README.md

client

We created a basic working client-server UDP setup using ENet and defined the data types we'll be sending back and forth between the client and server.

Our next step is to:

1. Client: Figure out how to get a window up and running. And then using server data (potentially dummy data at first) and rendering that. Also need to install other packages. GLFW, GLM, etc.
2. Server: Looking at the cube_connect code and extracting what needs to go on the server. Use the drawing_snapshot.hpp to help figure that out.

7/07/24 We copy pasted the cube_connect code into the client and server repos. We added a network loop with ENet and began refactoring the app to use data sent/received over the network.

For client:

• implemented matrices for cubies and camera (NetworkDraw for Drawables)
• TODO: text for TextRenderer (NetworkDraw for IWidget)
• TODO: send over InputSnapshot after populating with keypresses/mouse (potential idea in comments in Input.cpp)

2024-08-05 Populated and sent InputSnapshot. Got working client and server over network.

TODO:

• Implement some sort of lock to ensure only one client can control the cube at a time.
• Reimplement DrawingSnapshot to use dynamic size vector instead of array.
• TextRenderer
• (later) simplify codebase

while loop -> request ID server sends back struct THEN start sending normal packets

Clients should have an ID (token based) SHIFT + ENTER to request admin status (toggle) in_charge = -1 in_charge = ID (until toggle from that client)

TODO: send back current admin from server (then don't send data)

#include <enet/enet.h> #include #include #include #include

struct DrawingSnapshot { std::array<float, 3> camera_pos; std::array<float, 16> world_to_camera; // view matrix std::array<float, 16> camera_to_clip; // projection matrix std::vector<std::array<float, 16>> local_to_world_matrices; // TODO: put in unique ID to identify object };

std::vector<uint8_t> serialize_snapshot(const DrawingSnapshot& snapshot) { size_t size = sizeof(snapshot.camera_pos) + sizeof(snapshot.world_to_camera) + sizeof(snapshot.camera_to_clip) + sizeof(size_t) + snapshot.local_to_world_matrices.size() * sizeof(std::array<float, 16>);

std::vector<uint8_t> buffer(size);
uint8_t* ptr = buffer.data();

std::memcpy(ptr, snapshot.camera_pos.data(), sizeof(snapshot.camera_pos));
ptr += sizeof(snapshot.camera_pos);

std::memcpy(ptr, snapshot.world_to_camera.data(), sizeof(snapshot.world_to_camera));
ptr += sizeof(snapshot.world_to_camera);

std::memcpy(ptr, snapshot.camera_to_clip.data(), sizeof(snapshot.camera_to_clip));
ptr += sizeof(snapshot.camera_to_clip);

size_t matrix_count = snapshot.local_to_world_matrices.size();
std::memcpy(ptr, &matrix_count, sizeof(size_t));
ptr += sizeof(size_t);

if (matrix_count > 0) {
    std::memcpy(ptr, snapshot.local_to_world_matrices.data(), matrix_count * sizeof(std::array<float, 16>));
}

return buffer;

}

DrawingSnapshot deserialize_snapshot(const uint8_t* data, size_t length) { DrawingSnapshot snapshot; const uint8_t* ptr = data;

std::memcpy(snapshot.camera_pos.data(), ptr, sizeof(snapshot.camera_pos));
ptr += sizeof(snapshot.camera_pos);

std::memcpy(snapshot.world_to_camera.data(), ptr, sizeof(snapshot.world_to_camera));
ptr += sizeof(snapshot.world_to_camera);

std::memcpy(snapshot.camera_to_clip.data(), ptr, sizeof(snapshot.camera_to_clip));
ptr += sizeof(snapshot.camera_to_clip);

size_t matrix_count;
std::memcpy(&matrix_count, ptr, sizeof(size_t));
ptr += sizeof(size_t);

snapshot.local_to_world_matrices.resize(matrix_count);
if (matrix_count > 0) {
    std::memcpy(snapshot.local_to_world_matrices.data(), ptr, matrix_count * sizeof(std::array<float, 16>));
}

return snapshot;

}

void receive_snapshot(const ENetPacket* packet) { const uint8_t* data = packet->data; size_t length = packet->dataLength;

DrawingSnapshot snapshot = deserialize_snapshot(data, length);

// Use the received snapshot (for example, print some values)
std::cout << "Camera Position: (" << snapshot.camera_pos[0] << ", " << snapshot.camera_pos[1] << ", " << snapshot.camera_pos[2] << ")\n";
std::cout << "Number of Local to World Matrices: " << snapshot.local_to_world_matrices.size() << "\n";

}

int main(int argc, char** argv) { if (enet_initialize() != 0) { std::cerr << "Failed to initialize ENet\n"; return EXIT_FAILURE; }

ENetAddress address;
ENetHost* server;

address.host = ENET_HOST_ANY;
address.port = 1234;

server = enet_host_create(&address, 32, 2, 0, 0);
if (server == nullptr) {
    std::cerr << "Failed to create ENet server\n";
    enet_deinitialize();
    return EXIT_FAILURE;
}

while (true) {
    ENetEvent event;
    while (enet_host_service(server, &event, 1000) > 0) {
        switch (event.type) {
            case ENET_EVENT_TYPE_CONNECT:
                std::cout << "A new client connected from " << event.peer->address.host << ":" << event.peer->address.port << "\n";
                break;

            case ENET_EVENT_TYPE_RECEIVE:
                receive_snapshot(event.packet);
                enet_packet_destroy(event.packet);
                break;

            case ENET_EVENT_TYPE_DISCONNECT:
                std::cout << "Client disconnected\n";
                break;

            default:
                break;
        }
    }
}

enet_host_destroy(server);
enet_deinitialize();

return 0;

}