tips:revmedia:r45

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tips:revmedia:r45 [2023/11/05 22:15] – created - external edit 127.0.0.1tips:revmedia:r45 [2024/06/19 20:20] (current) – external edit 127.0.0.1
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 +====== Changes to BORDER.UP for Advanced Revelation Version 2.0=====
  
 +^Published By^Date^Version^Knowledge Level^Keywords^
 +|Revelation Technologies|01 FEB 1990|2.X|INTERMEDIATE|BORDER.UP, DISPLAY, SHADOWS, VIDEO.RW, VIDEO, ATTRIBUTES|
 +
 +Advanced Revelation Version 2.0 provides the option of displaying shadows
 +below and to the right of windows, popups, and messages. BORDER.UP, the
 +system subroutine that draws borders onto the screen, has been modified to
 +automatically handle display of shadows. A flag has been added to the
 +parameters passed to BORDER.UP to turn this feature on and off.
 +
 +==== Displaying Shadows ====
 +
 +To display shadows using an R/BASIC program, there are two conditions.
 +First, the environment flag for displaying border shadows must be set to
 +true (field 76 in the current environment record). This flag can be set from
 +the Video Environment window or by changing the 76th field of @ENVIRON.SET.
 +
 +Second, the call to BORDER.UP must have the sixth field of the border type
 +(fifth) argument set to logical true. Even if the call to BORDER.UP requests
 +shadows they will not display if the environment flag is turned off. For an
 +example of a BORDER.UP call that displays a shadow, see Figure 1.
 +
 +Shadows will not display if the environment flag for border shadows is
 +turned off, regardless of the border type flag setting.
 +
 +==== Using VIDEO.RW with Shadows ====
 +
 +When implementing shadows, you must be sure to accommodate shadows in calls
 +to VIDEO.RW that save and restore the screen. To do so, add 2 to the top
 +right X coordinate, and 1 to the bottom left Y coordinate so that the space
 +occupied by shadows is included. A sample call to VIDEO.RW is illustrated in
 +Figure 2.
 +
 +==== Examples ====
 +
 +=== Figure 1 ===
 +
 +<code>
 +* setting shadow flag
 +
 +$INSERT INCLUDE, WINDOW.POINTERS
 +
 +DECLARE SUBROUTINE BORDER.UP
 +
 +EQU TRUE$     TO 1
 +EQU SHADOWON$ TO 6 ; * 6th attribute of border type
 +
 +ULX   = 10     ; * upper left col
 +ULY   = 5      ; * upper left row
 +BRX   = 40     ; * bottom right col
 +BRY   = 15     ; * bottom right row
 +BTYPE = @AW<CBORDER.TYPE>         ;* border type
 +BTYPE<SHADOWON$> = TRUE$          ;* shadows on
 +ATTR             = @AW<CBORDER>   ;* border attribute
 +
 +BORDER.UP(ULX,ULY,BRX,BRY,BTYPE,ATTR)
 +</code>
 +
 +=== Figure 2 ===
 +
 +<code>
 +* including shadow offsets to VIDEO.RW call
 +
 +$INSERT INCLUDE, WINDOW.POINTERS
 +DECLARE SUBROUTINE BORDER.UP, VIDEO.RW
 +
 +EQU X_OFFSET$ TO 2 ; * offset for columns (add 2 columns)
 +EQU Y_OFFSET$ TO 1 ; * offset for rows (add 1 row)
 +EQU TRUE$     TO 1
 +EQU SHADOWON$ TO 6
 +
 +IMAGE = ''
 +ULX   = 10     ; * upper left col
 +ULY   = 5      ; * upper left row
 +BRX   = 40     ; * bottom right col
 +BRY   = 15     ; * bottom right row
 +
 +BTYPE = @AW<CBORDER.TYPE>       ;* border type
 +BTYPE<SHADOWON$> = TRUE$        ;* shadows on
 +ATTR             = @AW<CBORDER> ;* border attribute
 +
 +
 +/* these lines read the current video image and post a border
 +(spacing in the lines is used for clarity) */
 +
 +VIDEO.RW( ULX, ULY, BRX X_OFFSET$, BRY Y_OFFSET$, 'R', IMAGE )
 +BORDER.UP( ULX, ULY, BRX, BRY, BTYPE, ATTR )
 +*
 +* your code here
 +*
 +* restore video image when done
 +VIDEO.RW(ULX,ULY,BRX X_OFFSET$,BRY Y_OFFSET$,'W',IMAGE)
 +</code>