#!/bin/bash
# This script is used to generate the previews needed by the mod
# This script can also use pngcrush and imagemagick to reduce output size,
# Warning: any file in previews and textures might be deleted without asking.
# Copyright (c) 2014 Diego Martínez @kaeza https://kaeza.github.io/
# Copyright (c) 2024 PICCORO Lenz Mckay @mckaygerhard

gm=`which gm`
cvt="";
cmp="";

if [ "$gm" ]; then
    cvt="$gm convert";
    cmp="$gm composite";
else
    cvt=`which convert`;
    cmp=`which composite`;
fi

if [ ! "$cmp$cvt" ]; then
    echo "*** Neither GraphicsMagick nor ImageMagick could be found." >&2;
    echo "*** Please install one of them and run this script again." >&2;
    echo "*** using apt install graphicsmagick or apk add graphicsmagick." >&2;
    echo "*** Stop." >&2;
    exit 1;
fi

cd "$(dirname "$0")";

blit() # ID SX SY DX DY W H [HFLIP]
{

    $cvt ../textures/character_$1.png -crop $6x$7+$2+$3 .tmp/blit_tmp.png;

    if [ "$8" ]; then
	$cvt -flop .tmp/blit_tmp.png .tmp/blit_tmp.png;
    fi

    $cmp -compose src-over -geometry +$4+$5 .tmp/blit_tmp.png .tmp/char_tmp.png .tmp/char_tmp_out.png;

    mv .tmp/char_tmp_out.png .tmp/char_tmp.png;

}

convert_one() # ID
{

    id="$1";

    mkdir -p .tmp/;

    # Eh... this is one huge overkill. There are prolly better ways to do
    # As always, patches welcome :) -- kaeza

    # Front view
    $cvt -size 16x32 canvas:none .tmp/char_tmp.png
    blit $id  8  8  4  0  8  8      # Head
    blit $id 40  8  4  0  8  8      # Headgear
    blit $id 20 20  4  8  8 12      # Body
    blit $id  4 20  4 20  4 12      # Right Leg
    blit $id  4 20  8 20  4 12 t    # Left Leg
    blit $id 44 20  0  8  4 12      # Right Arm
    blit $id 44 20 12  8  4 12 t    # Left Arm
    mv .tmp/char_tmp.png ../textures/character_${id}_preview.png;

    # Back view
    $cvt -size 16x32 canvas:none .tmp/char_tmp.png
    blit $id 24  8  4  0  8  8      # Head
    blit $id 56  8  4  0  8  8      # Headgear
    blit $id 32 20  4  8  8 12      # Body
    blit $id 12 20  4 20  4 12 t    # Right Leg
    blit $id 12 20  8 20  4 12      # Left Leg
    blit $id 52 20  0  8  4 12 t    # Right Arm
    blit $id 52 20 12  8  4 12      # Left Arm
    mv .tmp/char_tmp.png ../textures/character_${id}_preview_back.png;

}

x=1;
while [ -f "../character_$x.png" ]; do
    convert_one $x;
    x=$[x+1];
done