- draw models in mirrors and portals at the right location in the software renderer

src/swrenderer/scene/r_portal.cpp

@@ -173,6 +173,7 @@ namespace swrenderer
 			Thread->Viewport->viewpoint.sector = port->mDestination;
 			assert(Thread->Viewport->viewpoint.sector != nullptr);
 			R_SetViewAngle(Thread->Viewport->viewpoint, Thread->Viewport->viewwindow);
+			Thread->Viewport->SetupPolyViewport(Thread);
 			Thread->OpaquePass->ClearSeenSprites();
 			Thread->Clip3D->ClearFakeFloors();
 
@@ -239,6 +240,7 @@ namespace swrenderer
 			// Masked textures and planes need the view coordinates restored for proper positioning.
 			viewposStack.Pop(Thread->Viewport->viewpoint.Pos);
 			
+			Thread->Viewport->SetupPolyViewport(Thread);
 			Thread->TranslucentPass->Render();
 
 			VisiblePlane *pl = nullptr;	// quiet, GCC!
@@ -259,6 +261,7 @@ namespace swrenderer
 		Thread->Viewport->viewpoint.extralight = savedextralight;
 		Thread->Viewport->viewpoint.Angles = savedangles;
 		R_SetViewAngle(Thread->Viewport->viewpoint, Thread->Viewport->viewwindow);
+		Thread->Viewport->SetupPolyViewport(Thread);
 
 		CurrentPortalInSkybox = false;
 		Thread->Clip3D->LeaveSkybox();
@@ -426,6 +429,8 @@ namespace swrenderer
 			else MirrorFlags |= RF_XFLIP;
 		}
 
+		Thread->Viewport->SetupPolyViewport(Thread);
+
 		// some portals have height differences, account for this here
 		Thread->Clip3D->EnterSkybox(); // push 3D floor height map
 		CurrentPortalInSkybox = false; // first portal in a skybox should set this variable to false for proper clipping in skyboxes.
@@ -478,6 +483,8 @@ namespace swrenderer
 		viewpoint.Pos = startpos;
 		viewpoint.Path[0] = savedpath[0];
 		viewpoint.Path[1] = savedpath[1];
+
+		viewport->SetupPolyViewport(Thread);
 	}
 
 #if 0

src/swrenderer/scene/r_scene.cpp

@@ -159,6 +159,8 @@ namespace swrenderer
 		if (r_models)
 			MainThread()->Viewport->SetupPolyViewport(MainThread());
 
+		FRenderViewpoint origviewpoint = MainThread()->Viewport->viewpoint;
+
 		ActorRenderFlags savedflags = MainThread()->Viewport->viewpoint.camera->renderflags;
 		// Never draw the player unless in chasecam mode
 		if (!MainThread()->Viewport->viewpoint.showviewer)
@@ -167,6 +169,12 @@ namespace swrenderer
 		}
 
 		RenderThreadSlices();
+
+		// Mirrors fail to restore the original viewpoint -- we need it for the HUD weapon to draw correctly.
+		MainThread()->Viewport->viewpoint = origviewpoint;
+		if (r_models)
+			MainThread()->Viewport->SetupPolyViewport(MainThread());
+
 		RenderPSprites();
 
 		MainThread()->Viewport->viewpoint.camera->renderflags = savedflags;

src/swrenderer/things/r_model.cpp

@@ -47,12 +47,22 @@ namespace swrenderer
 		if (tz < MINZ)
 			return;
 
-		// too far off the side?
 		double tx = tr_x * thread->Viewport->viewpoint.Sin - tr_y * thread->Viewport->viewpoint.Cos;
+
+		// Flip for mirrors
+		if (thread->Portal->MirrorFlags & RF_XFLIP)
+		{
+			tx = viewwidth - tx - 1;
+		}
+
+		// too far off the side?
 		if (fabs(tx / 64) > fabs(tz))
 			return;
 
 		RenderModel *vis = thread->FrameMemory->NewObject<RenderModel>(x, y, z, smf, actor, float(1 / tz));
+		vis->CurrentPortalUniq = thread->Portal->CurrentPortalUniq;
+		vis->WorldToClip = thread->Viewport->WorldToClip;
+		vis->MirrorWorldToClip = !!(thread->Portal->MirrorFlags & RF_XFLIP);
 		thread->SpriteList->Push(vis);
 	}
 
@@ -64,7 +74,7 @@ namespace swrenderer
 
 	void RenderModel::Render(RenderThread *thread, short *cliptop, short *clipbottom, int minZ, int maxZ, Fake3DTranslucent clip3DFloor)
 	{
-		SWModelRenderer renderer(thread, clip3DFloor);
+		SWModelRenderer renderer(thread, clip3DFloor, &WorldToClip, MirrorWorldToClip);
 		renderer.RenderModel(x, y, z, smf, actor);
 	}
 
@@ -72,13 +82,14 @@ namespace swrenderer
 
 	void RenderHUDModel(RenderThread *thread, DPSprite *psp, float ofsx, float ofsy)
 	{
-		SWModelRenderer renderer(thread, Fake3DTranslucent());
+		SWModelRenderer renderer(thread, Fake3DTranslucent(), &thread->Viewport->WorldToClip, false);
 		renderer.RenderHUDModel(psp, ofsx, ofsy);
 	}
 
 	/////////////////////////////////////////////////////////////////////////////
 
-	SWModelRenderer::SWModelRenderer(RenderThread *thread, Fake3DTranslucent clip3DFloor) : Thread(thread), Clip3DFloor(clip3DFloor)
+	SWModelRenderer::SWModelRenderer(RenderThread *thread, Fake3DTranslucent clip3DFloor, Mat4f *worldToClip, bool mirrorWorldToClip)
+		: Thread(thread), Clip3DFloor(clip3DFloor), WorldToClip(worldToClip), MirrorWorldToClip(mirrorWorldToClip)
 	{
 	}
 
@@ -123,7 +134,7 @@ namespace swrenderer
 
 		if (actor->RenderStyle == LegacyRenderStyles[STYLE_Normal] || !!(smf->flags & MDL_DONTCULLBACKFACES))
 			PolyTriangleDrawer::SetTwoSided(Thread->DrawQueue, true);
-		PolyTriangleDrawer::SetCullCCW(Thread->DrawQueue, !mirrored);
+		PolyTriangleDrawer::SetCullCCW(Thread->DrawQueue, !(mirrored ^ MirrorWorldToClip));
 	}
 
 	void SWModelRenderer::EndDrawModel(AActor *actor, FSpriteModelFrame *smf)
@@ -194,7 +205,7 @@ namespace swrenderer
 
 		if (actor->RenderStyle == LegacyRenderStyles[STYLE_Normal])
 			PolyTriangleDrawer::SetTwoSided(Thread->DrawQueue, true);
-		PolyTriangleDrawer::SetCullCCW(Thread->DrawQueue, mirrored);
+		PolyTriangleDrawer::SetCullCCW(Thread->DrawQueue, !(mirrored ^ MirrorWorldToClip));
 	}
 
 	void SWModelRenderer::EndDrawHUDModel(AActor *actor)
@@ -225,7 +236,7 @@ namespace swrenderer
 		swapYZ.Matrix[2 + 1 * 4] = 1.0f;
 		swapYZ.Matrix[3 + 3 * 4] = 1.0f;
 
-		PolyTriangleDrawer::SetTransform(Thread->DrawQueue, Thread->FrameMemory->NewObject<Mat4f>(Thread->Viewport->WorldToClip * swapYZ * ObjectToWorld));
+		PolyTriangleDrawer::SetTransform(Thread->DrawQueue, Thread->FrameMemory->NewObject<Mat4f>((*WorldToClip) * swapYZ * ObjectToWorld));
 	}
 
 	void SWModelRenderer::DrawArrays(int start, int count)

src/swrenderer/things/r_model.h

@@ -47,12 +47,14 @@ namespace swrenderer
 		float x, y, z;
 		FSpriteModelFrame *smf;
 		AActor *actor;
+		Mat4f WorldToClip;
+		bool MirrorWorldToClip;
 	};
 
 	class SWModelRenderer : public FModelRenderer
 	{
 	public:
-		SWModelRenderer(RenderThread *thread, Fake3DTranslucent clip3DFloor);
+		SWModelRenderer(RenderThread *thread, Fake3DTranslucent clip3DFloor, Mat4f *worldToClip, bool mirrorWorldToClip);
 
 		ModelRendererType GetType() const override { return SWModelRendererType; }
 
@@ -81,6 +83,8 @@ namespace swrenderer
 		unsigned int *IndexBuffer = nullptr;
 		TriVertex *VertexBuffer = nullptr;
 		float InterpolationFactor = 0.0;
+		Mat4f *WorldToClip = nullptr;
+		bool MirrorWorldToClip = false;
 	};
 
 	class SWModelVertexBuffer : public IModelVertexBuffer

src/swrenderer/viewport/r_viewport.cpp

@@ -62,6 +62,10 @@ namespace swrenderer
 	void RenderViewport::SetupPolyViewport(RenderThread *thread)
 	{
 		WorldToView = SoftwareWorldToView(viewpoint);
+
+		if (thread->Portal->MirrorFlags & RF_XFLIP)
+			WorldToView = Mat4f::Scale(-1.0f, 1.0f, 1.0f) * WorldToView;
+
 		ViewToClip = SoftwareViewToClip();
 		WorldToClip = ViewToClip * WorldToView;
 	}