Skip to content

Latest commit

 

History

History
53 lines (38 loc) · 1.53 KB

ReadPixelLine8.md

File metadata and controls

53 lines (38 loc) · 1.53 KB
Raw

NAME

ReadPixelLine8 -- read the pen number value of a horizontal line of pixels starting at a specified x,y location and continuing right for count pixels. (V36)

SYNOPSIS

    count = ReadPixelLine8(rp,xstart,ystart,width,array,temprp)
    D0                     A0 D0:16  D1:16  D2    A2    A1

    LONG ReadPixelLine8(struct RastPort *, UWORD, UWORD, UWORD,
         UBYTE *, struct RastPort * );

Links: RastPort RastPort

FUNCTION

For each pixel in a rectangular region, combine the bits from each of the bit-planes used to describe a particular RastPort into the pen number selector which that bit combination normally forms for the system hardware selection of pixel color.

INPUTS

rp - pointer to a RastPort structure (x,y) - a point in the RastPort width - count of horizontal pixels to read array - pointer to an array of UBYTEs from which to fetch the pixel data allocate at least (((width+15)>>4)<<4) bytes. temprp - temporary rastport (copy of rp with Layer set == NULL, temporary memory allocated for temprp->BitMap with Rows set == 1, temprp->BytesPerRow == (((width+15)>>4)<<1), and temporary memory allocated for temprp->BitMap->Planes[])

RESULT For each pixel in the array: Pen - (0..255) number at that position is returned count - the number of pixels read.

NOTE width must be non negative

BUGS

SEE ALSO

ReadPixel graphics/rastport.h