implement save request on OSX, add Quick Look extentions

engine/app.cpp

@@ -33,7 +33,9 @@ void App::create()
 bool App::request_close()
 {
     static bool dialog_already_opened = false;
-    if (ui::Canvas::I->m_unsaved && !dialog_already_opened)
+    if (!ui::Canvas::I->m_unsaved)
+        return true;
+    if (!dialog_already_opened)
     {
         async_start();
         auto* m = layout[main_id]->add_child<NodeMessageBox>();
@@ -43,9 +45,15 @@ bool App::request_close()
         m->btn_ok->on_click = [](Node*) {
         };
         m->btn_cancel->m_text->set_text("No");
-        m->btn_cancel->on_click = [](Node*) {
+        m->btn_cancel->on_click = [this](Node*) {
+            #ifdef _WIN32
             destroy_window();
             PostQuitMessage(0);
+            #endif
+            #ifdef __OSX__
+            [osx_view close];
+            #endif
+            ui::Canvas::I->m_unsaved = false;
         };
         async_redraw();
         async_end();

engine/canvas_modes.cpp

@@ -160,9 +160,11 @@ void CanvasModePen::on_MouseEvent(MouseEvent* me, glm::vec2& loc)
 void CanvasModePen::on_Draw(const glm::mat4& ortho, const glm::mat4& proj, const glm::mat4& camera)
 {
 #ifndef __IOS__
-    if (!m_dragging && !m_picking || m_resizing)
+    if (1)
     {
         auto pos = m_resizing ? m_size_pos_start : m_cur_pos;
+        if (App::I.keys[(int)kKey::KeyAlt])
+            pos.x = pos.x - canvas->m_current_brush.m_tip_size * 500;
         ui::ShaderManager::use(ui::kShader::StrokePreview);
         ui::ShaderManager::u_int(ui::kShaderUniform::Tex, 0);
         ui::ShaderManager::u_float(ui::kShaderUniform::Alpha, canvas->m_current_brush.m_tip_flow);