Function pattern

test/test.cpp:963–994

}

void pattern( canvas &that, float width, float height )
{
    unsigned char checker[ 256 ];
    for ( int index = 0; index < 256; ++index )
        checker[ index ] = static_cast< unsigned char >(
            ( ( ( index >> 2 & 1 ) ^ ( index >> 5 & 1 ) ) |
              ( ( index & 3 ) == 3 ) ) * 255 );
    that.arc( 0.5f * width, 0.5f * height, 32.0f, 0.0f, 6.28318531f );
    that.close_path();
    that.set_line_width( 20.0f );
    that.set_color( stroke_style, 0.0f, 0.0f, 0.0f, 1.0f );
    that.set_pattern( stroke_style, 0, 8, 8, 32, repeat );
    that.stroke();
    that.set_line_width( 16.0f );
    that.set_pattern( stroke_style, checker, 8, 8, 32, repeat );
    that.stroke();
    for ( float scale = 8.0f; scale >= 1.0f; scale /= 2.0f )
    {
        that.set_transform( 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f );
        that.scale( scale, scale );
        float size_x = 0.5f * width / scale;
        float size_y = 0.5f * height / scale;
        that.set_pattern( fill_style, checker, 8, 8, 32, no_repeat );
        that.fill_rectangle( 0.0f, 0.0f, size_x, size_y );
        that.set_pattern( fill_style, checker, 8, 8, 32, repeat_x );
        that.fill_rectangle( size_x, 0.0f, size_x, size_y );
        that.set_pattern( fill_style, checker, 8, 8, 32, repeat_y );
        that.fill_rectangle( 0.0f, size_y, size_x, size_y );
        that.set_pattern( fill_style, checker, 8, 8, 32, repeat );
        that.fill_rectangle( size_x, size_y, size_x, size_y );
    }
}

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