Class PegScreen

Class PegScreen is the RTPEG-32 abstract device driver class that provides the drawing primitives used by the individual PEG objects to draw themselves on the display device. PegScreen provides a layer of isolation between the video hardware and the rest of the RTPEG-32 library.

PegScreen is an abstract class that defines the functions and function parameters instantiable PegScreen derived target specific interface classes must provide. Abstract class means the class contains one or more pure virtual functions which are placeholders in the class definition. They tell the compiler that all classes derived from the PegScreen base class must provide working versions of the virtual functions. In addition to the virtual functions, PegScreen also provides functionality that is common to all implementations.

RTPEG-32 is shipped with the following instantiatable classes derived from class PegScreen:

Driver	Creating Function	Comment
vga_4	CreatePegScreen_VGA_4	Supports graphics modes VGA 12h and VESA 102h 16 colors, 640x480 and 800x600).
vesa_8	CreatePegScreen_VESA_8	Supports all VGA and VESA 256 color modes. Linear frame buffer support is required if the required video RAM is larger than 64k.
vesa_16	CreatePegScreen_VESA_16	Supports all VESA 15/16 bit (32k/64k) color modes. Linear frame buffer support is required.
vesa_24	CreatePegScreen_VESA_24	Supports all VESA 24-bit (16M) true color modes. Linear frame buffer support is required.
vesa_32	CreatePegScreen_VESA_32	Supports all VESA 32-bit true color modes. Linear frame buffer support is required.
vgascrn	CreatePegScreen	Supports VGA mode 640x480, 16 colors on any VGA compatible graphics controller by programming this mode. This is the only driver which does not need a BIOS.