上篇讲到了，可以设置一定角度发炮弹了！这时接着做，首先我们把炮弹去掉，只要炮弹出来舞台左、右和下我们就将该MC去掉。
代码：
Mouse.hide();
gravity = 2;
attachMovie("crosshair", "crosshair", 1);
attachMovie("tank", "tank", 2, {_x:230, _y:350});
crosshair.onEnterFrame = function() {
this._x = _xmouse;
this._y = _ymouse;
};
tank.onEnterFrame = function() {
mousex = _xmouse-this._x;
mousey = (_ymouse-this._y)*-1;
angle = Math.atan(mousey/mousex)/(Math.PI/180);
if (mousex<0) {
angle += 180;
}
if (mousex>=0 && mousey<0) {
angle += 360;
}
if (angle>160) {
angle = 160;
}
if (angle<20) {
angle = 20;
}
firepower = Math.sqrt(mousex*mousex+mousey*mousey);
if (firepower>200) {
firepower = 200;
}
this.cannon._rotation = angle*-1;
};
function onMouseDown() {
angle = tank.cannon._rotation-1;
start_ball_x = tank._x+48*Math.cos(angle*Math.PI/180);
start_ball_y = tank._y+48*Math.sin(angle*Math.PI/180);
cannonball_fired = attachMovie("cannonball", "cannonball_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:start_ball_x, _y:start_ball_y});
cannonball_fired.dirx = Math.cos(angle*Math.PI/180)*firepower;
cannonball_fired.diry = Math.sin(angle*Math.PI/180)*firepower;
cannonball_fired.onEnterFrame = function() {
this.diry += gravity;
this._x += this.dirx/30;
this._y += this.diry/30;
if ((this._x<0) or (this._x>500) or (this._y>350)) {
this.removeMovieClip();
}
};
}
效果（速度明显变快了）：
然后再继续完善，设置同一时间开火的次数。
Mouse.hide();
gravity = 2;
fired = 0;
max_firepower = 3;
attachMovie("crosshair", "crosshair", 1);
attachMovie("tank", "tank", 2, {_x:230, _y:350});
crosshair.onEnterFrame = function() {
this._x = _xmouse;
this._y = _ymouse;
};
tank.onEnterFrame = function() {
mousex = _xmouse-this._x;
mousey = (_ymouse-this._y)*-1;
angle = Math.atan(mousey/mousex)/(Math.PI/180);
if (mousex<0) {
angle += 180;
}
if (mousex>=0 && mousey<0) {
angle += 360;
}
if (angle>160) {
angle = 160;
}
if (angle<20) {
angle = 20;
}
firepower = Math.sqrt(mousex*mousex+mousey*mousey);
if (firepower>200) {
firepower = 200;
}
this.cannon._rotation = angle*-1;
};
function onMouseDown() {
if (fired<max_firepower) {
fired++;
angle = tank.cannon._rotation-1;
start_ball_x = tank._x+48*Math.cos(angle*Math.PI/180);
start_ball_y = tank._y+48*Math.sin(angle*Math.PI/180);
cannonball_fired = attachMovie("cannonball", "cannonball_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:start_ball_x, _y:start_ball_y});
cannonball_fired.dirx = Math.cos(angle*Math.PI/180)*firepower;
cannonball_fired.diry = Math.sin(angle*Math.PI/180)*firepower;
cannonball_fired.onEnterFrame = function() {
this.diry += gravity;
this._x += this.dirx/30;
this._y += this.diry/30;
if (this._y>350) {
this.removeMovieClip();
fired--;
}
};
}
}
效果（你这时连续按鼠标试试！）
在舞台上加上一个地面。
Mouse.hide();
gravity = 2;
fired = 0;
max_firepower = 3;
attachMovie("crosshair", "crosshair", 1);
attachMovie("tank", "tank", 2, {_x:295, _y:255});
attachMovie("ground", "ground", 3, {_x:0, _y:200});
crosshair.onEnterFrame = function() {
this._x = _xmouse;
this._y = _ymouse;
};
tank.onEnterFrame = function() {
mousex = _xmouse-this._x;
mousey = (_ymouse-this._y)*-1;
angle = Math.atan(mousey/mousex)/(Math.PI/180);
if (mousex<0) {
angle += 180;
}
if (mousex>=0 && mousey<0) {
angle += 360;
}
if (angle>160) {
angle = 160;
}
if (angle<20) {
angle = 20;
}
firepower = Math.sqrt(mousex*mousex+mousey*mousey);
if (firepower>200) {
firepower = 200;
}
this.cannon._rotation = angle*-1;
};
function onMouseDown() {
if (fired<max_firepower) {
fired++;
angle = tank.cannon._rotation-1;
start_ball_x = tank._x+48*Math.cos(angle*Math.PI/180);
start_ball_y = tank._y+48*Math.sin(angle*Math.PI/180);
cannonball_fired = attachMovie("cannonball", "cannonball_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:start_ball_x, _y:start_ball_y});
cannonball_fired.dirx = Math.cos(angle*Math.PI/180)*firepower;
cannonball_fired.diry = Math.sin(angle*Math.PI/180)*firepower;
cannonball_fired.onEnterFrame = function() {
this.diry += gravity;
this._x += this.dirx/30;
this._y += this.diry/30;
if ((this._y>350) or (ground.hitTest(this._x, this._y, true))) {
this.removeMovieClip();
fired--;
}
};
}
}
效果如下：
然后再加上一个敌人。
Mouse.hide();
gravity = 2;
fired = 0;
max_firepower = 3;
place_enemy();
attachMovie("crosshair", "crosshair", 1);
attachMovie("tank", "tank", 2, {_x:295, _y:255});
attachMovie("ground", "ground", 3, {_x:0, _y:200});
crosshair.onEnterFrame = function() {
this._x = _xmouse;
this._y = _ymouse;
};
tank.onEnterFrame = function() {
mousex = _xmouse-this._x;
mousey = (_ymouse-this._y)*-1;
angle = Math.atan(mousey/mousex)/(Math.PI/180);
if (mousex<0) {
angle += 180;
}
if (mousex>=0 && mousey<0) {
angle += 360;
}
if (angle>160) {
angle = 160;
}
if (angle<20) {
angle = 20;
}
firepower = Math.sqrt(mousex*mousex+mousey*mousey);
if (firepower>200) {
firepower = 200;
}
this.cannon._rotation = angle*-1;
};
function onMouseDown() {
if (fired<max_firepower) {
fired++;
angle = tank.cannon._rotation-1;
start_ball_x = tank._x+48*Math.cos(angle*Math.PI/180);
start_ball_y = tank._y+48*Math.sin(angle*Math.PI/180);
cannonball_fired = attachMovie("cannonball", "cannonball_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:start_ball_x, _y:start_ball_y});
cannonball_fired.dirx = Math.cos(angle*Math.PI/180)*firepower;
cannonball_fired.diry = Math.sin(angle*Math.PI/180)*firepower;
cannonball_fired.onEnterFrame = function() {
this.diry += gravity;
this._x += this.dirx/30;
this._y += this.diry/30;
if ((this._y>350) or (ground.hitTest(this._x, this._y, true))) {
this.removeMovieClip();
fired--;
}
};
}
}
function place_enemy() {
enemy_placed = attachMovie("enemy", "enemy", _root.getNextHighestDepth(), {_x:0, _y:350});
enemy_placed.yspeed = 0;
enemy_placed.onEnterFrame = function() {
this.yspeed += gravity/10;
this._x++;
while (_root.ground.hitTest(this._x+this._width/2, this._y+this._height, true)) {
this._y--;
this.yspeed = 0;
}
if (!_root.ground.hitTest(this._x+this._width/2, this._y+this._height+1, true)) {
this._y += this.yspeed;
} else {
this.yspeed = 0;
}
if (this._x>500) {
this.removeMovieClip();
place_enemy();
}
};
}
效果如下：
最后完成。
Mouse.hide();
gravity = 2;
fired = 0;
max_firepower = 3;
place_enemy();
attachMovie("crosshair", "crosshair", 1);
attachMovie("tank", "tank", 2, {_x:295, _y:255});
attachMovie("ground", "ground", 3, {_x:0, _y:200});
crosshair.onEnterFrame = function() {
this._x = _xmouse;
this._y = _ymouse;
};
tank.onEnterFrame = function() {
mousex = _xmouse-this._x;
mousey = (_ymouse-this._y)*-1;
angle = Math.atan(mousey/mousex)/(Math.PI/180);
if (mousex<0) {
angle += 180;
}
if (mousex>=0 && mousey<0) {
angle += 360;
}
if (angle>160) {
angle = 160;
}
if (angle<20) {
angle = 20;
}
firepower = Math.sqrt(mousex*mousex+mousey*mousey);
if (firepower>200) {
firepower = 200;
}
this.cannon._rotation = angle*-1;
};
function onMouseDown() {
if (fired<max_firepower) {
fired++;
angle = tank.cannon._rotation-1;
start_ball_x = tank._x+48*Math.cos(angle*Math.PI/180);
start_ball_y = tank._y+48*Math.sin(angle*Math.PI/180);
cannonball_fired = attachMovie("cannonball", "cannonball_"+_root.getNextHighestDepth(), _root.getNextHighestDepth(), {_x:start_ball_x, _y:start_ball_y});
cannonball_fired.dirx = Math.cos(angle*Math.PI/180)*firepower;
cannonball_fired.diry = Math.sin(angle*Math.PI/180)*firepower;
cannonball_fired.onEnterFrame = function() {
this.diry += gravity;
this._x += this.dirx/30;
this._y += this.diry/30;
if ((this._y>350) or (ground.hitTest(this._x, this._y, true))) {
this.removeMovieClip();
fired--;
}
if (enemy.hitTest(this._x, this._y, true)) {
this.removeMovieClip();
enemy.removeMovieClip();
fired--;
place_enemy();
}
};
}
}
function place_enemy() {
enemy_placed = attachMovie("enemy", "enemy", _root.getNextHighestDepth(), {_x:0, _y:350});
enemy_placed.yspeed = 0;
enemy_placed.onEnterFrame = function() {
this.yspeed += gravity/10;
this._x++;
while (_root.ground.hitTest(this._x+this._width/2, this._y+this._height, true)) {
this._y--;
this.yspeed = 0;
}
if (!_root.ground.hitTest(this._x+this._width/2, this._y+this._height+1, true)) {
this._y += this.yspeed;
} else {
this.yspeed = 0;
}
if (this._x>500) {
this.removeMovieClip();
place_enemy();
}
};
}
最终简单游戏：
本教程中所用到所有源文件下载：点击这里下载源文件
