In the Presentation Manager for OS/2 2.1 and previous versions, a presentation driver had to support more than 70 functions. In addition, it was also mandatory that the presentation driver keep device-contextual state information and, in the case of display presentation drivers, run some functions at interrupt time.

The design of the graphics engine in OS/2 Warp, Version 3 focuses on taking the complexity out of developing a presentation driver while keeping the expandability and flexibility it was originally designed to have.

This graphics engine has two major changes from OS/2 2.1 and previous versions:

• Device-independent functions merged into the graphics engine

• System rasterization support (referred to as SOFTDRAW)

This design is intended to do the following:

• Make presentation drivers simple and easy to develop

• Allow developers to add functionality in increments

• Move contextual and state management out of the presentation drivers

• Move common rasterization management out of the presentation drivers

The following table identifies the support for the Presentation Driver Model that is available in various versions of OS/2.

┌────────────────────────┬────────────┬────────────┬────────────┐│OS/2 Release            │16BPD       │32BPD       │NMPD        │
├────────────────────────┼────────────┼────────────┼────────────┤
│Runs on OS/2 1.X        │X           │            │            │
├────────────────────────┼────────────┼────────────┼────────────┤
│Runs on OS/2 2.0, 2.1   │X           │X           │            │
├────────────────────────┼────────────┼────────────┼────────────┤
│Runs on OS/2 Warp,      │X           │X           │X           │
│Version 3               │            │            │            │
└────────────────────────┴────────────┴────────────┴────────────┘

Note:

16BPD

Presentation Driver compiled as 16 bit

Presentation Driver compiled as 32 bit

New model of Presentation Driver