用RGD绘制Bézier曲线

有丘直方

RUBY 代码复制

class Vector
 
  include(Enumerable)
 
  attr_accessor :x
  attr_accessor :y
 
  def initialize(*args)
    case args.size
    when 0
      @x = 0
      @y = 0
    when 1
      @x = args[0]
      @y = args[0]
    when 2
      @x = args[0]
      @y = args[1]
    end
  end
 
  def +@
    self
  end
 
  def -@
    Vector.new(-@x, -@y)
  end
 
  def +(other)
    Vector.new(@x + other.x, @y + other.y)
  end
 
  def -(other)
    self + -other
  end
 
  def *(other)
    case other
    when Numeric
      Vector.new(@x * other, @y * other)
    when Vector
      @x * other.x + @y * other.y
    end
  end
 
  def dot(other)
    self * other
  end
 
  def cross(other)
    self.x * other.y - other.x * self.y
  end
 
  def slope
    y / x
  end
 
  def square_length
    self * self
  end
 
  def length
    Math.sqrt(square_length)
  end
 
  def is_out_of?(other)
    @x.abs > other.x.abs || @y.abs > other.y.abs
  end
 
  def abs
    Vector.new(@x.abs, @y.abs)
  end
 
  def each
    yield @x
    yield @y
  end
end
 
module Math
 
  def self.definite_proportion(point1, point2, proportion)
    point1 * (1 - proportion) + point2 * proportion
  end
end
 
class Rect
 
  alias ulysses201811181949_initialize initialize
  def initialize(*args)
    args = case args.size
    when 0, 4
      args
    when 2
      [args[0].x, args[0].y, args[1].x, args[1].y]
    end
    ulysses201811181949_initialize(*args)
  end
 
  def position
    Vector.new(x, y)
  end
 
  def position=(position)
    self.x = position.x
    self.y = position.y
  end
 
  def size
    Vector.new(width, height)
  end
 
  def size=(size)
    self.width = size.x
    self.height = size.y
  end
end
 
module Kernel
 
  def do_by_step(from, to, step)
    if block_given?
      i = from
      until i >= to
        yield i
        i += step
      end
    else
      to_enum(__method__, from, to, step)
    end
  end
end
 
class Bitmap
 
  alias ulysses201811181708_initialize initialize
  def initialize(*args)
    args = if args.size == 2 || args[0].is_a?(String)
      args
    elsif args.size == 1
      [args[0].x, args[0].y]
    else
      [0, 0]
    end
    ulysses201811181708_initialize(*args)
  end
 
  def fill_circle(center, radius, color)
    i_max = (radius * 707) / 1000 + 1
    square_distance_max = radius * radius + radius / 2
    x = radius
    fill_rect(center.x - radius, center.y, 2 * radius, 1, color)
    for i in 1..i_max
      if Vector.new(center.x, i).square_length > square_distance_max
        if x > i_max
          fill_rect(center.x - i + 1, center.y + x, 2 * (i - 1), 1, color)
          fill_rect(center.x - i + 1, center.y - x, 2 * (i - 1), 1, color)
        end
        x -= 1
      end
      fill_rect(center.x - x, center.y + i, 2 * x, 1, color)
      fill_rect(center.x - x, center.y - i, 2 * x, 1, color)
    end
  end
 
  def draw_line(point1, point2, color)
    difference = point2 - point1
    abs_difference = difference.abs
    total_step = abs_difference.max
    delta = difference * (1.0 / total_step)
    vector = point1
    (total_step - 1).to_i.times do
      set_pixel(vector, color)
      vector += delta
    end
  end
 
  alias ulysses201811182036_set_pixel set_pixel
  def set_pixel(*args)
    args = case args.size
    when 3
      args
    when 2
      [args[0].x, args[0].y, args[1]]
    end
    ulysses201811182036_set_pixel(*args)
  end
 
  def text_vector(text)
    text_size(text).size
  end
 
  def size
    Vector.new(width, height)
  end
 
  def size=(size)
    self.rect.size = size
  end
 
  alias ulysses201811181952_draw_text draw_text
  def draw_text(*args)
    args = case args[0]
    when Numeric, Rect
      args
    when Vector
      a = [args[0].x, args[0].y, args[1].x, args[1].y, args[2]]
      a.push(args[3]) if args.size >= 4
      a
    end
    ulysses201811181952_draw_text(*args)
  end
end
 
class Sprite
 
  alias ulysses201811181903_initialize initialize
  def initialize(viewport = nil)
    ulysses201811181903_initialize(viewport)
    self.bitmap = Bitmap.new
  end
 
  def position=(position)
    self.x = position.x
    self.y = position.y
  end
end
 
module Graphics
 
  def self.size
    Vector.new(width, height)
  end
end
 
module Mouse
 
  def self.position
    Vector.new(x, y)
  end
end
 
module Scene
 
  POINT_RADIUS = 3
  POINT_COLOR = Color.new(255, 255, 255, 255)
  POINT_Z = 10
  CURVE_RADIUS = 2
  CURVE_COLOR = Color.new(255, 255, 255, 255)
  LINE_COLOR = Color.new(255, 255, 255, 255)
  T_BEGINNING = 0.0
  T_END = 1.0
  T_STEP = 0.001
  UPDATE_STEPS = 20
 
  def self.init
    Graphics.resize_screen(1024, 768)
    @graph_sprite = Sprite.new
    @graph_sprite.bitmap = Bitmap.new(Graphics.size)
    @line_sprite = Sprite.new
    @line_sprite.bitmap = Bitmap.new(Graphics.size)
    @points = []
    @point_sprites = []
    @temp_bitmap = Bitmap.new(32, 32)
    @line_visible = true
    @point_visible = true
    @fast_mode = false
    @covering_drawing = 0
  end
 
  def self.create_point(point)
    sprite = Sprite.new
    sprite.visible = @point_visible
    radius_vector = Vector.new(POINT_RADIUS)
    text_vector = @temp_bitmap.text_vector(@points.size)
    radius_text_vector = radius_vector + text_vector
    sprite.bitmap = Bitmap.new(radius_text_vector + radius_vector)
    flip = (point + radius_text_vector).is_out_of?(Graphics.size)
    excursion = flip ? radius_text_vector : radius_vector
    sprite.position = point - excursion
    sprite.bitmap.fill_circle(excursion, POINT_RADIUS, POINT_COLOR)
    text_position = flip ? Vector.new : radius_vector * 2
    sprite.bitmap.draw_text(text_position, text_vector, @points.size)
    sprite.z = POINT_Z
    @points.push(point)
    @point_sprites.push(sprite)
    refresh_graph
  end
 
  def self.delete_point
    @points.pop
    @point_sprites.pop.dispose
    refresh_graph
  end
 
  def self.refresh_graph
    @covering_drawing += 1
    @graph_sprite.bitmap.clear
    return if @points.empty?
    step_count = 0
    will_update = false
    do_by_step(T_BEGINNING, T_END, T_STEP) do |t|
      will_update = true if !@fast_mode && (step_count += 1) >= UPDATE_STEPS
      @line_sprite.bitmap.clear
      sequences = [@points]
      (@points.size - 1).times do |i|
        last_sequence = sequences.last
        sequences.push([])
        (last_sequence.size - 1).times do |j|
          if @line_visible && will_update
            @line_sprite.bitmap.draw_line(*last_sequence[j, 2], LINE_COLOR)
          end
          sequences.last.push(Math.definite_proportion(*last_sequence[j, 2], t))
        end
      end
      @graph_sprite.bitmap.fill_circle(*sequences.last, CURVE_RADIUS, CURVE_COLOR)
      if will_update
        step_count = 0
        will_update = false
        last_covering_drawing = @covering_drawing
        update
        return if @covering_drawing > last_covering_drawing
      end
    end
    (@points.size - 1).times do |i|
      @line_sprite.bitmap.draw_line(*@points[i, 2], LINE_COLOR)
    end
  end
 
  def self.toggle_line_visible
    @line_visible = !@line_visible
    @line_sprite.visible = @line_visible
  end
 
  def self.toggle_point_visible
    @point_visible = !@point_visible
    @point_sprites.each {|sprite| sprite.visible = @point_visible }
  end
 
  def self.toggle_fast_mode
    @fast_mode = !@fast_mode
  end
 
  def self.update_basic
    Graphics.update
    Input.update
    Mouse.update
  end
 
  def self.update
    update_basic
    if Mouse.click?(:L)
      create_point(Mouse.position)
    elsif Mouse.click?(:R)
      delete_point
    elsif Input.trigger?(:A)
      toggle_fast_mode
    elsif Input.trigger?(:B)
      toggle_line_visible
    elsif Input.trigger?(:C)
      toggle_point_visible
    end
  end
  def self.main
    init
    loop { update }
  end
end
 
Scene.main

class Vector


 


  include(Enumerable)


 


  attr_accessor :x


  attr_accessor :y


 


  def initialize(*args)


    case args.size


    when 0


      @x = 0


      @y = 0


    when 1


      @x = args[0]


      @y = args[0]


    when 2


      @x = args[0]


      @y = args[1]


    end


  end


 


  def +@


    self


  end


 


  def -@


    Vector.new(-@x, -@y)


  end


 


  def +(other)


    Vector.new(@x + other.x, @y + other.y)


  end


 


  def -(other)


    self + -other


  end


 


  def *(other)


    case other


    when Numeric


      Vector.new(@x * other, @y * other)


    when Vector


      @x * other.x + @y * other.y


    end


  end


 


  def dot(other)


    self * other


  end


 


  def cross(other)


    self.x * other.y - other.x * self.y


  end


 


  def slope


    y / x


  end


 


  def square_length


    self * self


  end


 


  def length


    Math.sqrt(square_length)


  end


 


  def is_out_of?(other)


    @x.abs > other.x.abs || @y.abs > other.y.abs


  end


 


  def abs


    Vector.new(@x.abs, @y.abs)


  end


 


  def each


    yield @x


    yield @y


  end


end


 


module Math


 


  def self.definite_proportion(point1, point2, proportion)


    point1 * (1 - proportion) + point2 * proportion


  end


end


 


class Rect


 


  alias ulysses201811181949_initialize initialize


  def initialize(*args)


    args = case args.size


    when 0, 4


      args


    when 2


      [args[0].x, args[0].y, args[1].x, args[1].y]


    end


    ulysses201811181949_initialize(*args)


  end


 


  def position


    Vector.new(x, y)


  end


 


  def position=(position)


    self.x = position.x


    self.y = position.y


  end


 


  def size


    Vector.new(width, height)


  end


 


  def size=(size)


    self.width = size.x


    self.height = size.y


  end


end


 


module Kernel


 


  def do_by_step(from, to, step)


    if block_given?


      i = from


      until i >= to


        yield i


        i += step


      end


    else


      to_enum(__method__, from, to, step)


    end


  end


end


 


class Bitmap


 


  alias ulysses201811181708_initialize initialize


  def initialize(*args)


    args = if args.size == 2 || args[0].is_a?(String)


      args


    elsif args.size == 1


      [args[0].x, args[0].y]


    else


      [0, 0]


    end


    ulysses201811181708_initialize(*args)


  end


 


  def fill_circle(center, radius, color)


    i_max = (radius * 707) / 1000 + 1


    square_distance_max = radius * radius + radius / 2


    x = radius


    fill_rect(center.x - radius, center.y, 2 * radius, 1, color)


    for i in 1..i_max


      if Vector.new(center.x, i).square_length > square_distance_max


        if x > i_max


          fill_rect(center.x - i + 1, center.y + x, 2 * (i - 1), 1, color)


          fill_rect(center.x - i + 1, center.y - x, 2 * (i - 1), 1, color)


        end


        x -= 1


      end


      fill_rect(center.x - x, center.y + i, 2 * x, 1, color)


      fill_rect(center.x - x, center.y - i, 2 * x, 1, color)


    end


  end


 


  def draw_line(point1, point2, color)


    difference = point2 - point1


    abs_difference = difference.abs


    total_step = abs_difference.max


    delta = difference * (1.0 / total_step)


    vector = point1


    (total_step - 1).to_i.times do


      set_pixel(vector, color)


      vector += delta


    end


  end


 


  alias ulysses201811182036_set_pixel set_pixel


  def set_pixel(*args)


    args = case args.size


    when 3


      args


    when 2


      [args[0].x, args[0].y, args[1]]


    end


    ulysses201811182036_set_pixel(*args)


  end


 


  def text_vector(text)


    text_size(text).size


  end


 


  def size


    Vector.new(width, height)


  end


 


  def size=(size)


    self.rect.size = size


  end


 


  alias ulysses201811181952_draw_text draw_text


  def draw_text(*args)


    args = case args[0]


    when Numeric, Rect


      args


    when Vector


      a = [args[0].x, args[0].y, args[1].x, args[1].y, args[2]]


      a.push(args[3]) if args.size >= 4


      a


    end


    ulysses201811181952_draw_text(*args)


  end


end


 


class Sprite


 


  alias ulysses201811181903_initialize initialize


  def initialize(viewport = nil)


    ulysses201811181903_initialize(viewport)


    self.bitmap = Bitmap.new


  end


 


  def position=(position)


    self.x = position.x


    self.y = position.y


  end


end


 


module Graphics


 


  def self.size


    Vector.new(width, height)


  end


end


 


module Mouse


 


  def self.position


    Vector.new(x, y)


  end


end


 


module Scene


 


  POINT_RADIUS = 3


  POINT_COLOR = Color.new(255, 255, 255, 255)


  POINT_Z = 10


  CURVE_RADIUS = 2


  CURVE_COLOR = Color.new(255, 255, 255, 255)


  LINE_COLOR = Color.new(255, 255, 255, 255)


  T_BEGINNING = 0.0


  T_END = 1.0


  T_STEP = 0.001


  UPDATE_STEPS = 20


 


  def self.init


    Graphics.resize_screen(1024, 768)


    @graph_sprite = Sprite.new


    @graph_sprite.bitmap = Bitmap.new(Graphics.size)


    @line_sprite = Sprite.new


    @line_sprite.bitmap = Bitmap.new(Graphics.size)


    @points = []


    @point_sprites = []


    @temp_bitmap = Bitmap.new(32, 32)


    @line_visible = true


    @point_visible = true


    @fast_mode = false


    @covering_drawing = 0


  end


 


  def self.create_point(point)


    sprite = Sprite.new


    sprite.visible = @point_visible


    radius_vector = Vector.new(POINT_RADIUS)


    text_vector = @temp_bitmap.text_vector(@points.size)


    radius_text_vector = radius_vector + text_vector


    sprite.bitmap = Bitmap.new(radius_text_vector + radius_vector)


    flip = (point + radius_text_vector).is_out_of?(Graphics.size)


    excursion = flip ? radius_text_vector : radius_vector


    sprite.position = point - excursion


    sprite.bitmap.fill_circle(excursion, POINT_RADIUS, POINT_COLOR)


    text_position = flip ? Vector.new : radius_vector * 2


    sprite.bitmap.draw_text(text_position, text_vector, @points.size)


    sprite.z = POINT_Z


    @points.push(point)


    @point_sprites.push(sprite)


    refresh_graph


  end


 


  def self.delete_point


    @points.pop


    @point_sprites.pop.dispose


    refresh_graph


  end


 


  def self.refresh_graph


    @covering_drawing += 1


    @graph_sprite.bitmap.clear


    return if @points.empty?


    step_count = 0


    will_update = false


    do_by_step(T_BEGINNING, T_END, T_STEP) do |t|


      will_update = true if !@fast_mode && (step_count += 1) >= UPDATE_STEPS


      @line_sprite.bitmap.clear


      sequences = [@points]


      (@points.size - 1).times do |i|


        last_sequence = sequences.last


        sequences.push([])


        (last_sequence.size - 1).times do |j|


          if @line_visible && will_update


            @line_sprite.bitmap.draw_line(*last_sequence[j, 2], LINE_COLOR)


          end


          sequences.last.push(Math.definite_proportion(*last_sequence[j, 2], t))


        end


      end


      @graph_sprite.bitmap.fill_circle(*sequences.last, CURVE_RADIUS, CURVE_COLOR)


      if will_update


        step_count = 0


        will_update = false


        last_covering_drawing = @covering_drawing


        update


        return if @covering_drawing > last_covering_drawing


      end


    end


    (@points.size - 1).times do |i|


      @line_sprite.bitmap.draw_line(*@points[i, 2], LINE_COLOR)


    end


  end


 


  def self.toggle_line_visible


    @line_visible = !@line_visible


    @line_sprite.visible = @line_visible


  end


 


  def self.toggle_point_visible


    @point_visible = !@point_visible


    @point_sprites.each {|sprite| sprite.visible = @point_visible }


  end


 


  def self.toggle_fast_mode


    @fast_mode = !@fast_mode


  end


 


  def self.update_basic


    Graphics.update


    Input.update


    Mouse.update


  end


 


  def self.update


    update_basic


    if Mouse.click?(:L)


      create_point(Mouse.position)


    elsif Mouse.click?(:R)


      delete_point


    elsif Input.trigger?(:A)


      toggle_fast_mode


    elsif Input.trigger?(:B)


      toggle_line_visible


    elsif Input.trigger?(:C)


      toggle_point_visible


    end


  end


  def self.main


    init


    loop { update }


  end


end


 


Scene.main

马上要睡了，不多说了，看图

本来想用shader的，后来还是屈服于Bitmap了……
按左键添加节点，按右键去除节点，按A开启快速模式（不显示绘制过程），按B切换线段的显示，按C切换节点的显示（此处ABC不是键盘上的ABC）

---

RUBY 代码复制

# 二维向量
class Vector
 
  # 可以进行枚举，参见#each
  include(Enumerable)
 
  attr_accessor :x # x方向上的分量
  attr_accessor :y # y方向上的分量
 
  # 初始化
  # 无参数时：(0, 0)
  # 有一个参数r时：(r, r)
  # 有两个参数x, y时：(x, y)
  def initialize(*args)
    case args.size
    when 0
      @x = 0
      @y = 0
    when 1
      @x = args[0]
      @y = args[0]
    when 2
      @x = args[0]
      @y = args[1]
    end
  end
 
  def +@
    self
  end
 
  # 反向量
  def -@
    Vector.new(-@x, -@y)
  end
 
  # 加法
  def +(other)
    Vector.new(@x + other.x, @y + other.y)
  end
 
  # 减法
  def -(other)
    self + -other
  end
 
  # 点乘或数乘运算
  def *(other)
    case other
    when Numeric
      Vector.new(@x * other, @y * other)
    when Vector
      @x * other.x + @y * other.y
    end
  end
 
  # 点积
  def dot(other)
    @x * other.x + @y * other.y
  end
 
  # 叉积
  def cross(other)
    self.x * other.y - other.x * self.y
  end
 
  # 斜率
  def slope
    x =! 0 ? y / x : Float::Infinity
  end
 
  # 模的平方
  def square_length
    self * self
  end
 
  # 模
  def length
    Math.sqrt(square_length)
  end
 
  # 超出范围
  def is_out_of?(other)
    @x.abs > other.x.abs || @y.abs > other.y.abs
  end
 
  # 对x和y方向的分量分别取绝对值
  def abs
    Vector.new(@x.abs, @y.abs)
  end
 
  # 切向
  def normal
    Vector.new(-@y, @x)
  end
 
  # 枚举，先对x计算，后对y计算
  def each
    yield @x
    yield @y
  end
 
  def inspect
    "(#{@x}, #{@y})"
  end
end
 
module Math
 
  # 获得两点之间由某个比例决定的分点
  def self.definite_proportion(point1, point2, proportion)
    point1 * (1 - proportion) + point2 * proportion
  end
end
 
class Rect
 
  # 初始化
  # 除了原先的参数列表，支持由两个向量来决定其位置大小
  # 如果用向量表示，第一个向量是position，第二个向量是size
  alias ulysses201811181949_initialize initialize
  def initialize(*args)
    args = case args.size
    when 0, 4
      args
    when 2
      [args[0].x, args[0].y, args[1].x, args[1].y]
    end
    ulysses201811181949_initialize(*args)
  end
 
  def position
    Vector.new(x, y)
  end
 
  def position=(position)
    self.x = position.x
    self.y = position.y
  end
 
  def size
    Vector.new(width, height)
  end
 
  def size=(size)
    self.width = size.x
    self.height = size.y
  end
end
 
module Kernel
 
  # 令变量从from到to按照step进行线性变化并传递到块中
  def do_by_step(from, to, step)
    if block_given?
      i = from
      until i >= to
        yield i
        i += step
      end
    else
      to_enum(__method__, from, to, step)
    end
  end
 
  def gets(*args)
    $stdin.gets(*args)
  end
 
  def Vector(*args)
    Vector.new(*args)
  end
end
 
class Bitmap
 
  # 初始化
  # 支持向量表示
  alias ulysses201811181708_initialize initialize
  def initialize(*args)
    args = if args.size == 2 || args[0].is_a?(String)
      args
    elsif args.size == 1
      [args[0].x, args[0].y]
    else
      [0, 0]
    end
    ulysses201811181708_initialize(*args)
  end
 
  # 填充一个圆
  def fill_circle(center, radius, color)
    i_max = (radius * 707) / 1000 + 1
    square_distance_max = radius * radius + radius / 2
    x = radius
    fill_rect(center.x - radius, center.y, 2 * radius, 1, color)
    for i in 1..i_max
      if Vector.new(center.x, i).square_length > square_distance_max
        if x > i_max
          fill_rect(center.x - i + 1, center.y + x, 2 * (i - 1), 1, color)
          fill_rect(center.x - i + 1, center.y - x, 2 * (i - 1), 1, color)
        end
        x -= 1
      end
      fill_rect(center.x - x, center.y + i, 2 * x, 1, color)
      fill_rect(center.x - x, center.y - i, 2 * x, 1, color)
    end
  end
 
  # 用一条1像素宽的线段联结两点
  def draw_line(point1, point2, color)
    difference = point2 - point1
    abs_difference = difference.abs
    total_step = abs_difference.max
    delta = difference * (1.0 / total_step)
    vector = point1
    (total_step.to_i + 1).times do
      set_pixel(vector, color)
      vector += delta
    end
  end
 
  alias ulysses201811182036_set_pixel set_pixel
  def set_pixel(*args)
    args = case args.size
    when 3
      args
    when 2
      [args[0].x, args[0].y, args[1]]
    end
    ulysses201811182036_set_pixel(*args)
  end
 
  def text_vector(text)
    text_size(text).size
  end
 
  def size
    Vector.new(width, height)
  end
 
  def size=(size)
    self.rect.size = size
  end
 
  alias ulysses201811181952_draw_text draw_text
  def draw_text(*args)
    args = case args[0]
    when Numeric, Rect
      args
    when Vector
      a = [args[0].x, args[0].y, args[1].x, args[1].y, args[2]]
      a.push(args[3]) if args.size >= 4
      a
    end
    ulysses201811181952_draw_text(*args)
  end
end
 
class Sprite
 
  def position=(position)
    self.x = position.x
    self.y = position.y
  end
end
 
class Viewport
 
  # 让add_fast_layer接受默认参数blend_type = 0
  alias ulysses201812021851_add_fast_layer add_fast_layer
  def add_fast_layer(z, blend_type = 0)
    ulysses201812021851_add_fast_layer(z, blend_type)
  end
end
 
# 重写了Input模块
# 支持全键盘和鼠标按键
# 如果不需要判断鼠标位置的话，可以不update
module Input
 
  REPEAT_TIME = 4 # 当key被按超过此数时，repeat?(key) == true
  GetKeyState = Win32API.new("user32", "GetAsyncKeyState", ['I'], 'I')
 
  @key_states = {}
  @key_repeat_times = {}
 
  def self.press?(key)
    key < 0x08 ? Mouse.press?(key) : GetKeyState.call(key) != 0
  end
 
  def self.repeat?(key)
    if press?(key)
      unless @key_repeat_times[key]
        @key_repeat_times[key] = 0
        return true
      end
      @key_repeat_times[key] += 1
    else
      @key_repeat_times[key] = nil
      @key_states[key] = 0
    end
    if !@key_repeat_times[key].nil? && @key_repeat_times[key] > REPEAT_TIME
      @key_repeat_times[key] = 0
      return true
    end
    false
  end
 
  def self.trigger?(key)
    if press?(key)
      return false if @key_states[key] == 1
      @key_states[key] = 1
      true
    else
      @key_states[key] = 0
      false
    end
  end
 
  def self.update
    Mouse.update
  end
end
 
class << Graphics
 
  def size
    Vector.new(width, height)
  end
 
  alias ulysses201811251830_resize_screen resize_screen
  def resize_screen(*args)
    case args.size
    when 2
      ulysses201811251830_resize_screen(*args)
    when 1
      ulysses201811251830_resize_screen(args[0].x, args[0].y)
    end
  end
end
 
Graphics.resize_screen(1024, 768) # 更改分辨率
 
module Mouse
 
  def self.position
    Vector.new(x, y)
  end
end
 
# 封装为模块的场景
module Scene
 
  # 绘制控制点的参数
  POINTS_RADIUS = 3
  POINTS_COLOR = Color.new(255, 255, 255, 255)
  POINTS_Z = 10
  # 绘制曲线的参数
  CURVE_COLOR = Color.new(255, 255, 255, 255)
  CURVE_Z = 0
  # 绘制线段的参数
  LINES_COLOR = Color.new(255, 255, 255, 127)
  LINES_Z = -10
  # 用于调整绘制的范围和精度
  T_BEGINNING = 0.0
  T_END = 1.0
  T_STEP = 0.01
  UPDATE_STEPS = 5
  TEMP_BITMAP = Bitmap.new(32, 32) # 临时位图，用于获取文字大小
  # 按键
  CREATE_CONTROL_POINT_KEY = 0x01 # left
  DELETE_CONTROL_POINT_KEY = 0x02 # right
  FAST_MODE_KEY = 0x41 # A
  LINES_VISIBLE_KEY = 0x42 # B
  CONTROL_POINTS_VISIBLE_KEY = 0x43 # C
 
  # 显示端口
  @viewport = Viewport.new
  @viewport.add_fast_layer(POINTS_Z)
  # 曲线
  @curve_sprite = Sprite.new(@viewport)
  @curve_sprite.bitmap = Bitmap.new(Graphics.size)
  @curve_sprite.z = CURVE_Z
  # 线段
  @lines_sprite = Sprite.new(@viewport)
  @lines_sprite.bitmap = Bitmap.new(Graphics.size)
  @lines_sprite.z = LINES_Z
  # 控制点
  @control_points = []
  @control_point_sprites = []
  # 模式控制
  @lines_visible = true
  @control_points_visible = true
  @fast_mode = false
  # 阻断刷新控制
  @covering_drawing = 0
 
  # 创建控制点
  def self.create_control_point(point)
    sprite = Sprite.new(@viewport)
    sprite.visible = @control_points_visible
    radius_vector = Vector.new(POINTS_RADIUS)
    text_vector = TEMP_BITMAP.text_vector(@control_points.size)
    radius_text_vector = radius_vector + text_vector
    sprite.bitmap = Bitmap.new(radius_text_vector + radius_vector)
    sprite.bitmap.font.color = POINTS_COLOR
    x_flip = (point + radius_text_vector).x > Graphics.width
    y_flip = (point + radius_text_vector).y > Graphics.height
    excursion = Vector.new
    excursion.x = x_flip ? radius_text_vector.x : radius_vector.x
    excursion.y = y_flip ? radius_text_vector.y : radius_vector.y
    sprite.position = point - excursion
    sprite.bitmap.fill_circle(excursion, POINTS_RADIUS, POINTS_COLOR)
    text_position = Vector.new
    text_position.x = x_flip ? 0 : radius_vector.x * 2
    text_position.y = y_flip ? 0 : radius_vector.y * 2
    sprite.bitmap.draw_text(text_position, text_vector, @control_points.size)
    sprite.z = POINTS_Z
    @control_point_sprites.push(sprite)
    @control_points.push(point)
    refresh_graph
    point
  end
 
  # 删除上一个控制点
  def self.delete_control_point
    return if @control_points.empty?
    point = @control_points.pop
    sprite = @control_point_sprites.pop
    sprite.bitmap.dispose
    sprite.dispose
    refresh_graph
    point
  end
 
  # 刷新图形
  # 该方法在非快速模式下会阻塞，但update不会停且可以被打断
  def self.refresh_graph
    @covering_drawing += 1
    @curve_sprite.bitmap.clear
    return if @control_points.empty?
    graph_points = []
    steps_count = 0
    do_by_step(T_BEGINNING, T_END, T_STEP) do |t|
      will_update = !@fast_mode && (steps_count += 1) >= UPDATE_STEPS
      graph_points.push(next_graph_point(t, will_update))
      if graph_points.size > 1
        @curve_sprite.bitmap.draw_line(*graph_points.last(2), CURVE_COLOR)
      end
      if will_update
        steps_count = 0
        last_covering_drawing = @covering_drawing
        update
        return if @covering_drawing > last_covering_drawing
      end
    end
    connect_control_points_with_lines
  end
 
  # 根据t返回曲线上的点坐标
  # 若@lines_visible && will_update则会绘制线段
  def self.next_graph_point(t, will_update = false)
    is_drawing = @lines_visible && will_update
    @lines_sprite.bitmap.clear if is_drawing
    sequences = [@control_points]
    (@control_points.size - 1).times do |i|
      last_sequence = sequences.last
      sequences.push([])
      (last_sequence.size - 1).times do |j|
        if is_drawing
          @lines_sprite.bitmap.draw_line(*last_sequence[j, 2], LINES_COLOR)
        end
        sequences.last.push(Math.definite_proportion(*last_sequence[j, 2], t))
      end
    end
    sequences.last.first
  end
 
  # 用线段将控制点联结
  def self.connect_control_points_with_lines
    @lines_sprite.bitmap.clear
    (@control_points.size - 1).times do |i|
      @lines_sprite.bitmap.draw_line(*@control_points[i, 2], LINES_COLOR)
    end
    nil
  end
 
  # 切换线段可见
  def self.toggle_lines_visible
    @lines_visible = !@lines_visible
    @lines_sprite.visible = @lines_visible
  end
 
  # 切换控制点可见
  def self.toggle_points_visible
    @control_points_visible = !@control_points_visible
    @control_point_sprites.each do |sprite|
      sprite.visible = @control_points_visible
    end
  end
 
  # 切换快速模式
  def self.toggle_fast_mode
    @fast_mode = !@fast_mode
  end
 
  # 基础更新，必须每帧调用
  def self.update_basic
    Graphics.update
    Input.update
  end
 
  # 更新，需每帧调用
  def self.update
    update_basic
    if Input.trigger?(CREATE_CONTROL_POINT_KEY)
      create_control_point(Mouse.position)
    elsif Input.trigger?(DELETE_CONTROL_POINT_KEY)
      delete_control_point
    elsif Input.trigger?(FAST_MODE_KEY)
      toggle_fast_mode
    elsif Input.trigger?(LINES_VISIBLE_KEY)
      toggle_lines_visible
    elsif Input.trigger?(CONTROL_POINTS_VISIBLE_KEY)
      toggle_points_visible
    end
  end
 
  # 简单的irb
  def self.simple_irb_start
    Thread.start do
      ans = nil
      loop { puts("=> #{(ans = eval(gets)).inspect}") rescue puts($!.message) }
    end
  end
 
  # 主进程
  def self.main
    simple_irb_start
    loop { update }
  end
end
 
# 入口
Scene.main

# 二维向量


class Vector


 


  # 可以进行枚举，参见#each


  include(Enumerable)


 


  attr_accessor :x # x方向上的分量


  attr_accessor :y # y方向上的分量


 


  # 初始化


  # 无参数时：(0, 0)


  # 有一个参数r时：(r, r)


  # 有两个参数x, y时：(x, y)


  def initialize(*args)


    case args.size


    when 0


      @x = 0


      @y = 0


    when 1


      @x = args[0]


      @y = args[0]


    when 2


      @x = args[0]


      @y = args[1]


    end


  end


 


  def +@


    self


  end


 


  # 反向量


  def -@


    Vector.new(-@x, -@y)


  end


 


  # 加法


  def +(other)


    Vector.new(@x + other.x, @y + other.y)


  end


 


  # 减法


  def -(other)


    self + -other


  end


 


  # 点乘或数乘运算


  def *(other)


    case other


    when Numeric


      Vector.new(@x * other, @y * other)


    when Vector


      @x * other.x + @y * other.y


    end


  end


 


  # 点积


  def dot(other)


    @x * other.x + @y * other.y


  end


 


  # 叉积


  def cross(other)


    self.x * other.y - other.x * self.y


  end


 


  # 斜率


  def slope


    x =! 0 ? y / x : Float::Infinity


  end


 


  # 模的平方


  def square_length


    self * self


  end


 


  # 模


  def length


    Math.sqrt(square_length)


  end


 


  # 超出范围


  def is_out_of?(other)


    @x.abs > other.x.abs || @y.abs > other.y.abs


  end


 


  # 对x和y方向的分量分别取绝对值


  def abs


    Vector.new(@x.abs, @y.abs)


  end


 


  # 切向


  def normal


    Vector.new(-@y, @x)


  end


 


  # 枚举，先对x计算，后对y计算


  def each


    yield @x


    yield @y


  end


 


  def inspect


    "(#{@x}, #{@y})"


  end


end


 


module Math


 


  # 获得两点之间由某个比例决定的分点


  def self.definite_proportion(point1, point2, proportion)


    point1 * (1 - proportion) + point2 * proportion


  end


end


 


class Rect


 


  # 初始化


  # 除了原先的参数列表，支持由两个向量来决定其位置大小


  # 如果用向量表示，第一个向量是position，第二个向量是size


  alias ulysses201811181949_initialize initialize


  def initialize(*args)


    args = case args.size


    when 0, 4


      args


    when 2


      [args[0].x, args[0].y, args[1].x, args[1].y]


    end


    ulysses201811181949_initialize(*args)


  end


 


  def position


    Vector.new(x, y)


  end


 


  def position=(position)


    self.x = position.x


    self.y = position.y


  end


 


  def size


    Vector.new(width, height)


  end


 


  def size=(size)


    self.width = size.x


    self.height = size.y


  end


end


 


module Kernel


 


  # 令变量从from到to按照step进行线性变化并传递到块中


  def do_by_step(from, to, step)


    if block_given?


      i = from


      until i >= to


        yield i


        i += step


      end


    else


      to_enum(__method__, from, to, step)


    end


  end


 


  def gets(*args)


    $stdin.gets(*args)


  end


 


  def Vector(*args)


    Vector.new(*args)


  end


end


 


class Bitmap


 


  # 初始化


  # 支持向量表示


  alias ulysses201811181708_initialize initialize


  def initialize(*args)


    args = if args.size == 2 || args[0].is_a?(String)


      args


    elsif args.size == 1


      [args[0].x, args[0].y]


    else


      [0, 0]


    end


    ulysses201811181708_initialize(*args)


  end


 


  # 填充一个圆


  def fill_circle(center, radius, color)


    i_max = (radius * 707) / 1000 + 1


    square_distance_max = radius * radius + radius / 2


    x = radius


    fill_rect(center.x - radius, center.y, 2 * radius, 1, color)


    for i in 1..i_max


      if Vector.new(center.x, i).square_length > square_distance_max


        if x > i_max


          fill_rect(center.x - i + 1, center.y + x, 2 * (i - 1), 1, color)


          fill_rect(center.x - i + 1, center.y - x, 2 * (i - 1), 1, color)


        end


        x -= 1


      end


      fill_rect(center.x - x, center.y + i, 2 * x, 1, color)


      fill_rect(center.x - x, center.y - i, 2 * x, 1, color)


    end


  end


 


  # 用一条1像素宽的线段联结两点


  def draw_line(point1, point2, color)


    difference = point2 - point1


    abs_difference = difference.abs


    total_step = abs_difference.max


    delta = difference * (1.0 / total_step)


    vector = point1


    (total_step.to_i + 1).times do


      set_pixel(vector, color)


      vector += delta


    end


  end


 


  alias ulysses201811182036_set_pixel set_pixel


  def set_pixel(*args)


    args = case args.size


    when 3


      args


    when 2


      [args[0].x, args[0].y, args[1]]


    end


    ulysses201811182036_set_pixel(*args)


  end


 


  def text_vector(text)


    text_size(text).size


  end


 


  def size


    Vector.new(width, height)


  end


 


  def size=(size)


    self.rect.size = size


  end


 


  alias ulysses201811181952_draw_text draw_text


  def draw_text(*args)


    args = case args[0]


    when Numeric, Rect


      args


    when Vector


      a = [args[0].x, args[0].y, args[1].x, args[1].y, args[2]]


      a.push(args[3]) if args.size >= 4


      a


    end


    ulysses201811181952_draw_text(*args)


  end


end


 


class Sprite


 


  def position=(position)


    self.x = position.x


    self.y = position.y


  end


end


 


class Viewport


 


  # 让add_fast_layer接受默认参数blend_type = 0


  alias ulysses201812021851_add_fast_layer add_fast_layer


  def add_fast_layer(z, blend_type = 0)


    ulysses201812021851_add_fast_layer(z, blend_type)


  end


end


 


# 重写了Input模块


# 支持全键盘和鼠标按键


# 如果不需要判断鼠标位置的话，可以不update


module Input


 


  REPEAT_TIME = 4 # 当key被按超过此数时，repeat?(key) == true


  GetKeyState = Win32API.new("user32", "GetAsyncKeyState", ['I'], 'I')


 


  @key_states = {}


  @key_repeat_times = {}


 


  def self.press?(key)


    key < 0x08 ? Mouse.press?(key) : GetKeyState.call(key) != 0


  end


 


  def self.repeat?(key)


    if press?(key)


      unless @key_repeat_times[key]


        @key_repeat_times[key] = 0


        return true


      end


      @key_repeat_times[key] += 1


    else


      @key_repeat_times[key] = nil


      @key_states[key] = 0


    end


    if !@key_repeat_times[key].nil? && @key_repeat_times[key] > REPEAT_TIME


      @key_repeat_times[key] = 0


      return true


    end


    false


  end


 


  def self.trigger?(key)


    if press?(key)


      return false if @key_states[key] == 1


      @key_states[key] = 1


      true


    else


      @key_states[key] = 0


      false


    end


  end


 


  def self.update


    Mouse.update


  end


end


 


class << Graphics


 


  def size


    Vector.new(width, height)


  end


 


  alias ulysses201811251830_resize_screen resize_screen


  def resize_screen(*args)


    case args.size


    when 2


      ulysses201811251830_resize_screen(*args)


    when 1


      ulysses201811251830_resize_screen(args[0].x, args[0].y)


    end


  end


end


 


Graphics.resize_screen(1024, 768) # 更改分辨率


 


module Mouse


 


  def self.position


    Vector.new(x, y)


  end


end


 


# 封装为模块的场景


module Scene


 


  # 绘制控制点的参数


  POINTS_RADIUS = 3


  POINTS_COLOR = Color.new(255, 255, 255, 255)


  POINTS_Z = 10


  # 绘制曲线的参数


  CURVE_COLOR = Color.new(255, 255, 255, 255)


  CURVE_Z = 0


  # 绘制线段的参数


  LINES_COLOR = Color.new(255, 255, 255, 127)


  LINES_Z = -10


  # 用于调整绘制的范围和精度


  T_BEGINNING = 0.0


  T_END = 1.0


  T_STEP = 0.01


  UPDATE_STEPS = 5


  TEMP_BITMAP = Bitmap.new(32, 32) # 临时位图，用于获取文字大小


  # 按键


  CREATE_CONTROL_POINT_KEY = 0x01 # left


  DELETE_CONTROL_POINT_KEY = 0x02 # right


  FAST_MODE_KEY = 0x41 # A


  LINES_VISIBLE_KEY = 0x42 # B


  CONTROL_POINTS_VISIBLE_KEY = 0x43 # C


 


  # 显示端口


  @viewport = Viewport.new


  @viewport.add_fast_layer(POINTS_Z)


  # 曲线


  @curve_sprite = Sprite.new(@viewport)


  @curve_sprite.bitmap = Bitmap.new(Graphics.size)


  @curve_sprite.z = CURVE_Z


  # 线段


  @lines_sprite = Sprite.new(@viewport)


  @lines_sprite.bitmap = Bitmap.new(Graphics.size)


  @lines_sprite.z = LINES_Z


  # 控制点


  @control_points = []


  @control_point_sprites = []


  # 模式控制


  @lines_visible = true


  @control_points_visible = true


  @fast_mode = false


  # 阻断刷新控制


  @covering_drawing = 0


 


  # 创建控制点


  def self.create_control_point(point)


    sprite = Sprite.new(@viewport)


    sprite.visible = @control_points_visible


    radius_vector = Vector.new(POINTS_RADIUS)


    text_vector = TEMP_BITMAP.text_vector(@control_points.size)


    radius_text_vector = radius_vector + text_vector


    sprite.bitmap = Bitmap.new(radius_text_vector + radius_vector)


    sprite.bitmap.font.color = POINTS_COLOR


    x_flip = (point + radius_text_vector).x > Graphics.width


    y_flip = (point + radius_text_vector).y > Graphics.height


    excursion = Vector.new


    excursion.x = x_flip ? radius_text_vector.x : radius_vector.x


    excursion.y = y_flip ? radius_text_vector.y : radius_vector.y


    sprite.position = point - excursion


    sprite.bitmap.fill_circle(excursion, POINTS_RADIUS, POINTS_COLOR)


    text_position = Vector.new


    text_position.x = x_flip ? 0 : radius_vector.x * 2


    text_position.y = y_flip ? 0 : radius_vector.y * 2


    sprite.bitmap.draw_text(text_position, text_vector, @control_points.size)


    sprite.z = POINTS_Z


    @control_point_sprites.push(sprite)


    @control_points.push(point)


    refresh_graph


    point


  end


 


  # 删除上一个控制点


  def self.delete_control_point


    return if @control_points.empty?


    point = @control_points.pop


    sprite = @control_point_sprites.pop


    sprite.bitmap.dispose


    sprite.dispose


    refresh_graph


    point


  end


 


  # 刷新图形


  # 该方法在非快速模式下会阻塞，但update不会停且可以被打断


  def self.refresh_graph


    @covering_drawing += 1


    @curve_sprite.bitmap.clear


    return if @control_points.empty?


    graph_points = []


    steps_count = 0


    do_by_step(T_BEGINNING, T_END, T_STEP) do |t|


      will_update = !@fast_mode && (steps_count += 1) >= UPDATE_STEPS


      graph_points.push(next_graph_point(t, will_update))


      if graph_points.size > 1


        @curve_sprite.bitmap.draw_line(*graph_points.last(2), CURVE_COLOR)


      end


      if will_update


        steps_count = 0


        last_covering_drawing = @covering_drawing


        update


        return if @covering_drawing > last_covering_drawing


      end


    end


    connect_control_points_with_lines


  end


 


  # 根据t返回曲线上的点坐标


  # 若@lines_visible && will_update则会绘制线段


  def self.next_graph_point(t, will_update = false)


    is_drawing = @lines_visible && will_update


    @lines_sprite.bitmap.clear if is_drawing


    sequences = [@control_points]


    (@control_points.size - 1).times do |i|


      last_sequence = sequences.last


      sequences.push([])


      (last_sequence.size - 1).times do |j|


        if is_drawing


          @lines_sprite.bitmap.draw_line(*last_sequence[j, 2], LINES_COLOR)


        end


        sequences.last.push(Math.definite_proportion(*last_sequence[j, 2], t))


      end


    end


    sequences.last.first


  end


 


  # 用线段将控制点联结


  def self.connect_control_points_with_lines


    @lines_sprite.bitmap.clear


    (@control_points.size - 1).times do |i|


      @lines_sprite.bitmap.draw_line(*@control_points[i, 2], LINES_COLOR)


    end


    nil


  end


 


  # 切换线段可见


  def self.toggle_lines_visible


    @lines_visible = !@lines_visible


    @lines_sprite.visible = @lines_visible


  end


 


  # 切换控制点可见


  def self.toggle_points_visible


    @control_points_visible = !@control_points_visible


    @control_point_sprites.each do |sprite|


      sprite.visible = @control_points_visible


    end


  end


 


  # 切换快速模式


  def self.toggle_fast_mode


    @fast_mode = !@fast_mode


  end


 


  # 基础更新，必须每帧调用


  def self.update_basic


    Graphics.update


    Input.update


  end


 


  # 更新，需每帧调用


  def self.update


    update_basic


    if Input.trigger?(CREATE_CONTROL_POINT_KEY)


      create_control_point(Mouse.position)


    elsif Input.trigger?(DELETE_CONTROL_POINT_KEY)


      delete_control_point


    elsif Input.trigger?(FAST_MODE_KEY)


      toggle_fast_mode


    elsif Input.trigger?(LINES_VISIBLE_KEY)


      toggle_lines_visible


    elsif Input.trigger?(CONTROL_POINTS_VISIBLE_KEY)


      toggle_points_visible


    end


  end


 


  # 简单的irb


  def self.simple_irb_start


    Thread.start do


      ans = nil


      loop { puts("=> #{(ans = eval(gets)).inspect}") rescue puts($!.message) }


    end


  end


 


  # 主进程


  def self.main


    simple_irb_start


    loop { update }


  end


end


 


# 入口


Scene.main

更新了很多地方，懒得说了，依赖这玩意https://rpg.blue/thread-400462-1-1.html

Munchen1921

厉害啊太强了。。。。。。

KB.Driver

太强了……