TSCLED 1.0
Dec 29, 2001

by Safak Cinar
scinar@shaw.ca
http://members.shaw.ca/safak

Based on the component TDynaLED 1.0 by Samson Fu 

LEGAL
=====
     
You are free to use and modify this component in any project
(freeware or commercial) but cannot sell or distribute
the component itself (whether as source code or in
compiled form), individually or bundled in a package without
prior written consent from the author.

That out of the way, feel free to modify the code. If you publish
your own component based on this one, make it freeware with
full source code and drop me a note. Alternatively, you can send
me your ideas, suggestions and bug reports and I will try to include
the functionality in the next version, with proper credit of course.

DESCRIPTION
===========

TSCLED is a multiline dot matrix LED display emulator that uses a 
monochrome offscreen bitmap to draw on. Text can be displayed using 
any installed font and it has a dozen or so built in animation 
sequences and custom draw functionality.

TSCLED is based on the component TDynaLED 1.0 by Samson Fu. You can 
download his component from http://www.torry.net/leds.htm.

TSCLED displays a monochrome bitmap (accessible through BITMAP 
property) with adjustable pixel size and inter pixel spacing. 
Although this BITMAP is exposed, you need not use it directly when 
simply displaying text, which you do by assigning strings to either 
the CAPTION or LINES properties.

Most of the features are quite straightforward, with a couple of 
exceptions:

* For LEDSTYLE, sclsSQUARE and sclsROUND yield identical looking 
displays unless LEDSIZE is larger than 2 pixels.

* TSCLED has both a LINES and a CAPTION property. If LINES is empty, 
CAPTION is used,otherwise LINES is used. It is a little easier using 
LINES at design time when entering multi-line text.

* The AUTOSIZE property may not be what you expect. If it is set to 
true, any change in LEDSIZE, LEDDISTANCE or LEDCOUNTX or LEDCOUNTY 
will change the component size, in other words, component WIDTH and 
HEIGHT become derived properties. Otherwise, LEDCOUNTX and LEDCOUNTY 
are derived from the other properties. Mainly a design time convenience.

* CLIPMODE can either be set to sccmTEXT or sccmDISPLAY. If set to 
sccmTEXT, the monochrome BITMAP will be the minimum size to 
accomodate the text drawn on it. Otherwise, the BITMAP will be the 
same size as display (ie LEDCOUNTX by LEDCOUNTY pixels). To better 
visualize this, enable ONAFTERDRAW on the this demo page, which will 
draw a frame around the BITMAP. As a rule of thumb, use sccmTEXT 
unless you are doing custom drawing.

* ALIGNMENTH doesn not use Delphi's TALIGNMENT values but a custom 
enumerated type. This is in anticipation of a later feature.
 
ANIMATION
=========

The ANIMATE method takes 6 arguments:

Procedure Animate(Style,Interval,Steps:Integer;P1,P2,P3:Integer);

Style    : 1..13, the various animation styles.
Interval : (Minimum) duration, in milliseconds, of each animation step
Steps    : The  total number of animation steps
P1,P2,P3 : Parameters. These are specific to each animation style.

Animation Styles:

1 : Blink Foreground
    (no parameters)

2 : Blink Background
    (no parameters)

3 : Blink background and foreground (ie. Toggle)
    (no parameters)

4 : Stretch X
    P1 = Angle (*1) increment (in degrees).
    P2 = X coordinate of the vertical center line (*2)
5 : Stretch Y
    P1 = Angle (*1) increment (in degrees).
    P2 = Y coordinate of the horizontal center line (*2)
6 : Flip X
    P1 = Angle increment (in degrees).
    P2 = X coordinate of the vertical center line (*2)
7 : Flip Y
    P1 = Angle increment (in degrees).
    P2 = Y coordinate of the horizontal center line (*2)
8 : Pulasate 
    P1 = Angle (*3) increment (in degrees).
    P2 = X coordinate of the center point (*2)
    P3 = Y coordinate of the center point (*2)

9 : Rotate
    P1 = Angle increment (in degrees).
         For full cycle rotation Steps*P1 has to be a multiple of 360.
    P2 = X coordinate of the center point (*2)
    P3 = Y coordinate of the center point (*2)

10: Scroll X
    P1 = Pixel increment (can be negative).
    P2 = Wraparound value. After this many pixels, "what goes around comes
         around". For nice cyclic animation, make sure that
           a. Steps is larger than or equal to Bitmap.Width 
              or GetLEDCountX (depending on ClipMode).
           b. Wraparound value is a multiple of pixel increment and steps.

11: Scroll Y
    P1 = Pixel increment (can be negative).
    P2 = Wraparound value. Same considerations for "Scroll X" apply.

12: Wipe X
    P1 = Pixel increment (can NOT be negative).

13: Wipe Y
    P1 = Pixel increment (can NOT be negative).

Notes:
  (1) Stretching uses cosecant in the transformation filter, hence the angle.
  (2) Center of display is "SCLED.LEDCountX Div 2, SCLED.LEDCountY Div 2"
      Center of text is "SCLED.Bitmap.Width Div 2, SCLED.Bitmap.Height Div 2"
      In the demo animations display center has been used.
  (3) Pulsating uses cosine in the transformation filter, hence the angle.