Simple texture + matrix shader animation.

gistfile1.txt

#include <osgViewer/Viewer>
#include <osg/Geometry>
#include <osg/Texture2D>
#include <osgEarth/Utils>
#include <osgDB/ReadFile>


using namespace osgEarth;

int main(int argc, char** argv)
{
    osg::ArgumentParser arguments(&argc, argv);
    osgViewer::Viewer viewer(arguments);

    auto geom = new osg::Geometry();
    geom->setUseVertexBufferObjects(true);
    geom->setUseDisplayList(false);

    osg::Vec3f verts[4] = { {0,0,0}, {1,0,0}, {1,0,1}, {0,0,1} };
    geom->setVertexArray(new osg::Vec3Array(4, verts));

    osg::Vec2f uvs[4] = { {0,0}, {1,0}, {1,1}, {0,1} };
    geom->setTexCoordArray(0, new osg::Vec2Array(4, uvs));

    std::uint8_t indices[6] = { 0,1,2, 0,2,3 };
    geom->addPrimitiveSet(new osg::DrawElementsUByte(GL_TRIANGLES, 6, indices));

    auto ss = geom->getOrCreateStateSet();

    auto image = osgDB::readRefImageFile("https://github.com/gwaldron/osgearth/blob/master/data/icon.png?raw=true");
    auto tex = new osg::Texture2D(image);
    ss->setTextureAttributeAndModes(0, tex, 1);

    auto mat = new osg::Uniform("mat", osg::Matrixf::identity());
    ss->addUniform(mat);

    auto vs = new osg::Shader(osg::Shader::VERTEX, R"(
        #version 130
        out vec2 uv;
        void main(void) {
            gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
            uv = gl_MultiTexCoord0.st;
        }
    )");

    auto fs = new osg::Shader(osg::Shader::FRAGMENT, R"(
        #version 130
        in vec2 uv;
        uniform sampler2D tex;
        uniform mat4 mat;
        out vec4 frag_color;
        void main(void) {
            frag_color = texture(tex, (mat*vec4(uv,0,1)).st);
        }
    )");

    auto program = new osg::Program();
    program->addShader(vs);
    program->addShader(fs);
    ss->setAttribute(program, 1);

    geom->setUpdateCallback(new LambdaCallback<>([mat](osg::NodeVisitor& nv) {
        static float n = 0.0f;
        osg::Matrixf m;
        float sn = sin(n), cn = cos(n);
        m(3, 0) = (0.25 * sn);
        m(3, 1) = (0.25 * cn);
        mat->set(m);
        n += 0.01;
    }));

    viewer.setThreadingModel(viewer.SingleThreaded);
    viewer.setSceneData(geom);

    return viewer.run();
}