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The graPHIGS Programming Interface : Subroutine Reference

GPRRCT - Read Rectangle

GPRRCT (sibid, sorigin, size, format, parm, torigin, data)

Purpose

Use GPRRCT to read pixel data from an image board.

The specified target rectangle need not be inside of the target application image; however, the specified source rectangle must be inside of the source image board. When the target rectangle exceeds the target application image boundaries, pixel data outside the boundaries is discarded. If source and target storage have different bit depth, then source pixels are adjusted to the target bit length by removing most significant bits or adding 0-bit to the most significant part.

See The graPHIGS Programming Interface: Understanding Concepts for a discussion on image processing.

Parameters

sibid -- specified by user, fullword integer

Source image board identifier

sorigin -- specified by user, two fullword integers

Source rectangle origin (x, y) (>=0)

size -- specified by user, two fullword integers

Rectangle size (SX, SY) (>=1)

format -- specified by user, fullword integer

Application image format (1=PIXEL_ARRAY )

parm -- specified by user, array of fullword quantities

Format dependent parameters. The image format 1 requires the following parameters:

  • bit depth -- fullword integer 1, 2, 4, 8, or 16

  • x size -- fullword integer (>=1)

  • y size -- fullword integer (>=1)

  • pixel order -- fullword integer (1=LEFT_RIGHT_BOTTOM_TOP,2=LEFT_RIGHT_TOP_BOTTOM )

    • The product of the bit depth and x size must be a multiple of 8. This is to ensure that each row of the application's image data starts on a byte boundary.

    torigin -- specified by user, two fullword integers

    Target rectangle origin (x, y) (>=0)

    data -- returned by the graPHIGS API, array of pixels

    Target application image data. For the purpose of byte swapping between different shell/nucleus environments, the source application image data with bit depth of 16 will be handled as 16-bit halfwords. For all other bit depths, the application image data will be treated as 8-bit unsigned characters.

    Error Codes

    232
    SPECIFIED IMAGE BOARD DOES NOT EXIST
    236
    RECTANGLE DEFINITION IS INVALID
    237
    SPECIFIED APPLICATION IMAGE FORMAT IS NOT SUPPORTED
    240
    APPLICATION IMAGE DESCRIPTION IS INVALID

    Related Subroutines

    None

    RCP code

    201346316 (X'0C004D0C')

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