Class: Chingu::Rect

Inherits:
Array
  • Object
show all
Defined in:
lib/chingu/rect.rb

Overview

A Rect is a representation of a rectangle, with four core attributes (x offset, y offset, width, and height) and a variety of functions for manipulating and accessing these attributes.

Like all coordinates in Rubygame (and its base library, SDL), x and y offsets are measured from the top-left corner of the screen, with greater y offsets being lower. Thus, specifying the x and y offsets of the Rect is equivalent to setting the location of its top-left corner.

In Rubygame, Rects are used for collision detection and describing the area of a Surface to operate on.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*argv) ⇒ Rect

Create a new Rect, attempting to extract its own information from the given arguments. The arguments must fall into one of these cases:

- 4 integers +(x, y, w, h)+.
- 1 Rect or Array containing 4 integers +([x, y, w, h])+.
- 2 Arrays containing 2 integers each +([x,y], [w,h])+.
- 1 object with a +rect+ attribute which is a valid Rect object.

All rect core attributes (x,y,w,h) must be integers.



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# File 'lib/chingu/rect.rb', line 86

def initialize(*argv)
  case argv.length
  when 1
    if argv[0].kind_of? Array; super(argv[0])
    elsif argv[0].respond_to? :rect; super(argv[0])
    end
  when 2
    super(argv[0].concat(argv[1]))
  when 4
    super(argv)
  end
  return self
end

Class Method Details

.new_from_object(object) ⇒ Object

Extract or generate a Rect from the given object, if possible, using the following process:

1. If it's a Rect already, return a duplicate Rect.
2. Elsif it's an Array with at least 4 values, make a Rect from it.
3. Elsif it has a +rect+ attribute., perform (1) and (2) on that.
4. Otherwise, raise TypeError.

See also Surface#make_rect()



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# File 'lib/chingu/rect.rb', line 109

def Rect.new_from_object(object)
  case(object)
  when Rect
    return object.dup
  when Array 
    if object.length >= 4
      return Rect.new(object)
    else
      raise(ArgumentError,"Array does not have enough indices to be made into a Rect (%d for 4)."%object.length )
    end
  else
    begin
      case(object.rect)
      when Rect
        return object.rect.dup
      when Array
        if object.rect.length >= 4
          return Rect.new(object.rect)
        else
          raise(ArgumentError,"Array does not have enough indices to be made into a Rect (%d for 4)."%object.rect.length )
        end
      end        # case object.rect
    rescue NoMethodError # if no rect.rect
      raise(TypeError,"Object must be a Rect or Array [x,y,w,h], or have an attribute called 'rect'. (Got %s instance.)"%object.class)
    end
  end # case object
end

Instance Method Details

#bottom ⇒ Object Also known as: b

Return the y coordinate of the bottom side of the Rect.



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# File 'lib/chingu/rect.rb', line 205

def bottom; return self.at(1)+self.at(3); end

#bottom=(b) ⇒ Object Also known as: b=

Set the y coordinate of the bottom side of the Rect by translating the Rect (adjusting the y offset).



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# File 'lib/chingu/rect.rb', line 209

def bottom=(b); self[1] = b - self.at(3); return b; end

#bottomleft ⇒ Object Also known as: bl

Return the x and y coordinates of the bottom-left corner of the Rect



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# File 'lib/chingu/rect.rb', line 276

def bottomleft; return self.at(0), self.bottom; end

#bottomleft=(bottomleft) ⇒ Object Also known as: bl=

Set the x and y coordinates of the bottom-left corner of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 280

def bottomleft=(bottomleft)
  raise ArgumentError, "Rect#bottomleft= takes an Array of form [x, y]." if bottomleft.size != 2
  self[0], self.bottom = bottomleft
  return bottomleft
end

#bottomright ⇒ Object Also known as: br

Return the x and y coordinates of the bottom-right corner of the Rect



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# File 'lib/chingu/rect.rb', line 290

def bottomright; return self.right, self.bottom; end

#bottomright=(bottomright) ⇒ Object Also known as: br=

Set the x and y coordinates of the bottom-right corner of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 294

def bottomright=(bottomright)
  raise ArgumentError, "Rect#bottomright= takes an Array of form [x, y]." if bottomright.size != 2
  self.right, self.bottom = bottomright
  return bottomright
end

#center ⇒ Object Also known as: c

Return the x and y coordinates of the center of the Rect.



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# File 'lib/chingu/rect.rb', line 215

def center; return self.centerx, self.centery; end

#center=(center) ⇒ Object Also known as: c=

Set the x and y coordinates of the center of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 219

def center=(center)
    raise ArgumentError, "Rect#center= takes an Array of the form [x,y]." if center.size != 2
  self.centerx, self.centery = center
  center
end

#centerx ⇒ Object Also known as: cx

Return the x coordinate of the center of the Rect



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# File 'lib/chingu/rect.rb', line 228

def centerx; return self.at(0)+(self.at(2).div(2)); end

#centerx=(x) ⇒ Object Also known as: cx=

Set the x coordinate of the center of the Rect by translating the Rect (adjusting the x offset).



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# File 'lib/chingu/rect.rb', line 232

def centerx=(x); self[0] = x - (self.at(2).div(2)); return x; end

#centery ⇒ Object Also known as: cy

Return the y coordinate of the center of the Rect



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# File 'lib/chingu/rect.rb', line 238

def centery; return self.at(1)+(self.at(3).div(2)); end

#centery=(y) ⇒ Object Also known as: cy=

Set the y coordinate of the center of the Rect by translating the Rect (adjusting the y offset).



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# File 'lib/chingu/rect.rb', line 242

def centery=(y); self[1] = y- (self.at(3).div(2)); return y; end

#clamp(rect) ⇒ Object

As #clamp!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 369

def clamp(rect)
  self.dup.clamp!(rect)
end

#clamp!(rect) ⇒ Object

Translate the calling Rect to be entirely inside the given Rect. If the caller is too large along either axis to fit in the given rect, it is centered with respect to the given rect, along that axis.



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# File 'lib/chingu/rect.rb', line 376

def clamp!(rect)
  nself = self.normalize
  rect = Rect.new_from_object(rect)
  #If self is inside given, there is no need to move self
  unless rect.contain?(nself)

    #If self is too wide:
    if nself.at(2) >= rect.at(2)
      self[0] = rect.centerx - nself.at(2).div(2)
      #Else self is not too wide
    else
      #If self is to the left of arg
      if nself.at(0) < rect.at(0)
        self[0] = rect.at(0)
      #If self is to the right of arg
      elsif nself.right > rect.right
        self[0] = rect.right - nself.at(2)
      #Otherwise, leave x alone
      end
    end

    #If self is too tall:
    if nself.at(3) >= rect.at(3)
      self[1] = rect.centery - nself.at(3).div(2)
      #Else self is not too tall
    else
      #If self is above arg
      if nself.at(1) < rect.at(1)
        self[1] = rect.at(1)
      #If self below arg
      elsif nself.bottom > rect.bottom
        self[1] = rect.bottom - nself.at(3)
      #Otherwise, leave y alone
      end
    end
  end
  return self
end

#clip(rect) ⇒ Object

As #clip!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 416

def clip(rect)
  self.dup.clip!(rect)
end

#clip!(rect) ⇒ Object

Crop the calling Rect to be entirely inside the given Rect. If the caller does not intersect the given Rect at all, its width and height are set to zero, but its x and y offsets are not changed.

As a side effect, the Rect is normalized.



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# File 'lib/chingu/rect.rb', line 425

def clip!(rect)
  nself = self.normalize
  other = Rect.new_from_object(rect).normalize!
  if self.collide_rect?(other)
    self[0] = [nself.at(0), other.at(0)].max
    self[1] = [nself.at(1), other.at(1)].max
    self[2] = [nself.right, other.right].min - self.at(0)
    self[3] = [nself.bottom, other.bottom].min - self.at(1)
  else #if they do not intersect at all:
    self[0], self[1] = nself.topleft
    self[2], self[3] = 0, 0
  end
  return self
end

#collide_array(array_rects) ⇒ Object

Iterate through all elements in the given Array, and return the index of the first element which is a Rect that collides with the caller.



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# File 'lib/chingu/rect.rb', line 468

def collide_array(array_rects)
  for i in (0...(array_rects.length))
    if array_rects[i].collide_rect?(self)
      return i
    end
  end
  return nil
end

#collide_array_all(array_rects) ⇒ Object

Iterate through all elements in the given Array, and return an Array containing the indices of every element that is a Rect that collides with the caller.



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# File 'lib/chingu/rect.rb', line 480

def collide_array_all(array_rects)
  indexes = []
  for i in (0...(array_rects.length))
    if array_rects[i].collide_rect?(self)
      indexes += [i]
    end
  end
  return indexes
end

#collide_hash(hash_rects) ⇒ Object

Iterate through all key/value pairs in the given hash table, and return the first pair whose value is a Rect that collides with the caller.

Because a hash table is unordered, you should not expect any particular Rect to be returned first.



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# File 'lib/chingu/rect.rb', line 446

def collide_hash(hash_rects)
  hash_rects.each { |key,value|
    if value.collide_rect?+(self); return [key,value]; end
  }
  return nil
end

#collide_hash_all(hash_rects) ⇒ Object

Iterate through all key/value pairs in the given hash table, and return an Array of every pair whose value is a Rect that collides the caller.

Because a hash table is unordered, you should not expect the returned pairs to be in any particular order.



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# File 'lib/chingu/rect.rb', line 459

def collide_hash_all(hash_rects)
  hash_rects.select { |key,value|
    value.collide_rect?+(self)
  }
end

#collide_point?(x, y) ⇒ Boolean

True if the point is inside (including on the border) of the caller. If you have Array of coordinates, you can use collide_point?(*coords).

Returns:

  • (Boolean) 


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# File 'lib/chingu/rect.rb', line 492

def collide_point?(x,y)
  nself = normalize()
  x.between?(nself.left,nself.right) && y.between?(nself.top,nself.bottom)
end

#collide_rect?(rect) ⇒ Boolean

True if the caller and the given Rect overlap (or touch) at all.

Returns:

  • (Boolean) 


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# File 'lib/chingu/rect.rb', line 498

def collide_rect?(rect)
  nself = self.normalize
  rect  = Rect.new_from_object(rect).normalize!
  return ((nself.l >= rect.l && nself.l <= rect.r) or (rect.l >= nself.l && rect.l <= nself.r)) &&
         ((nself.t >= rect.t && nself.t <= rect.b) or (rect.t >= nself.t && rect.t <= nself.b))
end

#contain?(rect) ⇒ Boolean

True if the given Rect is totally within the caller. Borders may overlap.

Returns:

  • (Boolean) 


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# File 'lib/chingu/rect.rb', line 507

def contain?(rect)
  nself = self.normalize
  rect = Rect.new_from_object(rect).normalize!
  return (nself.left <= rect.left and rect.right <= nself.right and
        nself.top <= rect.top and rect.bottom <= nself.bottom)
end

#h ⇒ Object Also known as: height

Returns self.at(3)



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# File 'lib/chingu/rect.rb', line 177

def h; return self.at(3); end

#h=(val) ⇒ Object Also known as: height=

Sets self to val



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# File 'lib/chingu/rect.rb', line 179

def h=(val); self[3] = val; end

#inflate(x, y) ⇒ Object

As #inflate!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 515

def inflate(x,y)
  return self.class.new(self.at(0) - x.div(2),
                        self.at(1) - y.div(2),
                        self.at(2) + x,
                        self.at(3) + y)
end

#inflate!(x, y) ⇒ Object

Increase the Rect’s size is the x and y directions, while keeping the same center point. For best results, expand by an even number. X and y inflation can be given as an Array or as separate values.



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# File 'lib/chingu/rect.rb', line 525

def inflate!(x,y)
  self[0] -= x.div(2)
  self[1] -= y.div(2)
  self[2] += x
  self[3] += y
  return self
end

#inspect ⇒ Object

Print the Rect in the form “+#<Rect:id [x,y,w,h]>+”



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# File 'lib/chingu/rect.rb', line 142

def inspect; "#<Rect:#{self.object_id} [%s,%s,%s,%s]>"%self; end

#midbottom ⇒ Object Also known as: mb

Return the x and y coordinates of the midpoint on the left side of the Rect.



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# File 'lib/chingu/rect.rb', line 350

def midbottom; return self.centerx, self.bottom; end

#midbottom=(midbottom) ⇒ Object Also known as: mb=

Set the x and y coordinates of the midpoint on the bottom side of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 354

def midbottom=(midbottom)
    raise ArgumentError, "Rect#midbottom= takes an Array of form [x, y]." if midbottom.size != 2
  self.centerx, self.bottom = midbottom
  return midbottom
end

#midleft ⇒ Object Also known as: ml

Return the x and y coordinates of the midpoint on the left side of the Rect.



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# File 'lib/chingu/rect.rb', line 305

def midleft; return self.at(0), self.centery; end

#midleft=(midleft) ⇒ Object Also known as: ml=

Set the x and y coordinates of the midpoint on the left side of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 309

def midleft=(midleft)
    raise ArgumentError, "Rect#midleft= takes an Array of form [x, y]." if midleft.size != 2
  self[0], self.centery = midleft
  return midleft
end

#midright ⇒ Object Also known as: mr

Return the x and y coordinates of the midpoint on the left side of the Rect.



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# File 'lib/chingu/rect.rb', line 335

def midright; return self.right, self.centery; end

#midright=(midright) ⇒ Object Also known as: mr=

Set the x and y coordinates of the midpoint on the right side of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 339

def midright=(midright)
    raise ArgumentError, "Rect#midright= takes an Array of form [x, y]." if midright.size != 2
  self.right, self.centery = midright
  return midright
end

#midtop ⇒ Object Also known as: mt

Return the x and y coordinates of the midpoint on the left side of the Rect.



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# File 'lib/chingu/rect.rb', line 320

def midtop; return self.centerx, self.at(1); end

#midtop=(midtop) ⇒ Object Also known as: mt=

Set the x and y coordinates of the midpoint on the top side of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 324

def midtop=(midtop)
    raise ArgumentError, "Rect#midtop= takes an Array of form [x, y]." if midtop.size != 2
  self.centerx, self[1] = midtop
  return midtop
end

#move(x, y) ⇒ Object

As #move!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 534

def move(x,y)
  self.dup.move!(x,y)
end

#move!(x, y) ⇒ Object

Translate the Rect by the given amounts in the x and y directions. Positive values are rightward for x and downward for y. X and y movement can be given as an Array or as separate values.



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# File 'lib/chingu/rect.rb', line 541

def move!(x,y)
  self[0]+=x; self[1]+=y
  return self
end

#normalize ⇒ Object

As #normalize!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 547

def normalize
  self.dup.normalize!()
end

#normalize! ⇒ Object

Fix Rects that have negative width or height, without changing the area it represents. Has no effect on Rects with non-negative width and height. Some Rect methods will automatically normalize the Rect.



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# File 'lib/chingu/rect.rb', line 554

def normalize!
  if self.at(2) < 0
    self[0], self[2] = self.at(0)+self.at(2), -self.at(2)
  end
  if self.at(3) < 0
    self[1], self[3] = self.at(1)+self.at(3), -self.at(3)
  end
  self
end

#right ⇒ Object Also known as: r

Return the x coordinate of the right side of the Rect.



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# File 'lib/chingu/rect.rb', line 195

def right; return self.at(0)+self.at(2); end

#right=(r) ⇒ Object Also known as: r=

Set the x coordinate of the right side of the Rect by translating the Rect (adjusting the x offset).



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# File 'lib/chingu/rect.rb', line 199

def right=(r); self[0] = r - self.at(2); return r; end

#size ⇒ Object

Return the width and height of the Rect.



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# File 'lib/chingu/rect.rb', line 185

def size; return self[2,2]; end

#size=(size) ⇒ Object

Set the width and height of the Rect.

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 188

def size=(size)
 raise ArgumentError, "Rect#size= takes an Array of form [width, height]." if size.size != 2
 self[2,2] = size
 size
end

#to_s ⇒ Object

Print the Rect in the form “+#<Rect [x,y,w,h]>+”



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# File 'lib/chingu/rect.rb', line 139

def to_s; "#<Rect [%s,%s,%s,%s]>"%self; end

#topleft ⇒ Object Also known as: tl

Return the x and y coordinates of the top-left corner of the Rect



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# File 'lib/chingu/rect.rb', line 248

def topleft; return self[0,2].to_a; end

#topleft=(topleft) ⇒ Object Also known as: tl=

Set the x and y coordinates of the top-left corner of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 252

def topleft=(topleft)
    raise ArgumentError, "Rect#topright= takes an Array of form [x, y]." if topleft.size != 2
  self[0,2] = topleft
  return topleft
end

#topright ⇒ Object Also known as: tr

Return the x and y coordinates of the top-right corner of the Rect



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# File 'lib/chingu/rect.rb', line 262

def topright; return self.right, self.at(1); end

#topright=(topright) ⇒ Object Also known as: tr=

Set the x and y coordinates of the top-right corner of the Rect by translating the Rect (adjusting the x and y offsets).

Raises:

  • (ArgumentError) 


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# File 'lib/chingu/rect.rb', line 266

def topright=(topright)
    raise ArgumentError, "Rect#topright= takes an Array of form [x, y]." if topright.size != 2
  self.right, self[1] = topright
  return topright
end

#union(rect) ⇒ Object

As #union!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 565

def union(rect)
  self.dup.union!(rect)
end

#union!(rect) ⇒ Object

Expand the caller to also cover the given Rect. The Rect is still a rectangle, so it may also cover areas that neither of the original Rects did, for example areas between the two Rects.



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# File 'lib/chingu/rect.rb', line 572

def union!(rect)
  self.normalize!
   rleft, rtop = self.topleft
   rright, rbottom = self.bottomright
  r2 = Rect.new_from_object(rect).normalize!

  rleft = [rleft, r2.left].min
  rtop = [rtop, r2.top].min
  rright = [rright, r2.right].max
  rbottom = [rbottom, r2.bottom].max

  self[0,4] = rleft, rtop, rright - rleft, rbottom - rtop
  return self
end

#union_all(array_rects) ⇒ Object

As #union_all!, but the original caller is not changed.



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# File 'lib/chingu/rect.rb', line 588

def union_all(array_rects)
  self.dup.union_all!(array_rects)
end

#union_all!(array_rects) ⇒ Object

Expand the caller to cover all of the given Rects. See also #union!



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# File 'lib/chingu/rect.rb', line 593

def union_all!(array_rects)
  array_rects.each do |r|
     self.union!(r)
  end
  return self
end

#w ⇒ Object Also known as: width

Returns self.at(2)



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# File 'lib/chingu/rect.rb', line 169

def w; return self.at(2); end

#w=(val) ⇒ Object Also known as: width=

Sets self to val



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# File 'lib/chingu/rect.rb', line 171

def w=(val); self[2] = val; end

#x ⇒ Object Also known as: left, l

Returns self.at(0)



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# File 'lib/chingu/rect.rb', line 149

def x; return self.at(0); end

#x=(val) ⇒ Object Also known as: left=, l=

Sets self to val



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# File 'lib/chingu/rect.rb', line 151

def x=(val); self[0] = val; end

#y ⇒ Object Also known as: top, t

Returns self.at(1)



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# File 'lib/chingu/rect.rb', line 159

def y; return self.at(1); end

#y=(val) ⇒ Object Also known as: top=, t=

Sets self to val



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# File 'lib/chingu/rect.rb', line 161

def y=(val); self[1] = val; end