Function example_knot

test/test.cpp:1952–1991

}

void example_knot( canvas &that, float width, float height )
{
    float points[ 6 ][ 8 ] = {
        {  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,  0.0f,  1.0f },
        { -1.0f, -1.0f, -1.0f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f },
        {  2.0f,  1.0f,  2.0f, -2.0f, -1.0f, -2.0f, -1.0f, -1.0f },
        { -2.0f, -1.0f, -2.0f,  2.0f,  1.0f,  2.0f,  1.0f,  1.0f },
        { -2.0f, -1.0f, -2.0f, -3.0f,  0.0f, -3.0f,  0.0f, -1.0f },
        {  2.0f,  1.0f,  2.0f,  3.0f,  0.0f,  3.0f,  0.0f,  1.0f },
    };
    that.translate( width * 0.5f, height * 0.5f );
    that.scale( width * 0.17f, height * 0.17f );
    that.rotate( -15.0f * 3.14159265f / 180.0f );
    for ( int index = 0; index < 6; ++index )
    {
        that.begin_path();
        that.move_to(
            1.01f * points[ index ][ 0 ] - 0.01f * points[ index ][ 2 ],
            1.01f * points[ index ][ 1 ] - 0.01f * points[ index ][ 3 ] );
        that.line_to( points[ index ][ 0 ], points[ index ][ 1 ] );
        that.bezier_curve_to( points[ index ][ 2 ], points[ index ][ 3 ],
                              points[ index ][ 4 ], points[ index ][ 5 ],
                              points[ index ][ 6 ], points[ index ][ 7 ] );
        that.line_to(
            -0.01f * points[ index ][ 4 ] + 1.01f * points[ index ][ 6 ],
            -0.01f * points[ index ][ 5 ] + 1.01f * points[ index ][ 7 ] );
        that.set_color( stroke_style, 0.0f, 0.0f, 0.0f, 1.0f );
        that.set_line_width( 0.75f );
        that.line_cap = butt;
        that.stroke();
        that.set_radial_gradient( stroke_style,
                                  0.0f, 0.0f, 0.0f,
                                  0.0f, 0.0f, 3.0f );
        that.add_color_stop( stroke_style, 0.0f, 0.8f, 1.0f, 0.6f, 1.0f );
        that.add_color_stop( stroke_style, 1.0f, 0.1f, 0.5f, 0.1f, 1.0f );
        that.set_line_width( 0.5f );
        that.line_cap = circle;
        that.stroke();
    }
}

void example_icon( canvas &that, float width, float height )
{