SHADE_RANGE(3G)

NAME

shade_range − set intensity-to-frame-buffer-index mapping

SYNOPSIS

C Syntax:

void shade_range(fildes,min,max);
int fildes,min,max;

FORTRAN77 Syntax:

subroutine shade_range(fildes,min,max)
integer∗4 fildes,min,max

Pascal Syntax:

procedure shade_range(fildes,min,max:integer);

DESCRIPTION

Input Parameters

fildes Integer file descriptor returned by open when an I/O path to a graphics device is opened.

min Frame buffer index that intensity 0.0 maps to.

max Frame buffer index that intensity 1.0 maps to.

Discussion

When CMAP_MONOTONIC is specified in shade_mode, subsequent red, green, blue values are converted to an intensity, then mapped into the frame buffer using min and max. The min value must be less than the max value. It is left to the user to make sure the color map is set up in a monotonically increasing intensity between the two values. See shade_mode(3G) for the formula used to convert red,green,blue values to intensity.

DEFAULTS

min = 0; max is set to highest available index value.

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