Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

#include <iostream>
#include <string>
#include <vector>
#include <memory>

// Abstract base — defines the interface
class IRenderer {
public:
    virtual ~IRenderer() = default;

virtual void beginFrame() = 0;
    virtual void drawTriangle(float x, float y, float z) = 0;
    virtual void endFrame()   = 0;

// Non-pure helper that calls pure virtuals
    void renderScene(const std::vector<float>& vertices) {
        beginFrame();
        for (std::size_t i = 0; i + 2 < vertices.size(); i += 3)
            drawTriangle(vertices[i], vertices[i+1], vertices[i+2]);
        endFrame();
    }
};

// Concrete implementation A
class OpenGLRenderer : public IRenderer {
public:
    void beginFrame()  override { std::cout << "[GL] Begin frame
"; }
    void drawTriangle(float x, float y, float z) override {
        std::cout << "[GL] Triangle (" << x<<","<<y<<","<<z<<")
";
    }
    void endFrame()    override { std::cout << "[GL] End frame
";   }
};

// Concrete implementation B
class ConsoleRenderer : public IRenderer {
public:
    void beginFrame()  override { std::cout << "[CON] ---
"; }
    void drawTriangle(float x, float y, float z) override {
        std::cout << "[CON] tri " << x<<" "<<y<<" "<<z<<"
";
    }
    void endFrame()    override { std::cout << "[CON] ---
"; }
};

int main() {
    std::vector<float> verts = {0,0,0, 1,0,0, 0,1,0};

std::unique_ptr<IRenderer> r = std::make_unique<OpenGLRenderer>();
    r->renderScene(verts);

r = std::make_unique<ConsoleRenderer>();
    r->renderScene(verts);

return 0;
}