OpenGL纹理设置过滤器和环绕模式的疑惑

Question

最近在学习《OpenGL超级宝典》，关于纹理这个地方一直不太理解。就是为每个纹理对象进行绑定之后，为什么在设置过滤器和环绕模式的时候，会多次调用 glTexParameteri函数，一直很困惑?
for(iLoop = 0; iLoop < TEXTURE__COUNT; iLoop++)
{
// Bind to next texture object
glBindTexture(GL_TEXTURE_2D, textures[iLoop]);

    // Load texture, set filter and wrap modes
    pBytes = gltReadTGABits(szTextureFiles[iLoop],&iWidth, &iHeight,
                          &iComponents, &eFormat);

    // Load texture, set filter and wrap modes
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexImage2D(GL_TEXTURE_2D, 0, iComponents, iWidth, iHeight, 0, eFormat, GL_UNSIGNED_BYTE, pBytes);
    glGenerateMipmap(GL_TEXTURE_2D);
    // Don't need original texture data any more
    free(pBytes);
    }