Function get_image_data

test/test.cpp:1800–1830

}

void get_image_data( canvas &that, float width, float height )
{
    for ( int index = 0; index < 100; ++index )
    {
        that.set_color( fill_style,
                        static_cast< float >( index /  2 % 2 ),
                        static_cast< float >( index /  4 % 2 ),
                        static_cast< float >( index /  8 % 2 ),
                        static_cast< float >( index / 16 % 2 ) );
        that.fill_rectangle( 3.0f * static_cast< float >( index % 10 ),
                             3.0f * static_cast< float >( index / 10 ),
                             3.0f, 3.0f );
    }
    unsigned char data[ 4939 ];
    data[ 0 ] = 150;
    for ( int index = 1; index < 4939; ++index )
        data[ index ] = static_cast< unsigned char >(
            ( data[ index - 1 ] * 137 + 53 ) & 255 );
    that.get_image_data( data + 2, 35, 35, 141, -10, -10 );
    unsigned hash = 0;
    for ( int index = 0; index < 4939; ++index )
        hash = ( ( ( hash & 0x1ffff ) << 15 ) | ( hash >> 17 ) ) ^ data[ index ];
    unsigned const expected = 0xf53f9792;
    that.set_color( fill_style, hash != expected, hash == expected, 0.0f, 1.0f );
    that.fill_rectangle( 30.0f, 0.0f, width, 30.0f );
    that.set_linear_gradient( fill_style, 0.0f, 0.0f, width, 0.0f );
    that.add_color_stop( fill_style, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f );
    that.add_color_stop( fill_style, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f );
    that.fill_rectangle( 0.0f, 0.45f * height, width, 0.1f * height );
    that.get_image_data( 0, 32, 32, 128, 0, 0 );
}

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