GLWINDOWPOS(3gl)GLWINDOWPOS(3gl)NAME
glWindowPos2d, glWindowPos2f, glWindowPos2i, glWindowPos2s, glWindow‐
Pos3d, glWindowPos3f, glWindowPos3i, glWindowPos3s, glWindowPos2dv,
glWindowPos2fv, glWindowPos2iv, glWindowPos2sv, glWindowPos3dv, glWin‐
dowPos3fv, glWindowPos3iv, glWindowPos3sv - specify the raster position
for pixel operations
C SPECIFICATION
void glWindowPos2d( GLdouble x,
GLdouble y )
void glWindowPos2f( GLfloat x,
GLfloat y )
void glWindowPos2i( GLint x,
GLint y )
void glWindowPos2s( GLshort x,
GLshort y )
void glWindowPos3d( GLdouble x,
GLdouble y,
GLdouble z )
void glWindowPos3f( GLfloat x,
GLfloat y,
GLfloat z )
void glWindowPos3i( GLint x,
GLint y,
GLint z )
void glWindowPos3s( GLshort x,
GLshort y,
GLshort z )
PARAMETERS
x, y, z
Specify the x, y, and z window coordinates (if present) for the
raster position.
C SPECIFICATION
void glWindowPos2dv( const GLdouble *v )
void glWindowPos2fv( const GLfloat *v )
void glWindowPos2iv( const GLint *v )
void glWindowPos2sv( const GLshort *v )
void glWindowPos3dv( const GLdouble *v )
void glWindowPos3fv( const GLfloat *v )
void glWindowPos3iv( const GLint *v )
void glWindowPos3sv( const GLshort *v )
PARAMETERS
v Specifies a pointer to an array of two or three elements, speci‐
fying x, y, and z coordinates, respectively.
DESCRIPTION
The GL maintains a 3D position in window coordinates. This position,
called the raster position, is used to position pixel and bitmap write
operations. It is maintained with subpixel accuracy. See glBitmap,
glDrawPixels, and glCopyPixels.
The current raster position consists of three window coordinates (x, y,
z), a clip coordinate value (w), an eye coordinate distance, a valid
bit, and associated color data and texture coordinates. glWindowPos3
specifies window coordinate x, y, and z explicitly. glWindowPos2 uses
the argument values for x and y while implicitly setting z to 0.
Unlike glRasterPos, the window coordinates presented by glWindowPos are
not transformed by the current modelview and projection matrices. They
directly set the new current raster position.
The current raster position also includes some associated color data
and texture coordinates. If lighting is enabled, then GL_CUR‐
RENT_RASTER_COLOR (in RGBA mode) or GL_CURRENT_RASTER_INDEX (in color
index mode) is set to the color produced by the lighting calculation
(see glLight, glLightModel, and
glShadeModel). If lighting is disabled, current color (in RGBA mode,
state variable GL_CURRENT_COLOR) or color index (in color index mode,
state variable GL_CURRENT_INDEX) is used to update the current raster
color.
Likewise, GL_CURRENT_RASTER_TEXTURE_COORDS is updated as a function of
GL_CURRENT_TEXTURE_COORDS, based on the texture matrix and the texture
generation functions (see glTexGen). Finally, the distance from the
origin of the eye coordinate system to the vertex as transformed by
only the modelview matrix replaces GL_CURRENT_RASTER_DISTANCE.
Initially, the current raster position is (0, 0, 0, 1), the current
raster distance is 0, the valid bit is set, the associated RGBA color
is (1, 1, 1, 1), the associated color index is 1, and the associated
texture coordinates are (0, 0, 0, 1). In RGBA mode, GL_CUR‐
RENT_RASTER_INDEX is always 1; in color index mode, the current raster
RGBA color always maintains its initial value.
NOTES
The raster position is modified by glRasterPos, glWindowPos, and by
glBitmap.
Calling glDrawElements may leave the current color or index indetermi‐
nate. If glWindowPos is executed while the current color or index is
indeterminate, the current raster color or current raster index remains
indeterminate.
ERRORS
GL_INVALID_OPERATION is generated if glWindowPos 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_POSITION_VALID
glGet with argument GL_CURRENT_RASTER_DISTANCE
glGet with argument GL_CURRENT_RASTER_COLOR
glGet with argument GL_CURRENT_RASTER_INDEX
glGet with argument GL_CURRENT_RASTER_TEXTURE_COORDS
SEE ALSO
glBitmap, glCopyPixels, glDrawElements, glDrawPixels, glLight, glLight‐
Model, glShadeModel, glTexCoord, glTexGen, glVertex, glRasterPos
15 Mar 97 GLWINDOWPOS(3gl)