+ added test triangle rendering

* on close mainloop is ended

KKK/game/src/main.cpp

@@ -0,0 +1,36 @@
+#include <include/opengl.h>
+#include <iostream>
+
+class MainWindow : public endofthejedi::GLWindow {
+private:
+protected:
+  void init() override {
+    glClearColor(0.5f, 0.6f, 0.7f, 1.0f);
+    resize();
+
+    glEnable(GL_DEPTH_TEST);
+  }
+  void render(double time) override {
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    glBegin(GL_TRIANGLES);
+    glColor3f(1.0f, 0.0f, 0.0f);
+    glVertex3f(0.0f, -1.0f, 0.0f);
+    glColor3f(0.0f, 1.0f, 0.0f);
+    glVertex3f(-1.0f, 1.0f, 0.0f);
+    glColor3f(0.0f, 0.0f, 1.0f);
+    glVertex3f(1.0f, 1.0f, 0.0f);
+    glEnd();
+  }
+  void resize() override { glViewport(0, 0, getwidth(), getheight()); }
+
+public:
+  MainWindow(unsigned int width, unsigned int height)
+      : endofthejedi::GLWindow(width, height) {}
+};
+
+int main(int argc, const char *argv[]) {
+  MainWindow window(500, 500);
+  window.loop();
+  window.stop();
+}

KKK/game/src/opengl.cpp

@@ -0,0 +1,122 @@
+#include <include/opengl.h>
+
+#include <iostream>
+#include <sys/time.h>
+
+#define UNUSED(foo) (void)foo;
+
+timespec diff(timespec start, timespec end) {
+  timespec result;
+  if ((end.tv_nsec - start.tv_nsec) < 0) {
+    result.tv_sec = end.tv_sec - start.tv_sec - 1;
+    result.tv_nsec = 1000000000 + end.tv_nsec - start.tv_nsec;
+  } else {
+    result.tv_sec = end.tv_sec - start.tv_sec;
+    result.tv_nsec = end.tv_nsec - start.tv_nsec;
+  }
+  return result;
+}
+
+endofthejedi::GLWindow::GLWindow(unsigned int width, unsigned int height)
+    : m_width(width), m_height(height) {
+  m_display = XOpenDisplay(NULL);
+
+  if (m_display == NULL) {
+    throw std::runtime_error("XOpenDisplay NULL");
+  }
+
+  m_rootwnd = DefaultRootWindow(m_display);
+
+  m_visualinfo = glXChooseVisual(m_display, 0, m_attributes);
+
+  if (m_visualinfo == NULL) {
+    throw std::runtime_error("glXChooseVisual NULL");
+  }
+
+  m_colormap =
+      XCreateColormap(m_display, m_rootwnd, m_visualinfo->visual, AllocNone);
+
+  m_swa.colormap = m_colormap;
+  m_swa.event_mask = ExposureMask | KeyPressMask;
+
+  m_window = XCreateWindow(
+      m_display, m_rootwnd, 0, 0, width, height, 0, m_visualinfo->depth,
+      InputOutput, m_visualinfo->visual, CWColormap | CWEventMask, &m_swa);
+
+  m_atomWmDeleteWindow = XInternAtom(m_display, "WM_DELETE_WINDOW", False);
+  XSetWMProtocols(m_display, m_window, &m_atomWmDeleteWindow, 1);
+
+  XMapWindow(m_display, m_window);
+  XStoreName(m_display, m_window, "NAME");
+
+  m_glcontext = glXCreateContext(m_display, m_visualinfo, NULL, GL_TRUE);
+
+  XSync(m_display, False);
+
+  glXMakeCurrent(m_display, m_window, m_glcontext);
+
+  std::cout << "GL Renderer: " << glGetString(GL_RENDERER) << "\n";
+  std::cout << "GL Version: " << glGetString(GL_VERSION) << "\n";
+  std::cout << "GLSL Version: " << glGetString(GL_SHADING_LANGUAGE_VERSION)
+            << "\n";
+
+  init();
+
+  XClearWindow(m_display, m_window);
+  XMapRaised(m_display, m_window);
+}
+
+endofthejedi::GLWindow::~GLWindow() {
+  glXMakeCurrent(m_display, None, NULL);
+  glXDestroyContext(m_display, m_glcontext);
+  XDestroyWindow(m_display, m_window);
+  XCloseDisplay(m_display);
+}
+
+void endofthejedi::GLWindow::handle(XEvent event) {
+  if (event.type == Expose) {
+    XWindowAttributes attribs;
+    XGetWindowAttributes(m_display, m_window, &attribs);
+    m_width = attribs.width;
+    m_height = attribs.height;
+    resize();
+  } else if (event.type == ClientMessage) {
+    if (event.xclient.data.l[0] == m_atomWmDeleteWindow) {
+      stop();
+    }
+  } else if (event.type == DestroyNotify) {
+    stop();
+  }
+}
+
+void endofthejedi::GLWindow::swap() { glXSwapBuffers(m_display, m_window); }
+
+void endofthejedi::GLWindow::loop() {
+  m_running = true;
+  timespec prev;
+  clock_gettime(CLOCK_MONOTONIC_RAW, &prev);
+  timespec current;
+  clock_gettime(CLOCK_MONOTONIC_RAW, &current);
+  double delta = 0.0;
+  while (m_running) {
+
+    if (XPending(m_display) > 0) {
+      XEvent xev;
+      XNextEvent(m_display, &xev);
+      handle(xev);
+    }
+
+    render(delta);
+    swap();
+
+    clock_gettime(CLOCK_MONOTONIC_RAW, &current);
+    delta = diff(prev, current).tv_nsec;
+    prev = current;
+  }
+}
+
+void endofthejedi::GLWindow::stop() { m_running = false; }
+
+void endofthejedi::GLWindow::init() {}
+void endofthejedi::GLWindow::render(double time) { UNUSED(time) }
+void endofthejedi::GLWindow::resize() {}