#!/bin/bash
#
# rm2-template-cover
# John Simpson <jms1@jms1.net> 2023-07-04
#
# Create a simple "cover page" template
#
# 2023-07-09 jms1 - renamed script

########################################
# Page dimensions
#
# These values are correct for reMarkable tablets, only change if you're
# making a cover image to fit some other device.

PAGE_W=1404
PAGE_H=1872

########################################
# Background colour. This can be anything ImageMagick recognizes, you can run
# "magick -list color" to see a list of pre-defined colour names.
#
# Examples: (these are all the same colour)
# - "gray75"
# - "#BFBFBF"
# - "srgb(191,191,191)"

PAGE_BG="gray75"

########################################
# Box outer dimensions and Y position.
# - X will be calculated so the box is centered on the page.

BOX_W=900
BOX_H=400

BOX_Y=300

########################################
# Calculate the boxes' corner positions.
# - Each box will be "inside" the one before it.

AX1=$(( ( PAGE_W - BOX_W ) / 2 ))
AY1=$BOX_Y
AX2=$(( AX1 + BOX_W ))
AY2=$(( AY1 + BOX_H ))

BX1=$(( AX1 + 3 ))
BY1=$(( AY1 + 3 ))
BX2=$(( AX2 - 3 ))
BY2=$(( AY2 - 3 ))

CX1=$(( BX1 + 2 ))
CY1=$(( BY1 + 2 ))
CX2=$(( BX2 - 2 ))
CY2=$(( BY2 - 2 ))

DX1=$(( CX1 + 1 ))
DY1=$(( CY1 + 1 ))
DX2=$(( CX2 - 1 ))
DY2=$(( CY2 - 1 ))

########################################
# Do it

rm -f cover-simple.png

magick \
    -type GrayScale -depth 8 -size "${PAGE_W}x${PAGE_H}" "xc:${PAGE_BG}" \
    -fill black \
    -draw "rectangle $AX1 $AY1 $AX2 $AY2" \
    -fill $PAGE_BG \
    -draw "rectangle $BX1 $BY1 $BX2 $BY2" \
    -fill black \
    -draw "rectangle $CX1 $CY1 $CX2 $CY2" \
    -fill white \
    -draw "rectangle $DX1 $DY1 $DX2 $DY2" \
    cover-simple.png