From 21c2d3834270e43d9b9a1e2d6dee7fb6fae13f11 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Sun, 15 Apr 2018 16:05:29 +0200
Subject: [PATCH] - fix softpoly canvas drawing not restoring all globals
 properly - add null pointer check on camera

---
 src/polyrenderer/poly_renderer.cpp | 45 ++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/src/polyrenderer/poly_renderer.cpp b/src/polyrenderer/poly_renderer.cpp
index d5e525bb0..4eb6c5b0e 100644
--- a/src/polyrenderer/poly_renderer.cpp
+++ b/src/polyrenderer/poly_renderer.cpp
@@ -62,11 +62,6 @@ void PolyRenderer::RenderView(player_t *player, DCanvas *target)
 
 	RenderTarget = target;
 	RenderToCanvas = false;
-	int width = SCREENWIDTH;
-	int height = SCREENHEIGHT;
-	float trueratio;
-	ActiveRatio(width, height, &trueratio);
-	//viewport->SetViewport(&Thread, width, height, trueratio);
 
 	RenderActorView(player->mo, false);
 
@@ -78,24 +73,40 @@ void PolyRenderer::RenderView(player_t *player, DCanvas *target)
 
 void PolyRenderer::RenderViewToCanvas(AActor *actor, DCanvas *canvas, int x, int y, int width, int height, bool dontmaplines)
 {
-	const bool savedviewactive = viewactive;
+	// Save a bunch of silly globals:
+	auto savedViewpoint = Viewpoint;
+	auto savedViewwindow = Viewwindow;
+	auto savedviewwindowx = viewwindowx;
+	auto savedviewwindowy = viewwindowy;
+	auto savedviewwidth = viewwidth;
+	auto savedviewheight = viewheight;
+	auto savedviewactive = viewactive;
+	auto savedRenderTarget = RenderTarget;
 
-	viewwidth = width;
+	// Setup the view:
 	RenderTarget = canvas;
 	RenderToCanvas = true;
 	R_SetWindow(Viewpoint, Viewwindow, 12, width, height, height, true);
-	//viewport->SetViewport(&Thread, width, height, Viewwindow.WidescreenRatio);
 	viewwindowx = x;
 	viewwindowy = y;
 	viewactive = true;
 	
+	// Render:
 	RenderActorView(actor, dontmaplines);
 	Threads.MainThread()->FlushDrawQueue();
 	DrawerThreads::WaitForWorkers();
 
-	RenderTarget = nullptr;
 	RenderToCanvas = false;
+
+	// Restore silly globals:
+	Viewpoint = savedViewpoint;
+	Viewwindow = savedViewwindow;
+	viewwindowx = savedviewwindowx;
+	viewwindowy = savedviewwindowy;
+	viewwidth = savedviewwidth;
+	viewheight = savedviewheight;
 	viewactive = savedviewactive;
+	RenderTarget = savedRenderTarget;
 }
 
 void PolyRenderer::RenderActorView(AActor *actor, bool dontmaplines)
@@ -126,10 +137,15 @@ void PolyRenderer::RenderActorView(AActor *actor, bool dontmaplines)
 	PolyCameraLight::Instance()->SetCamera(Viewpoint, RenderTarget, actor);
 	//Viewport->SetupFreelook();
 
-	ActorRenderFlags savedflags = Viewpoint.camera->renderflags;
-	// Never draw the player unless in chasecam mode
-	if (!Viewpoint.showviewer)
-		Viewpoint.camera->renderflags |= RF_INVISIBLE;
+	ActorRenderFlags savedflags = 0;
+	if (Viewpoint.camera)
+	{
+		savedflags = Viewpoint.camera->renderflags;
+
+		// Never draw the player unless in chasecam mode
+		if (!Viewpoint.showviewer)
+			Viewpoint.camera->renderflags |= RF_INVISIBLE;
+	}
 
 	ScreenTriangle::FuzzStart = (ScreenTriangle::FuzzStart + 14) % FUZZTABLE;
 
@@ -147,7 +163,8 @@ void PolyRenderer::RenderActorView(AActor *actor, bool dontmaplines)
 	Scene.RenderTranslucent(&mainViewpoint);
 	PlayerSprites.Render(Threads.MainThread());
 
-	Viewpoint.camera->renderflags = savedflags;
+	if (Viewpoint.camera)
+		Viewpoint.camera->renderflags = savedflags;
 	interpolator.RestoreInterpolations ();
 	
 	NetUpdate();