zdraw Subroutine

Purpose

Enables or prohibits drawing to the z-buffer.

Libraries

Graphics Library

C (libgl.a)

FORTRAN (libfgl.a)

C Syntax

void zdraw(Int32 bool)

FORTRAN Syntax

SUBROUTINE ZDRAW(bool)
LOGICAL bool

Description

The zdraw subroutine allows or prohibits drawing into the z-buffer. The current color mode (either color map or RGB) applies. All current drawing attributes apply as well (color or RGBcolor, writemask or RGBwritemask, pattern, linestyle). However, if you enable drawing to the z-buffer with the zdraw subroutine, you must turn z-buffer mode off with the zbuffer subroutine. By default, drawing into the z-buffer is prohibited.

Calling the gconfig subroutine disables drawing to the z-buffer.

Parameter

Implementation Specifics

This subroutine is part of GL in the AIXwindows Environment/6000 Version 1, Release 2 with AIXwindows/3D Feature.

On the 3-D Color Graphics Processor and on the POWER Gt4, POWER Gt4x, and POWERgraphics GTO, and POWER GXT1000 adapters, calling the zdraw subroutine with a value of True affects only the writepixels, writeRGB, rectwrite, lrectwrite, and rectcopy pixel writing subroutines. If drawing into the z-buffer is enabled when other drawing subroutines (such as those for polygons or lines) are issued, the drawing subroutines draw as normal into the color bitplanes and write depth values into the z-buffer.

BLITs to and from the z-buffer are currently inoperational on the POWER GXT1000 adapter.

On the 3-D Color Graphics Processor, calling the frontbuffer subroutine with a value of True also prohibits drawing to the z-buffer.

Files

Related Information

Enabling drawing to the back buffer with the backbuffer subroutine.

Enabling drawing to the front buffer with the frontbuffer subroutine.

AIX Graphics Library Overview, Configuring the Frame Buffer, and Removing Hidden Surfaces.