rectf(3G)rectf(3G)NAME
rectf, rectfi, rectfs - fills a rectangular area
C SPECIFICATION
void rectf(x1, y1, x2, y2)
Coord x1, y1, x2, y2;
void rectfi(x1, y1, x2, y2)
Icoord x1, y1, x2, y2;
void rectfs(x1, y1, x2, y2)
Scoord x1, y1, x2, y2;
All of the above routines are functionally the same. They differ only in
the type declarations of their parameters.
PARAMETERS
x1 expects the x coordinate of one corner of the rectangle that is to
be drawn.
y1 expects the y coordinate of one corner of the rectangle that is to
be drawn.
x2 expects the x coordinate of the opposite corner of the rectangle
that is to be drawn.
y2 expects the y coordinate of the opposite corner of the rectangle
that is to be drawn.
DESCRIPTION
rect draws a filled rectangle in the x-y plane with z assumed to be zero.
The sides of the rectangle are parallel to the x and y axes. To create a
rectangle that does not lie in the x-y plane, draw the rectangle in the
x-y plane, then rotate and/or translate the rectangle.
A rectangle is drawn as a single polygon, and therefore inherits all
properties that affect the drawing of polygons. These include the
current color, writemask, fill pattern, shade model, polygon antialiasing
mode, polygon scan conversion mode, and subpixel mode. Front-face and
back-face elimination work correctly with filled rectangles. The front-
face of a rectangle faces the positive z half-space when (x1, y1) is the
lower-left corner of the rectangle in object coordinates. Some polygon
modes are applicable only if old-style scan conversion is defeated. (See
note below.)
After rectf executes, the graphics position is undefined.
SEE ALSO
backface, bgnpolygon, glcompat, frontface, polymode, polysmooth, rect,
scrsubdivide, setpattern, shademodel, subpixel
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rectf(3G)rectf(3G)NOTES
Previous graphics library implementations set the current graphics
position to (x1, y1) after the rectangle was drawn. Current graphics
position is now undefined after a rectangle is drawn.
By default rectf draws a polygon using the old-style scan conversion
algorithm, rather than the point sampling algorithm used by bgnpolygon
and endpolygon. Point sampling is prefered over old-style scan
conversion because it has higher performance, it results in higher-
quality images when blending, logical operations, or stenciling are used,
and it supports new rendering features such as texture mapping, fog, and
antialiasing. Call glcompat(GLC_OLDPOLYGON,0) to enable point sampling
of polygons generated by rectf.
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