Fix scissor on macos (#2170)

* Expose GetRenderWidth and GetRenderHeight functions

* Fix scissor on macos

* Fix typo

src/raylib.h

@@ -928,6 +928,8 @@ RLAPI void SetWindowSize(int width, int height);                  // Set window
 RLAPI void *GetWindowHandle(void);                                // Get native window handle
 RLAPI int GetScreenWidth(void);                                   // Get current screen width
 RLAPI int GetScreenHeight(void);                                  // Get current screen height
+RLAPI int GetRenderWidth(void);                                   // Get current render width
+RLAPI int GetRenderHeight(void);                                  // Get current render height
 RLAPI int GetMonitorCount(void);                                  // Get number of connected monitors
 RLAPI int GetCurrentMonitor(void);                                // Get current connected monitor
 RLAPI Vector2 GetMonitorPosition(int monitor);                    // Get specified monitor position

src/rcore.c

@@ -2184,6 +2184,14 @@ void BeginScissorMode(int x, int y, int width, int height)
 
     rlEnableScissorTest();
 
+#if defined(__APPLE__)
+    Vector2 scale = GetWindowScaleDPI();
+    rlScissor(
+            (int)(x*scale.x),
+            (int)(GetScreenHeight() * scale.y - (((y + height) * scale.y))),
+            (int)(width*scale.x),
+            (int)(height*scale.y));
+#else
     if ((CORE.Window.flags & FLAG_WINDOW_HIGHDPI) > 0)
     {
         Vector2 scale = GetWindowScaleDPI();
@@ -2194,6 +2202,7 @@ void BeginScissorMode(int x, int y, int width, int height)
     {
         rlScissor(x, CORE.Window.currentFbo.height - (y + height), width, height);
     }
+#endif
 }
 
 // End scissor mode