q3map2: add -externalnames option to write explicit external lightmap names when...

It makes possible for game engines to run less code on each rendering
frame by not doing any computation to find the file.

On some game engines it may even make the lightmaps be processed
with simpler GLSL code as they will be processed as simple colormaps
instead of more complex code purposed for usual lightmaps with
features that aren't needed in such situation anyway.

Or some engine may implement a specific GLSL code to blend multiple
colormaps in a single pass without having to implement alternate code
for lightmaps.

Example with scripts/q3map2_gloom2.shader:

```
-gloom2/7C9AD47A87BC98CCA1FF30C4D788DD47
+gloom2/72353935F9542782B847B2E329A8CC80
 { // Q3Map2 defaulted
 	{
 		map $lightmap
 		rgbGen identity
 	}

 	// Q3Map2 custom lightstyle stage(s)
 	{
-		map $lightmap
+		map maps/gloom2/lm_0000.tga
 		blendFunc GL_SRC_ALPHA GL_ONE
 		rgbGen wave noise 1 .75 1.6 4.2 // style 2
 		tcGen lightmap
 		tcMod transform 1 0 0 1 0.54492 0.10156
 	}
 	{
-		map $lightmap
+		map maps/gloom2/lm_0000.tga
 		blendFunc GL_SRC_ALPHA GL_ONE
 		rgbGen wave noise 1 .5 3.7 4.9 // style 3
 		tcGen lightmap
 		tcMod transform 1 0 0 1 -0.38672 0.19043
 	}
 	{
-		map $lightmap
+		map maps/gloom2/lm_0000.tga
 		blendFunc GL_SRC_ALPHA GL_ONE
 		rgbGen wave noise 1 1 2.6 1.3 // style 4
 		tcGen lightmap
 		tcMod transform 1 0 0 1 0.24023 0.19043
 	}

 	{
 		map textures/gloom2/e8clangfloor05c.tga
 		blendFunc GL_DST_COLOR GL_ZERO
 		rgbGen identity
 	}
 }
```

diff --git a/tools/quake3/q3map2/help.c b/tools/quake3/q3map2/help.c
index 60631e3d72f175a38c581b28a50df232ea8289ab..f21476a0b3656bb79d42ec85830efd0388a47505 100644 (file)
--- a/tools/quake3/q3map2/help.c
+++ b/tools/quake3/q3map2/help.c
@@ -215,6 +215,7 @@ void HelpLight()
                {"-export", "Export lightmaps when compile finished (like `-export` mode)"},
                {"-exposure <F>", "Lightmap exposure to better support overbright spots"},
                {"-external", "Force external lightmaps even if at size of internal lightmaps"},
+               {"-externalnames", "Write lightstyle shader using external lightmap names"},
                {"-extradist <F>", "Extra distance for lights in map units"},
                {"-extravisnudge", "Broken feature to nudge the luxel origin to a better vis cluster"},
                {"-extrawide", "Deprecated alias for `-super 2 -filter`"},

diff --git a/tools/quake3/q3map2/light.c b/tools/quake3/q3map2/light.c
index 99d794840f6787fa836f2450ea2060afc44a1b37..39e5c7adbd0826552769fcac9af8c5fb96189392 100644 (file)
--- a/tools/quake3/q3map2/light.c
+++ b/tools/quake3/q3map2/light.c
@@ -2546,6 +2546,12 @@ int LightMain( int argc, char **argv ){
                        Sys_Printf( "Storing all lightmaps externally\n" );
                }
 
+               else if ( !strcmp( argv[ i ], "-externalnames" ) ) {
+                       externalLightmaps = qtrue;
+                       externalLightmapNames = qtrue;
+                       Sys_Printf( "Writing lightstyle shader using external lightmap names\n" );
+               }
+
                else if ( !strcmp( argv[ i ], "-lightmapsize" ) ) {
                        lmCustomSize = atoi( argv[ i + 1 ] );
 

diff --git a/tools/quake3/q3map2/lightmaps_ydnar.c b/tools/quake3/q3map2/lightmaps_ydnar.c
index 37bb6da4fc5c394048ed002089a21ec9b4493982..70e59b2f36e148da80b9e57161ebde8380e01d19 100644 (file)
--- a/tools/quake3/q3map2/lightmaps_ydnar.c
+++ b/tools/quake3/q3map2/lightmaps_ydnar.c
@@ -3355,7 +3355,8 @@ void StoreSurfaceLightmaps( qboolean fastAllocate, qboolean storeForReal ){
                                        olm = &outLightmaps[ lm->outLightmapNums[ lightmapNum ] ];
 
                                        /* lightmap name */
-                                       if ( lm->outLightmapNums[ lightmapNum ] == lm->outLightmapNums[ 0 ] ) {
+                                       if ( !externalLightmapNames
+                                               && lm->outLightmapNums[ lightmapNum ] == lm->outLightmapNums[ 0 ] ) {
                                                strcpy( lightmapName, "$lightmap" );
                                        }
                                        else{

diff --git a/tools/quake3/q3map2/q3map2.h b/tools/quake3/q3map2/q3map2.h
index 5721ae255ef06c70ce98c9ce4b93de95dcea28ab..42c7121063e0134e615ed726f693033e5c183f12 100644 (file)
--- a/tools/quake3/q3map2/q3map2.h
+++ b/tools/quake3/q3map2/q3map2.h
@@ -2310,6 +2310,7 @@ Q_EXTERN qboolean noCollapse Q_ASSIGN( qfalse );
 Q_EXTERN int lightmapSearchBlockSize Q_ASSIGN( 0 );
 Q_EXTERN qboolean exportLightmaps Q_ASSIGN( qfalse );
 Q_EXTERN qboolean externalLightmaps Q_ASSIGN( qfalse );
+Q_EXTERN qboolean externalLightmapNames Q_ASSIGN( qfalse );
 Q_EXTERN int lmCustomSize Q_ASSIGN( LIGHTMAP_WIDTH );
 Q_EXTERN char *             lmCustomDir Q_ASSIGN( NULL );
 Q_EXTERN int lmLimitSize Q_ASSIGN( 0 );