Class: HostSystem

Inherits:
Object
  • Object
show all
Extended by:
SubclassTracking
Defined in:
lib/HostSystem.rb

Direct Known Subclasses

AcornBBC, Apple2, Atari800, Coco, Ti99, Trs80

Constant Summary collapse

MAX_SCREENDUMP_LINES = 
200

Class Method Summary collapse

Methods included from SubclassTracking

extended

Class Method Details

.all_host_systems ⇒ Object 



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# File 'lib/HostSystem.rb', line 26

def HostSystem.all_host_systems
  HostSystem.subclasses
end

.default_background_colour ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 109

def self.default_background_colour
  PNG::Color::Black
end

.default_foreground_colour ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 104

def self.default_foreground_colour  
    PNG::Color::White
end

.default_screen_width ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 80

def self.default_screen_width
  40
end

.font_data ⇒ Object 



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# File 'lib/HostSystem.rb', line 69

def self.font_data
  @font_data=File.new(font_data_filename,"rb").read if @font_data.nil?
  @font_data
end

.font_height ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 94

def self.font_height
  8
end

.font_width ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 89

def self.font_width
  8
end

.full_name ⇒ Object

each subclass should override this method with a 2-5 word description of this host system



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# File 'lib/HostSystem.rb', line 13

def self.full_name
  nil
end

.hex_dump(buffer) ⇒ Object

given a buffer (e.g a sector or a file), produce a formatted hex dump which includes chars converted to ASCII



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# File 'lib/HostSystem.rb', line 44

def HostSystem.hex_dump(buffer)
   	s=""
		(0..(buffer.length/16)).each {|line_number|
			 lhs=""
			 rhs=""
			 start_byte=line_number*16
			 line=buffer[start_byte,16]
			if line.length>0 then
				 line.each_byte {|byte|
					  lhs+= sprintf("%02X ", byte)
					  rhs+= to_ascii(byte).sub(/[\x00-\x1f]/,'.')
			 	}
				lhs+=" "*(16-line.length)*3
				s+=sprintf("%02X\t%s %s\n",start_byte,lhs,rhs)
			end
		}
		s
end

.line_break_chars ⇒ Object 



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# File 'lib/HostSystem.rb', line 129

def self.line_break_chars
  [0x0D]
end

.max_screen_width ⇒ Object 



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# File 'lib/HostSystem.rb', line 84

def self.max_screen_width
  80
end

.pixels_between_characters ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 99

def self.pixels_between_characters
  0
end

.possible_file_systems ⇒ Object 



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# File 'lib/HostSystem.rb', line 17

def HostSystem.possible_file_systems
  results=[]
  FileSystem.all_file_systems.each do |candidate| 
    results<<candidate if self==candidate.host_system
  end
  results
end

.s_to_ascii(s) ⇒ Object 



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# File 'lib/HostSystem.rb', line 35

def HostSystem.s_to_ascii(s)
  r=""
  s.each_byte do |b|
    r+=to_ascii(b)
  end
  r
end

.screen_rows ⇒ Object

default - should be overridden by each host system



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# File 'lib/HostSystem.rb', line 75

def self.screen_rows
  25
end

.start_track ⇒ Object

does counting of tracks start at track 0 (e.g. Apple 2) or track 1 (e.g. C64)?



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# File 'lib/HostSystem.rb', line 64

def HostSystem.start_track
  0
end

.to_ascii(byte) ⇒ Object

each subclass should override to_ascii with a function that converts a character in the native format to an ASCII equivalent



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# File 'lib/HostSystem.rb', line 31

def HostSystem.to_ascii(byte)
  byte.chr
end

.to_screendump(text, screen_width) ⇒ Object 



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# File 'lib/HostSystem.rb', line 113

def self.to_screendump(text,screen_width)
  lines=split_into_lines(text,screen_width)  
  canvas = PNG::Canvas.new font_width*screen_width, (pixels_between_characters+font_height)*[lines.length,screen_rows].max, default_background_colour
  line_number=0
  lines.each do |line|
    col=0
    line.each_byte do |char|
     draw_char_at(canvas,char,line_number,col) 
     col+=1 
    end    
    line_number+=1
  end  
  PNG.new(canvas).raw_bytes
end