tutorial_07.htm

如果你相信它就好好学学吧,同样这里也只是个入门

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<pre>		<font color="#ffffaa">// 创建 MipMapped 纹理</font>
		glBindTexture(GL_TEXTURE_2D, texture[2]);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST); </pre>
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      <td valign="top" width="100%">下面一行生成 mipmapped 纹理。我们使用三种颜色(红，绿，蓝)来生成一个2D纹理。TextureImage[0]-&gt;sizeX 
        是位图宽度，extureImage[0]-&gt;sizeY 是位图高度，GL_RGB意味着我们依次使用RGB色彩。GL_UNSIGNED_BYTE 
        意味着纹理数据的单位是字节。TextureImage[0]-&gt;data指向我们创建纹理所用的位图。 </td>
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<pre>		gluBuild2DMipmaps(GL_TEXTURE_2D, 3, TextureImage[0]-&gt;sizeX, TextureImage[0]-&gt;sizeY, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]-&gt;data); 
	}
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      <td valign="top" width="100%">现在释放用来存放位图数据的内存。我们先查看位图数据是否存放在 TextureImage[0] 
        中，如果有，删掉。然后释放位图结构以确保内存被释放。</td>
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<pre>	if (TextureImage[0])							<font color="#ffffaa">// 纹理是否存在</font>
	{
		if (TextureImage[0]-&gt;data)					<font color="#ffffaa">// 纹理图像是否存在</font>
		{
			free(TextureImage[0]-&gt;data);				<font color="#ffffaa">// 释放纹理图像占用的内存</font>
		}

		free(TextureImage[0]);						<font color="#ffffaa">// 释放图像结构</font>
	}
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      <td valign="top" width="100%">最后我们返回 status 变量。如果一切OK，status 变量的值为TRUE。否则为FALSE。</td>
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<pre>	return Status;								<font color="#ffffaa">// 返回 Status 变量</font>
}
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      <td valign="top" width="100%">接着应该载入纹理并初始化OpenGL设置了。InitGL函数的第一行使用上面的代码载入纹理。创建纹理之后，我们调用<br>
        glEnable(GL_TEXTURE_2D)启用2D纹理映射。阴影模式设为平滑阴影( smooth shading ）。背景色设为黑色，我们启用深度测试，然后我们启用优化透视计算。</td>
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      <td valign="top" width="100%">现在开始设置光源。下面下面一行设置环境光的发光量，光源light1开始发光。这一课的开始处我们我们将环境光的发光量存放在LightAmbient数组中。现在我们就使用此数组(半亮度环境光)。在int 
        InitGL(GLvoid)函数中添加下面的代码。</td>
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<pre>	glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);				<font color="#ffffaa">// 设置环境光</font>
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      <td valign="top" width="100%">接下来我们设置漫射光的发光量。它存放在LightDiffuse数组中(全亮度白光)。</td>
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<pre>	glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);				<font color="#ffffaa">// 设置漫射光</font>
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      <td valign="top" width="100%">然后设置光源的位置。位置存放在 LightPosition 数组中(正好位于木箱前面的中心，X－0.0f，Y－0.0f，Z方向移向观察者2个单位&lt;位于屏幕外面&gt;)。</td>
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<pre>	glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);			<font color="#ffffaa">// 设置光源位置</font>
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      <td valign="top" width="100%">最后，我们启用一号光源。我们还没有启用GL_LIGHTING，所以您看不见任何光线。记住：只对光源进行设置、定位、甚至启用，光源都不会工作。除非我们启用GL_LIGHTING。</td>
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