SCREEN pages

[DragonEye Software]

Could someone shed some light on the PAGE functions used in SCREEN Statement?

QB HELP States:
SCREEN mode% [, [colorswitch%] [, [activepage%] [, visiblepage%]] ]

What exactly are the PAGE functions used for?

[Dr_Davenstein]

You can use them to draw on a page in memory, and then display all the graphics at once using PCOPY. Here's a cheap example to show you how it works...

Code: Select all

DEFINT A-Z
SCREEN 7, , 0, 1

DO
 CLS ' clear the backbuffer, Page 0.

 ' Draw some stuff on the backbuffer
 FOR R = 1 TO 100
  Col = INT(RND * 15) + 1
  CIRCLE (INT(RND * 320), INT(RND * 200)), 16, Col
  PAINT STEP(0, 0), 0, Col
  PAINT STEP(0, 0), Col, Col
 NEXT

 WAIT &H3DA, 8'Wait for vertical retrace
 WAIT &H3DA, 8, 8'
 PCOPY 0, 1'Copies the Active Page 0 to the Visual Page 1, which is the screen.
LOOP UNTIL INKEY$ = CHR$(27) 'ESC to exit

[DragonEye Software]

Alrighty then, thanks, ill give it a shot.