glBitmap(3G)glBitmap(3G)NAMEglBitmap - draw a bitmap
const GLubyte *bitmap );
Specify the pixel width and height of the bitmap image. 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 posi‐
tive axes. Specify the x and y offsets to be added to the current
raster position after the bitmap is drawn. Specifies the address of
the bitmap image.
A bitmap is a binary image. When drawn, the bitmap is positioned rela‐
tive to the current raster position, and frame buffer pixels corre‐
sponding 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 glPixel‐
Transfer() do not.
If the current raster position is invalid, glBitmap() is ignored. Oth‐
erwise, the lower left corner of the bitmap image is positioned at the
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 corre‐
sponding to a 1 (one) in the bitmap image. These fragments are gener‐
ated 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
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.
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.
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 GETSglGet() 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 ALSOglDrawPixels(3), glPixelStore(3), glPixelTransfer(3), glRasterPos(3)glBitmap(3G)