POSITION_VALID

SEE ALSO
       glDrawPixels(3G), glPixelStore(3G), glPixelTransfer(3G), glRasterPos(3G)





                                                                                                GLBITMAP(3G)