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
* 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)
Figure 2
* 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)