[Mesa-dev] [PATCH 2/2] st/mesa: add texture gather support. (v2)

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

This respects the CAP and adds glsl->tgsi support for the TG4 opcode.

v2: propogate the component selection to gallium

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 src/mesa/state_tracker/st_extensions.c     |  4 ++++
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 19 ++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 9829eb5..8509304 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -266,6 +266,7 @@ void st_init_limits(struct st_context *st)
    c->MinProgramTexelOffset = screen->get_param(screen, PIPE_CAP_MIN_TEXEL_OFFSET);
    c->MaxProgramTexelOffset = screen->get_param(screen, PIPE_CAP_MAX_TEXEL_OFFSET);
 
+   c->MaxProgramTextureGatherComponents = screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_GATHER_COMPONENTS);
    c->UniformBooleanTrue = ~0;
 
    c->MaxTransformFeedbackBuffers =
@@ -777,4 +778,7 @@ void st_init_extensions(struct st_context *st)
       if (!ctx->Extensions.EXT_transform_feedback)
          ctx->Const.DisableVaryingPacking = GL_TRUE;
    }
+
+   if (ctx->Const.MaxProgramTextureGatherComponents > 0)
+      ctx->Extensions.ARB_texture_gather = GL_TRUE;
 }
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 610fc68..f46658e 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -2685,7 +2685,7 @@ glsl_to_tgsi_visitor::visit(ir_call *ir)
 void
 glsl_to_tgsi_visitor::visit(ir_texture *ir)
 {
-   st_src_reg result_src, coord, cube_sc, lod_info, projector, dx, dy, offset, sample_index;
+   st_src_reg result_src, coord, cube_sc, lod_info, projector, dx, dy, offset, sample_index, component;
    st_dst_reg result_dst, coord_dst, cube_sc_dst;
    glsl_to_tgsi_instruction *inst = NULL;
    unsigned opcode = TGSI_OPCODE_NOP;
@@ -2779,12 +2779,18 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
       ir->lod_info.sample_index->accept(this);
       sample_index = this->result;
       break;
+   case ir_tg4:
+      opcode = TGSI_OPCODE_TG4;
+      ir->lod_info.component->accept(this);
+      component = this->result;
+      if (ir->offset) {
+         ir->offset->accept(this);
+         offset = this->result;
+      }
+      break;
    case ir_lod:
       assert(!"Unexpected ir_lod opcode");
       break;
-   case ir_tg4:
-      assert(!"Unexpected ir_tg4 opcode");
-      break;
    case ir_query_levels:
       assert(!"Unexpected ir_query_levels opcode");
       break;
@@ -2892,7 +2898,9 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
       inst = emit(ir, opcode, result_dst, coord, lod_info);
    } else if (opcode == TGSI_OPCODE_TEX2) {
       inst = emit(ir, opcode, result_dst, coord, cube_sc);
-   } else 
+   } else if (opcode == TGSI_OPCODE_TG4) {
+      inst = emit(ir, opcode, result_dst, coord, component);
+   } else
       inst = emit(ir, opcode, result_dst, coord);
 
    if (ir->shadow_comparitor)
@@ -4450,6 +4458,7 @@ compile_tgsi_instruction(struct st_translate *t,
    case TGSI_OPCODE_TEX2:
    case TGSI_OPCODE_TXB2:
    case TGSI_OPCODE_TXL2:
+   case TGSI_OPCODE_TG4:
       src[num_src++] = t->samplers[inst->sampler];
       for (i = 0; i < inst->tex_offset_num_offset; i++) {
          texoffsets[i] = translate_tex_offset(t, &inst->tex_offsets[i]);
-- 
1.8.3.1