diff --git a/lib/squall b/lib/squall
index 3d14119..cdd3413 160000
--- a/lib/squall
+++ b/lib/squall
@@ -1 +1 @@
-Subproject commit 3d141195362dc7557d09deab5b25c3647ee4764e
+Subproject commit cdd3413a1b8d96ad2e6a89c73686ae8de80221de
diff --git a/src/gx/Screen.cpp b/src/gx/Screen.cpp
index e9a4c10..4fa0f2c 100644
--- a/src/gx/Screen.cpp
+++ b/src/gx/Screen.cpp
@@ -43,26 +43,26 @@ int32_t OnPaint(const void* a1, void* a2) {
     baseRect.right = 1.0f;
     baseRect.top = 1.0f;
 
-    SRgnCombineRectf(&rgn.m_handle, &baseRect, 0, 2);
+    SRgnCombineRectf(rgn.m_handle, &baseRect, nullptr, 2);
 
     layer = Screen::s_zorderlist.Head();
 
     while (layer) {
-        SRgnGetBoundingRectf(&rgn.m_handle, &layer->visible);
+        SRgnGetBoundingRectf(rgn.m_handle, &layer->visible);
 
         layer->visible.left = std::max(layer->visible.left, layer->rect.left);
         layer->visible.bottom = std::max(layer->visible.bottom, layer->rect.bottom);
-        layer->visible.right = std::max(layer->visible.right, layer->rect.right);
-        layer->visible.top = std::max(layer->visible.top, layer->rect.top);
+        layer->visible.right = std::min(layer->visible.right, layer->rect.right);
+        layer->visible.top = std::min(layer->visible.top, layer->rect.top);
 
-        if (layer->flags & 0x1) {
-            SRgnCombineRectf(&rgn.m_handle, &layer->rect, 0, 4);
+        if (!(layer->flags & 0x1)) {
+            SRgnCombineRectf(rgn.m_handle, &layer->rect, nullptr, 4);
         }
 
         layer = layer->zorderlink.Next();
     }
 
-    SRgnDelete(&rgn.m_handle);
+    SRgnDelete(rgn.m_handle);
 
     // Save viewport
     float minX, maxX, minY, maxY, minZ, maxZ;
@@ -218,19 +218,3 @@ void ScrnSetStockFont(SCRNSTOCK stockID, const char* fontTexturePath) {
     HTEXTFONT font = TextBlockGenerateFont(fontTexturePath, 0, fontHeight);
     Screen::s_stockObjects[stockID] = font;
 }
-
-void SRgnCombineRectf(HSRGN* handle, RECTF* rect, void* param, int32_t combinemode) {
-    // TODO
-}
-
-void SRgnCreate(HSRGN* handle, uint32_t reserved) {
-    // TODO
-}
-
-void SRgnDelete(HSRGN* handle) {
-    // TODO
-}
-
-void SRgnGetBoundingRectf(HSRGN* handle, RECTF* rect) {
-    // TODO
-}
diff --git a/src/gx/Screen.hpp b/src/gx/Screen.hpp
index 2476c5e..0cf7f1c 100644
--- a/src/gx/Screen.hpp
+++ b/src/gx/Screen.hpp
@@ -4,9 +4,9 @@
 #include <cstdint>
 #include <common/Handle.hpp>
 #include <storm/List.hpp>
+#include <storm/Region.hpp>
 
 typedef HOBJECT HLAYER;
-typedef HOBJECT HSRGN;
 
 enum SCRNSTOCK {
     STOCK_SYSFONT = 0,
@@ -14,13 +14,6 @@ enum SCRNSTOCK {
     SCRNSTOCKOBJECTS = 2
 };
 
-struct RECTF {
-    float left;
-    float bottom;
-    float right;
-    float top;
-};
-
 class CILayer : public CHandleObject {
     public:
         RECTF rect;
@@ -56,12 +49,4 @@ void ScrnLayerCreate(const RECTF*, float, unsigned long, void*, void (*)(void*,
 
 void ScrnSetStockFont(SCRNSTOCK, const char*);
 
-void SRgnCombineRectf(HSRGN*, RECTF*, void*, int32_t);
-
-void SRgnCreate(HSRGN*, uint32_t);
-
-void SRgnDelete(HSRGN*);
-
-void SRgnGetBoundingRectf(HSRGN*, RECTF*);
-
 #endif