[Mesa-dev] [PATCH 2/3] softpipe: handle NULL sampler views for texture sampling / queries

[sroland at vmware.com]

From: Roland Scheidegger <sroland at vmware.com>

Instead of crashing just return all zero.
---
 src/gallium/auxiliary/tgsi/tgsi_exec.c       |    1 +
 src/gallium/drivers/softpipe/sp_tex_sample.c |   30 +++++++++++++++++++++-----
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index 1ffd9e9..0750a50 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -2076,6 +2076,7 @@ exec_txq(struct tgsi_exec_machine *mach,
 
    fetch_source(mach, &src, &inst->Src[0], TGSI_CHAN_X, TGSI_EXEC_DATA_INT);
 
+   /* XXX: This interface can't return per-pixel values */
    mach->Sampler->get_dims(mach->Sampler, unit, src.i[0], result);
 
    for (i = 0; i < TGSI_QUAD_SIZE; i++) {
diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.c b/src/gallium/drivers/softpipe/sp_tex_sample.c
index 4121857..8dcc297 100644
--- a/src/gallium/drivers/softpipe/sp_tex_sample.c
+++ b/src/gallium/drivers/softpipe/sp_tex_sample.c
@@ -3112,7 +3112,11 @@ sp_tgsi_get_dims(struct tgsi_sampler *tgsi_sampler,
    struct sp_tgsi_sampler *sp_samp = (struct sp_tgsi_sampler *)tgsi_sampler;
 
    assert(sview_index < PIPE_MAX_SHADER_SAMPLER_VIEWS);
-   /* TODO should have defined behavior if no texture is bound. */
+   /* always have a view here but texture is NULL if no sampler view was set. */
+   if (!sp_samp->sp_sview[sview_index].base.texture) {
+      dims[0] = dims[1] = dims[2] = dims[3] = 0;
+      return;
+   }
    sp_get_dims(&sp_samp->sp_sview[sview_index], level, dims);
 }
 
@@ -3136,8 +3140,16 @@ sp_tgsi_get_samples(struct tgsi_sampler *tgsi_sampler,
    assert(sview_index < PIPE_MAX_SHADER_SAMPLER_VIEWS);
    assert(sampler_index < PIPE_MAX_SAMPLERS);
    assert(sp_samp->sp_sampler[sampler_index]);
-   /* FIXME should have defined behavior if no texture is bound. */
-   assert(sp_samp->sp_sview[sview_index].get_samples);
+   /* always have a view here but texture is NULL if no sampler view was set. */
+   if (!sp_samp->sp_sview[sview_index].base.texture) {
+      int i, j;
+      for (j = 0; j < TGSI_NUM_CHANNELS; j++) {
+         for (i = 0; i < TGSI_QUAD_SIZE; i++) {
+            rgba[j][i] = 0.0f;
+         }
+      }
+      return;
+   }
    sp_samp->sp_sview[sview_index].get_samples(&sp_samp->sp_sview[sview_index],
                                               sp_samp->sp_sampler[sampler_index],
                                               s, t, p, c0, lod, control, rgba);
@@ -3155,8 +3167,16 @@ sp_tgsi_get_texel(struct tgsi_sampler *tgsi_sampler,
    struct sp_tgsi_sampler *sp_samp = (struct sp_tgsi_sampler *)tgsi_sampler;
 
    assert(sview_index < PIPE_MAX_SHADER_SAMPLER_VIEWS);
-   /* FIXME should have defined behavior if no texture is bound. */
-   assert(sp_samp->sp_sview[sview_index].base.texture);
+   /* always have a view here but texture is NULL if no sampler view was set. */
+   if (!sp_samp->sp_sview[sview_index].base.texture) {
+      int i, j;
+      for (j = 0; j < TGSI_NUM_CHANNELS; j++) {
+         for (i = 0; i < TGSI_QUAD_SIZE; i++) {
+            rgba[j][i] = 0.0f;
+         }
+      }
+      return;
+   }
    sp_get_texels(&sp_samp->sp_sview[sview_index], i, j, k, lod, offset, rgba);
 }
 
-- 
1.7.9.5