Route canvas input policy through platform services

src/app.h

@@ -192,6 +192,8 @@ public:
     [[nodiscard]] bool uses_ppbr_export_data_directory_override() const;
     [[nodiscard]] bool platform_supports_sonarpen() const;
     void start_platform_sonarpen();
+    [[nodiscard]] bool draws_canvas_tip_for_input(kEventSource source, kEventType type) const;
+    [[nodiscard]] float adjust_canvas_input_pressure(float pressure) const;
     void pick_dir(std::function<void(std::string path)> callback);
     void display_file(std::string path);
     void share_file(std::string path);

src/app_events.cpp

@@ -211,6 +211,19 @@ void App::start_platform_sonarpen()
     active_platform_services().start_sonarpen();
 }
 
+bool App::draws_canvas_tip_for_input(kEventSource source, kEventType type) const
+{
+    return active_platform_services().draws_canvas_tip_for_pointer(
+        source == kEventSource::Mouse,
+        source == kEventSource::Stylus,
+        type == kEventType::MouseUpL);
+}
+
+float App::adjust_canvas_input_pressure(float pressure) const
+{
+    return active_platform_services().adjust_canvas_input_pressure(pressure);
+}
+
 void App::pick_dir(std::function<void(std::string path)> callback)
 {
     redraw = true;

src/canvas_modes.cpp

@@ -140,21 +140,13 @@ void CanvasModePen::on_GestureEvent(GestureEvent* ge)
 
 void CanvasModePen::on_MouseEvent(MouseEvent* me, glm::vec2& loc)
 {
-#if defined(__IOS__)
-    m_draw_tip = (me->m_source == kEventSource::Mouse && me->m_type != kEventType::MouseUpL);
-#else
-    m_draw_tip = (me->m_source == kEventSource::Mouse || me->m_source == kEventSource::Stylus);
-#endif
+    m_draw_tip = App::I->draws_canvas_tip_for_input(me->m_source, me->m_type);
     m_draw_outline = true;
 
     if (Canvas::I->m_touch_lock && me->m_source == kEventSource::Touch)
         return;
 
-#if _WIN32
-    // curve https://www.wolframalpha.com/input/?i=plot+(1-(x-1)%5E2)%5E2+from+x%3D0+to+1
-    auto curve = [](float x, float max) { return x > max ? 1.f : glm::pow(1.f - glm::pow(x / max - 1.f, 2.f), 2.f); };
-    me->m_pressure = curve(me->m_pressure, 0.95f);
-#endif
+    me->m_pressure = App::I->adjust_canvas_input_pressure(me->m_pressure);
 
     switch (me->m_type)
     {
@@ -344,11 +336,7 @@ void CanvasModePen::enter(kCanvasMode prev)
 
 void CanvasModeLine::on_MouseEvent(MouseEvent* me, glm::vec2& loc)
 {
-#if defined(__IOS__)
-    m_draw_tip = (me->m_source == kEventSource::Mouse && me->m_type != kEventType::MouseUpL);
-#else
-    m_draw_tip = (me->m_source == kEventSource::Mouse || me->m_source == kEventSource::Stylus);
-#endif
+    m_draw_tip = App::I->draws_canvas_tip_for_input(me->m_source, me->m_type);
     if (Canvas::I->m_touch_lock && me->m_source == kEventSource::Touch)
         return;
     switch (me->m_type)
@@ -1636,11 +1624,7 @@ void CanvasModeTransform::on_MouseEvent(MouseEvent* me, glm::vec2& loc)
 
 void CanvasModeFloodFill::on_MouseEvent(MouseEvent* me, glm::vec2& loc)
 {
-#if defined(__IOS__)
-    m_draw_tip = (me->m_source == kEventSource::Mouse && me->m_type != kEventType::MouseUpL);
-#else
-    m_draw_tip = (me->m_source == kEventSource::Mouse || me->m_source == kEventSource::Stylus);
-#endif
+    m_draw_tip = App::I->draws_canvas_tip_for_input(me->m_source, me->m_type);
     if (Canvas::I->m_touch_lock && me->m_source == kEventSource::Touch)
         return;
 

src/platform_api/platform_services.h

@@ -71,6 +71,11 @@ public:
     [[nodiscard]] virtual bool uses_ppbr_export_data_directory_override() = 0;
     [[nodiscard]] virtual bool supports_sonarpen() = 0;
     virtual void start_sonarpen() = 0;
+    [[nodiscard]] virtual bool draws_canvas_tip_for_pointer(
+        bool is_mouse,
+        bool is_stylus,
+        bool is_left_button_release) = 0;
+    [[nodiscard]] virtual float adjust_canvas_input_pressure(float pressure) = 0;
     [[nodiscard]] virtual PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,

src/platform_legacy/legacy_platform_services.cpp

@@ -499,6 +499,25 @@ public:
 #endif
     }
 
+    [[nodiscard]] bool draws_canvas_tip_for_pointer(
+        bool is_mouse,
+        bool is_stylus,
+        bool is_left_button_release) override
+    {
+#if defined(__IOS__)
+        (void)is_stylus;
+        return is_mouse && !is_left_button_release;
+#else
+        (void)is_left_button_release;
+        return is_mouse || is_stylus;
+#endif
+    }
+
+    [[nodiscard]] float adjust_canvas_input_pressure(float pressure) override
+    {
+        return pressure;
+    }
+
     [[nodiscard]] pp::platform::PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,

src/platform_windows/windows_platform_services.cpp

@@ -496,6 +496,23 @@ public:
     {
     }
 
+    [[nodiscard]] bool draws_canvas_tip_for_pointer(
+        bool is_mouse,
+        bool is_stylus,
+        bool is_left_button_release) override
+    {
+        (void)is_left_button_release;
+        return is_mouse || is_stylus;
+    }
+
+    [[nodiscard]] float adjust_canvas_input_pressure(float pressure) override
+    {
+        const auto curve = [](float x, float max) {
+            return x > max ? 1.f : glm::pow(1.f - glm::pow(x / max - 1.f, 2.f), 2.f);
+        };
+        return curve(pressure, 0.95f);
+    }
+
     [[nodiscard]] pp::platform::PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,