raylib-wasm-transpiler/test-js-c-interop/test.c

#include <stdio.h>
#include <stdlib.h>
#include <emscripten/websocket.h>
#include <assert.h>

// Vector3, 3 components
typedef struct Vector3 {
    float x;                // Vector x component
    float y;                // Vector y component
    float z;                // Vector z component
} Vector3;

// Camera, defines position/orientation in 3d space
typedef struct Camera3D {
    Vector3 position;       // Camera position
    Vector3 target;         // Camera target it looks-at
    Vector3 up;             // Camera up vector (rotation over its axis)
    float fovy;             // Camera field-of-view aperture in Y (degrees) in perspective, used as near plane width in orthographic
    int projection;         // Camera projection: CAMERA_PERSPECTIVE or CAMERA_ORTHOGRAPHIC
} Camera3D;

EM_BOOL WebSocketOpen(int eventType, const EmscriptenWebSocketOpenEvent *e, void *userData) {
  printf("open(eventType=%d, userData=%p)\n", eventType, userData);

  Camera3D camera = {0};
  camera.position = (Vector3){-9.0f, 9.0f, 4.0f};
  camera.target = (Vector3){9.0f, 9.0f, 0.0f};
  camera.up = (Vector3){0.0f, 1.0f, 0.0f};
  camera.fovy = 60.0f;
  camera.projection = 0;

  emscripten_websocket_send_binary(e->socket, &camera, sizeof(camera));

  return 0;
}

EM_BOOL WebSocketClose(int eventType, const EmscriptenWebSocketCloseEvent *e, void *userData) {
  printf("close(eventType=%d, wasClean=%d, code=%d, reason=%s, userData=%p)\n", eventType, e->wasClean, e->code, e->reason, userData);
  return 0;
}

EM_BOOL WebSocketError(int eventType, const EmscriptenWebSocketErrorEvent *e, void *userData) {
  printf("error(eventType=%d, userData=%p)\n", eventType, userData);
  return 0;
}

EM_BOOL WebSocketMessage(int eventType, const EmscriptenWebSocketMessageEvent *e, void *userData) {
  printf("message(eventType=%d, userData=%p data=%p, numBytes=%d, isText=%d)\n", eventType, userData, e->data, e->numBytes, e->isText);
  static int text_received = 0;
  if (e->isText) {
    printf("text data: \"%s\"\n", e->data);
    assert(strcmp((const char*)e->data, "hello on the other side") == 0);
    text_received = 1;
    return 0;
  }

  Camera3D camera;
  memcpy(&camera, e->data, sizeof camera);

  printf("x: %f", camera.position.x);
  printf(" y: %f", camera.position.y);
  printf(" z: %f", camera.position.z);
  printf(" fovy: %f", camera.fovy);
  printf("\n");

  emscripten_websocket_close(e->socket, 0, 0);
  emscripten_websocket_delete(e->socket);
  emscripten_force_exit(0);
  return 0;
}

int main() {
  assert(emscripten_websocket_is_supported());

  EmscriptenWebSocketCreateAttributes attr;
  emscripten_websocket_init_create_attributes(&attr);

  const char *url = "ws://localhost:8089/";
  attr.url = url;
  // We don't really use a special protocol on the server backend in this test,
  // but check that it can be passed.
  attr.protocols = "binary,base64";

  EMSCRIPTEN_WEBSOCKET_T socket = emscripten_websocket_new(&attr);
  assert(socket >= 0);

  // URL:
  int urlLength = 0;
  EMSCRIPTEN_RESULT res = emscripten_websocket_get_url_length(socket, &urlLength);
  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
  assert(urlLength == strlen(url)+1);

  char *url2 = malloc(urlLength);
  res = emscripten_websocket_get_url(socket, url2, urlLength);
  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
  printf("url: %s, verified: %s, length: %d\n", url, url2, urlLength);
  assert(!strcmp(url, url2));

  // Protocol:
  int protocolLength = 0;
  res = emscripten_websocket_get_protocol_length(socket, &protocolLength);
  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
  assert(protocolLength == 1); // Null byte

  char *protocol = malloc(protocolLength);
  res = emscripten_websocket_get_protocol(socket, protocol, protocolLength);
  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
  // We don't really use a special protocol on the server backend in this test,
  // but test that it comes out as an empty string at least.
  assert(!strcmp(protocol, ""));

  // Extensions:
  int extensionsLength = 0;
  res = emscripten_websocket_get_extensions_length(socket, &extensionsLength);
  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
  assert(extensionsLength == 1); // Null byte

  char *extensions = malloc(extensionsLength);
  res = emscripten_websocket_get_extensions(socket, extensions, extensionsLength);
  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
  // We don't really use any extensions on the server backend in this test, but
  // test that it comes out as an empty string at least.
  assert(!strcmp(extensions, ""));

  emscripten_websocket_set_onopen_callback(socket, (void*)0x42, WebSocketOpen);
  emscripten_websocket_set_onclose_callback(socket, (void*)0x43, WebSocketClose);
  emscripten_websocket_set_onerror_callback(socket, (void*)0x44, WebSocketError);
  emscripten_websocket_set_onmessage_callback(socket, (void*)0x45, WebSocketMessage);
  emscripten_exit_with_live_runtime();
  return 0;
}