tutorial_19.htm

如果你相信它就好好学学吧,同样这里也只是个入门

    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>			particle[loop].life-=particle[loop].fade;		<font color="#ffffaa">// 减少粒子的生命值</font>
</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">现在我们检查当生命为零的话粒子是否活着 </td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>			if (particle[loop].life&lt;0.0f)					<font color="#ffffaa">// 如果粒子生命值小于0</font>
			{
</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">如果粒子是小时(烧尽),我们将会使它复原.我们给它全值生命和新的衰弱速度.</td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>				particle[loop].life=1.0f;				<font color="#ffffaa">// 产生一个新的粒子</font>
				particle[loop].fade=float(rand()%100)/1000.0f+0.003f;	<font color="#ffffaa">// 随机生成衰减速率</font>
</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">我们也重新设定粒子在屏幕中心放置.我们重新设定粒子的x,y和z位置为零</td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>				particle[loop].x=0.0f;					<font color="#ffffaa">// 新粒子出现在屏幕的中央</font>
				particle[loop].y=0.0f;					
				particle[loop].z=0.0f;					</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">在
粒子从新设置之后,将给它新的移动速度/方向.注意:我增加最大和最小值,粒子移动速度为从50到60的任意值,但是这次我们没将移动速度乘10.我们这
次不想要一个爆发的效果,而要比较慢地移动粒子.也注意我把xspeed和x轴移动速度相加,y轴移动速度和yspeed相加.这个控制粒子的移动方向.</td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>				particle[loop].xi=xspeed+float((rand()%60)-32.0f);	<font color="#ffffaa">// 随机生成粒子速度</font>
				particle[loop].yi=yspeed+float((rand()%60)-30.0f);	
				particle[loop].zi=float((rand()%60)-30.0f);		</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">
最后我们分配粒子一种新的颜色.变量col保存一个数字从1到11(12种颜色),我们用这个变量去找红,绿,蓝亮度在颜色箱里面.下面第一行表示红色的
强度,数值保存在colors[col][0].所以如果col是0,红色的亮度就是1.0f.绿色的和蓝色的值用相同的方法读取.如果你不了解为什么红
色亮度为1.0f那col就为0.我将一点点的解释.看着程序的最前面.找到那行:static GLfloat
colors[12][3].注意:12行3列.三个数字的第一行是红色强度.第二行是绿色强度而且第三行是蓝色强度.[0],[1]和[2]下面描述的
1st,2nd和3rd就是我刚提及的.如果col等于0,我们要看第一个组.11 是最後一个组(第12种颜色).<br></td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>				particle[loop].r=colors[col][0];			<font color="#ffffaa">// 设置粒子颜色</font>
				particle[loop].g=colors[col][1];			
				particle[loop].b=colors[col][2];			
			}
</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">下行描述加速度的数值是多少.通过小键盘8号键,我们增加yg(y 地心引力)值.这引起向上的力.如果这个程序在循环外面,那么我们必须生成另一个循环做相同的工作,因此我们最好放在这里<br></td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>			<font color="#ffffaa">// 如果小键盘8被按住，增加Y轴方向的加速度</font>
			if (keys[VK_NUMPAD8] &amp;&amp; (particle[loop].yg&lt;1.5f)) particle[loop].yg+=0.01f;
</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">这行是产生相反的效果.通过2号键,减小yg值,引起向下的力<br></td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/bc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/br.gif" height="28" width="28"></td>
  </tr>
</tbody></table>
<font color="#aaffaa" size="3">

<pre>			<font color="#ffffaa">// 如果小键盘2被按住，减少Y轴方向的加速度</font>
			if (keys[VK_NUMPAD2] &amp;&amp; (particle[loop].yg&gt;-1.5f)) particle[loop].yg-=0.01f;
</pre>
</font>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/tl.jpg" height="28" width="28"></td>
    <td width="100%"><img src="Tutorial_19_files/tc.gif" height="28" width="100%"></td>
    <td><img src="Tutorial_19_files/tr.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td background="Tutorial_19_files/l.gif"><img src="Tutorial_19_files/l.gif" height="28" width="28"></td>
    <td valign="top" width="100%">现在更改向右的拉力.如果按下6号键时增加向右的拉力.<br></td>
    <td background="Tutorial_19_files/r.gif"><img src="Tutorial_19_files/r.gif" height="28" width="28"></td>
  </tr>
</tbody></table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody><tr>
    <td><img src="Tutorial_19_files/bl.gif" height="28" width="28"></td>
    <td width="100%"><img src="Tutoria