Files
i-mic-rts/lib/camera.rb

100 lines
2.8 KiB
Ruby

class IMICRTS
class Camera
attr_reader :position, :velocity, :zoom, :drag
def initialize(scroll_speed: 10, position: CyberarmEngine::Vector.new(0.0, 0.0))
@scroll_speed = scroll_speed
@position = position
@velocity = CyberarmEngine::Vector.new(0.0, 0.0)
@zoom = 1.0
@min_zoom = 0.25
@max_zoom = 4.0
@drag = 0.8 # Used to arrest velocity
@grab_drag = 0.5 # Used when camera is panned using middle mouse button
end
def window; $window; end
def draw(&block)
if block
Gosu.translate(@position.x, @position.y) do
center_point = center
Gosu.scale(@zoom, @zoom, center.x, center.y) do
block.call
end
end
end
end
def update
move
@velocity *= @drag
@position += @velocity * @scroll_speed
end
def mouse_pick(x, y)
mouse = CyberarmEngine::Vector.new(x, y) / @zoom
normalized = (mouse / @zoom - @position / @zoom) * @zoom
normalized.x = normalized.x.floor
normalized.y = normalized.y.floor
return normalized
end
def center
(CyberarmEngine::Vector.new(window.width / 2, window.height / 2) / @zoom - @position / @zoom) * @zoom
end
def center_around(vector, factor)
@velocity *= 0
delta = lerp(self.center, vector, factor)
@position += delta * window.dt
end
def lerp(vec1, vec2, factor)
(vec1 - vec2) * factor.clamp(0.0, 1.0)
end
def aspect_ratio
window.height / window.width.to_f
end
def move
@velocity.x += @scroll_speed * window.dt if Gosu.button_down?(Gosu::KB_LEFT) || window.mouse_x < 15
@velocity.x -= @scroll_speed * window.dt if Gosu.button_down?(Gosu::KB_RIGHT) || window.mouse_x > window.width - 15
@velocity.y += @scroll_speed * window.dt if Gosu.button_down?(Gosu::KB_UP) || window.mouse_y < 15
@velocity.y -= @scroll_speed * window.dt if Gosu.button_down?(Gosu::KB_DOWN) || window.mouse_y > window.height - 15
if @drag_start
@velocity *= 0.0
@position = lerp(@position, CyberarmEngine::Vector.new(window.mouse_x, window.mouse_y) - @drag_start, @grab_drag)
end
end
def button_down(id)
case id
when Gosu::KB_H
@position.x, @position.y = 0.0, 0.0
@velocity *= 0.0
when Gosu::MS_WHEEL_UP
@zoom = (@zoom + 0.25).clamp(@min_zoom, @max_zoom)
when Gosu::MS_WHEEL_DOWN
@zoom = (@zoom - 0.25).clamp(@min_zoom, @max_zoom)
when Gosu::MS_MIDDLE
@position_start = @position.clone
@drag_start = CyberarmEngine::Vector.new(window.mouse_x, window.mouse_y)
end
end
def button_up(id)
case id
when Gosu::MS_MIDDLE
@position_start = nil
@drag_start = nil
end
end
end
end