Project1

标题: 用RGD绘制Bézier曲线 [打印本页]

作者: 有丘直方 时间: 2018-11-18 21:30
标题: 用RGD绘制Bézier曲线
本帖最后由有丘直方于 2018-12-2 20:29 编辑

[pre lang="ruby"]
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
[/pre]马上要睡了，不多说了，看图
(, 下载次数: 109)
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）[line]1[/line][pre lang="ruby"]
# 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
[/pre]更新了很多地方，懒得说了，依赖这玩意https://rpg.blue/thread-400462-1-1.html

作者: Munchen1921 时间: 2018-11-18 22:18
厉害啊太强了。。。。。。

作者: KB.Driver 时间: 2018-11-18 23:19
太强了……

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