Class: AppleHiResPic

Inherits:
NativeFileType show all
Defined in:
lib/native_file_types/apple2/AppleHiResPic.rb

Overview

generic class for a HI-RES picture

Direct Known Subclasses

AppleDosPic, NADOLPic, PascalPic, ProDosBinPic

Constant Summary collapse

@@scanline_offsets =

per Apple // Reference Manual for //e chapter 2, pages 22-35 also TechNote - Apple IIe #3 Double High-Resolution Graphics - web.pdx.edu/~heiss/technotes/aiie/tn.aiie.03.html HGR screen consists of 3 bands of 8 rows of 8 scanlines for each absolute scanline, what is the offset into screen ram that the 40 bytes for this scanline is stored?

Array.new(Apple2::HGR_ROWS)

Instance Attribute Summary

Attributes inherited from NativeFileType

#aux_code, #contents, #file_system_image, #file_type, #filename, #meta_data

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from NativeFileType

#<=>, #==, all_native_file_types, best_fit, code_for_tests, compatability_score, #data_without_header, file_type_matches?, #full_filename, #header_length, #initialize, is_valid_file_if, load_address, #load_address, native_file_types_possible_on_file_system, non_matching_score, #to_hex_dump, #to_info_dump, #type_description

Methods included from SubclassTracking

extended

Constructor Details

This class inherits a constructor from NativeFileType

Class Method Details

.buffer_to_picture(buffer) ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 49

def self.buffer_to_picture(buffer)
  canvas = PNG::Canvas.new Apple2::HGR_COLS, Apple2::HGR_ROWS, PNG::Color::Black
  Apple2::HGR_ROWS.times do |y|
    last_bit_set=false
    40.times do |x_byte|
      offset=@@scanline_offsets[y]+x_byte
      current_byte=buffer[offset]				
      current_byte=0 if current_byte.nil? #if we overrun the buffer then assume it's black
      7.times do |x_bit|
        x=x_byte*7+x_bit
        bit_set=((current_byte & (2**x_bit))>0)
        if (bit_set) then
          if (last_bit_set) then 
            #adjacent pixels should both be white
            AppleHiResPic.set_pixel(canvas,x-1,y,Apple2::HGR_WHITE) 
            AppleHiResPic.set_pixel(canvas,x,y,Apple2::HGR_WHITE)
          else
            if current_byte>=0x80 then
              pallete=[Apple2::HGR_BLUE,Apple2::HGR_ORANGE]
            else
              pallete=[Apple2::HGR_VIOLET,Apple2::HGR_GREEN]
            end
            this_pixel_colour=pallete[x%2]
            AppleHiResPic.set_pixel(canvas,x,y,this_pixel_colour)
            AppleHiResPic.set_pixel(canvas,x+1,y,this_pixel_colour) unless x>=Apple2::HGR_COLS-1
          end
        end
        
        last_bit_set=bit_set
      end
    end
  end
  
  png = PNG.new canvas
  result=png.raw_bytes
  result
end

.file_system_file_types ⇒ Object

should be a subclass for each file system



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 12

def self.file_system_file_types
  {}
end

.matching_score ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 44

def self.matching_score
  [AppleBinary.matching_score+1,NADOLFile.matching_score+1].max
end

.scanline_offsets ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 40

def self.scanline_offsets
    @@scanline_offsets
end

Instance Method Details

#picture_format ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 98

def picture_format
  :png
end

#picture_height ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 94

def picture_height
  Apple2::HGR_ROWS
end

#picture_width ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 91

def picture_width
  Apple2::HGR_COLS
end

#to_picture ⇒ Object 



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# File 'lib/native_file_types/apple2/AppleHiResPic.rb', line 87

def to_picture
  AppleHiResPic.buffer_to_picture(unpacked_picture_bytes)
end