From caef58820a8e3982e49389c1ee74cb22d58cd859 Mon Sep 17 00:00:00 2001
From: myT <>
Date: Sun, 15 Dec 2024 20:47:10 +0100
Subject: [PATCH] fixed unlit maps forcing shader duplication

- assigning a new lightmapIndex value makes shader search fail
- fog shader duplicates don't have isFog set
---
 code/renderer/tr_bsp.cpp    | 24 +++++++++++++++++-------
 code/renderer/tr_local.h    |  2 +-
 code/renderer/tr_shader.cpp | 15 ++++++++-------
 3 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/code/renderer/tr_bsp.cpp b/code/renderer/tr_bsp.cpp
index adda9da..97a5f61 100644
--- a/code/renderer/tr_bsp.cpp
+++ b/code/renderer/tr_bsp.cpp
@@ -224,11 +224,10 @@ static void R_LoadLightmaps( const lump_t* l )
 }
 
 
-static void R_GetLightmapTransform( int* number, vec2_t scale, vec2_t bias )
+static void R_GetLightmapTransform( int* number, vec2_t scale, vec2_t bias, qbool* isBrokenOut = NULL )
 {
 	const int i = *number;
-
-	if ( i >= 0 ) {
+	if ( i >= 0 && i < MAX_LIGHTMAPS ) {
 		scale[0] = lightmapScale[0];
 		scale[1] = lightmapScale[1];
 		bias[0] = lightmapBiases[i][0];
@@ -239,9 +238,16 @@ static void R_GetLightmapTransform( int* number, vec2_t scale, vec2_t bias )
 		scale[1] = 1.0f;
 		bias[0] = 0.0f;
 		bias[1] = 0.0f;
-		if ( *number <= LIGHTMAP_2D || *number >= tr.numLightmaps )
-			*number = LIGHTMAP_BROKEN;
 	}
+
+	qbool isBroken = qfalse;
+	if ( *number <= LIGHTMAP_2D || *number >= tr.numLightmaps ) {
+		*number = LIGHTMAP_NONE;
+		isBroken = qtrue;
+	}
+
+	if ( isBrokenOut != NULL )
+		*isBrokenOut = isBroken;
 }
 
 
@@ -333,8 +339,10 @@ static void ParseFace( const dsurface_t* ds, const drawVert_t* verts, msurface_t
 	surf->fogIndex = LittleLong( ds->fogNum ) + 1;
 	int lightmapNum = LittleLong( ds->lightmapNum );
 	vec2_t lmScale, lmBias;
-	R_GetLightmapTransform( &lightmapNum, lmScale, lmBias );
+	qbool isLightmapBroken;
+	R_GetLightmapTransform( &lightmapNum, lmScale, lmBias, &isLightmapBroken );
 	shader_t* const shader = ShaderForShaderNum( ds->shaderNum, lightmapNum );
+	shader->isLightmapBroken = isLightmapBroken;
 	surf->shader = shader;
 	R_SaveLightmapTransform( shader, lmScale, lmBias );
 
@@ -419,8 +427,10 @@ static void ParseMesh( const dsurface_t* ds, const drawVert_t* verts, msurface_t
 	surf->fogIndex = LittleLong( ds->fogNum ) + 1;
 	int lightmapNum = LittleLong(ds->lightmapNum);
 	vec2_t lmScale, lmBias;
-	R_GetLightmapTransform( &lightmapNum, lmScale, lmBias );
+	qbool isLightmapBroken;
+	R_GetLightmapTransform( &lightmapNum, lmScale, lmBias, &isLightmapBroken );
 	shader_t* const shader = ShaderForShaderNum( ds->shaderNum, lightmapNum );
+	shader->isLightmapBroken = isLightmapBroken;
 	surf->shader = shader;
 	R_SaveLightmapTransform( shader, lmScale, lmBias );
 
diff --git a/code/renderer/tr_local.h b/code/renderer/tr_local.h
index 343ef25..b7f92c4 100644
--- a/code/renderer/tr_local.h
+++ b/code/renderer/tr_local.h
@@ -323,7 +323,6 @@ typedef struct {
 } shaderStage_t;
 
 
-#define LIGHTMAP_BROKEN		-4		// invalid data in the .bsp file
 #define LIGHTMAP_2D			-3		// shader is for 2D rendering
 #define LIGHTMAP_BY_VERTEX	-2		// pre-lit triangle models
 #define LIGHTMAP_NONE		-1
@@ -368,6 +367,7 @@ struct pipeline_t {
 struct shader_t {
 	char		name[MAX_QPATH];		// game path, including extension
 	int			lightmapIndex;			// for a shader to match, both name and lightmapIndex must match
+	qbool		isLightmapBroken;		// was the lightmap index broken in the .bsp file?
 
 	int			index;					// this shader == tr.shaders[index]
 	int			sortedIndex;			// this shader == tr.sortedShaders[sortedIndex]
diff --git a/code/renderer/tr_shader.cpp b/code/renderer/tr_shader.cpp
index 6578e76..e7960e2 100644
--- a/code/renderer/tr_shader.cpp
+++ b/code/renderer/tr_shader.cpp
@@ -2792,9 +2792,9 @@ shader_t* R_FindShader( const char *name, int lightmapIndex, int flags )
 	stages[0].type = ST_DIFFUSE;
 	stages[0].bundle.image[0] = image;
 
-	if ( shader.lightmapIndex == LIGHTMAP_BROKEN ) {
-		stages[0].rgbGen = CGEN_VERTEX;
-		stages[0].alphaGen = AGEN_VERTEX;
+	if ( shader.isLightmapBroken ) {
+		stages[0].rgbGen = CGEN_IDENTITY_LIGHTING;
+		stages[0].alphaGen = AGEN_SKIP;
 		stages[0].stateBits = GLS_DEFAULT;
 	} else if ( shader.lightmapIndex == LIGHTMAP_NONE ) {
 		// dynamic colors at vertexes
@@ -3024,12 +3024,13 @@ void R_ShaderInfo_f()
 		const char* type;
 		if ( sh->vlApplied ) {
 			type = "vertex-lit surface";
+		} else if ( sh->isLightmapBroken ) {
+			type = "broken lit surface";
 		} else {
 			switch ( sh->lightmapIndex ) {
-				case LIGHTMAP_BROKEN:    type = "broken lit surface"; break;
-				case LIGHTMAP_2D:        type = "UI element";         break;
-				case LIGHTMAP_NONE:      type = "opaque surface";     break;
-				default:                 type = "lit surface";        break;
+				case LIGHTMAP_2D:   type = "UI element";     break;
+				case LIGHTMAP_NONE: type = "opaque surface"; break;
+				default:            type = "lit surface";    break;
 			}
 		}
 		ri.Printf( PRINT_ALL, "shader has no code (type: %s)\n", type );