trunk/freesc/surface.scm

//
// Surface draw
//

defun Surface_Draw
        local($i $n $rlat $rlon $alt $bitmap $lat $lon $x $y $scale)

        if (%# < 3 || ((%# - 3) % 2) != 0) 
                Error(ENUMPARAM)
        endif

        $bitmap = %1
        $alt = %2
        $scale = %3
        Shift(3)

        $n = %# / 2

        // Calculate center position for RefPoint
        $rlat = 0
        $rlon = 0

        for ($i = 0, $i < $n, $i = $i + 1)      
                $rlat = $rlat + mparam([$i * 2])
                $rlon = $rlon + mparam([$i * 2 + 1])
        fend
        $rlat = $rlat / $n
        $rlon = $rlon / $n

        // Start Area/RefPoint
        Area(5 $rlat $rlon 20)
        if ($alt == 0)
                RefPoint( 7 : $scale $rlat $rlon )
        else
                RefPoint( 2 : $scale $rlat $rlon E= $alt )
        endif

        // Define Points
        local(@points)
        for ($i = 0, $i < $n, $i = $i + 1)
                $lat = mparam([$i * 2])
                $lon = mparam([$i * 2 + 1])

                $y = ($lat - $rlat) / 360.0 * 40007.0 * 1000.0;
                $x = ($lon - $rlon) / 360.0 * 40007.0 * 1000.0
                        * cos($rlat);

                $y = $y / $scale;
                $x = $x / $scale;

                $points{[$i * 3    ]} = $x
                $points{[$i * 3 + 1]} = 0
                $points{[$i * 3 + 2]} = $y
        fend
        
        Points( 0 @points )

        // draw
        LFNBitmap($bitmap)

        ConcavePoly

        // Poly
        local(@pts)
        for ($i = 0, $i < $n, $i = $i + 1)
                $pts{$i} = $i;
        fend
        Poly(m 0 32767 0 0 @pts)

        
//      StartSurface
//      MoveToPt( 0 )

//      $i = 1
//      while ($i < $n)
//              DrawToPt($i)
//              $i = $i + 1
//      wend
//      EndSurface

        EndA
endfun