public void Polygon_Segment( ref ZLineCoords LineCoords )
{
float dx, dy, Divider, x, y, dwidth, dheight;
int xint, yint;
int Steps;
dwidth = Width;
dheight = Height;
x = LineCoords.Start.x;
y = LineCoords.Start.y;
dx = LineCoords.End.x - LineCoords.Start.x;
dy = LineCoords.End.y - LineCoords.Start.y;
Divider = ( Math.Abs( dy ) > Math.Abs( dx ) ) ? Math.Abs( dy ) : Math.Abs( dx );
dx /= Divider;
dy /= Divider;
for( Steps = (int)Divider; Steps >= 0; Steps-- )
{
if( x >= 0.0 && x < dwidth )
{
xint = (int)x;
if( y > MinMax_H[xint].Max ) MinMax_H[xint].Max = y;
if( y < MinMax_H[xint].Min ) MinMax_H[xint].Min = y;
}
if( y >= 0.0 && y < dheight )
{
yint = (int)y;
if( x > MinMax_V[yint].Max ) MinMax_V[yint].Max = x;
if( x < MinMax_V[yint].Min ) MinMax_V[yint].Min = x;
}
x += dx;
y += dy;
}
}
public void Line( ref ZLineCoords LineCoords, byte Color )
{
float dx, dy, x, y;
uint i, Steps;
// Line Clipping algorithm : Clip lines into canva and don't draw if completely out of the drawing area.
if( !ClipCoords( ref LineCoords ) ) return;
// Compute line delta.
x = LineCoords.Start.x;
y = LineCoords.Start.y;
dx = LineCoords.End.x - LineCoords.Start.x;
dy = LineCoords.End.y - LineCoords.Start.y;
Steps = (uint)( ( Math.Abs( dx ) > Math.Abs( dy ) ) ? Math.Abs( dx ) : Math.Abs( dy ) );
dx /= Steps;
dy /= Steps;
for( i = 0; i < Steps; i++ )
{
SetPoint_Secure( (int)x, (int)y, Color );
x += dx; y += dy;
}
SetPoint_Secure( (int)LineCoords.End.x, (int)LineCoords.End.y, Color );
}
public bool ClipCoords( ref ZLineCoords LineCoords )
{
CLIP Start_ClipCode, End_ClipCode;
float sx, sy, ex, ey, dwidth, dheight;
sx = LineCoords.Start.x;
sy = LineCoords.Start.y;
ex = LineCoords.End.x;
ey = LineCoords.End.y;
dwidth = Width - 1;
dheight = Height - 1;
Start_ClipCode = EvalPoint( sx, sy );
End_ClipCode = EvalPoint( ex, ey );
while( true )
{
if( ( Start_ClipCode | End_ClipCode ) == 0 )
{
LineCoords.Start.x = sx; LineCoords.Start.y = sy; LineCoords.End.x = ex; LineCoords.End.y = ey;
return ( true ); // Line is visible and in the frame, so draw it.
}
if( ( Start_ClipCode & End_ClipCode ) != 0 )
{
LineCoords.Start.x = sx; LineCoords.Start.y = sy; LineCoords.End.x = ex; LineCoords.End.y = ey;
return ( false ); // Line is out of the frame, so don't draw it.
}
if( ( Start_ClipCode ) == 0 )
{
if( ( Start_ClipCode & CLIP.LEFT ) != 0 ) { sy = sy + ( ey - sy ) / ( ex - sx ) * ( 0 - sx ); sx = 0; }
else if( ( Start_ClipCode & CLIP.RIGHT ) != 0 ) { sy = sy + ( ey - sy ) / ( ex - sx ) * ( dwidth - sx ); sx = dwidth; }
else if( ( Start_ClipCode & CLIP.TOP ) != 0 ) { sx = sx + ( ex - sx ) / ( ey - sy ) * ( 0 - sy ); sy = 0; }
else if( ( Start_ClipCode & CLIP.BOTTOM ) != 0 ) { sx = sx + ( ex - sx ) / ( ey - sy ) * ( dheight - sy ); sy = dheight; }
Start_ClipCode = EvalPoint( sx, sy );
}
else
{
if( ( End_ClipCode & CLIP.LEFT ) != 0 ) { ey = sy + ( ey - sy ) / ( ex - sx ) * ( 0 - sx ); ex = 0; }
else if( ( End_ClipCode & CLIP.RIGHT ) != 0 ) { ey = sy + ( ey - sy ) / ( ex - sx ) * ( dwidth - sx ); ex = dwidth; }
else if( ( End_ClipCode & CLIP.TOP ) != 0 ) { ex = sx + ( ex - sx ) / ( ey - sy ) * ( 0 - sy ); ey = 0; }
else if( ( End_ClipCode & CLIP.BOTTOM ) != 0 ) { ex = sx + ( ex - sx ) / ( ey - sy ) * ( dheight - sy ); ey = dheight; }
End_ClipCode = EvalPoint( ex, ey );
}
}
return ( false );
}
