From eaefa355801f0c30dbbb58945c995aeab614389c Mon Sep 17 00:00:00 2001
From: Zack Middleton <zack@cloemail.com>
Date: Fri, 9 Feb 2024 09:48:51 -0600
Subject: [PATCH] OpenGL2: Fix merged lightmap hacks to have real lightmap
 index

This fixes the texcoord range to be 0.0 to 1.0 for external lightmaps in
shaders that also have an internal lightmap. (Instead of 2.0 to 3.0 for
example.) This only affects clampMap as repeating wrapping sampled the
correct location. I haven't found such a shader but I need to get real
lightmap index for future merged lightmap hacks.
---
 code/renderergl2/tr_bsp.c    |  6 +++---
 code/renderergl2/tr_local.h  |  1 +
 code/renderergl2/tr_shader.c | 16 +++++++++++++---
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/code/renderergl2/tr_bsp.c b/code/renderergl2/tr_bsp.c
index b316351e..15f5f3cd 100644
--- a/code/renderergl2/tr_bsp.c
+++ b/code/renderergl2/tr_bsp.c
@@ -617,7 +617,7 @@ static shader_t *ShaderForShaderNum( int shaderNum, int lightmapNum ) {
 		lightmapNum = LIGHTMAP_WHITEIMAGE;
 	}
 
-	shader = R_FindShader( dsh->shader, lightmapNum, qtrue );
+	shader = R_FindShaderEx( dsh->shader, FatLightmap( lightmapNum ), qtrue, lightmapNum );
 
 	// if the shader had errors, just use default shader
 	if ( shader->defaultShader ) {
@@ -706,7 +706,7 @@ static void ParseFace( dsurface_t *ds, drawVert_t *verts, float *hdrVertColors,
 	surf->fogIndex = LittleLong( ds->fogNum ) + 1;
 
 	// get shader value
-	surf->shader = ShaderForShaderNum( ds->shaderNum, FatLightmap(realLightmapNum) );
+	surf->shader = ShaderForShaderNum( ds->shaderNum, realLightmapNum );
 	if ( r_singleShader->integer && !surf->shader->isSky ) {
 		surf->shader = tr.defaultShader;
 	}
@@ -813,7 +813,7 @@ static void ParseMesh ( dsurface_t *ds, drawVert_t *verts, float *hdrVertColors,
 	surf->fogIndex = LittleLong( ds->fogNum ) + 1;
 
 	// get shader value
-	surf->shader = ShaderForShaderNum( ds->shaderNum, FatLightmap(realLightmapNum) );
+	surf->shader = ShaderForShaderNum( ds->shaderNum, realLightmapNum );
 	if ( r_singleShader->integer && !surf->shader->isSky ) {
 		surf->shader = tr.defaultShader;
 	}
diff --git a/code/renderergl2/tr_local.h b/code/renderergl2/tr_local.h
index 4ee61fde..6a0aa36f 100644
--- a/code/renderergl2/tr_local.h
+++ b/code/renderergl2/tr_local.h
@@ -1995,6 +1995,7 @@ const void *RB_TakeVideoFrameCmd( const void *data );
 // tr_shader.c
 //
 shader_t	*R_FindShader( const char *name, int lightmapIndex, qboolean mipRawImage );
+shader_t	*R_FindShaderEx( const char *name, int lightmapIndex, qboolean mipRawImage, int realLightmapIndex );
 shader_t	*R_GetShaderByHandle( qhandle_t hShader );
 shader_t	*R_GetShaderByState( int index, long *cycleTime );
 shader_t *R_FindShaderByName( const char *name );
diff --git a/code/renderergl2/tr_shader.c b/code/renderergl2/tr_shader.c
index 4b9fa991..cfd87f05 100644
--- a/code/renderergl2/tr_shader.c
+++ b/code/renderergl2/tr_shader.c
@@ -30,6 +30,7 @@ static char *s_shaderText;
 static	shaderStage_t	stages[MAX_SHADER_STAGES];		
 static	shader_t		shader;
 static	texModInfo_t	texMods[MAX_SHADER_STAGES][TR_MAX_TEXMODS];
+static	int				shader_realLightmapIndex;
 
 #define FILE_HASH_SIZE		1024
 static	shader_t*		hashTable[FILE_HASH_SIZE];
@@ -2929,7 +2930,7 @@ static void FixFatLightmapTexCoords(void)
 		return;
 	}
 
-	lightmapnum = shader.lightmapIndex;
+	lightmapnum = shader_realLightmapIndex;
 
 	if (tr.worldDeluxeMapping)
 		lightmapnum >>= 1;
@@ -2987,7 +2988,7 @@ static void FixFatLightmapTexCoords(void)
 InitShader
 ===============
 */
-static void InitShader( const char *name, int lightmapIndex ) {
+static void InitShaderEx( const char *name, int lightmapIndex, int realLightmapIndex ) {
 	int i;
 
 	// clear the global shader
@@ -2996,6 +2997,7 @@ static void InitShader( const char *name, int lightmapIndex ) {
 
 	Q_strncpyz( shader.name, name, sizeof( shader.name ) );
 	shader.lightmapIndex = lightmapIndex;
+	shader_realLightmapIndex = realLightmapIndex;
 
 	for ( i = 0 ; i < MAX_SHADER_STAGES ; i++ ) {
 		stages[i].bundle[0].texMods = texMods[i];
@@ -3016,6 +3018,10 @@ static void InitShader( const char *name, int lightmapIndex ) {
 	}
 }
 
+static void InitShader( const char *name, int lightmapIndex ) {
+	InitShaderEx( name, lightmapIndex, lightmapIndex );
+}
+
 /*
 =========================
 FinishShader
@@ -3337,6 +3343,10 @@ most world construction surfaces.
 ===============
 */
 shader_t *R_FindShader( const char *name, int lightmapIndex, qboolean mipRawImage ) {
+	return R_FindShaderEx( name, lightmapIndex, mipRawImage, lightmapIndex );
+}
+
+shader_t *R_FindShaderEx( const char *name, int lightmapIndex, qboolean mipRawImage, int realLightmapIndex ) {
 	char		strippedName[MAX_QPATH];
 	int			hash;
 	char		*shaderText;
@@ -3376,7 +3386,7 @@ shader_t *R_FindShader( const char *name, int lightmapIndex, qboolean mipRawImag
 		}
 	}
 
-	InitShader( strippedName, lightmapIndex );
+	InitShaderEx( strippedName, lightmapIndex, realLightmapIndex );
 
 	//
 	// attempt to define shader from an explicit parameter file