## Presentation Device Driver Reference for OS/2

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### SDLine Parameter - pInput

pInput (PLINEINFO) - input Pointer to LINEINFO data structure.

ulLength Length of the LINEINFO data structure.

ulType Defines line type.

LINE_SOLID Line will be solid in Foreground color.

LINE_INVISIBLE Line is not drawn.

LINE_ALTERNATE Line will be alternating Foreground and Background color; ignores style.

ulStyleMask A 32-bit style mask.

cLines Count of lines to be drawn.

ulFGColor Line Foreground color.

ulBGColor Line Background color.

usForeROP Line Foreground mix.

usBackROP Line Background mix.

pDstBmapInfo Destination surface (BMAPINFO).

alpkLinePack Array of line details information.

ulStyleStep The value to be added to ulStyleValue on each pel stepped along the line style's direction.

ulStyleValue The style value at the current pel. It is composed of an error value and a mask position, as follows:

    /---------------------------------------------------------------\

    |high word      |3 bits         |5 bits         |8 bits         |

    |---------------+---------------+---------------+---------------|

    |not used       |not used       |mask pos       |error value    |

    \---------------------------------------------------------------/

ulFlags Miscellaneous flags used for the LINEPACK data structure.

LINE_DO_FIRST_PEL Draws the first pel.

LINE_DIR_Y_POSITIVE Indicates line direction is bottom-to-top.

LINE_HORIZONTAL Indicates line is horizontal. No Bresenham algorithm.

LINE_X_MAJOR Line is XMAJOR.

LINE_DIR_X_POSITIVE Indicates line direction is right-to-left.

LINE_VERTICAL Indicates line is vertical. No Bresenham algorithm.

LINE_STYLE_X_MAJOR Line style is XMAJOR.

LINE_DO_LAST_PEL Draws the last pel.

ulAbsDeltaX Clipped Bresenham Delta X, absolute (ptlStart.x - ptlEnd.x).

ulAbsDeltaY Clipped Bresenham Delta Y, absolute (ptlStart.y - ptlEnd.y).

ptlClipStart Pointer to location where device performs the Bresenham algorithm. Sets only the pels from ptlClipStart to ptlClipEnd, inclusive.

ptlClipEnd Ending location for Bresenham algorithm (see previous parameter, ptlClipStart).

ptlStart Pointer to starting location for line. The device can perform the Bresenham algorithm from ptlStart or ptlClipStart.

ptlEnd Ending location for line.

lClipStartError The standard Bresenham error at the clipped start point. This error is calculated from the initial error at the start point and the error increments for major step and diagonal step. The initial error and the error increments are as follows:

MAX Maximum (ulAbsDeltaX, ulAbsDeltaY)
MIN Minimum (ulAbsDeltaX, ulAbsDeltaY)
Major Increment Increment to the error for stepping along the major axis:
2 * MIN.
Diagonal Increment Increment to the error for stepping along the major and minor axes:
2 * MIN - 2 * MAX.
Initial Error Error at the start point:
2 * MIN - MAX, if LINE_DIR_X_POSITIVE is On

2 * MIN - MAX - 1, if LINE_DIR_Y_POSITIVE is Off.

Horizontal and vertical lines. The line is drawn from the clipped start to clipped end. The lClipStartError will not be given.

First pel consideration. Set the first pel at the ptlStart (not ptlClipStart) only if LINE_DO_FIRST_PEL is set and the first pel is not clipped.

Last pel consideration. Set the last pel at the ptlEnd (not ptlClipEnd) only if LINE_DO_LAST_PEL is set and the last pel is not clipped.

Styling. Lines are styled using the ulStyleMask, ulStyleStep and ulStyleValue.
Error Value Error value at the current pel.

Mask Position Bit position of the ulStyleMask.

If this bit is on, set the current pel to the ulFGColor through usForeROP; otherwise, set the current pel to the ulBGColor through usBackROP.

prclBounds Bounding rect of the clipped line.