light equalizing: minimum ambient level feature (prevents dark players in diffuselit...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@9426 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/gl_rmain.c b/gl_rmain.c
index 887b4ad564520afc99adf163121d03089d70ece7..9cc5d0df1d0dd509190319ff63bd0d47185ce34e 100644 (file)
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -46,8 +46,9 @@ cvar_t r_motionblur_randomize = {CVAR_SAVE, "r_motionblur_randomize", "0.1", "ra
 
 // TODO do we want a r_equalize_entities cvar that works on all ents, or would that be a cheat?
 cvar_t r_equalize_entities_fullbright = {CVAR_SAVE, "r_equalize_entities_fullbright", "0", "render fullbright entities by equalizing their lightness, not by not rendering light"};
-cvar_t r_equalize_entities_by = {CVAR_SAVE, "r_equalize_entities_by", "0.7", "equalize entity lighting (exponent)"};
-cvar_t r_equalize_entities_to = {CVAR_SAVE, "r_equalize_entities_to", "0.8", "equalize entity lighting (level)"};
+cvar_t r_equalize_entities_minambient = {CVAR_SAVE, "r_equalize_entities_minambient", "1", "light equalizing: ensure at least this ambient/diffuse ratio"};
+cvar_t r_equalize_entities_by = {CVAR_SAVE, "r_equalize_entities_by", "0.7", "light equalizing: exponent of dynamics compression (0 = no compression, 1 = full compression)"};
+cvar_t r_equalize_entities_to = {CVAR_SAVE, "r_equalize_entities_to", "0.8", "light equalizing: target light level"};
 
 cvar_t r_animcache = {CVAR_SAVE, "r_animcache", "1", "cache animation frames to save CPU usage, primarily optimizes shadows and reflections"};
 
@@ -2832,6 +2833,7 @@ void GL_Main_Init(void)
        Cvar_RegisterVariable(&r_motionblur_randomize);
        Cvar_RegisterVariable(&r_damageblur);
        Cvar_RegisterVariable(&r_equalize_entities_fullbright);
+       Cvar_RegisterVariable(&r_equalize_entities_minambient);
        Cvar_RegisterVariable(&r_equalize_entities_by);
        Cvar_RegisterVariable(&r_equalize_entities_to);
        Cvar_RegisterVariable(&r_animcache);
@@ -3233,7 +3235,7 @@ static void R_View_UpdateEntityLighting (void)
        int i;
        entity_render_t *ent;
        vec3_t tempdiffusenormal, avg;
-       vec_t f;
+       vec_t f, fa, fd, fdd;
 
        for (i = 0;i < r_refdef.scene.numentities;i++)
        {
@@ -3262,15 +3264,45 @@ static void R_View_UpdateEntityLighting (void)
                        vec3_t org;
                        Matrix4x4_OriginFromMatrix(&ent->matrix, org);
                        r_refdef.scene.worldmodel->brush.LightPoint(r_refdef.scene.worldmodel, org, ent->modellight_ambient, ent->modellight_diffuse, tempdiffusenormal);
-                       if(r_equalize_entities_by.value != 0 && r_equalize_entities_to.value != 0 && (ent->flags & RENDER_EQUALIZE))
+                       if(ent->flags & RENDER_EQUALIZE)
                        {
-                               VectorMA(ent->modellight_ambient, 0.25f, ent->modellight_diffuse, avg);
-                               f = 0.299f * avg[0] + 0.587f * avg[1] + 0.114f * avg[2];
-                               if(f > 0)
+                               // first fix up ambient lighting...
+                               if(r_equalize_entities_minambient.value > 0)
                                {
-                                       f = pow(f / r_equalize_entities_to.value, -r_equalize_entities_by.value);
-                                       VectorScale(ent->modellight_ambient, f, ent->modellight_ambient);
-                                       VectorScale(ent->modellight_diffuse, f, ent->modellight_diffuse);
+                                       fd = 0.299f * ent->modellight_diffuse[0] + 0.587f * ent->modellight_diffuse[1] + 0.114f * ent->modellight_diffuse[2];
+                                       if(fd > 0)
+                                       {
+                                               fa = (0.299f * ent->modellight_ambient[0] + 0.587f * ent->modellight_ambient[1] + 0.114f * ent->modellight_ambient[2]);
+                                               if(fa < r_equalize_entities_minambient.value * fd)
+                                               {
+                                                       // solve:
+                                                       //   fa'/fd' = minambient
+                                                       //   fa'+0.25*fd' = fa+0.25*fd
+                                                       //   ...
+                                                       //   fa' = fd' * minambient
+                                                       //   fd'*(0.25+minambient) = fa+0.25*fd
+                                                       //   ...
+                                                       //   fd' = (fa+0.25*fd) * 1 / (0.25+minambient)
+                                                       //   fa' = (fa+0.25*fd) * minambient / (0.25+minambient)
+                                                       //   ...
+                                                       fdd = (fa + 0.25f * fd) / (0.25f + r_equalize_entities_minambient.value);
+                                                       f = fdd / fd; // f>0 because all this is additive; f<1 because fdd<fd because this follows from fa < r_equalize_entities_minambient.value * fd
+                                                       VectorMA(ent->modellight_ambient, (1-f)*0.25f, ent->modellight_diffuse, ent->modellight_ambient);
+                                                       VectorScale(ent->modellight_diffuse, f, ent->modellight_diffuse);
+                                               }
+                                       }
+                               }
+
+                               if(r_equalize_entities_to.value > 0 && r_equalize_entities_by.value != 0)
+                               {
+                                       VectorMA(ent->modellight_ambient, 0.25f, ent->modellight_diffuse, avg);
+                                       f = 0.299f * avg[0] + 0.587f * avg[1] + 0.114f * avg[2];
+                                       if(f > 0)
+                                       {
+                                               f = pow(f / r_equalize_entities_to.value, -r_equalize_entities_by.value);
+                                               VectorScale(ent->modellight_ambient, f, ent->modellight_ambient);
+                                               VectorScale(ent->modellight_diffuse, f, ent->modellight_diffuse);
+                                       }
                                }
                        }
                }