Information on clipper functions from VGATEXT

 

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IsVga:

Arguments : None.
Return : Integer. (0 or 1)

This function is the one in charge to detect the presence of a compatible VGA board, the Return of a 1 (one) means that the presence of this board has been detected thus all the functions will be executed normally. The Return of a 0 (zero) means that the presence of this board has NOT been detected, therefore the functions will not do the awaited effects, but the internal control of each function will determine the execution of an alternative effect, supported by the current video board (Example: If  the VGA effect was a special progresive cleaning of the screen, the effect without VGA, will be of a normal cleaning). This means, that although the clipper application uses the sophisticated visual effects that require VGA, the program will be executed normally in PC's with monitors like Monochrome, although replacing internally and automaticaly the exclusive parts for VGA video boards.


AlterCol:

Arguments : (ColorNUMBER, RED, GREEN, BLUE)
Return : None.

Modifies a color with the given primary ingredients. ColorNUMBER is the color number to modify (0 to 15), RED, GREEN and BLUE vary between 0 and 63, combining them with the suitable values, any color of the 262,144 of the complete VGA palette can be created.
This is the table of values for ColorNUMBER:

Background color -> 0 Black 		8 Dark Gray
		    1 Blue 		9 Light Blue
		    2 Green 		10 Light Green
		    3 Cyan 		11 Light Cyan
		    4 Red 		12 Light Red
		    5 Magenta 		13 Light Magenta
		    6 Brown 		14 Yellow
ForeGround Color -> 7 Light Gray (W) 	15 White (W+)

Note : The First Argument (ColorNUMBER) must be a integer (0..15), Avoid letters (like "W").


RESTORE:

Arguments : None.
Return : None.

This function MUST be called at the end of your clipper application!
It is the one in charge To return to "normality" the colors altered with function ALTERCOL.

Note: It is not necessary to call this function if your clipper application has not used any time the AlterCol function.


VGA_off:

Arguments : None.
Return : None.

It disables the display visualization . The content of the screen will not be visible, but it remains and can be modified

Note: Nothing bad happens if you call this function when the display already has been disabled.


VGA_on:

Arguments : None.
Return : None.

It enables the visualization of display. The content of the previously "hidden" screen will be visible now.

Note: Nothing bad happens if you call this function when the display already has been enabled


FadeOut:

Arguments : None.
Return : None.

The content of the screen makes a visual effect of " Fading ", the contents are totally erased .

Note: Unlike the VGA_off, this function Erases the contents of the screen, like as a clipper "Clear", thus are not recoverable.


FadeIn:

Arguments : None.
Return : None.

The contents of the screen makes a visual effect of "Fade In".

Way of use:

A) Call the VGA_off function, which disables the visualization of the display.
b) Update/compose the contents of the screen
c) Call the FadeIn function

Note: It is not necessary to call the VGA_on function after the FadeIn, since this last one, makes that work internally.


Copper:

Arguments : (ColorNUMBER, ClearAfter, Max Time, Texture)
Return : None.

Multiple degradee effect on a color, shows up to 400 different simultaneous colors (Text Mode), ideal for presentation.

ColorNUMBER: Color Number on which to act the effect (0..15)

ClearAfter: If it is 1 (one), the function cleans the contents of the screen after finished the effect.

Max Time: Maximum time in seconds that effect will last,  if the < ESC > key was not pressed, ESC key finishes the effect immediately. The time varies between 1 and 255 Seconds, if a 0 (zero) is passed as argument, there will be no time limit and the effect will last until the ESC> key is pressed

Texture: color combinations to be used for the effect (0..4)
0) Multicolor degradee, great  for boxes or big letters.
1) White Degradee.
2) Red Degradee.
3) Green Degradee.
4) Blue Degradee, similar to the one of Windows TM (But works in clipper under DOS!)


Cascada:

Arguments : None.
Return : None.

It unfolds the contents of the screen quickly and showy, very recommended for full/complete screens!

Way of use:

A) Call to the VGA_off function, which disables the visualization of the display.
b) Update/compose the contents of the screen to be unfolded.
c) Call the Cascada function.

Note: It is not necessary to call to the VGA_on function from clipper after calling the Cascade function, since this last one, makes that work internally.

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