Flash教程:制作随机画圆弧动画

一个随机画圆弧的效果
有几个属性可调整
也不多描述了
看看就知道了

点击这里看演示
贴一下代码
有兴趣的看一下吧
刚加了下注释
//******************* draw_arc ************************
//******************* 作者：boenlee *******************
//舞台元件：
//可视区域元件--mask
//移动按钮--up_btn, down_btn, left_btn, right_btn
//文本框--angle_txt, time_txt, r_txt, thickness_txt
//复选按钮--trace_check, leaf_check
//重画按钮--redraw_btn
//库链接元件：
//叶子--leaf
//***************************************************
//画小于等于45度的圆弧，任意角度开始
//mc：目标mc名称
//ox：原点x位置
//oy：原点y位置
//r：半径
//origin_angle：起始角度
//angle：弧的角度，正数顺时针画弧，负数逆时针画弧
//thickness：线的粗细
//rbg：线的颜色
//alpha：线的透明度
//返回：圆弧终点坐标，终点为角度大的点，与angle符号无关
function draw_small_arc (mc:movieclip, ox:number, oy:number, r:number, origin_angle:number, angle:number, thickness:number, rbg:number, alpha:number):object {
var origin_angle:number = origin_angle % 360;
var angle:number = angle % 360;
origin_angle = angle < 0 ? origin_angle angle : origin_angle;
angle = math.abs (angle);
angle = angle > 45 ? 45 : angle;
var ctrl_r:number = maintain_digit (1 / cosd (angle / 2) * r, 4);
var ctrl_sin:number = maintain_digit (sind (origin_angle angle / 2), 4);
var ctrl_cos:number = maintain_digit (cosd (origin_angle angle / 2), 4);
var org_sin:number = maintain_digit (sind (origin_angle), 4);
var org_cos:number = maintain_digit (cosd (origin_angle), 4);
var achr_sin:number = maintain_digit (sind (origin_angle angle), 4);
var achr_cos:number = maintain_digit (cosd (origin_angle angle), 4);
with (mc) {
linestyle (thickness, rbg, alpha, false, "normal", "none");
moveto (org_cos * r ox, org_sin * r oy);
curveto (ctrl_cos * ctrl_r ox, ctrl_sin * ctrl_r oy, achr_cos * r ox, achr_sin * r oy);
}
return {x:achr_cos * r ox, y:achr_sin * r oy};
}
//画小于等于360度的圆弧，任意角度开始
//参数及返回值与draw_small_arc函数相同
function draw_arc (mc:movieclip, ox:number, oy:number, r:number, origin_angle:number, angle:number, thickness:number, rbg:number, alpha:number):object {
var origin_angle:number = angle < 0 ? origin_angle angle : origin_angle;
var angle:number = math.abs (angle);
var times:number = int (angle / 45);
var last_angle:number = angle % 45;
if (times >= 8) {
times = 8;
last_angle = 0;
}
for (var i:number = 0; i < times; i ) {
draw_small_arc (mc, ox, oy, r, 45 * i origin_angle, 45, thickness, rbg, alpha);
}
return draw_small_arc (mc, ox, oy, r, 45 * times origin_angle, last_angle, thickness, rbg, alpha);
}
//小数保留
//val：要处理数值
//maintain：保留位数
//返回：处理后的数
function maintain_digit (val:number, maintain:number):number {
var multiple:number = math.pow (10, math.abs (maintain));
return math.round (val * multiple) / multiple;
}
//以角度为参数计算sin值
function sind (angle:number):number {
return math.sin (math.pi / 180 * angle);
}
//以角度为参数计算cos值
function cosd (angle:number):number {
return math.cos (math.pi / 180 * angle);
}
//随机颜色
function rnd_color ():number {
return random (255) << 16 | random (255) << 8 | random (255);
}
//弧线颜色数组，由于随机颜色比较丑，所以选择几个比较好的颜色
var color_arr:array = [0xff1111, 0xedb83d, 0xebeb1d, 0x99e91f, 0x20e91f, 0x23e4e3, 0x1dc2eb, 0x1b45ed, 0x6f1bed, 0xc21bed, 0xeb1deb, 0xf017af, 0xf01784, 0xffffff];
//叶子颜色数组，原因同上
var leaf_color_arr:array = [0x25eb25, 0xf3f347, 0x4af09d, 0xf2ad48];
//起始角度
var origin_angle:number;
//弧的角度
var angle:number;
//弧度是否随机
var angle_rnd:boolean;
//方向
var dir:number;
//上一个弧的方向
var old_dir:number;
//弧的个数
var time:number;
//弧所在圆的坐标
var posx:number;
var posy:number;
//弧终点位置
var pos_obj:object;
//半径
var r:number;
//弧线粗细
var thickness:number;
//是否跟踪
var is_trace:boolean = false;
//是否有树叶生长效果
var leaf_grow:boolean = false;
//用于画弧线的mc
var line_mc:movieclip;
//初始化属性
function init_prop () {
line_mc.removemovieclip ();
line_mc = this.createemptymovieclip ("line_mc", 1);
line_mc.setmask (mask);
line_mc._x = mask._x;
line_mc._y = mask._y;
origin_angle = random (4) * 90;
angle = get_txt_value (angle_txt, 0, 0, 10, 360);
if (angle == 0) {
angle_rnd = true;
} else {
angle_rnd = false;
}
dir = random (2) ? 1 : -1;
posx = random (100) - 50;
posy = random (100) - 50;
time = get_txt_value (time_txt, 50, 10, 10, 200);
r = get_txt_value (r_txt, 20, 5, 5, 50);
thickness = get_txt_value (thickness_txt, 5, 1, 1, 10);
}
//主函数
function main () {
if (--time > 0) {
dir = random (2) ? 1 : -1;
origin_angle = angle;
//如果当前弧的方向与前一个的不同，计算当前弧所在圆的原点位置
if (dir old_dir == 0) {
posx = cosd (origin_angle) * 2 * r;
posy = sind (origin_angle) * 2 * r;
origin_angle = 180;
}
if (angle_rnd) {
angle = dir * (random (50) 50);
} else {
angle = dir * math.abs (angle);
}
pos_obj = draw_arc (line_mc, posx, posy, r, origin_angle, angle, thickness, color_arr[random (color_arr.length)], 100);
//加载树叶
if (leaf_grow) {
line_mc.attachmovie ("leaf", "leaf" time, time, {_x:pos_obj.x, _y:pos_obj.y, _rotation:random (360), _xscale:random (50) r * 2 thickness * 5, _yscale:random (50) r * 2 thickness * 5, _alpha:random (100) thickness * 5});
var leaf_color:color = new color (line_mc["leaf" time]);
leaf_color.setrgb (leaf_color_arr[random (leaf_color_arr.length)]);
}
//跟踪
if (is_trace) {
line_mc._x = mask._x - pos_obj.x;
line_mc._y = mask._y - pos_obj.y;
}
old_dir = dir;
} else {
delete line_mc.onenterframe;
}
}
//获取文本框内容，为数值
//txt_name：文本框名称
//nan_val：文本内容非数字时所取值
//zero_val：文本内容为0时所取值
//min_val：文本内容最小值
//max_val：文本内容最大值
function get_txt_value (txt_name:textfield, nan_val:number, zero_val:number, min_val:number, max_val:number) {
if (isnan (number (txt_name.text))) {
txt_name.text = string (nan_val);
} else if (number (txt_name.text) == 0) {
txt_name.text = string (zero_val);
} else if (number (txt_name.text) < min_val) {
txt_name.text = string (min_val);
} else if (number (txt_name.text) > max_val) {
txt_name.text = string (max_val);
}
return number (txt_name.text);
}
//重画
redraw_btn.onrelease = function () {
delete line_mc.onenterframe;
init_prop ();
line_mc.onenterframe = main;
};
//选择是否跟踪
trace_check.onrelease = function () {
is_trace = !is_trace;
this.gotoandstop (number (is_trace) 1);
};
//选择是否生长树叶
leaf_check.onrelease = function () {
leaf_grow = !leaf_grow;
this.gotoandstop (number (leaf_grow) 1);
};
var keep_moving:movieclip = this.createemptymovieclip ("keep_moving", 2);
var speed:number = 10;
//移动line_mc
function moving (speedx:number, speedy:number) {
keep_moving.onenterframe = function () {
line_mc._x = speedx;
line_mc._y = speedy;
};
}
//停止移动
function stop_move () {
delete keep_moving.onenterframe;
}
//按钮控制
up_btn.onpress = function () {
moving (0, speed);
};
down_btn.onpress = function () {
moving (0, -speed);
};
left_btn.onpress = function () {
moving (speed, 0);
};
right_btn.onpress = function () {
moving (-speed, 0);
};
up_btn.onrelease = up_btn.onreleaseoutside = down_btn.onrelease = down_btn.onreleaseoutside = left_btn.onrelease = left_btn.onreleaseoutside = right_btn.onrelease = right_btn.onreleaseoutside = function () {
stop_move ();
};
//键盘控制
var key_lis:object = new object ();
key_lis.onkeydown = function () {
switch (key.getcode ()) {
case 37 :
moving (speed, 0);
break;
case 38 :
moving (0, speed);
break;
case 39 :
moving (-speed, 0);
break;
case 40 :
moving (0, -speed);
break;
}
};
key_lis.onkeyup = function () {
stop_move ();
};
key.addlistener (key_lis);
init_prop ();
line_mc.onenterframe = main;