add pinch to zoom on android

src/features/FixMouseControls.cpp

@@ -1,14 +1,15 @@
 
-#include <Geode/Bindings.hpp>
 #include <Geode/modify/EditorUI.hpp>
-#include <Geode/Loader.hpp>
+#include <Geode/loader/Mod.hpp>
 #include <numbers>
 
 #undef min
 #undef max
 
 using namespace geode::prelude;
 
+#ifdef GEODE_IS_DESKTOP
+
 class $modify(EditorUI) {
     $override
     virtual void scrollWheel(float y, float x) {
@@ -84,3 +85,5 @@ class $modify(EditorUI) {
         m_swipeStart = m_swipeStart + rel;
     }
 };
+
+#endif

src/features/PinchToZoom.cpp

@@ -0,0 +1,90 @@
+
+#include <Geode/modify/EditorUI.hpp>
+#include <Geode/loader/Mod.hpp>
+#include <numbers>
+
+#undef min
+#undef max
+
+using namespace geode::prelude;
+
+#ifdef GEODE_IS_MOBILE
+
+// thank you camila icreate 🙏
+
+class $modify(EditorUI) {
+    std::unordered_set<Ref<CCTouch>> touches;
+
+    $override
+    bool ccTouchBegan(CCTouch* touch, CCEvent* event) override {
+        if (m_fields->touches.size() == 1 || EditorUI::ccTouchBegan(touch, event)) {
+            m_fields->touches.insert(touch);
+            return true;
+        }
+        return false;
+    }
+
+    $override
+    void ccTouchMoved(CCTouch* touch, CCEvent* event) override {
+        if (m_fields->touches.size() == 2) {
+            // thanks https://math.stackexchange.com/questions/4408515/calculate-coordinates-after-pinch-to-zoom-gesture!!
+
+            auto winSize = CCDirector::get()->getWinSize();
+            auto objLayer = m_editorLayer->m_objectLayer;
+
+            auto it = m_fields->touches.begin();
+            auto a = *it;
+            auto b = *++it;
+
+            auto aPrev = a->getPreviousLocationInView();
+            if (aPrev == CCPointZero) {
+                aPrev = a->getLocationInView();
+            }
+            auto bPrev = b->getPreviousLocationInView();
+            if (bPrev == CCPointZero) {
+                bPrev = b->getLocationInView();
+            }
+
+            auto prevAspectDiv = fabsf(aPrev.x - bPrev.x);
+            if (fpclassify(prevAspectDiv) == FP_ZERO) {
+                return;
+            }
+            auto prevAspect = fabsf(aPrev.y - bPrev.y) / prevAspectDiv;
+
+            auto aNext = a->getLocationInView();
+            auto bNext = b->getLocationInView();
+
+            auto bMapped = ccp(bNext.x, fabsf(prevAspect * fabsf(aNext.x - bNext.x) - aNext.y));
+
+            auto zoomDiv = fabsf(aPrev.y - bPrev.y);
+            if (fpclassify(zoomDiv) == FP_ZERO) {
+                return;
+            }
+            auto zoom = fabsf(aNext.y - bMapped.y) / zoomDiv;
+
+            auto objPos = objLayer->getPosition();
+            this->updateZoom(objLayer->getScale() * zoom);
+            objLayer->setPosition(ccp(
+                aNext.x + zoom * (objPos.x - aPrev.x),
+                (winSize.height - aNext.y) + zoom * (objPos.y - (winSize.height - aPrev.y))
+            ));
+        }
+        else {
+            EditorUI::ccTouchMoved(touch, event);
+        }
+    }
+
+    $override
+    void ccTouchEnded(CCTouch* touch, CCEvent* event) override {
+        EditorUI::ccTouchEnded(touch, event);
+        m_fields->touches.erase(touch);
+    }
+
+    $override
+    void ccTouchCancelled(CCTouch* touch, CCEvent* event) override {
+        EditorUI::ccTouchCancelled(touch, event);
+        m_fields->touches.erase(touch);
+    }
+};
+
+#endif