From bbf4a9f1898772dce2053b26cb3094a7f063e510 Mon Sep 17 00:00:00 2001
From: Daniel Svensson <dsvensson@gmail.com>
Date: Thu, 24 Aug 2023 16:53:30 +0300
Subject: [PATCH] soft: LIGHTMAPS: Add support for LMSHIFT.

Could be extended to support the LMSHIFT BSPX blob. Currently mostly a
cleanup to make DECOUPLEDLM changes more readable.
---
 src/client/refresh/soft/header/model.h |  1 +
 src/client/refresh/soft/sw_light.c     | 29 +++++++++++++-------------
 src/client/refresh/soft/sw_model.c     |  1 +
 src/client/refresh/soft/sw_surf.c      |  2 +-
 4 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/src/client/refresh/soft/header/model.h b/src/client/refresh/soft/header/model.h
index 8156b417..8dd7ffc0 100644
--- a/src/client/refresh/soft/header/model.h
+++ b/src/client/refresh/soft/header/model.h
@@ -59,6 +59,7 @@ typedef struct msurface_s
 
 	short		texturemins[2];
 	short		extents[2];
+	short		lmshift;
 
 	mtexinfo_t	*texinfo;
 
diff --git a/src/client/refresh/soft/sw_light.c b/src/client/refresh/soft/sw_light.c
index caf1a715..4db6b254 100644
--- a/src/client/refresh/soft/sw_light.c
+++ b/src/client/refresh/soft/sw_light.c
@@ -141,13 +141,13 @@ RecursiveLightPoint (mnode_t *node, vec3_t start, vec3_t end, vec3_t pointcolor)
 		if (!surf->samples)
 			return 0;
 
-		ds >>= 4;
-		dt >>= 4;
+		ds >>= surf->lmshift;
+		dt >>= surf->lmshift;
 
 		lightmap = surf->samples;
 		VectorCopy (vec3_origin, pointcolor);
 
-		lightmap += 3 * (dt * ((surf->extents[0] >> 4) + 1) + ds);
+		lightmap += 3 * (dt * ((surf->extents[0] >> surf->lmshift) + 1) + ds);
 
 		for (maps = 0 ; maps < MAXLIGHTMAPS && surf->styles[maps] != 255 ;
 				maps++)
@@ -166,8 +166,8 @@ RecursiveLightPoint (mnode_t *node, vec3_t start, vec3_t end, vec3_t pointcolor)
 				pointcolor[j] += lightmap[j] * scale * (1.0 / 255);
 			}
 
-			lightmap += 3 * ((surf->extents[0] >> 4) + 1) *
-						((surf->extents[1] >> 4) + 1);
+			lightmap += 3 * ((surf->extents[0] >> surf->lmshift) + 1) *
+						((surf->extents[1] >> surf->lmshift) + 1);
 		}
 
 		return 1;
@@ -252,8 +252,8 @@ R_AddDynamicLights (drawsurf_t* drawsurf)
 	mtexinfo_t	*tex;
 
 	surf = drawsurf->surf;
-	smax = (surf->extents[0]>>4)+1;
-	tmax = (surf->extents[1]>>4)+1;
+	smax = (surf->extents[0] >> surf->lmshift) + 1;
+	tmax = (surf->extents[1] >> surf->lmshift) + 1;
 	tex = surf->texinfo;
 
 	if (blocklight_max <= blocklights + smax*tmax*3)
@@ -318,24 +318,23 @@ R_AddDynamicLights (drawsurf_t* drawsurf)
 		local[0] -= surf->texturemins[0];
 		local[1] -= surf->texturemins[1];
 
-		for (t = 0 ; t<tmax ; t++)
+		for (t = 0 ; t < tmax ; t++)
 		{
 			int s, td;
-
-			td = local[1] - t*16;
+			td = local[1] - t * (1 << surf->lmshift);
 			if (td < 0)
 				td = -td;
 			for (s=0 ; s<smax ; s++)
 			{
 				int sd;
 
-				sd = local[0] - s*16;
+				sd = local[0] - s * (1 << surf->lmshift);
 				if (sd < 0)
 					sd = -sd;
 				if (sd > td)
-					dist = sd + (td>>1);
+					dist = sd + (td >> 1);
 				else
-					dist = td + (sd>>1);
+					dist = td + (sd >> 1);
 
 				for (i=0; i<3; i++)
 				{
@@ -378,8 +377,8 @@ R_BuildLightMap (drawsurf_t* drawsurf)
 
 	surf = drawsurf->surf;
 
-	smax = (surf->extents[0]>>4)+1;
-	tmax = (surf->extents[1]>>4)+1;
+	smax = (surf->extents[0] >> surf->lmshift) + 1;
+	tmax = (surf->extents[1] >> surf->lmshift) + 1;
 	size = smax*tmax*3;
 
 	if (blocklight_max <= blocklights + size)
diff --git a/src/client/refresh/soft/sw_model.c b/src/client/refresh/soft/sw_model.c
index 7414be95..44498dc0 100644
--- a/src/client/refresh/soft/sw_model.c
+++ b/src/client/refresh/soft/sw_model.c
@@ -447,6 +447,7 @@ Mod_LoadFaces (model_t *loadmodel, byte *mod_base, lump_t *l)
 			ri.Sys_Error(ERR_DROP, "%s: bad texinfo number", __func__);
 		}
 		out->texinfo = loadmodel->texinfo + ti;
+		out->lmshift = DEFAULT_LMSHIFT;
 
 		CalcSurfaceExtents (loadmodel, out);
 
diff --git a/src/client/refresh/soft/sw_surf.c b/src/client/refresh/soft/sw_surf.c
index 32c7c10e..ffe1a87f 100644
--- a/src/client/refresh/soft/sw_surf.c
+++ b/src/client/refresh/soft/sw_surf.c
@@ -197,7 +197,7 @@ R_DrawSurface (drawsurf_t *drawsurf)
 	blocksize = 16 >> drawsurf->surfmip;
 	blockdivshift = NUM_MIPS - drawsurf->surfmip;
 
-	r_lightwidth = (drawsurf->surf->extents[0]>>4)+1;
+	r_lightwidth = (drawsurf->surf->extents[0] >> drawsurf->surf->lmshift) + 1;
 
 	r_numhblocks = drawsurf->surfwidth >> blockdivshift;
 	r_numvblocks = drawsurf->surfheight >> blockdivshift;