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TRIANGLE(3GC)         AVIATOR GRAPHICS INTERFACE CLASSES          TRIANGLE(3GC)



NAME
        FB_CLASS__TRIANGLE_2DS_OVERLAPPING,
        FB_CLASS__TRIANGLE_2DS_NONOVERLAPPING,
        FB_CLASS__TRIANGLE_2DX_OVERLAPPING,
        FB_CLASS__TRIANGLE_2DX_NONOVERLAPPING,
        FB_CLASS__TRIANGLE_3DX_OVERLAPPING,
        FB_CLASS__TRIANGLE_3DX_NONOVERLAPPING,
        FB_CLASS__TRIANGLE_4DX_OVERLAPPING,
        FB_CLASS__TRIANGLE_4DX_NONOVERLAPPING - triangle classes

SYNOPSIS
        #include <agi.h>
        register Fbuffer fbp;

        fbstart(fbp, FB_CLASS__TRIANGLE_2DS_OVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_2DS_NONOVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_2DX_OVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_2DX_NONOVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_3DX_OVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_3DX_NONOVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_4DX_OVERLAPPING)  {
        }  fbend(fbp);

        fbstart(fbp, FB_CLASS__TRIANGLE_4DX_NONOVERLAPPING)  {
        }  fbend(fbp);

DESCRIPTION
        The classes FB_CLASS__TRIANGLE_2DS_OVERLAPPING and
        FB_CLASS__TRIANGLE_2DS_NONOVERLAPPING are used for rendering triangles
        and chained triangles in two dimensional screen coordinates with no
        matrix transform applied.  Legal members for this class are:
                X, Y

        The classes FB_CLASS__TRIANGLE_2DX_OVERLAPPING and
        FB_CLASS__TRIANGLE_2DX_NONOVERLAPPING are used for rendering 2
        dimensional triangles and chained triangles with the current matrix
        transform applied.  Legal members for this class are:
                X, Y

        The classes FB_CLASS__TRIANGLE_3DX_OVERLAPPING and
        FB_CLASS__TRIANGLE_3DX_NONOVERLAPPING are used for rendering 3
        dimensional triangles and chained triangles with the current matrix
        transform applied.  Legal members for this class are:
                X, Y, Z

        The classes FB_CLASS__TRIANGLE_4DX_OVERLAPPING and
        FB_CLASS__TRIANGLE_4DX_NONOVERLAPPING are used for rendering 4
        dimensional triangles and chained triangles with the current matrix
        transform applied.  Legal members for this class are:
                X, Y, Z, W

        Overlapping triangles have the characteristic that two adjacent
        triangles using the same two points will overlap by exactly a line.
        If two adjacent triangles are rendered with the exclusive-OR raster
        operation, a line connecting the two points in common will be the
        original image.

        Nonoverlapping triangles have the characteristic that two adjacent
        triangles using the same two points will have no pixels in common.

MEMBERS
        The following public members can be accessed by using routines
        fbput(3G) and fbget(3G).  These 32 bit numbers can be signed integer,
        signed 16.16 fixed point, or IEEE single precision floating point
        format.  The coordinate (0,0) is the upper left corner of the paint
        canvas, or the upper left corner of the frame buffer when running
        without a windowing system.

        FB_MEMBER__X__INTEGER
        FB_MEMBER__X__FIXED
        FB_MEMBER__X__FLOAT
                X is the x component of the end point of the triangle
                currently being defined.
        FB_MEMBER__Y__INTEGER
        FB_MEMBER__Y__FIXED
        FB_MEMBER__Y__FLOAT
                Y is the y component of the end point of the triangle
                currently being defined.
        FB_MEMBER__Z__INTEGER
        FB_MEMBER__Z__FIXED
        FB_MEMBER__Z__FLOAT
                Z is the z component of the end point of the triangle
                currently being defined.
        FB_MEMBER__W__INTEGER
        FB_MEMBER__W__FIXED
        FB_MEMBER__W__FLOAT
                W is the w component of the end point of the triangle
                currently being defined.

FUNCTIONS
        The following public functions can be called by using the fbcall(3G)
        routine:

        FB_FUNCTION__STORE_INCREMENT
                The STORE function stores the current point (X, Y, Z, and W)
                into the frame buffer.  The point reference is then
                incremented to reference the next point on the triangle.
        FB_FUNCTION__RENDER
                The RENDER function causes the frame buffer to render the
                triangle.

SEE ALSO
        fbcall(3G), fbend(3G), fbget(3G), fbput(3G), fbstart(3G)

PERFORMANCE
        INTEGER is the fastest format for TRIANGLE_2DS classes.



AGI Release 1.8         Last change: 25 December 1991