From 2b969892e6fd23625951b017e2d8efa0825edb5a Mon Sep 17 00:00:00 2001
From: Nelson Gomez <nelson@ngomez.me>
Date: Sat, 19 Oct 2024 01:57:48 -0700
Subject: [PATCH] Mark framebuffer reads from the dirty rect backing buffer

---
 scgl/cGDriver.h                     |  1 +
 scgl/cGDriver_Viewport.cpp          |  1 +
 scgl/ext/cGDriver_BufferRegions.cpp | 14 +++++++-------
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/scgl/cGDriver.h b/scgl/cGDriver.h
index fcc33f2..905115b 100644
--- a/scgl/cGDriver.h
+++ b/scgl/cGDriver.h
@@ -102,6 +102,7 @@ namespace nSCGL
 		void* secondaryWindow;
 		void* secondaryDeviceContext;
 		void* pixels;
+		void* lineBrush;
 #endif
 
 	private:
diff --git a/scgl/cGDriver_Viewport.cpp b/scgl/cGDriver_Viewport.cpp
index edd414a..6a33265 100644
--- a/scgl/cGDriver_Viewport.cpp
+++ b/scgl/cGDriver_Viewport.cpp
@@ -251,6 +251,7 @@ namespace nSCGL
 
 				ShowWindow(secondaryHwnd, SW_SHOWNORMAL);
 				pixels = new char[3 * newMode.width * newMode.height];
+				lineBrush = CreateSolidBrush(RGB(255, 0, 0));
 			}
 #endif
 
diff --git a/scgl/ext/cGDriver_BufferRegions.cpp b/scgl/ext/cGDriver_BufferRegions.cpp
index af0220e..9f452b2 100644
--- a/scgl/ext/cGDriver_BufferRegions.cpp
+++ b/scgl/ext/cGDriver_BufferRegions.cpp
@@ -112,11 +112,8 @@ namespace nSCGL
 			InvalidateRect((HWND)secondaryWindow, nullptr, TRUE);
 
 			PAINTSTRUCT ps;
-			DWORD dwError;
 			HDC hdc = BeginPaint((HWND)secondaryWindow, &ps);
 
-			dwError = GetLastError();
-
 			BITMAPINFO bm;
 			bm.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
 			bm.bmiHeader.biWidth = width;
@@ -134,7 +131,7 @@ namespace nSCGL
 			bm.bmiColors->rgbRed = 255;
 			bm.bmiColors->rgbReserved = 0;
 
-			dwError = ::SetDIBitsToDevice(
+			::SetDIBitsToDevice(
 				hdc,
 				dstX0,
 				windowHeight - dstY1,
@@ -148,11 +145,14 @@ namespace nSCGL
 				&bm,
 				DIB_RGB_COLORS);
 
-			dwError = GetLastError();
+			RECT rect;
+			rect.left = srcX0;
+			rect.right = rect.left + width;
+			rect.top = windowHeight - dstY1;
+			rect.bottom = rect.top + height;
 
+			FrameRect(hdc, &rect, (HBRUSH)lineBrush);
 			EndPaint((HWND)secondaryWindow, &ps);
-
-			dwError = GetLastError();
 		}
 #endif