bool App::update()
{
game_time.update();
canvas.clear(clan::Colorf(0.0f,0.0f,0.0f, 0.0f));
rock.set_color(clan::Colorf(1.0f, 1.0f, 1.0f, 0.8f));
rock.draw(canvas, 0.0f, 0.0f);
// Rotate tux
rotation += game_time.get_time_elapsed() * 100.0f;
clan::Angle angle;
angle.set_degrees(rotation);
tux.set_angle(angle);
// Caculate tux position
clan::Pointf circle_center( (float) (canvas.get_width()/2), (float) (canvas.get_height()/2) );
const float radius = 210.0f;
int tux_circle = 12;
tux_position.x = -(radius - tux_radius - tux_circle) * cos( angle.to_radians() / 2.0f );
tux_position.y = (radius - tux_radius - tux_circle) * sin( angle.to_radians()/ 2.0f );
tux_position += circle_center;
tux_position.x -= tux.get_width()/2;
tux_position.y -= tux.get_height()/2;
// Give tux circle blue outer outline, because it looks nice
canvas.fill_circle(tux_position.x + tux_radius, tux_position.y + tux_radius, tux_radius+tux_circle, clan::Colorf(0.0f, 0.0f, 1.0f, 1.0f));
// Make see through border
canvas.set_blend_state(blend_state_off);
canvas.fill_circle(tux_position.x + tux_radius, tux_position.y + tux_radius, tux_radius+tux_circle-2, clan::Colorf(0.0f, 0.0f, 0.0f, 0.0f));
canvas.reset_blend_state();
// Give tux circle blue outline, to mask the alpha channel
canvas.fill_circle(tux_position.x + tux_radius, tux_position.y + tux_radius, tux_radius+2, clan::Colorf(0.0f, 0.0f, 1.0f, 1.0f));
// Draw tux
tux.draw(canvas, tux_position.x, tux_position.y);
// Draw text
font_large.draw_text(canvas, 10-2, 50-2, "ClanLib Layered Window", clan::Colorf(0.1f, 0.1f, 0.1f, 1.0f));
font_large.draw_text(canvas, 10, 50, "ClanLib Layered Window", clan::Colorf::green);
font_small.draw_text(canvas, 60-2, 80-2, "Click mouse on the penguin to exit", clan::Colorf(0.1f, 0.1f, 0.1f, 1.0f));
font_small.draw_text(canvas, 60, 80, "Click mouse on the penguin to exit", clan::Colorf::green);
font_small.draw_text(canvas, 110-2, 110-2, "Drag rock to move window", clan::Colorf(0.1f, 0.1f, 0.1f, 1.0f));
font_small.draw_text(canvas, 110, 110, "Drag rock to move window", clan::Colorf::green);
window.flip(1);
return !quit;
}
void TuxBall::draw(clan::Canvas &canvas)
{
sprite.set_scale(scale, scale);
sprite.set_alpha(0.5f);
sprite.draw(canvas, xpos, ypos);
}