mesa: Push the shine table into the tnl module.

All users of the shine table outside of the tnl module
are gone. Move the implementation into the tnl module and
prefix the public functions with _tnl.

Reviewed-by: Alex Deucher <[email protected]>
Reviewed-by: Brian Paul <[email protected]>
Signed-off-by: Mathias Froehlich <[email protected]>

1 files changed, 132 insertions, 2 deletions

diff --git a/src/mesa/tnl/t_vb_light.c b/src/mesa/tnl/t_vb_light.c
index 3acedf6e577..39467fac731 100644
--- a/src/mesa/tnl/t_vb_light.c
+++ b/src/mesa/tnl/t_vb_light.c
@@ -36,6 +36,7 @@
 
 #include "t_context.h"
 #include "t_pipeline.h"
+#include "tnl.h"
 
 #define LIGHT_TWOSIDE       0x1
 #define LIGHT_MATERIAL      0x2
@@ -76,6 +77,114 @@ struct light_stage_data {
 
 
 
+/**********************************************************************/
+/*****                  Lighting computation                      *****/
+/**********************************************************************/
+
+
+/*
+ * Notes:
+ *   When two-sided lighting is enabled we compute the color (or index)
+ *   for both the front and back side of the primitive.  Then, when the
+ *   orientation of the facet is later learned, we can determine which
+ *   color (or index) to use for rendering.
+ *
+ *   KW: We now know orientation in advance and only shade for
+ *       the side or sides which are actually required.
+ *
+ * Variables:
+ *   n = normal vector
+ *   V = vertex position
+ *   P = light source position
+ *   Pe = (0,0,0,1)
+ *
+ * Precomputed:
+ *   IF P[3]==0 THEN
+ *       // light at infinity
+ *       IF local_viewer THEN
+ *           _VP_inf_norm = unit vector from V to P      // Precompute
+ *       ELSE
+ *           // eye at infinity
+ *           _h_inf_norm = Normalize( VP + <0,0,1> )     // Precompute
+ *       ENDIF
+ *   ENDIF
+ *
+ * Functions:
+ *   Normalize( v ) = normalized vector v
+ *   Magnitude( v ) = length of vector v
+ */
+
+
+
+static void
+validate_shine_table( struct gl_context *ctx, GLuint side, GLfloat shininess )
+{
+   TNLcontext *tnl = TNL_CONTEXT(ctx);
+   struct tnl_shine_tab *list = tnl->_ShineTabList;
+   struct tnl_shine_tab *s;
+
+   ASSERT(side < 2);
+
+   foreach(s, list)
+      if ( s->shininess == shininess )
+	 break;
+
+   if (s == list) {
+      GLint j;
+      GLfloat *m;
+
+      foreach(s, list)
+	 if (s->refcount == 0)
+	    break;
+
+      m = s->tab;
+      m[0] = 0.0;
+      if (shininess == 0.0) {
+	 for (j = 1 ; j <= SHINE_TABLE_SIZE ; j++)
+	    m[j] = 1.0;
+      }
+      else {
+	 for (j = 1 ; j < SHINE_TABLE_SIZE ; j++) {
+            GLdouble t, x = j / (GLfloat) (SHINE_TABLE_SIZE - 1);
+            if (x < 0.005) /* underflow check */
+               x = 0.005;
+            t = pow(x, shininess);
+	    if (t > 1e-20)
+	       m[j] = (GLfloat) t;
+	    else
+	       m[j] = 0.0;
+	 }
+	 m[SHINE_TABLE_SIZE] = 1.0;
+      }
+
+      s->shininess = shininess;
+   }
+
+   if (tnl->_ShineTable[side])
+      tnl->_ShineTable[side]->refcount--;
+
+   tnl->_ShineTable[side] = s;
+   move_to_tail( list, s );
+   s->refcount++;
+}
+
+
+void
+_tnl_validate_shine_tables( struct gl_context *ctx )
+{
+   TNLcontext *tnl = TNL_CONTEXT(ctx);
+   GLfloat shininess;
+   
+   shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
+   if (!tnl->_ShineTable[0] || tnl->_ShineTable[0]->shininess != shininess)
+      validate_shine_table( ctx, 0, shininess );
+
+   shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_SHININESS][0];
+   if (!tnl->_ShineTable[1] || tnl->_ShineTable[1]->shininess != shininess)
+      validate_shine_table( ctx, 1, shininess );
+}
+
+
 /**
  * In the case of colormaterial, the effected material attributes
  * should already have been bound to point to the incoming color data,
@@ -101,7 +210,7 @@ update_materials(struct gl_context *ctx, struct light_stage_data *store)
    /* XXX we should only call this if we're tracking/changing the specular
     * exponent.
     */
-   _mesa_validate_all_lighting_tables( ctx );
+   _tnl_validate_shine_tables( ctx );
 }
 
 
@@ -149,11 +258,32 @@ prepare_materials(struct gl_context *ctx,
    /* FIXME: Is this already done?
     */
    _mesa_update_material( ctx, ~0 );
-   _mesa_validate_all_lighting_tables( ctx );
+
+   _tnl_validate_shine_tables( ctx );
 
    return store->mat_count;
 }
 
+/*
+ * Compute dp ^ SpecularExponent.
+ * Lerp between adjacent values in the f(x) lookup table, giving a
+ * continuous function, with adequate overall accuracy.  (Though still
+ * pretty good compared to a straight lookup).
+ */
+static inline GLfloat
+lookup_shininess(const struct gl_context *ctx, GLuint face, GLfloat dp)
+{
+   TNLcontext *tnl = TNL_CONTEXT(ctx);
+   const struct tnl_shine_tab *tab = tnl->_ShineTable[face];
+   float f = dp * (SHINE_TABLE_SIZE - 1);
+   int k = (int) f;
+   if (k < 0 /* gcc may cast an overflow float value to negative int value */
+	|| k > SHINE_TABLE_SIZE - 2)
+      return powf(dp, tab->shininess);
+   else
+      return tab->tab[k] + (f - k) * (tab->tab[k+1] - tab->tab[k]);
+}
+
 /* Tables for all the shading functions.
  */
 static light_func _tnl_light_tab[MAX_LIGHT_FUNC];