I represent a compact encoding of a set of Forms corresponding to characters in the ASCII character set. All the forms are placed side by side in a large form whose height is the font height, and whose width is the sum of all the character widths. The xTable variable gives the left-x coordinates of the subforms corresponding to the glyphs. Characters are mapped to glyphs by using the characterToGyphMap.

Subclasses can have non-trivial mapping rules as well as different representations for glyphs sizes (e.g., not using an xTable). If so, these classes should return nil when queried for xTable and/or the characterToGlyphMap. This will cause the CharacterScanner primitive to fail and query the font for the width of a character (so that a more programatical approach can be implemented).

For display, fonts need to implement two messages:
#installOn: aDisplayContext foregroundColor: foregroundColor backgroundColor: backgroundColor
This method installs the receiver (a font) on the given DisplayContext (which may be an instance of BitBlt or Canvas (or any of it's subclasses). The font should take the appropriate action to initialize the display context so that further display operations can be optimized.
#displayString: aString on: aDisplayContext from: startIndex to: stopIndex at: aPoint kern: kernDelta
This method is called for each subsequent run of characters in aString which is to be displayed with the (previously installed) settings.

	accessing
	ascent ascentKern baseKern characterToGlyphMap characterToGlyphMap: descent descentKern familyName familySizeFace fontNameWithPointSize glyphs height lineGrid maxAscii maxWidth minAscii name name: pointSize pointSize: raster setGlyphs: subscript superscript textStyle widthOf: xTable

	character shapes
	alter:formBlock: characterForm:pixelValueAt:put: characterFormAt: characterFormAt:put: edit: ensureCleanBold extendMaxAsciiTo: fillZeroWidthSlots fixOneWideChars makeCarriageReturnsWhite widen:by:

	copying
	veryDeepCopyWith:

	displaying
	characters:in:displayAt:clippedBy:rule:fillColor: composeWord:in:beginningAt: displayLine:at: displayString:on:from:to:at:kern: fontDisplay installOn:foregroundColor:backgroundColor: widthOfString:

	emphasis
	bonk:with: emphasis emphasis: emphasized: makeBoldGlyphs makeCondensedGlyphs makeItalicGlyphs makeStruckOutGlyphs makeUnderlinedGlyphs reset

	file in/out
	buildfontNamed:fromForms:startingAtAscii:ascent:descent:maxWid: displayChar:form: encodedForRemoteCanvas newFromStrike: objectForDataStream: printOn: readBDFFromFile:name: readBFHeaderFrom: readFromBitFont: readFromStrike2: readFromStrike2Stream: restOfLine:from: writeAsStrike2On: writeAsStrike2named:

	object fileIn

	private
	createCharacterToGlyphMap

	testing
	checkCharacter:

	derivative font caching
	shutDown

	examples
	convertFontsNamed: example readStrikeFont2Family:

	instance creation
	decodedFromRemoteCanvas: familyName:size:emphasized: fromStrike: newFromBDFFile:name: passwordFontSize:

	Mac reader	top
	aComment To read Mac font resources. 1) Use ResEdit in the Fonts folder in the System Folder. Open the file of the Font you want. (A screen font, not a TrueType outline font). 2) Open the FOND resource and scroll down to the list of sizes and resource numbers. Note the resource number of the size you want. 3) Open the NFNT resource. Click on the number you have noted. 4) Choose 'Open Using Hex Editor' from the resource editor. 5) Copy all of the hex numbers and paste into a text editor. Save the file into the Smalltalk folder under the name 'FontName 12 hex' (or other size). 6) Enter the fileName below and execute: TextStyle default fontAt: 8 put: (StrikeFont new readMacFontHex: 'fileName'). Select text and type Command-7 to change it to your new font. (There is some problem in the ParagraphEditor with the large size of Cairo 18. Its line heights are not the right.)
	fixKerning: Insert one pixel (extraWidth) between each character. And add the bits for the space character
	readMacFontHex: Read the hex version of a Mac FONT type resource. See the method aComment for how to prepare the input file. 4/26/96 tk
	strikeFromHex:width:height: read in just the raw strike bits from a hex file. No spaces or returns. W is in words (2 bytes), h in pixels.
	xTableFromHex:

	accessing	top
	ascent Answer the receiver's maximum extent of characters above the baseline.
	ascentKern Return the kern delta for ascenders.
	baseKern Return the base kern value to be used for all characters.
	characterToGlyphMap Return the character to glyph mapping table. If the table is not provided the character scanner will query the font directly for the width of each individual character.
	characterToGlyphMap:
	descent Answer the receiver's maximum extent of characters below the baseline.
	descentKern Return the kern delta for descenders.
	familyName
	familySizeFace Answer an array with familyName, a String, pointSize, an Integer, and faceCode, an Integer.
	fontNameWithPointSize
	glyphs Answer a Form containing the bits representing the characters of the receiver.
	height Answer the height of the receiver, total of maximum extents of characters above and below the baseline.
	lineGrid
	maxAscii Answer the integer that is the last Ascii character value of the receiver.
	maxWidth Answer the integer that is the width of the receiver's widest character.
	minAscii Answer the integer that is the first Ascii character value of the receiver.
	name Answer the receiver's name.
	name: Set the receiver's name.
	pointSize
	pointSize:
	raster Answer an integer that specifies the layout of the glyphs' form.
	setGlyphs: Replace the glyphs form. Used to make a synthetic bold or italic font quickly.
	subscript Answer an integer that is the further vertical offset relative to the baseline for positioning characters as subscripts.
	superscript Answer an integer that is the further vertical offset relative to the baseline for positioning characters as superscripts.
	textStyle
	widthOf: Answer the width of the argument as a character in the receiver.
	xTable Answer an Array of the left x-coordinate of characters in glyphs.

	character shapes	top
	alter:formBlock:
	characterForm:pixelValueAt:put:
	characterFormAt: Answer a Form copied out of the glyphs for the argument, character.
	characterFormAt:put: Copy characterForm over the glyph for the argument, character.
	edit: (TextStyle default fontAt: 1) edit: $_
	ensureCleanBold This ensures that all character glyphs have at least one pixel of white space on the right so as not to cause artifacts in neighboring characters in bold or italic.
	extendMaxAsciiTo: Extend the range of this font so that it can display glyphs up to newMax.
	fillZeroWidthSlots Note: this is slow because it copies the font once for every replacement.
	fixOneWideChars This fixes all 1-wide characters to be 2 wide with blank on the right so as not to cause artifacts in neighboring characters in bold or italic.
	makeCarriageReturnsWhite Some larger fonts have a gray carriage return (from the zero wide fixup) make it white so it doesn't show
	widen:by:

	copying	top
	veryDeepCopyWith: Return self. I am shared. Do not record me.

	displaying	top
	characters:in:displayAt:clippedBy:rule:fillColor: Simple, slow, primitive method for displaying a line of characters. No wrap-around is provided.
	composeWord:in:beginningAt: Non-primitive composition of a word--add up widths of characters, add sum to beginning x and answer the resulting x. Similar to performance of scanning primitive, but without stop conditions.
	displayLine:at: Display the characters in aString, starting at position aPoint.
	displayString:on:from:to:at:kern: Draw the given string from startIndex to stopIndex at aPoint on the (already prepared) BitBlt.
	fontDisplay TextStyle default defaultFont fontDisplay.
	installOn:foregroundColor:backgroundColor: Install the receiver on the given DisplayContext (either BitBlt or Canvas) for further drawing operations.
	widthOfString:

	emphasis	top
	bonk:with: Bonking means to run through the glyphs clearing out black pixels between characters to prevent them from straying into an adjacent character as a result of, eg, bolding or italicizing
	emphasis Answer the integer code for synthetic bold, italic, underline, and strike-out.
	emphasis: Set the integer code for synthetic bold, itallic, underline, and strike-out, where bold=1, italic=2, underlined=4, and struck out=8.
	emphasized: Answer a copy of the receiver with emphasis set to include code.
	makeBoldGlyphs Make a bold set of glyphs with same widths by ORing 1 bit to the right (requires at least 1 pixel of intercharacter space)
	makeCondensedGlyphs Make a condensed set of glyphs with same widths. NOTE: this has been superceded by kerning -- should not get called
	makeItalicGlyphs Make an italic set of glyphs with same widths by skewing left and right. In the process, characters would overlap, so we widen them all first.
	makeStruckOutGlyphs Make a struck-out set of glyphs with same widths
	makeUnderlinedGlyphs Make an underlined set of glyphs with same widths
	reset Reset the cache of derivative emphasized fonts

	file in/out	top
	buildfontNamed:fromForms:startingAtAscii:ascent:descent:maxWid: This builds a StrikeFont instance from existing forms.
	displayChar:form: Convenience utility used during conversion of BitFont files
	encodedForRemoteCanvas
	newFromStrike: Build an instance from the strike font file name. The '.strike' extension is optional.
	objectForDataStream: I am about to be written on an object file. Write a reference to a known Font in the other system instead.
	printOn: Append to the argument, aStream, a sequence of characters that identifies the receiver.
	readBDFFromFile:name: This builds a StrikeFont instance by reading the X11 Binary Distribution Format font source file. See the BDFFontReader class comment.
	readBFHeaderFrom:
	readFromBitFont: This builds a StrikeFont instance by reading the data file format produced by BitFont, a widely available font conversion utility written by Peter DiCamillo at Brown University
	readFromStrike2: StrikeFont new readFromStrike2: 'Palatino14.sf2'
	readFromStrike2Stream: Build an instance from the supplied binary stream on data in strike2 format
	restOfLine:from: Utility method to assist reading of BitFont data files
	writeAsStrike2On: Write me onto a file in strike2 format. fileName should be of the form: <family name><pointSize>.sf2
	writeAsStrike2named: Write me onto a file in strike2 format. fileName should be of the form: <family name><pointSize>.sf2

object fileIn

top

	private	top
	createCharacterToGlyphMap Private. Create the character to glyph mapping for a font that didn't have any before. This is basically equivalent to what the former setStopCondition did, only based on indexes.

	testing	top
	checkCharacter: Answer a Character that is within the ascii range of the receiver--either character or the last character in the receiver.

	accessing	top
	familyName:size: Answer a font (or the default font if the name is unknown) in the specified size.
	familyNames

	derivative font caching	top
	shutDown StrikeFont shutDown

	examples	top
	convertFontsNamed: StrikeFont convertFontsNamed: 'NewYork'
	example Displays a line of text on the display screen at the location of the cursor. Example depends on the strike font file, 'TimesRoman10.strike'. existing.
	readStrikeFont2Family: StrikeFont readStrikeFont2Family: 'Lucida'

	instance creation	top
	decodedFromRemoteCanvas:
	familyName:size:emphasized: Create the font with this emphasis
	fromStrike: Read a font from disk in the old ST-80 'strike' format. Note: this is an old format; use strike2 format instead
	newFromBDFFile:name: StrikeFont newFromBDFFile: 'helvR12.bdf' name: 'Helvetica12'
	passwordFontSize: