- Simplify ProjectedWallLight light step setup and positioning

src/swrenderer/line/r_line.cpp

@@ -490,8 +490,8 @@ namespace swrenderer
 							draw_segment->iscalestep = 0;
 						}
 					}
-					draw_segment->light = mLight.lightleft + mLight.lightstep * (start - WallC.sx1);
+					draw_segment->light = mLight.GetLightPos(start);
-					draw_segment->lightstep = mLight.lightstep;
+					draw_segment->lightstep = mLight.GetLightStep();
 
 					// Masked mMiddlePart.Textures should get the light level from the sector they reference,
 					// not from the current subsector, which is what the current lightlevel value
@@ -552,7 +552,7 @@ namespace swrenderer
 		// [ZZ] Only if not an active mirror
 		if (!markportal)
 		{
-			RenderDecal::RenderDecals(Thread, mLineSegment->sidedef, draw_segment, mLineSegment, WallC, mLight, walltop.ScreenY, wallbottom.ScreenY, false);
+			RenderDecal::RenderDecals(Thread, mLineSegment->sidedef, draw_segment, mLineSegment, mLight, walltop.ScreenY, wallbottom.ScreenY, false);
 		}
 
 		if (markportal)
@@ -786,18 +786,7 @@ namespace swrenderer
 
 			walltexcoords.Project(Thread->Viewport.get(), sidedef->TexelLength * lwallscale, WallC.sx1, WallC.sx2, WallT);
 
-			CameraLight *cameraLight = CameraLight::Instance();
+			mLight.SetLightLeft(Thread, mLineSegment, mFrontSector, WallC);
-			if (cameraLight->FixedColormap() == nullptr && cameraLight->FixedLightLevel() < 0)
-			{
-				mLight.lightlevel = mLineSegment->sidedef->GetLightLevel(mLight.foggy, mFrontSector->lightlevel);
-				mLight.lightleft = float(Thread->Light->WallVis(WallC.sz1, mLight.foggy));
-				mLight.lightstep = float((Thread->Light->WallVis(WallC.sz2, mLight.foggy) - mLight.lightleft) / (WallC.sx2 - WallC.sx1));
-			}
-			else
-			{
-				mLight.lightleft = 1;
-				mLight.lightstep = 0;
-			}
 		}
 	}
 
@@ -1164,8 +1153,6 @@ namespace swrenderer
 			offset = -offset;
 		}
 
-		mLight.light = mLight.lightleft + mLight.lightstep * (x1 - WallC.sx1);
-
 		RenderWallPart renderWallpart(Thread);
 		renderWallpart.Render(mFrontSector, mLineSegment, WallC, rw_pic, x1, x2, walltop.ScreenY, wallupper.ScreenY, mTopPart.TextureMid, walltexcoords.VStep, walltexcoords.UPos, yscale, MAX(mFrontCeilingZ1, mFrontCeilingZ2), MIN(mBackCeilingZ1, mBackCeilingZ2), false, false, OPAQUE, offset, mLight, GetLightList());
 	}
@@ -1197,8 +1184,6 @@ namespace swrenderer
 			offset = -offset;
 		}
 
-		mLight.light = mLight.lightleft + mLight.lightstep * (x1 - WallC.sx1);
-
 		RenderWallPart renderWallpart(Thread);
 		renderWallpart.Render(mFrontSector, mLineSegment, WallC, rw_pic, x1, x2, walltop.ScreenY, wallbottom.ScreenY, mMiddlePart.TextureMid, walltexcoords.VStep, walltexcoords.UPos, yscale, MAX(mFrontCeilingZ1, mFrontCeilingZ2), MIN(mFrontFloorZ1, mFrontFloorZ2), false, false, OPAQUE, offset, mLight, GetLightList());
 	}
@@ -1231,8 +1216,6 @@ namespace swrenderer
 			offset = -offset;
 		}
 
-		mLight.light = mLight.lightleft + mLight.lightstep * (x1 - WallC.sx1);
-
 		RenderWallPart renderWallpart(Thread);
 		renderWallpart.Render(mFrontSector, mLineSegment, WallC, rw_pic, x1, x2, walllower.ScreenY, wallbottom.ScreenY, mBottomPart.TextureMid, walltexcoords.VStep, walltexcoords.UPos, yscale, MAX(mBackFloorZ1, mBackFloorZ2), MIN(mFrontFloorZ1, mFrontFloorZ2), false, false, OPAQUE, offset, mLight, GetLightList());
 	}

src/swrenderer/line/r_renderdrawsegment.cpp

@@ -83,8 +83,7 @@ namespace swrenderer
 		mLight.basecolormap = GetColorTable(sec->Colormap, sec->SpecialColors[sector_t::walltop]);	// [RH] Set basecolormap
 		mLight.foggy = ds->foggy;
 		mLight.lightlevel = ds->lightlevel;
-		mLight.lightstep = ds->lightstep;
+		mLight.SetLightLeft(ds->light, ds->lightstep, ds->x1);
-		mLight.light = ds->light + (x1 - ds->x1) * mLight.lightstep;
 
 		Clip3DFloors *clip3d = Thread->Clip3D.get();
 
@@ -122,7 +121,7 @@ namespace swrenderer
 			const short *mceilingclip = ds->sprtopclip - ds->x1;
 
 			RenderFogBoundary renderfog;
-			renderfog.Render(Thread, x1, x2, mceilingclip, mfloorclip, mLight.lightlevel, ds->foggy, mLight.light, mLight.lightstep, mLight.basecolormap);
+			renderfog.Render(Thread, x1, x2, mceilingclip, mfloorclip, mLight.lightlevel, ds->foggy, mLight.GetLightPos(x1), mLight.GetLightStep(), mLight.basecolormap);
 
 			if (ds->maskedtexturecol == nullptr)
 				renderwall = false;
@@ -316,10 +315,11 @@ namespace swrenderer
 			if (visible)
 			{
 				Thread->PrepareTexture(tex, renderstyle);
+				float lightpos = mLight.GetLightPos(x1);
 				for (int x = x1; x < x2; ++x)
 				{
 					if (needslight)
-						columndrawerargs.SetLight(mLight.light, mLight.lightlevel, mLight.foggy, Thread->Viewport.get());
+						columndrawerargs.SetLight(lightpos, mLight.lightlevel, mLight.foggy, Thread->Viewport.get());
 
 					fixed_t iscale = xs_Fix<16>::ToFix(MaskedSWall[x] * MaskedScaleY);
 					double sprtopscreen;
@@ -330,7 +330,7 @@ namespace swrenderer
 
 					columndrawerargs.DrawMaskedColumn(Thread, x, iscale, tex, maskedtexturecol[x], spryscale, sprtopscreen, sprflipvert, mfloorclip, mceilingclip, renderstyle);
 
-					mLight.light += mLight.lightstep;
+					lightpos += mLight.GetLightStep();
 					spryscale += rw_scalestep;
 				}
 			}
@@ -415,8 +415,7 @@ namespace swrenderer
 		if (Alpha <= 0)
 			return;
 
-		mLight.lightstep = ds->lightstep;
+		mLight.SetLightLeft(ds->light, ds->lightstep, ds->x1);
-		mLight.light = ds->light + (x1 - ds->x1) * mLight.lightstep;
 
 		const short *mfloorclip = ds->sprbottomclip - ds->x1;
 		const short *mceilingclip = ds->sprtopclip - ds->x1;
@@ -502,7 +501,7 @@ namespace swrenderer
 		RenderWallPart renderWallpart(Thread);
 		renderWallpart.Render(frontsector, curline, WallC, rw_pic, x1, x2, wallupper.ScreenY, walllower.ScreenY, texturemid, MaskedSWall, walltexcoords.UPos, yscale, top, bot, true, (rover->flags & FF_ADDITIVETRANS) != 0, Alpha, rw_offset, mLight, nullptr);
 
-		RenderDecal::RenderDecals(Thread, curline->sidedef, ds, curline, WallC, mLight, wallupper.ScreenY, walllower.ScreenY, true);
+		RenderDecal::RenderDecals(Thread, curline->sidedef, ds, curline, mLight, wallupper.ScreenY, walllower.ScreenY, true);
 	}
 
 	// kg3D - walls of fake floors

src/swrenderer/line/r_walldraw.cpp

@@ -368,8 +368,8 @@ namespace swrenderer
 
 		double xmagnitude = 1.0;
 
-		float curlight = mLight.light;
+		float curlight = mLight.GetLightPos(x1);
-		for (int x = x1; x < x2; x++, curlight += mLight.lightstep)
+		for (int x = x1; x < x2; x++, curlight += mLight.GetLightStep())
 		{
 			int y1 = uwal[x];
 			int y2 = dwal[x];

src/swrenderer/line/r_wallsetup.cpp

@@ -241,4 +241,24 @@ namespace swrenderer
 			}
 		}
 	}
+
+	/////////////////////////////////////////////////////////////////////////
+
+	void ProjectedWallLight::SetLightLeft(RenderThread *thread, seg_t *lineseg, sector_t *frontsector, const FWallCoords &wallc)
+	{
+		x1 = wallc.sx1;
+
+		CameraLight *cameraLight = CameraLight::Instance();
+		if (cameraLight->FixedColormap() == nullptr && cameraLight->FixedLightLevel() < 0)
+		{
+			lightlevel = lineseg->sidedef->GetLightLevel(foggy, frontsector->lightlevel);
+			lightleft = float(thread->Light->WallVis(wallc.sz1, foggy));
+			lightstep = float((thread->Light->WallVis(wallc.sz2, foggy) - lightleft) / (wallc.sx2 - wallc.sx1));
+		}
+		else
+		{
+			lightleft = 1;
+			lightstep = 0;
+		}
+	}
 }

src/swrenderer/line/r_wallsetup.h

@@ -64,8 +64,15 @@ namespace swrenderer
 		bool foggy;
 		FDynamicColormap *basecolormap;
 
+		float GetLightPos(int x) const { return lightleft + lightstep * (x - x1); }
+		float GetLightStep() const { return lightstep; }
+
+		void SetLightLeft(float left, float step, int startx) { lightleft = left; lightstep = step; x1 = startx; }
+		void SetLightLeft(RenderThread *thread, seg_t *lineseg, sector_t *frontsector, const FWallCoords &wallc);
+
+	private:
+		int x1;
 		float lightleft;
 		float lightstep;
-		float light;
 	};
 }

src/swrenderer/things/r_decal.cpp

@@ -57,15 +57,15 @@ EXTERN_CVAR(Bool, r_fullbrightignoresectorcolor);
 
 namespace swrenderer
 {
-	void RenderDecal::RenderDecals(RenderThread *thread, side_t *sidedef, DrawSegment *draw_segment, seg_t *curline, const FWallCoords &wallC, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass)
+	void RenderDecal::RenderDecals(RenderThread *thread, side_t *sidedef, DrawSegment *draw_segment, seg_t *curline, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass)
 	{
 		for (DBaseDecal *decal = sidedef->AttachedDecals; decal != NULL; decal = decal->WallNext)
 		{
-			Render(thread, sidedef, decal, draw_segment, curline, wallC, light, walltop, wallbottom, drawsegPass);
+			Render(thread, sidedef, decal, draw_segment, curline, light, walltop, wallbottom, drawsegPass);
 		}
 	}
 
-	void RenderDecal::Render(RenderThread *thread, side_t *wall, DBaseDecal *decal, DrawSegment *clipper, seg_t *curline, const FWallCoords &savecoord, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass)
+	void RenderDecal::Render(RenderThread *thread, side_t *wall, DBaseDecal *decal, DrawSegment *clipper, seg_t *curline, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass)
 	{
 		DVector2 decal_left, decal_right, decal_pos;
 		int x1, x2;
@@ -264,7 +264,7 @@ namespace swrenderer
 			usecolormap = GetSpecialLights(usecolormap->Color, 0, usecolormap->Desaturate);
 		}
 
-		float lightpos = light.lightleft + (x1 - savecoord.sx1) * light.lightstep;
+		float lightpos = light.GetLightPos(x1);
 
 		cameraLight = CameraLight::Instance();
 
@@ -303,7 +303,7 @@ namespace swrenderer
 						drawerargs.SetLight(lightpos, light.lightlevel, light.foggy, thread->Viewport.get());
 					}
 					DrawColumn(thread, drawerargs, x, WallSpriteTile, walltexcoords, texturemid, maskedScaleY, sprflipvert, mfloorclip, mceilingclip, decal->RenderStyle);
-					lightpos += light.lightstep;
+					lightpos += light.GetLightStep();
 					x++;
 				}
 			}

src/swrenderer/things/r_decal.h

@@ -12,10 +12,10 @@ namespace swrenderer
 	class RenderDecal
 	{
 	public:
-		static void RenderDecals(RenderThread *thread, side_t *wall, DrawSegment *draw_segment, seg_t *curline, const FWallCoords &wallC, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass);
+		static void RenderDecals(RenderThread *thread, side_t *wall, DrawSegment *draw_segment, seg_t *curline, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass);
 
 	private:
-		static void Render(RenderThread *thread, side_t *wall, DBaseDecal *first, DrawSegment *clipper, seg_t *curline, const FWallCoords &wallC, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass);
+		static void Render(RenderThread *thread, side_t *wall, DBaseDecal *first, DrawSegment *clipper, seg_t *curline, const ProjectedWallLight &light, const short *walltop, const short *wallbottom, bool drawsegPass);
 		static void DrawColumn(RenderThread *thread, SpriteDrawerArgs &drawerargs, int x, FSoftwareTexture *WallSpriteTile, const ProjectedWallTexcoords &walltexcoords, double texturemid, float maskedScaleY, bool sprflipvert, const short *mfloorclip, const short *mceilingclip, FRenderStyle style);
 	};
 }