GPU: Replace `GPUMaterialVolumeGrid` by `GPUMaterialAttribute`

This is to make the codegen and shading nodes object type agnostic. This
is essential for flexibility of the engine to use the nodetree as it see
fits.

The essential volume attributes struct properties are moved to the
`GPUMaterialAttribute` which see its final input name set on creation.

The binding process is centralized into `draw_volume.cc` to avoid
duplicating the code between multiple engines. It mimics the hair attributes
process.

Volume object grid transforms and other per object uniforms are packed into
one UBO per object. The grid transform is now based on object which simplify
the matrix preparations.

This also gets rid of the double transforms and use object info orco factors
for volume objects.

Tagging @brecht because he did the initial implementation of Volume Grids.

1 files changed, 1 insertions, 49 deletions

diff --git a/source/blender/gpu/intern/gpu_codegen.cc b/source/blender/gpu/intern/gpu_codegen.cc
index 8963fa45c96..048928b2312 100644
--- a/source/blender/gpu/intern/gpu_codegen.cc
+++ b/source/blender/gpu/intern/gpu_codegen.cc
@@ -49,7 +49,6 @@ using namespace blender::gpu::shader;
 
 struct GPUCodegenCreateInfo : ShaderCreateInfo {
   struct NameBuffer {
-    char attr_names[16][GPU_MAX_SAFE_ATTR_NAME + 1];
     char var_names[16][8];
   };
 
@@ -171,10 +170,6 @@ static std::ostream &operator<<(std::ostream &stream, const GPUInput *input)
       return stream << input->texture->sampler_name;
     case GPU_SOURCE_TEX_TILED_MAPPING:
       return stream << input->texture->tiled_mapping_name;
-    case GPU_SOURCE_VOLUME_GRID:
-      return stream << input->volume_grid->sampler_name;
-    case GPU_SOURCE_VOLUME_GRID_TRANSFORM:
-      return stream << input->volume_grid->transform_name;
     default:
       BLI_assert(0);
       return stream;
@@ -276,28 +271,6 @@ class GPUCodegen {
   }
 };
 
-static char attr_prefix_get(CustomDataType type)
-{
-  switch (type) {
-    case CD_MTFACE:
-      return 'u';
-    case CD_TANGENT:
-      return 't';
-    case CD_MCOL:
-    case CD_MLOOPCOL:
-      return 'c';
-    case CD_PROP_COLOR:
-      return 'c';
-    case CD_AUTO_FROM_NAME:
-      return 'a';
-    case CD_HAIRLENGTH:
-      return 'l';
-    default:
-      BLI_assert_msg(0, "GPUVertAttr Prefix type not found : This should not happen!");
-      return '\0';
-  }
-}
-
 void GPUCodegen::generate_attribs()
 {
   if (BLI_listbase_is_empty(&graph.attributes)) {
@@ -317,24 +290,9 @@ void GPUCodegen::generate_attribs()
 
   int slot = 15;
   LISTBASE_FOREACH (GPUMaterialAttribute *, attr, &graph.attributes) {
-
-    /* NOTE: Replicate changes to mesh_render_data_create() in draw_cache_impl_mesh.c */
-    if (attr->type == CD_ORCO) {
-      /* OPTI: orco is computed from local positions, but only if no modifier is present. */
-      STRNCPY(info.name_buffer->attr_names[slot], "orco");
-    }
-    else {
-      char *name = info.name_buffer->attr_names[slot];
-      name[0] = attr_prefix_get(static_cast<CustomDataType>(attr->type));
-      name[1] = '\0';
-      if (attr->name[0] != '\0') {
-        /* XXX FIXME: see notes in mesh_render_data_create() */
-        GPU_vertformat_safe_attr_name(attr->name, &name[1], GPU_MAX_SAFE_ATTR_NAME);
-      }
-    }
     SNPRINTF(info.name_buffer->var_names[slot], "v%d", attr->id);
 
-    blender::StringRefNull attr_name = info.name_buffer->attr_names[slot];
+    blender::StringRefNull attr_name = attr->input_name;
     blender::StringRefNull var_name = info.name_buffer->var_names[slot];
 
     eGPUType input_type, iface_type;
@@ -395,12 +353,6 @@ void GPUCodegen::generate_resources()
       info.sampler(0, ImageType::FLOAT_2D, tex->sampler_name, Frequency::BATCH);
     }
   }
-  /* Volume Grids. */
-  LISTBASE_FOREACH (GPUMaterialVolumeGrid *, grid, &graph.volume_grids) {
-    info.sampler(0, ImageType::FLOAT_3D, grid->sampler_name, Frequency::BATCH);
-    /* TODO(@fclem): Global uniform. To put in an UBO. */
-    info.push_constant(Type::MAT4, grid->transform_name);
-  }
 
   if (!BLI_listbase_is_empty(&ubo_inputs_)) {
     /* NOTE: generate_uniform_buffer() should have sorted the inputs before this. */