{{DISPLAYTITLE:_DISPLAY}}
The [[_DISPLAY]] statement turns off the automatic display while only displaying the screen changes when called. 


{{PageSyntax}} 
::: '''_DISPLAY'''


''Usage:''
* '''_DISPLAY''' turns off the auto refresh screen default [[_AUTODISPLAY]] when used. Prevents screen flickering.
* Call _DISPLAY each time the screen graphics are to be displayed. Place call after the image has been changed.
* Re-enable automatic display refreshing by calling [[_AUTODISPLAY]]. If it isn't re-enabled, things may not be displayed later!
* _DISPLAY tells '''QB64GL''' to render all of the hardware [[_PUTIMAGE]] commands loaded into the buffer previously.
* '''QB64GL''' can set the graphic rendering order of _SOFTWARE, _HARDWARE, and _GLRENDER with [[_DISPLAYORDER]].


''Example 1:'' Displaying a circle bouncing around the screen.
{{CodeStart}} '' ''
{{Cl|SCREEN (statement)|SCREEN}} 12
x = 21: y =31              'start position
dx = 3: dy = 3             'number of pixel moves per loop       
{{Cl|DO}}
    {{Cl|_LIMIT}} 100       ' set to 100 frames per second
    x = x + dx: y = y + dy
    {{Cl|IF...THEN|IF}} x &lt; 0 {{Cl|OR}} x &gt; 640 {{Cl|THEN}} dx = -dx 'limit columns and reverse column direction each side
    {{Cl|IF...THEN|IF}} y &lt; 0 {{Cl|OR}} y &gt; 480 {{Cl|THEN}} dy = -dy 'limit rows and reverse row direction top or bottom
    IF px &lt;&gt; x OR py &lt;&gt; y THEN FOR d = 1 to 20: CIRCLE (px, py), d, 0: NEXT 'erase
    FOR c = 1 TO 20: {{Cl|CIRCLE}} (x, y), c, 6: NEXT  'draw new circle at new position
    px = x: py = y        'save older coordinates to erase older circle next loop
    {{Cl|_DISPLAY}}                'after new circle is set, show it
{{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} = CHR$(27) '' ''
{{CodeEnd}}

:''Explanation:'' The loop is set with [[_LIMIT]] to 100 frames per second to limit CPU usage and the speed of the ball. Each loop a circle is drawn while the previous one is erased when the coordinates change. _DISPLAY only shows the new circle position once each loop. The '''_DISPLAY''' routine eliminates the need for setting [[SCREEN (statement)|SCREEN]] swap pages, [[CLS]] and [[PCOPY]]. _DISPLAY keeps the image off of the screen until the changes have all completed. Drawing 40 circles every loop helps slow down the ball.


''Example 2:'' In ''QB64GL''' [[_DISPLAY]] must be used to render hardware images placed with [[_PUTIMAGE]].
{{CodeStart}} '' ''
{{Cl|CONST}} MenuHeight = 200


{{Cl|SCREEN}} {{Cl|_NEWIMAGE}}(640, 480, 32)
'{{Cl|SLEEP}} 1
{{Cl|LOCATE}} 20
DO
    {{Cl|_LIMIT}} 30
    DisplayMenu
    k = {{Cl|_KEYHIT}}
    {{Cl|IF...THEN|IF}} k &lt;&gt; 0 {{Cl|THEN}} {{Cl|PRINT}} k,
{{Cl|LOOP}} {{Cl|UNTIL}} k = 32 {{Cl|OR (boolean)|OR}} k = 27


{{Cl|SUB}} DisplayMenu
{{Cl|STATIC}} init, MS_HW {{Cl|AS}} {{Cl|LONG}}
{{Cl|IF...THEN|IF}} {{Cl|NOT}} init {{Cl|THEN}}
    init = -1
    MS = {{Cl|_NEWIMAGE}}(640, MenuHeight, 32) 'MenuScreen image
    D = {{Cl|_DEST}}: {{Cl|_DEST}} MS
    {{Cl|CLS}} , {{Cl|&amp;H}}FFAAAAAA 'background color gray
    {{Cl|_PRINTSTRING}} (20, 2), &quot;Menu Test&quot; 'image text
    MS_HW = {{Cl|_COPYIMAGE}}(MS, 33) 'create the MenuScreen_HardWare image
    {{Cl|_FREEIMAGE}} MS
    {{Cl|_DEST}} D
{{Cl|END IF}}
{{Cl|_PUTIMAGE}} (0, 0)-(640, MenuHeight), MS_HW
{{Cl|_DISPLAY}}
{{Cl|END SUB}} '' ''
{{CodeEnd}}{{small|Code adapted by Galleon}}
: ''Notes:'' When _DISPLAY is commented out, the hardware Menu Test screen portion will blink and key codes may be seen underneath.


{{PageSeeAlso}}
* [[_DISPLAY (function)]]
* [[_DISPLAYORDER]] {{text|(QB64GL only)}}
* [[_AUTODISPLAY]] {{text|(default display mode)}}
* [[_PUTIMAGE]]
* [[PCOPY]]


{{PageNavigation}}