gallium: Pass per-element (not per-quad) LOD bias values down to texture sampler.

5 files changed, 123 insertions, 98 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index 6beeb9a2ca0..dcf3cc0baaf 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -1509,7 +1509,7 @@ fetch_texel( struct tgsi_sampler *sampler,
              const union tgsi_exec_channel *s,
              const union tgsi_exec_channel *t,
              const union tgsi_exec_channel *p,
-             float lodbias,  /* XXX should be float[4] */
+             const union tgsi_exec_channel *lodbias,
              union tgsi_exec_channel *r,
              union tgsi_exec_channel *g,
              union tgsi_exec_channel *b,
@@ -1518,7 +1518,7 @@ fetch_texel( struct tgsi_sampler *sampler,
    uint j;
    float rgba[NUM_CHANNELS][QUAD_SIZE];
 
-   sampler->get_samples(sampler, s->f, t->f, p->f, lodbias, rgba);
+   sampler->get_samples(sampler, s->f, t->f, p->f, lodbias->f, rgba);
 
    for (j = 0; j < 4; j++) {
       r->f[j] = rgba[0][j];
@@ -1542,21 +1542,23 @@ exec_tex(struct tgsi_exec_machine *mach,
 {
    const uint unit = inst->Src[1].Register.Index;
    union tgsi_exec_channel r[4];
+   const union tgsi_exec_channel *lodBias = &ZeroVec;
    uint chan_index;
-   float lodBias = 0.0f;
+
+   if (modifier != TEX_MODIFIER_NONE) {
+      FETCH(&r[3], 0, CHAN_W);
+      if (modifier != TEX_MODIFIER_PROJECTED) {
+         lodBias = &r[3];
+      }
+   }
 
    switch (inst->Texture.Texture) {
    case TGSI_TEXTURE_1D:
    case TGSI_TEXTURE_SHADOW1D:
       FETCH(&r[0], 0, CHAN_X);
 
-      if (modifier != TEX_MODIFIER_NONE) {
-         FETCH(&r[1], 0, CHAN_W);
-         if (modifier == TEX_MODIFIER_PROJECTED) {
-            micro_div(&r[0], &r[0], &r[1]);
-         } else {
-            lodBias = r[1].f[0];
-         }
+      if (modifier == TEX_MODIFIER_PROJECTED) {
+         micro_div(&r[0], &r[0], &r[3]);
       }
 
       fetch_texel(mach->Samplers[unit],
@@ -1572,15 +1574,10 @@ exec_tex(struct tgsi_exec_machine *mach,
       FETCH(&r[1], 0, CHAN_Y);
       FETCH(&r[2], 0, CHAN_Z);
 
-      if (modifier != TEX_MODIFIER_NONE) {
-         FETCH(&r[3], 0, CHAN_W);
-         if (modifier == TEX_MODIFIER_PROJECTED) {
-            micro_div(&r[0], &r[0], &r[3]);
-            micro_div(&r[1], &r[1], &r[3]);
-            micro_div(&r[2], &r[2], &r[3]);
-         } else {
-            lodBias = r[3].f[0];
-         }
+      if (modifier == TEX_MODIFIER_PROJECTED) {
+         micro_div(&r[0], &r[0], &r[3]);
+         micro_div(&r[1], &r[1], &r[3]);
+         micro_div(&r[2], &r[2], &r[3]);
       }
 
       fetch_texel(mach->Samplers[unit],
@@ -1594,15 +1591,10 @@ exec_tex(struct tgsi_exec_machine *mach,
       FETCH(&r[1], 0, CHAN_Y);
       FETCH(&r[2], 0, CHAN_Z);
 
-      if (modifier != TEX_MODIFIER_NONE) {
-         FETCH(&r[3], 0, CHAN_W);
-         if (modifier == TEX_MODIFIER_PROJECTED) {
-            micro_div(&r[0], &r[0], &r[3]);
-            micro_div(&r[1], &r[1], &r[3]);
-            micro_div(&r[2], &r[2], &r[3]);
-         } else {
-            lodBias = r[3].f[0];
-         }
+      if (modifier == TEX_MODIFIER_PROJECTED) {
+         micro_div(&r[0], &r[0], &r[3]);
+         micro_div(&r[1], &r[1], &r[3]);
+         micro_div(&r[2], &r[2], &r[3]);
       }
 
       fetch_texel(mach->Samplers[unit],
@@ -1638,8 +1630,8 @@ exec_txd(struct tgsi_exec_machine *mach,
       FETCH(&r[0], 0, CHAN_X);
 
       fetch_texel(mach->Samplers[unit],
-                  &r[0], &ZeroVec, &ZeroVec, 0.0f,  /* S, T, P, BIAS */
-                  &r[0], &r[1], &r[2], &r[3]);      /* R, G, B, A */
+                  &r[0], &ZeroVec, &ZeroVec, &ZeroVec,   /* S, T, P, BIAS */
+                  &r[0], &r[1], &r[2], &r[3]);           /* R, G, B, A */
       break;
 
    case TGSI_TEXTURE_2D:
@@ -1652,8 +1644,8 @@ exec_txd(struct tgsi_exec_machine *mach,
       FETCH(&r[2], 0, CHAN_Z);
 
       fetch_texel(mach->Samplers[unit],
-                  &r[0], &r[1], &r[2], 0.0f,    /* inputs */
-                  &r[0], &r[1], &r[2], &r[3]);  /* outputs */
+                  &r[0], &r[1], &r[2], &ZeroVec,   /* inputs */
+                  &r[0], &r[1], &r[2], &r[3]);     /* outputs */
       break;
 
    case TGSI_TEXTURE_3D:
@@ -1664,7 +1656,7 @@ exec_txd(struct tgsi_exec_machine *mach,
       FETCH(&r[2], 0, CHAN_Z);
 
       fetch_texel(mach->Samplers[unit],
-                  &r[0], &r[1], &r[2], 0.0f,
+                  &r[0], &r[1], &r[2], &ZeroVec,
                   &r[0], &r[1], &r[2], &r[3]);
       break;
 
diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.h b/src/gallium/auxiliary/tgsi/tgsi_exec.h
index aa3a98d7f18..67853ed4fe4 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.h
@@ -2,6 +2,7 @@
  * 
  * Copyright 2007-2008 Tungsten Graphics, Inc., Cedar Park, Texas.
  * All Rights Reserved.
+ * Copyright 2009-2010 VMware, Inc.  All rights Reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
@@ -35,11 +36,13 @@
 extern "C" {
 #endif
 
+
 #define MAX_LABELS (4 * 1024)  /**< basically, max instructions */
 
 #define NUM_CHANNELS 4  /* R,G,B,A */
 #define QUAD_SIZE    4  /* 4 pixel/quad */
 
+
 /**
   * Registers may be treated as float, signed int or unsigned int.
   */
@@ -80,7 +83,7 @@ struct tgsi_sampler
                        const float s[QUAD_SIZE],
                        const float t[QUAD_SIZE],
                        const float p[QUAD_SIZE],
-                       float lodbias,
+                       const float lodbias[QUAD_SIZE],
                        float rgba[NUM_CHANNELS][QUAD_SIZE]);
 };
 
diff --git a/src/gallium/auxiliary/tgsi/tgsi_sse2.c b/src/gallium/auxiliary/tgsi/tgsi_sse2.c
index 118059ace9c..e133bc02558 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_sse2.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_sse2.c
@@ -1433,7 +1433,7 @@ fetch_texel( struct tgsi_sampler **sampler,
                               &store[0],  /* s */
                               &store[4],  /* t */
                               &store[8],  /* r */
-                              store[12],  /* lodbias */
+                              &store[12], /* lodbias */
                               rgba);      /* results */
 
       memcpy( store, rgba, 16 * sizeof(float));
diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.c b/src/gallium/drivers/softpipe/sp_tex_sample.c
index 903d21a0210..9c535f82a59 100644
--- a/src/gallium/drivers/softpipe/sp_tex_sample.c
+++ b/src/gallium/drivers/softpipe/sp_tex_sample.c
@@ -2,7 +2,7 @@
  * 
  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
  * All Rights Reserved.
- * Copyright 2008 VMware, Inc.  All rights reserved.
+ * Copyright 2008-2010 VMware, Inc.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
@@ -514,21 +514,15 @@ static float
 compute_lambda_1d(const struct sp_sampler_varient *samp,
                   const float s[QUAD_SIZE],
                   const float t[QUAD_SIZE],
-                  const float p[QUAD_SIZE],
-                  float lodbias)
+                  const float p[QUAD_SIZE])
 {
    const struct pipe_texture *texture = samp->texture;
    const struct pipe_sampler_state *sampler = samp->sampler;
    float dsdx = fabsf(s[QUAD_BOTTOM_RIGHT] - s[QUAD_BOTTOM_LEFT]);
    float dsdy = fabsf(s[QUAD_TOP_LEFT]     - s[QUAD_BOTTOM_LEFT]);
    float rho = MAX2(dsdx, dsdy) * texture->width0;
-   float lambda;
 
-   lambda = util_fast_log2(rho);
-   lambda += lodbias + sampler->lod_bias;
-   lambda = CLAMP(lambda, sampler->min_lod, sampler->max_lod);
-
-   return lambda;
+   return util_fast_log2(rho);
 }
 
 
@@ -536,8 +530,7 @@ static float
 compute_lambda_2d(const struct sp_sampler_varient *samp,
                   const float s[QUAD_SIZE],
                   const float t[QUAD_SIZE],
-                  const float p[QUAD_SIZE],
-                  float lodbias)
+                  const float p[QUAD_SIZE])
 {
    const struct pipe_texture *texture = samp->texture;
    const struct pipe_sampler_state *sampler = samp->sampler;
@@ -548,13 +541,8 @@ compute_lambda_2d(const struct sp_sampler_varient *samp,
    float maxx = MAX2(dsdx, dsdy) * texture->width0;
    float maxy = MAX2(dtdx, dtdy) * texture->height0;
    float rho  = MAX2(maxx, maxy);
-   float lambda;
-
-   lambda = util_fast_log2(rho);
-   lambda += lodbias + sampler->lod_bias;
-   lambda = CLAMP(lambda, sampler->min_lod, sampler->max_lod);
 
-   return lambda;
+   return util_fast_log2(rho);
 }
 
 
@@ -562,8 +550,7 @@ static float
 compute_lambda_3d(const struct sp_sampler_varient *samp,
                   const float s[QUAD_SIZE],
                   const float t[QUAD_SIZE],
-                  const float p[QUAD_SIZE],
-                  float lodbias)
+                  const float p[QUAD_SIZE])
 {
    const struct pipe_texture *texture = samp->texture;
    const struct pipe_sampler_state *sampler = samp->sampler;
@@ -576,31 +563,26 @@ compute_lambda_3d(const struct sp_sampler_varient *samp,
    float maxx = MAX2(dsdx, dsdy) * texture->width0;
    float maxy = MAX2(dtdx, dtdy) * texture->height0;
    float maxz = MAX2(dpdx, dpdy) * texture->depth0;
-   float rho, lambda;
+   float rho;
 
    rho = MAX2(maxx, maxy);
    rho = MAX2(rho, maxz);
 
-   lambda = util_fast_log2(rho);
-   lambda += lodbias + sampler->lod_bias;
-   lambda = CLAMP(lambda, sampler->min_lod, sampler->max_lod);
-
-   return lambda;
+   return util_fast_log2(rho);
 }
 
 
 /**
  * Compute lambda for a vertex texture sampler.
- * Since there aren't derivatives to use, just return the LOD bias.
+ * Since there aren't derivatives to use, just return 0.
  */
 static float
 compute_lambda_vert(const struct sp_sampler_varient *samp,
                     const float s[QUAD_SIZE],
                     const float t[QUAD_SIZE],
-                    const float p[QUAD_SIZE],
-                    float lodbias)
+                    const float p[QUAD_SIZE])
 {
-   return lodbias;
+   return 0.0f;
 }
 
 
@@ -769,7 +751,7 @@ img_filter_2d_linear_repeat_POT(struct tgsi_sampler *tgsi_sampler,
                                 const float s[QUAD_SIZE],
                                 const float t[QUAD_SIZE],
                                 const float p[QUAD_SIZE],
-                                float lodbias,
+                                const float lodbias[QUAD_SIZE],
                                 float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -827,7 +809,7 @@ img_filter_2d_nearest_repeat_POT(struct tgsi_sampler *tgsi_sampler,
                                  const float s[QUAD_SIZE],
                                  const float t[QUAD_SIZE],
                                  const float p[QUAD_SIZE],
-                                 float lodbias,
+                                 const float lodbias[QUAD_SIZE],
                                  float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -866,7 +848,7 @@ img_filter_2d_nearest_clamp_POT(struct tgsi_sampler *tgsi_sampler,
                                 const float s[QUAD_SIZE],
                                 const float t[QUAD_SIZE],
                                 const float p[QUAD_SIZE],
-                                float lodbias,
+                                const float lodbias[QUAD_SIZE],
                                 float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -914,7 +896,7 @@ img_filter_1d_nearest(struct tgsi_sampler *tgsi_sampler,
                         const float s[QUAD_SIZE],
                         const float t[QUAD_SIZE],
                         const float p[QUAD_SIZE],
-                        float lodbias,
+                        const float lodbias[QUAD_SIZE],
                         float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -949,7 +931,7 @@ img_filter_2d_nearest(struct tgsi_sampler *tgsi_sampler,
                       const float s[QUAD_SIZE],
                       const float t[QUAD_SIZE],
                       const float p[QUAD_SIZE],
-                      float lodbias,
+                      const float lodbias[QUAD_SIZE],
                       float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -996,7 +978,7 @@ img_filter_cube_nearest(struct tgsi_sampler *tgsi_sampler,
                         const float s[QUAD_SIZE],
                         const float t[QUAD_SIZE],
                         const float p[QUAD_SIZE],
-                        float lodbias,
+                        const float lodbias[QUAD_SIZE],
                         float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1035,7 +1017,7 @@ img_filter_3d_nearest(struct tgsi_sampler *tgsi_sampler,
                       const float s[QUAD_SIZE],
                       const float t[QUAD_SIZE],
                       const float p[QUAD_SIZE],
-                      float lodbias,
+                      const float lodbias[QUAD_SIZE],
                       float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1076,7 +1058,7 @@ img_filter_1d_linear(struct tgsi_sampler *tgsi_sampler,
                      const float s[QUAD_SIZE],
                      const float t[QUAD_SIZE],
                      const float p[QUAD_SIZE],
-                     float lodbias,
+                     const float lodbias[QUAD_SIZE],
                      float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1115,7 +1097,7 @@ img_filter_2d_linear(struct tgsi_sampler *tgsi_sampler,
                      const float s[QUAD_SIZE],
                      const float t[QUAD_SIZE],
                      const float p[QUAD_SIZE],
-                     float lodbias,
+                     const float lodbias[QUAD_SIZE],
                      float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1161,7 +1143,7 @@ img_filter_cube_linear(struct tgsi_sampler *tgsi_sampler,
                        const float s[QUAD_SIZE],
                        const float t[QUAD_SIZE],
                        const float p[QUAD_SIZE],
-                       float lodbias,
+                       const float lodbias[QUAD_SIZE],
                        float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1209,7 +1191,7 @@ img_filter_3d_linear(struct tgsi_sampler *tgsi_sampler,
                      const float s[QUAD_SIZE],
                      const float t[QUAD_SIZE],
                      const float p[QUAD_SIZE],
-                     float lodbias,
+                     const float lodbias[QUAD_SIZE],
                      float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    const struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1261,29 +1243,54 @@ img_filter_3d_linear(struct tgsi_sampler *tgsi_sampler,
 }
 
 
+/* Calculate level of detail for every fragment.
+ * Note that lambda has already been biased by global LOD bias.
+ */
+static INLINE void
+compute_lod(const struct pipe_sampler_state *sampler,
+            const float biased_lambda,
+            const float lodbias[QUAD_SIZE],
+            float lod[QUAD_SIZE])
+{
+   uint i;
+
+   for (i = 0; i < QUAD_SIZE; i++) {
+      lod[i] = biased_lambda + lodbias[i];
+      lod[i] = CLAMP(lod[i], sampler->min_lod, sampler->max_lod);
+   }
+}
+
+
 static void
 mip_filter_linear(struct tgsi_sampler *tgsi_sampler,
                   const float s[QUAD_SIZE],
                   const float t[QUAD_SIZE],
                   const float p[QUAD_SIZE],
-                  float lodbias,
+                  const float lodbias[QUAD_SIZE],
                   float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
    const struct pipe_texture *texture = samp->texture;
    int level0;
    float lambda;
+   float lod[QUAD_SIZE];
 
-   lambda = samp->compute_lambda(samp, s, t, p, lodbias);
+   lambda = samp->compute_lambda(samp, s, t, p) + samp->sampler->lod_bias;
+
+   compute_lod(samp->sampler, lambda, lodbias, lod);
+
+   /* XXX: Take into account all lod values.
+    */
+   lambda = lod[0];
    level0 = (int)lambda;
 
    if (lambda < 0.0) { 
       samp->level = 0;
-      samp->mag_img_filter( tgsi_sampler, s, t, p, 0, rgba );
+      samp->mag_img_filter( tgsi_sampler, s, t, p, NULL, rgba );
    }
    else if (level0 >= texture->last_level) {
       samp->level = texture->last_level;
-      samp->min_img_filter( tgsi_sampler, s, t, p, 0, rgba );
+      samp->min_img_filter( tgsi_sampler, s, t, p, NULL, rgba );
    }
    else {
       float levelBlend = lambda - level0;
@@ -1292,10 +1299,10 @@ mip_filter_linear(struct tgsi_sampler *tgsi_sampler,
       int c,j;
 
       samp->level = level0;
-      samp->min_img_filter( tgsi_sampler, s, t, p, 0, rgba0 );
+      samp->min_img_filter( tgsi_sampler, s, t, p, NULL, rgba0 );
 
       samp->level = level0+1;
-      samp->min_img_filter( tgsi_sampler, s, t, p, 0, rgba1 );
+      samp->min_img_filter( tgsi_sampler, s, t, p, NULL, rgba1 );
 
       for (j = 0; j < QUAD_SIZE; j++) {
          for (c = 0; c < 4; c++) {
@@ -1311,14 +1318,21 @@ mip_filter_nearest(struct tgsi_sampler *tgsi_sampler,
                    const float s[QUAD_SIZE],
                    const float t[QUAD_SIZE],
                    const float p[QUAD_SIZE],
-                   float lodbias,
+                   const float lodbias[QUAD_SIZE],
                    float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
    const struct pipe_texture *texture = samp->texture;
    float lambda;
+   float lod[QUAD_SIZE];
 
-   lambda = samp->compute_lambda(samp, s, t, p, lodbias);
+   lambda = samp->compute_lambda(samp, s, t, p) + samp->sampler->lod_bias;
+
+   compute_lod(samp->sampler, lambda, lodbias, lod);
+
+   /* XXX: Take into account all lod values.
+    */
+   lambda = lod[0];
 
    if (lambda < 0.0) { 
       samp->level = 0;
@@ -1327,7 +1341,7 @@ mip_filter_nearest(struct tgsi_sampler *tgsi_sampler,
    else {
       samp->level = (int)(lambda + 0.5) ;
       samp->level = MIN2(samp->level, (int)texture->last_level);
-      samp->min_img_filter( tgsi_sampler, s, t, p, 0, rgba );
+      samp->min_img_filter( tgsi_sampler, s, t, p, NULL, rgba );
    }
 
 #if 0
@@ -1345,17 +1359,26 @@ mip_filter_none(struct tgsi_sampler *tgsi_sampler,
                 const float s[QUAD_SIZE],
                 const float t[QUAD_SIZE],
                 const float p[QUAD_SIZE],
-                float lodbias,
+                const float lodbias[QUAD_SIZE],
                 float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
-   float lambda = samp->compute_lambda(samp, s, t, p, lodbias);
+   float lambda;
+   float lod[QUAD_SIZE];
+
+   lambda = samp->compute_lambda(samp, s, t, p) + samp->sampler->lod_bias;
+
+   compute_lod(samp->sampler, lambda, lodbias, lod);
+
+   /* XXX: Take into account all lod values.
+    */
+   lambda = lod[0];
 
    if (lambda < 0.0) { 
-      samp->mag_img_filter( tgsi_sampler, s, t, p, 0, rgba );
+      samp->mag_img_filter( tgsi_sampler, s, t, p, NULL, rgba );
    }
    else {
-      samp->min_img_filter( tgsi_sampler, s, t, p, 0, rgba );
+      samp->min_img_filter( tgsi_sampler, s, t, p, NULL, rgba );
    }
 }
 
@@ -1371,15 +1394,22 @@ mip_filter_linear_2d_linear_repeat_POT(
    const float s[QUAD_SIZE],
    const float t[QUAD_SIZE],
    const float p[QUAD_SIZE],
-   float lodbias,
+   const float lodbias[QUAD_SIZE],
    float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
    const struct pipe_texture *texture = samp->texture;
    int level0;
    float lambda;
+   float lod[QUAD_SIZE];
+
+   lambda = compute_lambda_2d(samp, s, t, p) + samp->sampler->lod_bias;
 
-   lambda = compute_lambda_2d(samp, s, t, p, lodbias);
+   compute_lod(samp->sampler, lambda, lodbias, lod);
+
+   /* XXX: Take into account all lod values.
+    */
+   lambda = lod[0];
    level0 = (int)lambda;
 
    /* Catches both negative and large values of level0:
@@ -1390,7 +1420,7 @@ mip_filter_linear_2d_linear_repeat_POT(
       else
          samp->level = texture->last_level;
 
-      img_filter_2d_linear_repeat_POT( tgsi_sampler, s, t, p, 0, rgba );
+      img_filter_2d_linear_repeat_POT( tgsi_sampler, s, t, p, NULL, rgba );
    }
    else {
       float levelBlend = lambda - level0;
@@ -1399,10 +1429,10 @@ mip_filter_linear_2d_linear_repeat_POT(
       int c,j;
 
       samp->level = level0;
-      img_filter_2d_linear_repeat_POT( tgsi_sampler, s, t, p, 0, rgba0 );
+      img_filter_2d_linear_repeat_POT( tgsi_sampler, s, t, p, NULL, rgba0 );
 
       samp->level = level0+1;
-      img_filter_2d_linear_repeat_POT( tgsi_sampler, s, t, p, 0, rgba1 );
+      img_filter_2d_linear_repeat_POT( tgsi_sampler, s, t, p, NULL, rgba1 );
 
       for (j = 0; j < QUAD_SIZE; j++) {
          for (c = 0; c < 4; c++) {
@@ -1422,7 +1452,7 @@ sample_compare(struct tgsi_sampler *tgsi_sampler,
                const float s[QUAD_SIZE],
                const float t[QUAD_SIZE],
                const float p[QUAD_SIZE],
-               float lodbias,
+               const float lodbias[QUAD_SIZE],
                float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
@@ -1508,7 +1538,7 @@ sample_cube(struct tgsi_sampler *tgsi_sampler,
             const float s[QUAD_SIZE],
             const float t[QUAD_SIZE],
             const float p[QUAD_SIZE],
-            float lodbias,
+            const float lodbias[QUAD_SIZE],
             float rgba[NUM_CHANNELS][QUAD_SIZE])
 {
    struct sp_sampler_varient *samp = sp_sampler_varient(tgsi_sampler);
diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.h b/src/gallium/drivers/softpipe/sp_tex_sample.h
index b0797711d37..d01b384e858 100644
--- a/src/gallium/drivers/softpipe/sp_tex_sample.h
+++ b/src/gallium/drivers/softpipe/sp_tex_sample.h
@@ -2,6 +2,7 @@
  * 
  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
  * All Rights Reserved.
+ * Copyright 2010 VMware, Inc.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
@@ -46,14 +47,13 @@ typedef void (*wrap_linear_func)(const float s[4],
 typedef float (*compute_lambda_func)(const struct sp_sampler_varient *sampler,
                                      const float s[QUAD_SIZE],
                                      const float t[QUAD_SIZE],
-                                     const float p[QUAD_SIZE],
-                                     float lodbias);
+                                     const float p[QUAD_SIZE]);
 
 typedef void (*filter_func)(struct tgsi_sampler *tgsi_sampler,
                             const float s[QUAD_SIZE],
                             const float t[QUAD_SIZE],
                             const float p[QUAD_SIZE],
-                            float lodbias,
+                            const float lodbias[QUAD_SIZE],
                             float rgba[NUM_CHANNELS][QUAD_SIZE]);