#!/bin/bash

# Tetris Game
# 10.21.2003 xhchen<[email]xhchen@winbond.com.tw[/email]>

#APP declaration
APP_NAME="${0##*[\\/]}"
APP_VERSION="1.0"

 
#颜色定义
cRed=1
cGreen=2
cYellow=3
cBlue=4
cFuchsia=5
cCyan=6
cWhite=7
colorTable=($cRed $cGreen $cYellow $cBlue $cFuchsia $cCyan $cWhite)

#位置和大小
iLeft=3
iTop=2
((iTrayLeft = iLeft + 2))
((iTrayTop = iTop + 1))
((iTrayWidth = 10))
((iTrayHeight = 15))

#颜色设置
cBorder=$cGreen
cScore=$cFuchsia
cScoreValue=$cCyan

#控制信号
#改游戏使用两个进程，一个用于接收输入，一个用于游戏流程和显示界面;
#当前者接收到上下左右等按键时，通过向后者发送signal的方式通知后者。
sigRotate=25
sigLeft=26
sigRight=27
sigDown=28
sigAllDown=29
sigExit=30

#七中不同的方块的定义
#通过旋转，每种方块的显示的样式可能有几种
box0=(0 0 0 1 1 0 1 1)
box1=(0 2 1 2 2 2 3 2 1 0 1 1 1 2 1 3)
box2=(0 0 0 1 1 1 1 2 0 1 1 0 1 1 2 0)
box3=(0 1 0 2 1 0 1 1 0 0 1 0 1 1 2 1)
box4=(0 1 0 2 1 1 2 1 1 0 1 1 1 2 2 2 0 1 1 1 2 0 2 1 0 0 1 0 1 1 1 2)
box5=(0 1 1 1 2 1 2 2 1 0 1 1 1 2 2 0 0 0 0 1 1 1 2 1 0 2 1 0 1 1 1 2)
box6=(0 1 1 1 1 2 2 1 1 0 1 1 1 2 2 1 0 1 1 0 1 1 2 1 0 1 1 0 1 1 1 2)
#所有其中方块的定义都放到box变量中
box=(${box0[@]} ${box1[@]} ${box2[@]} ${box3[@]} ${box4[@]} ${box5[@]} ${box6[@]})
#各种方块旋转后可能的样式数目
countBox=(1 2 2 2 4 4 4)
#各种方块再box数组中的偏移
offsetBox=(0 1 3 5 7 11 15)

#每提高一个速度级需要积累的分数
iScoreEachLevel=50        #be greater than 7

#运行时数据
sig=0                #接收到的signal
iScore=0        #总分
iLevel=0        #速度级
boxNew=()        #新下落的方块的位置定义
cBoxNew=0        #新下落的方块的颜色
iBoxNewType=0        #新下落的方块的种类
iBoxNewRotate=0        #新下落的方块的旋转角度
boxCur=()        #当前方块的位置定义
cBoxCur=0        #当前方块的颜色
iBoxCurType=0        #当前方块的种类
iBoxCurRotate=0        #当前方块的旋转角度
boxCurX=-1        #当前方块的x坐标位置
boxCurY=-1        #当前方块的y坐标位置
iMap=()                #背景方块图表

#初始化所有背景方块为-1, 表示没有方块
for ((i = 0; i < iTrayHeight * iTrayWidth; i++)); do iMap[$i]=-1; done

 
#接收输入的进程的主函数
function RunAsKeyReceiver()
{
        local pidDisplayer key aKey sig cESC sTTY

        pidDisplayer=$1
        aKey=(0 0 0)

        cESC=`echo -ne "\033"`
        cSpace=`echo -ne "\040"`

        #保存终端属性。在read -s读取终端键时，终端的属性会被暂时改变。
        #如果在read -s时程序被不幸杀掉，可能会导致终端混乱，
        #需要在程序退出时恢复终端属性。
        sTTY=`stty -g`

        #捕捉退出信号
        trap "MyExit;" INT TERM
        trap "MyExitNoSub;" $sigExit

        #隐藏光标
        echo -ne "\033[?25l"

 
        while :
        do
                #读取输入。注-s不回显，-n读到一个字符立即返回
                read -s -n 1 key

                aKey[0]=${aKey[1]}
                aKey[1]=${aKey[2]}
                aKey[2]=$key
                sig=0

                #判断输入了何种键
                if [[ $key == $cESC && ${aKey[1]} == $cESC ]]
                then
                        #ESC键
                        MyExit
                elif [[ ${aKey[0]} == $cESC && ${aKey[1]} == "[" ]]
                then
                        if [[ $key == "A" ]]; then sig=$sigRotate        #<向上键>
                        elif [[ $key == "B" ]]; then sig=$sigDown        #<向下键>
                        elif [[ $key == "D" ]]; then sig=$sigLeft        #<向左键>
                        elif [[ $key == "C" ]]; then sig=$sigRight        #<向右键>
                        fi
                elif [[ $key == "W" || $key == "w" ]]; then sig=$sigRotate        #W, w
                elif [[ $key == "S" || $key == "s" ]]; then sig=$sigDown        #S, s
                elif [[ $key == "A" || $key == "a" ]]; then sig=$sigLeft        #A, a
                elif [[ $key == "D" || $key == "d" ]]; then sig=$sigRight        #D, d
                elif [[ "[$key]" == "[]" ]]; then sig=$sigAllDown        #空格键
                elif [[ $key == "Q" || $key == "q" ]]                        #Q, q
                then
                        MyExit
                fi

                if [[ $sig != 0 ]]
                then
                        #向另一进程发送消息
                        kill -$sig $pidDisplayer
                fi
        done
}

#退出前的恢复
function MyExitNoSub()
{
        local y

        #恢复终端属性
        stty $sTTY
        ((y = iTop + iTrayHeight + 4))

        #显示光标
        echo -e "\033[?25h\033[${y};0H"
        exit
}

 
function MyExit()
{
        #通知显示进程需要退出
        kill -$sigExit $pidDisplayer

        MyExitNoSub
}

 
#处理显示和游戏流程的主函数
function RunAsDisplayer()
{
        local sigThis
        InitDraw

        #挂载各种信号的处理函数
        trap "sig=$sigRotate;" $sigRotate
        trap "sig=$sigLeft;" $sigLeft
        trap "sig=$sigRight;" $sigRight
        trap "sig=$sigDown;" $sigDown
        trap "sig=$sigAllDown;" $sigAllDown
        trap "ShowExit;" $sigExit

        while :
        do
                #根据当前的速度级iLevel不同，设定相应的循环的次数
                for ((i = 0; i < 21 - iLevel; i++))
                do
                        sleep 0.02
                        sigThis=$sig
                        sig=0

                        #根据sig变量判断是否接受到相应的信号
                        if ((sigThis == sigRotate)); then BoxRotate;        #旋转
                        elif ((sigThis == sigLeft)); then BoxLeft;        #左移一列
                        elif ((sigThis == sigRight)); then BoxRight;        #右移一列
                        elif ((sigThis == sigDown)); then BoxDown;        #下落一行
                        elif ((sigThis == sigAllDown)); then BoxAllDown;        #下落到底
                        fi
                done
                #kill -$sigDown $$
                BoxDown        #下落一行
        done
}

 
#BoxMove(y, x), 测试是否可以把移动中的方块移到(x, y)的位置, 返回0则可以, 1不可以
function BoxMove()
{
        local j i x y xTest yTest
        yTest=$1
        xTest=$2
        for ((j = 0; j < 8; j += 2))
        do
                ((i = j + 1))
                ((y = ${boxCur[$j]} + yTest))
                ((x = ${boxCur[$i]} + xTest))
                if (( y < 0 || y >= iTrayHeight || x < 0 || x >= iTrayWidth))
                then
                        #撞到墙壁了
                        return 1
                fi
                if ((${iMap[y * iTrayWidth + x]} != -1 ))
                then
                        #撞到其他已经存在的方块了
                        return 1
                fi
        done
        return 0;
}

 
#将当前移动中的方块放到背景方块中去,
#并计算新的分数和速度级。(即一次方块落到底部)
function Box2Map()
{
        local j i x y xp yp line

        #将当前移动中的方块放到背景方块中去
        for ((j = 0; j < 8; j += 2))
        do
                ((i = j + 1))
                ((y = ${boxCur[$j]} + boxCurY))
                ((x = ${boxCur[$i]} + boxCurX))
                ((i = y * iTrayWidth + x))
                iMap[$i]=$cBoxCur
        done

        #消去可被消去的行
        line=0
        for ((j = 0; j < iTrayWidth * iTrayHeight; j += iTrayWidth))
        do
                for ((i = j + iTrayWidth - 1; i >= j; i--))
                do
                        if ((${iMap[$i]} == -1)); then break; fi
                done
                if ((i >= j)); then continue; fi

                ((line++))
                for ((i = j - 1; i >= 0; i--))
                do
                        ((x = i + iTrayWidth))
                        iMap[$x]=${iMap[$i]}
                done
                for ((i = 0; i < iTrayWidth; i++))
                do
                        iMap[$i]=-1
                done
        done

        if ((line == 0)); then return; fi

        #根据消去的行数line计算分数和速度级
        ((x = iLeft + iTrayWidth * 2 + 7))
        ((y = iTop + 11))
        ((iScore += line * 2 - 1))
        #显示新的分数
        echo -ne "\033[1m\033[3${cScoreValue}m\033[${y};${x}H${iScore}         "
        if ((iScore % iScoreEachLevel < line * 2 - 1))
        then
                if ((iLevel < 20))
                then
                        ((iLevel++))
                        ((y = iTop + 14))
                        #显示新的速度级
                        echo -ne "\033[3${cScoreValue}m\033[${y};${x}H${iLevel}        "
                fi
        fi
        echo -ne "\033[0m"

 
        #重新显示背景方块
        for ((y = 0; y < iTrayHeight; y++))
        do
                ((yp = y + iTrayTop + 1))
                ((xp = iTrayLeft + 1))
                ((i = y * iTrayWidth))
                echo -ne "\033[${yp};${xp}H"
                for ((x = 0; x < iTrayWidth; x++))
                do
                        ((j = i + x))
                        if ((${iMap[$j]} == -1))
                        then
                                echo -ne "  "
                        else
                                echo -ne "\033[1m\033[7m\033[3${iMap[$j]}m\033[4${iMap[$j]}m[]\033[0m"
                        fi
                done
        done
}

 
#下落一行
function BoxDown()
{
        local y s
        ((y = boxCurY + 1))        #新的y坐标
        if BoxMove $y $boxCurX        #测试是否可以下落一行
        then
                s="`DrawCurBox 0`"        #将旧的方块抹去
                ((boxCurY = y))
                s="$s`DrawCurBox 1`"        #显示新的下落后方块
                echo -ne $s
        else
                #走到这儿, 如果不能下落了
                Box2Map                #将当前移动中的方块贴到背景方块中
                RandomBox        #产生新的方块
        fi
}

#左移一列
function BoxLeft()
{
        local x s
        ((x = boxCurX - 1))
        if BoxMove $boxCurY $x
        then
                s=`DrawCurBox 0`
                ((boxCurX = x))
                s=$s`DrawCurBox 1`
                echo -ne $s
        fi
}

#右移一列
function BoxRight()
{
        local x s
        ((x = boxCurX + 1))
        if BoxMove $boxCurY $x
        then
                s=`DrawCurBox 0`
                ((boxCurX = x))
                s=$s`DrawCurBox 1`
                echo -ne $s
        fi
}

 
#下落到底
function BoxAllDown()
{
        local k j i x y iDown s
        iDown=$iTrayHeight

        #计算一共需要下落多少行
        for ((j = 0; j < 8; j += 2))
        do
                ((i = j + 1))
                ((y = ${boxCur[$j]} + boxCurY))
                ((x = ${boxCur[$i]} + boxCurX))
                for ((k = y + 1; k < iTrayHeight; k++))
                do
                        ((i = k * iTrayWidth + x))
                        if (( ${iMap[$i]} != -1)); then break; fi
                done
                ((k -= y + 1))
                if (( $iDown > $k )); then iDown=$k; fi
        done

        s=`DrawCurBox 0`        #将旧的方块抹去
        ((boxCurY += iDown))
        s=$s`DrawCurBox 1`        #显示新的下落后的方块
        echo -ne $s
        Box2Map                #将当前移动中的方块贴到背景方块中
        RandomBox        #产生新的方块
}

 
#旋转方块
function BoxRotate()
{
        local iCount iTestRotate boxTest j i s
        iCount=${countBox[$iBoxCurType]}        #当前的方块经旋转可以产生的样式的数目

        #计算旋转后的新的样式
        ((iTestRotate = iBoxCurRotate + 1))
        if ((iTestRotate >= iCount))
        then
                ((iTestRotate = 0))
        fi

        #更新到新的样式, 保存老的样式(但不显示)
        for ((j = 0, i = (${offsetBox[$iBoxCurType]} + $iTestRotate) * 8; j < 8; j++, i++))
        do
                boxTest[$j]=${boxCur[$j]}
                boxCur[$j]=${box[$i]}
        done

        if BoxMove $boxCurY $boxCurX        #测试旋转后是否有空间放的下
        then
                #抹去旧的方块
                for ((j = 0; j < 8; j++))
                do
                        boxCur[$j]=${boxTest[$j]}
                done
                s=`DrawCurBox 0`

                #画上新的方块
                for ((j = 0, i = (${offsetBox[$iBoxCurType]} + $iTestRotate) * 8; j < 8; j++, i++))
                do
                        boxCur[$j]=${box[$i]}
                done
                s=$s`DrawCurBox 1`
                echo -ne $s
                iBoxCurRotate=$iTestRotate
        else
                #不能旋转，还是继续使用老的样式
                for ((j = 0; j < 8; j++))
                do
                        boxCur[$j]=${boxTest[$j]}
                done
        fi
}

 
#DrawCurBox(bDraw), 绘制当前移动中的方块, bDraw为1, 画上, bDraw为0, 抹去方块。
function DrawCurBox()
{
        local i j t bDraw sBox s
        bDraw=$1

        s=""
        if (( bDraw == 0 ))
        then
                sBox="\040\040"
        else
                sBox="[]"
                s=$s"\033[1m\033[7m\033[3${cBoxCur}m\033[4${cBoxCur}m"
        fi

        for ((j = 0; j < 8; j += 2))
        do
                ((i = iTrayTop + 1 + ${boxCur[$j]} + boxCurY))
                ((t = iTrayLeft + 1 + 2 * (boxCurX + ${boxCur[$j + 1]})))
                #\033[y;xH, 光标到(x, y)处
                s=$s"\033[${i};${t}H${sBox}"
        done
        s=$s"\033[0m"
        echo -n $s
}

 
#更新新的方块
function RandomBox()
{
        local i j t

        #更新当前移动的方块
        iBoxCurType=${iBoxNewType}
        iBoxCurRotate=${iBoxNewRotate}
        cBoxCur=${cBoxNew}
        for ((j = 0; j < ${#boxNew[@]}; j++))
        do
                boxCur[$j]=${boxNew[$j]}
        done

 
        #显示当前移动的方块
        if (( ${#boxCur[@]} == 8 ))
        then
                #计算当前方块该从顶端哪一行"冒"出来
                for ((j = 0, t = 4; j < 8; j += 2))
                do
                        if ((${boxCur[$j]} < t)); then t=${boxCur[$j]}; fi
                done
                ((boxCurY = -t))
                for ((j = 1, i = -4, t = 20; j < 8; j += 2))
                do
                        if ((${boxCur[$j]} > i)); then i=${boxCur[$j]}; fi
                        if ((${boxCur[$j]} < t)); then t=${boxCur[$j]}; fi
                done
                ((boxCurX = (iTrayWidth - 1 - i - t) / 2))

                #显示当前移动的方块
                echo -ne `DrawCurBox 1`

                #如果方块一出来就没处放，Game over!
                if ! BoxMove $boxCurY $boxCurX
                then
                        kill -$sigExit ${PPID}
                        ShowExit
                fi
        fi

 

        #清除右边预显示的方块
        for ((j = 0; j < 4; j++))
        do
                ((i = iTop + 1 + j))
                ((t = iLeft + 2 * iTrayWidth + 7))
                echo -ne "\033[${i};${t}H        "
        done

        #随机产生新的方块
        ((iBoxNewType = RANDOM % ${#offsetBox[@]}))
        ((iBoxNewRotate = RANDOM % ${countBox[$iBoxNewType]}))
        for ((j = 0, i = (${offsetBox[$iBoxNewType]} + $iBoxNewRotate) * 8; j < 8; j++, i++))
        do
                boxNew[$j]=${box[$i]};
        done

        ((cBoxNew = ${colorTable[RANDOM % ${#colorTable[@]}]}))

        #显示右边预显示的方块
        echo -ne "\033[1m\033[7m\033[3${cBoxNew}m\033[4${cBoxNew}m"
        for ((j = 0; j < 8; j += 2))
        do
                ((i = iTop + 1 + ${boxNew[$j]}))
                ((t = iLeft + 2 * iTrayWidth + 7 + 2 * ${boxNew[$j + 1]}))
                echo -ne "\033[${i};${t}H[]"
        done
        echo -ne "\033[0m"
}

 
#初始绘制
function InitDraw()
{
        clear
        RandomBox        #随机产生方块，这时右边预显示窗口中有方快了
        RandomBox        #再随机产生方块，右边预显示窗口中的方块被更新，原先的方块将开始下落
        local i t1 t2 t3

        #显示边框
        echo -ne "\033[1m"
        echo -ne "\033[3${cBorder}m\033[4${cBorder}m"

        ((t2 = iLeft + 1))
        ((t3 = iLeft + iTrayWidth * 2 + 3))
        for ((i = 0; i < iTrayHeight; i++))
        do
                ((t1 = i + iTop + 2))
                echo -ne "\033[${t1};${t2}H||"
                echo -ne "\033[${t1};${t3}H||"
        done

        ((t2 = iTop + iTrayHeight + 2))
        for ((i = 0; i < iTrayWidth + 2; i++))
        do
                ((t1 = i * 2 + iLeft + 1))
                echo -ne "\033[${iTrayTop};${t1}H=="
                echo -ne "\033[${t2};${t1}H=="
        done
        echo -ne "\033[0m"

 
        #显示"Score"和"Level"字样
        echo -ne "\033[1m"
        ((t1 = iLeft + iTrayWidth * 2 + 7))
        ((t2 = iTop + 10))
        echo -ne "\033[3${cScore}m\033[${t2};${t1}HScore"
        ((t2 = iTop + 11))
        echo -ne "\033[3${cScoreValue}m\033[${t2};${t1}H${iScore}"
        ((t2 = iTop + 13))
        echo -ne "\033[3${cScore}m\033[${t2};${t1}HLevel"
        ((t2 = iTop + 14))
        echo -ne "\033[3${cScoreValue}m\033[${t2};${t1}H${iLevel}"
        echo -ne "\033[0m"
}

 
#退出时显示GameOVer!
function ShowExit()
{
        local y
        ((y = iTrayHeight + iTrayTop + 3))
        echo -e "\033[${y};0HGameOver!\033[0m"
        exit
}

 
#显示用法.
function Usage
{
        cat << EOF
Usage: $APP_NAME
Start tetris game.

  -h, --help              display this help and exit
      --version           output version information and exit
EOF
}

 
#游戏主程序在这儿开始.
if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        Usage
elif [[ "$1" == "--version" ]]; then
        echo "$APP_NAME $APP_VERSION"
elif [[ "$1" == "--show" ]]; then
        #当发现具有参数--show时，运行显示函数
        RunAsDisplayer
else
        bash $0 --show&        #以参数--show将本程序再运行一遍
        RunAsKeyReceiver $!        #以上一行产生的进程的进程号作为参数
fi