Difference between revisions of "Unit Font"

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''To be documented''
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The fonts supported by Ultibo are a bitmap format that contains a block of data where each character is represented by a number of consecutive bytes.
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Fonts can either be statically compiled as a pascal unit and loaded during startup or can be dynamically loaded by passing a header and data block to the FontLoad() function. A Font Builder tool is available to change common bitmap font formats into a pascal unit for compiling with a project.
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For an 8x16 (8 pixels wide and 16 pixels high) font the data contains 8 bits (1 byte) for each of the 16 rows that make up a character and each character would be 16 bytes long.
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For a 12x22 font the data contains 12 bits padded to 16 bits (2 bytes) for each of the 22 rows that make up a character. Therefore each character would be 44 bytes in length.
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This unit can support any size font from 8x6 to 32x64 including every combination in between. For fonts where the bits per row is greater than one byte both little endian and big endian format is supported. Allowance has been made for including a Unicode translation table with each font so that writing of Unicode text to the console can be supported as well as an extended bitmap format where character data includes alpha or color information or both. These
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features are yet to be fully implemented.
  
 
=== Constants ===
 
=== Constants ===

Revision as of 04:49, 28 July 2016

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Description


The fonts supported by Ultibo are a bitmap format that contains a block of data where each character is represented by a number of consecutive bytes.

Fonts can either be statically compiled as a pascal unit and loaded during startup or can be dynamically loaded by passing a header and data block to the FontLoad() function. A Font Builder tool is available to change common bitmap font formats into a pascal unit for compiling with a project.

For an 8x16 (8 pixels wide and 16 pixels high) font the data contains 8 bits (1 byte) for each of the 16 rows that make up a character and each character would be 16 bytes long.

For a 12x22 font the data contains 12 bits padded to 16 bits (2 bytes) for each of the 22 rows that make up a character. Therefore each character would be 44 bytes in length.

This unit can support any size font from 8x6 to 32x64 including every combination in between. For fonts where the bits per row is greater than one byte both little endian and big endian format is supported. Allowance has been made for including a Unicode translation table with each font so that writing of Unicode text to the console can be supported as well as an extended bitmap format where character data includes alpha or color information or both. These features are yet to be fully implemented.

Constants


To be documented

Type definitions


To be documented

Public variables


To be documented

Function declarations



Initialization functions

procedure FontInit;
Description: To be documented
Note To be documented


Font functions

function FontLoad(Header:PFontHeader; Data:PFontData; Size:LongWord):TFontHandle;
Description: Load a Font from a font data block and add to the Font table
Header Pointer to the font header
Data Pointer to the font data
Size Size of the font data


function FontLoadEx(Header:PFontHeader; Data:PFontData; Unicode:PFontUnicode; Size:LongWord; Properties:PFontProperties):TFontHandle;
Description: Load a Font from a font data block and add to the Font table
Header Pointer to the font header
Data Pointer to the font data
Unicode Pointer to the unicode translation table (Optional)
Size Size of the font data
Properties Pointer to a font properties record to use instead of the header (Optional)


function FontUnload(Handle:TFontHandle):LongWord;
Description: To be documented
Note To be documented


function FontGetName(Handle:TFontHandle):String;
Description: To be documented
Note To be documented


function FontGetDescription(Handle:TFontHandle):String;
Description: To be documented
Note To be documented


function FontGetWidth(Handle:TFontHandle):LongWord;
Description: To be documented
Note To be documented


function FontGetHeight(Handle:TFontHandle):LongWord;
Description: To be documented
Note To be documented


function FontGetProperties(Handle:TFontHandle; Properties:PFontProperties):LongWord;
Description: To be documented
Note To be documented


function FontCharWidth(Handle:TFontHandle; Character:Word):LongWord;
Description: To be documented
Note To be documented


function FontCharHeight(Handle:TFontHandle; Character:Word):LongWord;
Description: To be documented
Note To be documented


function FontTextWidth(Handle:TFontHandle; const Text:String):LongWord;
Description: To be documented
Note To be documented


function FontTextHeight(Handle:TFontHandle; const Text:String):LongWord;
Description: To be documented
Note To be documented


function FontFindByName(const Name:String):TFontHandle;
Description: To be documented
Note To be documented


function FontFindByDescription(const Description:String):TFontHandle; 
Description: To be documented
Note To be documented


function FontEnumerate(Callback:TFontEnumerate; Data:Pointer):LongWord;
Description: To be documented
Note To be documented


PSF font functions

function PSFFontLoad(const FileName:String):TFontHandle;
Description: To be documented
Note To be documented


function PSFFontLoadEx(Data:Pointer;Size:LongWord):TFontHandle;
Description: To be documented
Note To be documented


Font helper functions

function FontGetCount:LongWord; inline;
Description: Get the current font count
Note To be documented


function FontGetDefault:TFontHandle; inline;
Description: Get the current default font
Note To be documented


function FontSetDefault(Handle:TFontHandle):LongWord;
Description: Set the current default font
Note To be documented


function FontCheck(Font:PFontEntry):PFontEntry;
Description: Check if the supplied Font is in the Font table
Note To be documented



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