mesa: remove gl_light::_SpotExpTable field

Just use pow() instead.  Spot lights aren't too common and fixed-function
lighting isn't as important as it used to me.

This saves 32KB per context.  Each table was 4KB and there's 8 lights.

6 files changed, 4 insertions, 68 deletions

diff --git a/src/mesa/main/light.c b/src/mesa/main/light.c
index bf4bee3d696..39a984b1f19 100644
--- a/src/mesa/main/light.c
+++ b/src/mesa/main/light.c
@@ -154,7 +154,6 @@ _mesa_light(struct gl_context *ctx, GLuint lnum, GLenum pname, const GLfloat *pa
 	 return;
       FLUSH_VERTICES(ctx, _NEW_LIGHT);
       light->SpotExponent = params[0];
-      _mesa_invalidate_spot_exp_table(light);
       break;
    case GL_SPOT_CUTOFF:
       ASSERT(params[0] == 180.0 || (params[0] >= 0.0 && params[0] <= 90.0));
@@ -911,46 +910,6 @@ _mesa_GetMaterialiv( GLenum face, GLenum pname, GLint *params )
 
 
 
-/*
- * Whenever the spotlight exponent for a light changes we must call
- * this function to recompute the exponent lookup table.
- */
-void
-_mesa_invalidate_spot_exp_table( struct gl_light *l )
-{
-   l->_SpotExpTable[0][0] = -1;
-}
-
-
-static void
-validate_spot_exp_table( struct gl_light *l )
-{
-   GLint i;
-   GLdouble exponent = l->SpotExponent;
-   GLdouble tmp = 0;
-   GLint clamp = 0;
-
-   l->_SpotExpTable[0][0] = 0.0;
-
-   for (i = EXP_TABLE_SIZE - 1; i > 0 ;i--) {
-      if (clamp == 0) {
-	 tmp = pow(i / (GLdouble) (EXP_TABLE_SIZE - 1), exponent);
-	 if (tmp < FLT_MIN * 100.0) {
-	    tmp = 0.0;
-	    clamp = 1;
-	 }
-      }
-      l->_SpotExpTable[i][0] = (GLfloat) tmp;
-   }
-   for (i = 0; i < EXP_TABLE_SIZE - 1; i++) {
-      l->_SpotExpTable[i][1] = (l->_SpotExpTable[i+1][0] -
-				l->_SpotExpTable[i][0]);
-   }
-   l->_SpotExpTable[EXP_TABLE_SIZE-1][1] = 0.0;
-}
-
-
-
 /* Calculate a new shine table.  Doing this here saves a branch in
  * lighting, and the cost of doing it early may be partially offset
  * by keeping a MRU cache of shine tables for various shine values.
@@ -1020,7 +979,6 @@ validate_shine_table( struct gl_context *ctx, GLuint side, GLfloat shininess )
 void
 _mesa_validate_all_lighting_tables( struct gl_context *ctx )
 {
-   GLuint i;
    GLfloat shininess;
    
    shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
@@ -1030,10 +988,6 @@ _mesa_validate_all_lighting_tables( struct gl_context *ctx )
    shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_SHININESS][0];
    if (!ctx->_ShineTable[1] || ctx->_ShineTable[1]->shininess != shininess)
       validate_shine_table( ctx, 1, shininess );
-
-   for (i = 0; i < ctx->Const.MaxLights; i++)
-      if (ctx->Light.Light[i]._SpotExpTable[0][0] == -1)
-	 validate_spot_exp_table( &ctx->Light.Light[i] );
 }
 
 
@@ -1180,11 +1134,8 @@ compute_light_positions( struct gl_context *ctx )
 					light->_NormSpotDirection);
 
 	    if (PV_dot_dir > light->_CosCutoff) {
-	       double x = PV_dot_dir * (EXP_TABLE_SIZE-1);
-	       int k = (int) x;
 	       light->_VP_inf_spot_attenuation =
-		  (GLfloat) (light->_SpotExpTable[k][0] +
-		   (x-k)*light->_SpotExpTable[k][1]);
+                  powf(PV_dot_dir, light->SpotExponent);
 	    }
 	    else {
 	       light->_VP_inf_spot_attenuation = 0;
@@ -1303,7 +1254,6 @@ init_light( struct gl_light *l, GLuint n )
    ASSIGN_4V( l->EyePosition, 0.0, 0.0, 1.0, 0.0 );
    ASSIGN_3V( l->SpotDirection, 0.0, 0.0, -1.0 );
    l->SpotExponent = 0.0;
-   _mesa_invalidate_spot_exp_table( l );
    l->SpotCutoff = 180.0;
    l->_CosCutoffNeg = -1.0f;
    l->_CosCutoff = 0.0;		/* KW: -ve values not admitted */
diff --git a/src/mesa/main/light.h b/src/mesa/main/light.h
index 9b66c7ed853..8b19e63a9c1 100644
--- a/src/mesa/main/light.h
+++ b/src/mesa/main/light.h
@@ -110,8 +110,6 @@ extern GLuint _mesa_material_bitmask( struct gl_context *ctx,
                                       GLuint legal,
                                       const char * );
 
-extern void _mesa_invalidate_spot_exp_table( struct gl_light *l );
-
 extern void _mesa_invalidate_shine_table( struct gl_context *ctx, GLuint i );
 
 extern void _mesa_validate_all_lighting_tables( struct gl_context *ctx );
@@ -135,7 +133,6 @@ extern void _mesa_allow_light_in_model( struct gl_context *ctx, GLboolean flag )
 #else
 #define _mesa_update_color_material( c, r ) ((void)0)
 #define _mesa_validate_all_lighting_tables( c ) ((void)0)
-#define _mesa_invalidate_spot_exp_table( l ) ((void)0)
 #define _mesa_material_bitmask( c, f, p, l, s ) 0
 #define _mesa_init_lighting( c ) ((void)0)
 #define _mesa_free_lighting_data( c ) ((void)0)
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index ce302ca0b6a..521bb39f992 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -689,7 +689,6 @@ struct gl_light
    GLfloat _NormSpotDirection[4]; /**< normalized spotlight direction */
    GLfloat _VP_inf_spot_attenuation;
 
-   GLfloat _SpotExpTable[EXP_TABLE_SIZE][2];  /**< to replace a pow() call */
    GLfloat _MatAmbient[2][3];	/**< material ambient * light ambient */
    GLfloat _MatDiffuse[2][3];	/**< material diffuse * light diffuse */
    GLfloat _MatSpecular[2][3];	/**< material spec * light specular */
diff --git a/src/mesa/tnl/t_rasterpos.c b/src/mesa/tnl/t_rasterpos.c
index a7e4397b660..bdd6129e727 100644
--- a/src/mesa/tnl/t_rasterpos.c
+++ b/src/mesa/tnl/t_rasterpos.c
@@ -167,10 +167,7 @@ shade_rastpos(struct gl_context *ctx,
 	       continue;
 	    }
 	    else {
-	       double x = PV_dot_dir * (EXP_TABLE_SIZE-1);
-	       int k = (int) x;
-	       GLfloat spot = (GLfloat) (light->_SpotExpTable[k][0]
-			       + (x-k)*light->_SpotExpTable[k][1]);
+               GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
 	       attenuation *= spot;
 	    }
 	 }
diff --git a/src/mesa/tnl/t_vb_lighttmp.h b/src/mesa/tnl/t_vb_lighttmp.h
index aae1d18ff7f..0b8c314685e 100644
--- a/src/mesa/tnl/t_vb_lighttmp.h
+++ b/src/mesa/tnl/t_vb_lighttmp.h
@@ -147,10 +147,7 @@ static void TAG(light_rgba_spec)( struct gl_context *ctx,
 		  continue; /* this light makes no contribution */
 	       }
 	       else {
-		  GLdouble x = PV_dot_dir * (EXP_TABLE_SIZE-1);
-		  GLint k = (GLint) x;
-		  GLfloat spot = (GLfloat) (light->_SpotExpTable[k][0]
-				    + (x-k)*light->_SpotExpTable[k][1]);
+                  GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
 		  attenuation *= spot;
 	       }
 	    }
@@ -331,10 +328,7 @@ static void TAG(light_rgba)( struct gl_context *ctx,
 		  continue; /* this light makes no contribution */
 	       }
 	       else {
-		  GLdouble x = PV_dot_dir * (EXP_TABLE_SIZE-1);
-		  GLint k = (GLint) x;
-		  GLfloat spot = (GLfloat) (light->_SpotExpTable[k][0]
-				  + (x-k)*light->_SpotExpTable[k][1]);
+                  GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
 		  attenuation *= spot;
 	       }
 	    }
diff --git a/src/mesa/x86/gen_matypes.c b/src/mesa/x86/gen_matypes.c
index 97f71f92cea..7af82b4aea6 100644
--- a/src/mesa/x86/gen_matypes.c
+++ b/src/mesa/x86/gen_matypes.c
@@ -209,7 +209,6 @@ int main( int argc, char **argv )
    OFFSET( "LIGHT_NORM_DIRECTION    ", struct gl_light, _NormSpotDirection );
    OFFSET( "LIGHT_VP_INF_SPOT_ATTEN ", struct gl_light, _VP_inf_spot_attenuation );
    printf( "\n" );
-   OFFSET( "LIGHT_SPOT_EXP_TABLE    ", struct gl_light, _SpotExpTable );
    OFFSET( "LIGHT_MAT_AMBIENT       ", struct gl_light, _MatAmbient );
    OFFSET( "LIGHT_MAT_DIFFUSE       ", struct gl_light, _MatDiffuse );
    OFFSET( "LIGHT_MAT_SPECULAR      ", struct gl_light, _MatSpecular );