Index for Section 3G

Alphabetical listing for G

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glBitmap(3G)
NAME
  glBitmap - draw a bitmap

SYNOPSIS
  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

	x[w] = x[r] - x[o]

       y[w] = y[r] - y[o]

  where ( x[r] , y[r] ) is the raster position and ( x [o] , y[o] ) is the
  bitmap origin. Fragments are then generated for each pixel corresponding to
  a 1 (one) in the bitmap image. These fragments are generated using the
  current raster z coordinate, color or color index, and current raster
  texture coordinates. 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
  viewport.

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(3), glPixelStore(3), glPixelTransfer(3), glRasterPos(3)

Index for Section 3G

Alphabetical listing for G

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