#!/bin/bash
# Compare make_png with ppmmake.

set -euo pipefail

if [[ $# -ne 1 ]]; then
   echo "$0 <make_png.exe>"
   exit 1
fi

MAKE_PNG=$1
EXPECTED_OUTPUT=$(mktemp)

function output_mismatched
{
   echo "Output mismatched for $@"
   rm -f "$EXPECTED_OUTPUT"
   exit 1
}

function test_white
{
   ppmmake rgb:ff/ff/ff $1 $2 | ppmtoppm > "$EXPECTED_OUTPUT"

   ./$MAKE_PNG $1 $2 \
      | pngtopnm \
      | ppmtoppm \
      | diff -q "$EXPECTED_OUTPUT" - \
      || output_mismatched $1 $2 white
}

function test_color
{
   ppmmake $(printf "rgb:%02x/%02x/%02x" $3 $4 $5) $1 $2 \
      | ppmtoppm > "$EXPECTED_OUTPUT"

   ./$MAKE_PNG $1 $2 $3 $4 $5 \
      | pngtopnm \
      | ppmtoppm \
      | diff -q "$EXPECTED_OUTPUT" - \
      || output_mismatched $1 $2 $3 $4 $5
}

function test_alpha
{
   ppmmake rgb:12/34/56 $1 $2 | ppmtoppm > "$EXPECTED_OUTPUT"

   ./$MAKE_PNG $1 $2 255 255 255 0 \
      | pngtopam -mix -background=rgb:12/34/56 \
      | ppmtoppm \
      | diff -q "$EXPECTED_OUTPUT" - \
      || output_mismatched $1 $2 alpha 0

   ./$MAKE_PNG $1 $2 18 52 86 255 \
      | pngtopam -mix -background=rgb:ee/dd/cc \
      | ppmtoppm \
      | diff -q "$EXPECTED_OUTPUT" - \
      || output_mismatched $1 $2 alpha 255
}

test_white 1 1
test_white 1 64
test_white 32 1
test_white 1024 1023

test_color 128 256 0 0 0
test_color 256 512 255 255 255

test_color 511 511 255 0 0
test_color 510 511 0 255 0
test_color 511 510 0 0 255

test_color 12 34 5 6 7
test_color 98 76 5 4 3

test_alpha 11 13
test_alpha 97 89

rm -f "$EXPECTED_OUTPUT"