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54 lines
2.3 KiB
Plaintext
54 lines
2.3 KiB
Plaintext
The [[_COPYIMAGE]] function creates an identical designated image in memory with a different negative [[LONG]] handle value.
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{{PageSyntax}}
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: newhandle& = '''_COPYIMAGE'''[({{parameter|imageHandle&}})]
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{{Parameters}}
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* The [[LONG]] ''newhandle'' value returned will be different than the source handle value supplied.
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* If ''imagehandle'' parameter is omitted the current [[_DEST]]ination screen or image is copied. Zero can be used to copy the current screen.
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''Usage:''
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* The function copies any image or screen handle to a new and unique negative [[LONG]] handle value.
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* Valid copy handles are less than -1. Invalid handles return -1 or 0 if it was never created.
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* Every attribute of the passed image or program screen is copied to a new handle value in memory.
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* '''32 bit screen surface backgrounds(black) have zero [[_ALPHA]] so that they are transparent when placed over other surfaces.'''
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: Use [[CLS]] or [[_DONTBLEND]] to make a new surface background [[_ALPHA]] 255 or opague.
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* '''Images are not deallocated when the [[SUB]] or [[FUNCTION]] they are created in ends. Free them with [[_FREEIMAGE]].'''
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* '''It is IMPORTANT to free discarded images with [[_FREEIMAGE]] to prevent PC memory allocation errors!'''
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* '''Do NOT try to free image handles currently being used as the active [[SCREEN]]! Change screen modes first.'''
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''Example:'' Restoring a Legacy SCREEN using the _COPYIMAGE return value.
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{{CodeStart}}'' ''
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{{Cl|SCREEN}} 13
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{{Cl|CIRCLE}} (160, 100), 100, 40
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DO: {{Cl|SLEEP}}: {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} <> ""
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'backup screen before changing {{Cl|SCREEN}} mode
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oldmode& = {{Cl|_COPYIMAGE}}(0) 'the 0 value designates the current destination {{Cl|SCREEN}}
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s& = {{Cl|_NEWIMAGE}}(800, 600, 32)
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{{Cl|SCREEN}} s&
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{{Cl|LINE}} (100, 100)-(500, 500), {{Cl|_RGB}}(0, 255, 255), BF
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DO: {{Cl|SLEEP}}: {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} <> ""
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{{Cl|SCREEN}} oldmode& 'restore original screen
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{{Cl|IF...THEN|IF}} s& < -1 THEN {{Cl|_FREEIMAGE}} s&
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{{Cl|END}} '' ''
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{{CodeEnd}}
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: ''Note:'' Only free valid handle values with [[_FREEIMAGE]] AFTER a new [[SCREEN]] mode is being used by the program.
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{{PageSeeAlso}}
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* [[_LOADIMAGE]], [[_NEWIMAGE]]
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* [[_SOURCE]], [[_DEST]]
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* [[_FREEIMAGE]]
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* [[_FILELIST$ (function)]] {{text|(Demo of _COPYIMAGE)}}
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{{PageNavigation}} |