web: Fix canvas size issues when zooming page

Author: WerWolv

dist/web/source/wasm-config.js

@@ -271,11 +271,11 @@ window.addEventListener('resize', js_resizeCanvas, false);
 function js_resizeCanvas() {
     let canvas = document.getElementById('canvas');
 
-    canvas.top    = document.documentElement.clientTop;
-    canvas.left   = document.documentElement.clientLeft;
+    canvas.top    = canvas.parentElement.clientTop;
+    canvas.left   = canvas.parentElement.clientLeft;
 
-    let width = Math.min(document.documentElement.clientWidth, window.innerWidth || 0);
-    let height = Math.min(document.documentElement.clientHeight, window.innerHeight || 0);
+    let width = Math.min(canvas.parentElement.clientWidth, window.innerWidth || 0);
+    let height = Math.min(canvas.parentElement.clientHeight, window.innerHeight || 0);
 
     canvas.style.width  = width + "px";
     canvas.style.height = height + "px";

main/gui/CMakeLists.txt

@@ -45,6 +45,7 @@ if (EMSCRIPTEN)
     target_link_options(main PRIVATE -sEXPORTED_RUNTIME_METHODS=ccall)
     target_link_options(main PRIVATE -sFETCH)
     target_link_options(main PRIVATE -sASSERTIONS)
+    target_link_options(main PRIVATE -sNO_DISABLE_EXCEPTION_CATCHING)
     target_link_options(main PRIVATE -sWASM_BIGINT)
     target_link_options(main PRIVATE -O2)
     target_link_options(main PRIVATE -fsanitize=null)

main/gui/source/window/platform/web.cpp

@@ -147,6 +147,7 @@ namespace hex {
             prevWidth  = width;
             prevHeight = height;
             this->resize(width, height);
+            resizeCanvas();
         }
     }
 
@@ -167,7 +168,7 @@ namespace hex {
             ImHexApi::System::impl::setNativeScale(currScaleFactor);
 
             ThemeManager::reapplyCurrentTheme();
-            ImGui::GetStyle().ScaleAllSizes(currScaleFactor);
+            ImGui::GetStyle().ScaleAllSizes(currScaleFactor / prevScaleFactor);
         }
 
         prevScaleFactor = currScaleFactor;