diff options
| author | Keith Whitwell <keith@tungstengraphics.com> | 2000-07-13 12:54:07 +0000 |
|---|---|---|
| committer | Keith Whitwell <keith@tungstengraphics.com> | 2000-07-13 12:54:07 +0000 |
| commit | 7b0ee9f64bf8bf9c676df072b0db76aedf974cb0 (patch) | |
| tree | 59dbf5b6c70a9530a39fad0dbbe8731410b7b89f | |
| parent | 865b03207c62bc9fd4dcb552dd2567d52a251e39 (diff) | |
Two new, more accurate methods for computing shine values.
| -rw-r--r-- | src/mesa/main/light.c | 20 | ||||
| -rw-r--r-- | src/mesa/main/light.h | 4 |
2 files changed, 15 insertions, 9 deletions
diff --git a/src/mesa/main/light.c b/src/mesa/main/light.c index c9772d0781..136d7af811 100644 --- a/src/mesa/main/light.c +++ b/src/mesa/main/light.c @@ -1,4 +1,4 @@ -/* $Id: light.c,v 1.8.2.7 2000/07/12 12:02:33 keithw Exp $ */ +/* $Id: light.c,v 1.8.2.8 2000/07/13 12:54:07 keithw Exp $ */ /* * Mesa 3-D graphics library @@ -1003,11 +1003,17 @@ static void compute_shine_table( struct gl_shine_tab *tab, GLfloat shininess ) int i; GLfloat *m = tab->tab; - m[0] = pow(0, shininess); /* special case for [0,1) -- sample at zero */ - for (i = 1 ; i < SHINE_TABLE_SIZE ; i++) { - double t = pow( (i+.5)/(GLfloat)(SHINE_TABLE_SIZE-1), shininess ); + for (i = 0 ; i < SHINE_TABLE_SIZE ; i++) { + double dp = i/(GLfloat)(SHINE_TABLE_SIZE-1); + double t = pow( dp, shininess ); if (t < 1e-20) t = 0; - m[i] = (GLfloat) t; + m[i*2] = (GLfloat) t; + + /* Also calculate the derivative of dp^shininess at this point, + scaling for table lookup. (Actually, given f'(x0), it's easy + to calculate f(x0), so maybe we only need this) + */ + m[i*2+1] = shininess * t / (dp * (SHINE_TABLE_SIZE-1)); } tab->shininess = shininess; @@ -1036,10 +1042,10 @@ void gl_compute_shine_table( GLcontext *ctx, GLuint i, GLfloat shininess ) foreach(s, list) if (s->refcount == 0) break; -/* compute_shine_table( s, shininess ); */ + compute_shine_table( s, shininess ); } - reset_shine_table( s, shininess ); +/* reset_shine_table( s, shininess ); */ ctx->ShineTable[i]->refcount--; ctx->ShineTable[i] = s; move_to_tail( list, s ); diff --git a/src/mesa/main/light.h b/src/mesa/main/light.h index f3f6843ea4..7377e9ec1b 100644 --- a/src/mesa/main/light.h +++ b/src/mesa/main/light.h @@ -1,4 +1,4 @@ -/* $Id: light.h,v 1.1.1.1.2.2 2000/07/12 12:02:33 keithw Exp $ */ +/* $Id: light.h,v 1.1.1.1.2.3 2000/07/13 12:54:07 keithw Exp $ */ /* * Mesa 3-D graphics library @@ -36,7 +36,7 @@ struct gl_shine_tab { struct gl_shine_tab *next, *prev; - GLfloat tab[SHINE_TABLE_SIZE]; + GLfloat tab[SHINE_TABLE_SIZE*2]; GLfloat shininess; GLuint refcount; }; |