Fix canvas textures getting clipped by wrong scissor box

src/common/rendering/v_framebuffer.cpp

@@ -170,6 +170,8 @@ void DFrameBuffer::SetViewportRects(IntRect *bounds)
 		mSceneViewport = *bounds;
 		mScreenViewport = *bounds;
 		mOutputLetterbox = *bounds;
+		mGameScreenWidth = mScreenViewport.width;
+		mGameScreenHeight = mScreenViewport.height;
 		return;
 	}
 
@@ -216,6 +218,9 @@ void DFrameBuffer::SetViewportRects(IntRect *bounds)
 		mSceneViewport.width = (int)round(mSceneViewport.width * scaleX);
 		mSceneViewport.height = (int)round(mSceneViewport.height * scaleY);
 	}
+
+	mGameScreenWidth = GetWidth();
+	mGameScreenHeight = GetHeight();
 }
 
 //===========================================================================
@@ -226,12 +231,12 @@ void DFrameBuffer::SetViewportRects(IntRect *bounds)
 
 int DFrameBuffer::ScreenToWindowX(int x)
 {
-	return mScreenViewport.left + (int)round(x * mScreenViewport.width / (float)GetWidth());
+	return mScreenViewport.left + (int)round(x * mScreenViewport.width / (float)mGameScreenWidth);
 }
 
 int DFrameBuffer::ScreenToWindowY(int y)
 {
-	return mScreenViewport.top + mScreenViewport.height - (int)round(y * mScreenViewport.height / (float)GetHeight());
+	return mScreenViewport.top + mScreenViewport.height - (int)round(y * mScreenViewport.height / (float)mGameScreenHeight);
 }
 
 void DFrameBuffer::ScaleCoordsFromWindow(int16_t &x, int16_t &y)

src/common/rendering/v_video.h

@@ -147,6 +147,8 @@ public:
 	BoneBuffer* mBones = nullptr;				// Model bones
 	IShadowMap mShadowMap;
 
+	int mGameScreenWidth = 0;
+	int mGameScreenHeight = 0;
 	IntRect mScreenViewport;
 	IntRect mSceneViewport;
 	IntRect mOutputLetterbox;

src/rendering/hwrenderer/hw_entrypoint.cpp

@@ -360,6 +360,7 @@ sector_t* RenderView(player_t* player)
 			{
 				screen->RenderTextureView(canvas->Tex, [=](IntRect& bounds)
 					{
+						screen->SetViewportRects(&bounds);
 						Draw2D(&canvas->Drawer, *screen->RenderState(), 0, 0, canvas->Tex->GetWidth(), canvas->Tex->GetHeight());
 						canvas->Drawer.Clear();
 					});