osg使用Shader实现动态线 代码实现

以下是一个简单的osg实现动态线的Shader代码示例：

// 顶点Shader
const char* vsCode =
    "#version 120\n"
    "attribute vec3 aPosition;\n"
    "void main()\n"
    "{\n"
    "    gl_Position = gl_ModelViewProjectionMatrix * vec4(aPosition, 1.0);\n"
    "}\n";

// 片段Shader
const char* fsCode =
    "#version 120\n"
    "uniform vec4 uColor;\n"
    "void main()\n"
    "{\n"
    "    gl_FragColor = uColor;\n"
    "}\n";

// 创建osg::Program和osg::Shader
osg::ref_ptr<osg::Program> program = new osg::Program();
osg::ref_ptr<osg::Shader> vs = new osg::Shader(osg::Shader::VERTEX, vsCode);
osg::ref_ptr<osg::Shader> fs = new osg::Shader(osg::Shader::FRAGMENT, fsCode);

// 将Shader添加到Program中
program->addShader(vs);
program->addShader(fs);

// 创建osg::Geometry
osg::ref_ptr<osg::Geometry> geom = new osg::Geometry();

// 创建osg::Vec3Array
osg::ref_ptr<osg::Vec3Array> verts = new osg::Vec3Array();
verts->push_back(osg::Vec3(0.0f, 0.0f, 0.0f));
verts->push_back(osg::Vec3(1.0f, 0.0f, 0.0f));

// 将osg::Vec3Array设置为Geometry的顶点数据
geom->setVertexArray(verts.get());

// 设置Geometry的绘制模式为GL_LINE_STRIP
geom->addPrimitiveSet(new osg::DrawArrays(GL_LINE_STRIP, 0, verts->size()));

// 创建osg::Vec4Array
osg::ref_ptr<osg::Vec4Array> colors = new osg::Vec4Array();
colors->push_back(osg::Vec4(1.0f, 0.0f, 0.0f, 1.0f));

// 将osg::Vec4Array设置为Geometry的颜色数据
geom->setColorArray(colors.get());
geom->setColorBinding(osg::Geometry::BIND_OVERALL);

// 设置Geometry的Shader程序
geom->getOrCreateStateSet()->setAttributeAndModes(program.get(), osg::StateAttribute::ON);

// 设置Geometry的ColorUniform
osg::ref_ptr<osg::Uniform> colorUniform = new osg::Uniform("uColor", osg::Vec4(1.0f, 0.0f, 0.0f, 1.0f));
geom->getOrCreateStateSet()->addUniform(colorUniform.get());

此代码将创建一个包含两个点的动态线，并在此线上应用上述Shader程序。这将使线条以红色呈现。要添加更多的线段，只需添加更多的点到osg::Vec3Array中，并将GL_LINE_STRIP修改为GL_LINES。