shape.h

#ifndef SHAPE_H
#define SHAPE_H

#include <vector>

struct Pixel{
    int rowOffset;
    int colOffset;
    char ch;
};

class Shape{
public:
    virtual ~Shape() = default;
    virtual std::vector<Pixel> pixels() const = 0;
    virtual void advanceFrame() {}
};

class CharShape: public Shape{
    char ch;
public:
    explicit CharShape(char c): ch{c} {}
    std::vector<Pixel> pixels() const override {
        return{ Pixel{0, 0, ch} };
    }
};

class RectShape: public Shape{
    int h, w;
    char ch;
public:
    RectShape(int height, int width, char c): h{height}, w{width}, ch{c} {}
    std::vector<Pixel> pixels() const override {
        std::vector<Pixel> pixels;
        pixels.reserve(h * w);
        for(int r = 0; r < h; ++r){
            for(int c = 0; c < w; ++c){
                pixels.push_back(Pixel{r, c, ch});
            }
        }
        return pixels;
    }
};

class BitmapShape: public Shape{
    std::vector<Pixel> data;
public:
    BitmapShape(std::vector<Pixel> pixels): data{std::move(pixels)}{}
    std::vector<Pixel> pixels() const override {
        return data;
    }
};

class AnimatedShape: public Shape{
    std::vector<std::vector<Pixel>> frames;
    int current = 0;
public:
    explicit AnimatedShape(std::vector<std::vector<Pixel>> f): frames{std::move(f)} {}

    std::vector<Pixel> pixels() const override {
        if(frames.empty()) return {};
        return frames[current];
    }

    void advanceFrame() override {
        if(!frames.empty()) current = (current + 1) % static_cast<int>(frames.size());
    }
};

#endif