Class: Doom::TextureLoader

Inherits:
Object
  • Object
show all
Defined in:
lib/doom/texture_loader.rb

Overview

TextureLoader is responsible for loading and parsing texture data from a WAD file

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(wad_loader) ⇒ TextureLoader

Initialize a new TextureLoader with the given WADLoader

Parameters:

  • wad_loader (WADLoader) —

    the WAD loader to use



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# File 'lib/doom/texture_loader.rb', line 10

def initialize(wad_loader)
  @wad_loader = wad_loader
  @textures = {}
  @patch_names = []
  load_patch_names
  load_textures
end

Instance Attribute Details

#patch_names ⇒ Object (readonly)

Returns the value of attribute patch_names.



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# File 'lib/doom/texture_loader.rb', line 6

def patch_names
  @patch_names
end

#textures ⇒ Object (readonly)

Returns the value of attribute textures.



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# File 'lib/doom/texture_loader.rb', line 6

def textures
  @textures
end

Instance Method Details

#get_texture(name) ⇒ Hash?

Get a specific texture by name

Parameters:

  • name (String) —

    the name of the texture

Returns:

  • (Hash, nil) —

    the texture data or nil if not found



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# File 'lib/doom/texture_loader.rb', line 121

def get_texture(name)
  @textures[name]
end

#load_patch_names ⇒ Object

Load the PNAMES lump which contains patch names



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# File 'lib/doom/texture_loader.rb', line 19

def load_patch_names
  pnames_data = @wad_loader.get_lump("PNAMES")
  return unless pnames_data
  
  # First 4 bytes is the number of patch names
  num_patches = pnames_data[0..3].unpack("V")[0]
  
  # Each patch name is 8 bytes
  num_patches.times do |i|
    offset = 4 + (i * 8)
    patch_name = pnames_data[offset..offset + 7].unpack("Z*")[0]
    @patch_names << patch_name
  end
end

#load_texture_lump(lump_name) ⇒ Object

Load a specific texture lump

Parameters:

  • lump_name (String) —

    the name of the texture lump (TEXTURE1 or TEXTURE2)



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# File 'lib/doom/texture_loader.rb', line 42

def load_texture_lump(lump_name)
  texture_data = @wad_loader.get_lump(lump_name)
  return unless texture_data
  
  # First 4 bytes is the number of textures
  num_textures = texture_data[0..3].unpack("V")[0]
  
  # Next num_textures * 4 bytes are offsets to each texture definition
  offsets = []
  num_textures.times do |i|
    offset = 4 + (i * 4)
    texture_offset = texture_data[offset..offset + 3].unpack("V")[0]
    offsets << texture_offset
  end
  
  # Parse each texture definition
  offsets.each do |offset|
    parse_texture_definition(texture_data, offset)
  end
end

#load_textures ⇒ Object

Load the TEXTURE1 and TEXTURE2 lumps which contain texture definitions



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# File 'lib/doom/texture_loader.rb', line 35

def load_textures
  load_texture_lump("TEXTURE1")
  load_texture_lump("TEXTURE2")
end

#parse_texture_definition(texture_data, offset) ⇒ Object

Parse a texture definition

Parameters:

  • texture_data (String) —

    the texture lump data

  • offset (Integer) —

    the offset to the texture definition



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# File 'lib/doom/texture_loader.rb', line 66

def parse_texture_definition(texture_data, offset)
  # Texture definition structure:
  # - 8 bytes: texture name
  # - 4 bytes: flags (unused)
  # - 2 bytes: width
  # - 2 bytes: height
  # - 4 bytes: column directory (unused)
  # - 2 bytes: number of patches
  # - patches: array of patch definitions
  
  texture_name = texture_data[offset..offset + 7].unpack("Z*")[0]
  # Skip flags (4 bytes)
  width = texture_data[offset + 12..offset + 13].unpack("v")[0]
  height = texture_data[offset + 14..offset + 15].unpack("v")[0]
  # Skip column directory (4 bytes)
  num_patches = texture_data[offset + 20..offset + 21].unpack("v")[0]
  
  patches = []
  
  # Parse each patch definition
  num_patches.times do |i|
    patch_offset = offset + 22 + (i * 10)
    
    # Patch definition structure:
    # - 2 bytes: x offset
    # - 2 bytes: y offset
    # - 2 bytes: patch number (index into PNAMES)
    # - 2 bytes: step dir (unused)
    # - 2 bytes: color map (unused)
    
    x_offset = texture_data[patch_offset..patch_offset + 1].unpack("s<")[0]
    y_offset = texture_data[patch_offset + 2..patch_offset + 3].unpack("s<")[0]
    patch_num = texture_data[patch_offset + 4..patch_offset + 5].unpack("v")[0]
    
    patch_name = @patch_names[patch_num] if patch_num < @patch_names.size
    
    patches << {
      x_offset: x_offset,
      y_offset: y_offset,
      patch_num: patch_num,
      patch_name: patch_name
    }
  end
  
  @textures[texture_name] = {
    name: texture_name,
    width: width,
    height: height,
    patches: patches
  }
end

#texture_exists?(name) ⇒ Boolean

Check if a texture exists

Parameters:

  • name (String) —

    the name of the texture

Returns:

  • (Boolean) —

    true if the texture exists



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# File 'lib/doom/texture_loader.rb', line 134

def texture_exists?(name)
  @textures.key?(name)
end

#texture_names ⇒ Array<String>

List all texture names

Returns:

  • (Array<String>) —

    array of texture names



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# File 'lib/doom/texture_loader.rb', line 127

def texture_names
  @textures.keys
end