#! /bin/bash

# This script tests: ppmmix

# Also requires: pamdepth pamenlarge pamsumm pbmmake

# Also requires: pgmtopgm pnminvert ppmtopgm

tmpdir=${tmpdir:-/tmp}

# Test 1. Print a pretty checkerboard pattern

a1_pgm=${tmpdir}/a1.pgm

a2_pgm=${tmpdir}/a2.pgm

pbmmake -g 8 8 | pgmtopgm > ${a1_pgm} &&

pbmmake -g 2 2 | pamenlarge 4 | pgmtopgm > ${a2_pgm} &&

ppmmix 0.75 ${a1_pgm} ${a2_pgm} | ppmtopgm | pamdepth 3 -plain &&

rm ${a1_pgm} ${a2_pgm}

# Mix image with itself.

# Output should match input regardless of ratio.

for i in 0 0.5 0.6 1

do

ppmmix $i testimg.ppm testimg.ppm | cksum

done

# Mix image with its own inverse.

# Output should be a monotone gray sheet.

a3_ppm=${tmpdir}/a3.ppm

pnminvert testimg.ppm | ppmmix .5 \

    testimg.ppm - | tee ${a3_ppm} | \

  pamsumm -brief -max &&

  pamsumm -brief -min ${a3_ppm} &&

rm ${a3_ppm}