Fix even more build issues

- The MSVC bug from the parent commit wasn't a macro, apparently
- Forgot to commit src/port/emscripten.cpp
- Emscripten doesn't support LTO very well, disable it for now

CMakeLists.txt

@@ -64,7 +64,13 @@ include(ExternalProject)
 include(CheckCXXCompilerFlag)
 include(CheckSymbolExists)
 
-option(SUPERTUX_IPO "Use interprocedural optimisation (Takes more RAM at compilation, gives smaller and faster builds)" ON)
+if(EMSCRIPTEN)
+  # FIXME: As of writing, Emscripten fails with "wasm-ld: error: /path/to/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten/thinlto/libc.a(fileno.o): attempt to add bitcode file after LTO (fileno)"
+  # Seems to be a known issue: https://github.com/emscripten-core/emscripten/issues/20275
+  option(SUPERTUX_IPO "Use interprocedural optimisation (Takes more RAM at compilation, gives smaller and faster builds)" OFF)
+else()
+  option(SUPERTUX_IPO "Use interprocedural optimisation (Takes more RAM at compilation, gives smaller and faster builds)" ON)
+endif()
 if(SUPERTUX_IPO)
   include(CheckIPOSupported)
   check_ipo_supported(RESULT result)

src/editor/scroller_widget.cpp

@@ -24,11 +24,7 @@
 #include "video/video_system.hpp"
 #include "video/viewport.hpp"
 
-namespace {
-
-#ifdef _MSC_VER
-#undef SIZE
-#endif
+namespace CONSTS {
 
 const float TOPLEFT = 16;
 const float MIDDLE = 48;
@@ -50,34 +46,34 @@ EditorScrollerWidget::EditorScrollerWidget(Editor& editor) :
 bool
 EditorScrollerWidget::can_scroll() const
 {
-  return m_scrolling && m_mouse_pos.x < SIZE && m_mouse_pos.y < SIZE;
+  return m_scrolling && m_mouse_pos.x < CONSTS::SIZE && m_mouse_pos.y < CONSTS::SIZE;
 }
 
 void
 EditorScrollerWidget::draw(DrawingContext& context)
 {
   if (!rendered) return;
 
-  context.color().draw_filled_rect(Rectf(Vector(0, 0), Vector(SIZE, SIZE)),
+  context.color().draw_filled_rect(Rectf(Vector(0, 0), Vector(CONSTS::SIZE, CONSTS::SIZE)),
                                      Color(0.9f, 0.9f, 1.0f, 0.6f),
-                                     MIDDLE, LAYER_GUI-10);
+                                     CONSTS::MIDDLE, LAYER_GUI-10);
   context.color().draw_filled_rect(Rectf(Vector(40, 40), Vector(56, 56)),
                                      Color(0.9f, 0.9f, 1.0f, 0.6f),
                                      8, LAYER_GUI-20);
   if (can_scroll()) {
     draw_arrow(context, m_mouse_pos);
   }
 
-  draw_arrow(context, Vector(TOPLEFT, MIDDLE));
-  draw_arrow(context, Vector(BOTTOMRIGHT, MIDDLE));
-  draw_arrow(context, Vector(MIDDLE, TOPLEFT));
-  draw_arrow(context, Vector(MIDDLE, BOTTOMRIGHT));
+  draw_arrow(context, Vector(CONSTS::TOPLEFT, CONSTS::MIDDLE));
+  draw_arrow(context, Vector(CONSTS::BOTTOMRIGHT, CONSTS::MIDDLE));
+  draw_arrow(context, Vector(CONSTS::MIDDLE, CONSTS::TOPLEFT));
+  draw_arrow(context, Vector(CONSTS::MIDDLE, CONSTS::BOTTOMRIGHT));
 }
 
 void
 EditorScrollerWidget::draw_arrow(DrawingContext& context, const Vector& pos)
 {
-  Vector dir = pos - Vector(MIDDLE, MIDDLE);
+  Vector dir = pos - Vector(CONSTS::MIDDLE, CONSTS::MIDDLE);
   if (dir.x != 0 || dir.y != 0) {
     // draw a triangle
     dir = glm::normalize(dir) * 8.0f;
@@ -109,7 +105,7 @@ EditorScrollerWidget::on_mouse_button_down(const SDL_MouseButtonEvent& button)
   if (button.button == SDL_BUTTON_LEFT) {
     if (!rendered) return false;
 
-    if (m_mouse_pos.x < SIZE && m_mouse_pos.y < SIZE) {
+    if (m_mouse_pos.x < CONSTS::SIZE && m_mouse_pos.y < CONSTS::SIZE) {
       m_scrolling = true;
       return true;
     } else {
@@ -126,8 +122,8 @@ EditorScrollerWidget::on_mouse_motion(const SDL_MouseMotionEvent& motion)
   if (!rendered) return false;
 
   m_mouse_pos = VideoSystem::current()->get_viewport().to_logical(motion.x, motion.y);
-  if (m_mouse_pos.x < SIZE && m_mouse_pos.y < SIZE) {
-    m_scrolling_vec = m_mouse_pos - Vector(MIDDLE, MIDDLE);
+  if (m_mouse_pos.x < CONSTS::SIZE && m_mouse_pos.y < CONSTS::SIZE) {
+    m_scrolling_vec = m_mouse_pos - Vector(CONSTS::MIDDLE, CONSTS::MIDDLE);
     if (m_scrolling_vec.x != 0 || m_scrolling_vec.y != 0) {
       float norm = glm::length(m_scrolling_vec);
       m_scrolling_vec *= powf(static_cast<float>(M_E), norm / 16.0f - 1.0f);

src/port/emscripten.cpp

@@ -0,0 +1,79 @@
+//  SuperTux
+//  Copyright (C) 2021 A. Semphris <[email protected]>
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "port/emscripten.hpp"
+
+#ifdef __EMSCRIPTEN__
+
+extern "C" {
+
+EMSCRIPTEN_KEEPALIVE // This is probably not useful, I just want ppl to know it exists
+void
+set_resolution(int w, int h)
+{
+  VideoSystem::current()->on_resize(w, h);
+  MenuManager::instance().on_window_resize();
+}
+
+EMSCRIPTEN_KEEPALIVE // Same as above
+void
+save_config()
+{
+  g_config->save();
+}
+
+void
+onDownloadProgress(int id, int loaded, int total)
+{
+  AddonManager::current()->onDownloadProgress(id, loaded, total);
+}
+
+void
+onDownloadFinished(int id)
+{
+  AddonManager::current()->onDownloadFinished(id);
+}
+
+void
+onDownloadError(int id)
+{
+  AddonManager::current()->onDownloadError(id);
+}
+
+void
+onDownloadAborted(int id)
+{
+  AddonManager::current()->onDownloadAborted(id);
+}
+
+const char*
+getExceptionMessage(intptr_t address)
+{
+  return reinterpret_cast<std::exception*>(address)->what();
+}
+
+} // extern "C"
+
+void
+init_emscripten()
+{
+  EM_ASM({
+    if (window.supertux_onready)
+      window.supertux_onready();
+  }, 0); // EM_ASM is a variadic macro and Clang requires at least 1 value for the variadic argument
+}
+
+#endif