Attributes: Infrastructure for generic 8-bit integer data type

This commit adds infrastructure for 8 bit signed integer attributes.
This can be useful given the discussion in T94193, where we want to
store spline type, Bezier handle type, and other small enums as
attributes.

This is only exposed in the interface in the attribute lists, so it
shouldn't be an option in geometry nodes, at least for now.
I expect that this type won't be used directly very often, it
should mostly be cast to an enum type. However, with support
for 8 bit integers, it also makes sense to add things like mixing
implementations for consistency.

Differential Revision: https://developer.blender.org/D13721

2 files changed, 12 insertions, 1 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_mesh.c b/source/blender/draw/intern/draw_cache_impl_mesh.c
index f57921d058c..e7e0e97499f 100644
--- a/source/blender/draw/intern/draw_cache_impl_mesh.c
+++ b/source/blender/draw/intern/draw_cache_impl_mesh.c
@@ -505,8 +505,9 @@ static bool custom_data_match_attribute(const CustomData *custom_data,
                                         int *r_layer_index,
                                         int *r_type)
 {
-  const int possible_attribute_types[6] = {
+  const int possible_attribute_types[7] = {
       CD_PROP_BOOL,
+      CD_PROP_INT8,
       CD_PROP_INT32,
       CD_PROP_FLOAT,
       CD_PROP_FLOAT2,
@@ -655,6 +656,7 @@ static DRW_MeshCDMask mesh_cd_calc_used_gpu_layers(const Object *object,
             break;
           }
           case CD_PROP_BOOL:
+          case CD_PROP_INT8:
           case CD_PROP_INT32:
           case CD_PROP_FLOAT:
           case CD_PROP_FLOAT2:
diff --git a/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_attributes.cc b/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_attributes.cc
index 4dcd821e607..b27633405b9 100644
--- a/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_attributes.cc
+++ b/source/blender/draw/intern/mesh_extractors/extract_mesh_vbo_attributes.cc
@@ -99,6 +99,7 @@ static uint gpu_component_size_for_attribute_type(CustomDataType type)
 {
   switch (type) {
     case CD_PROP_BOOL:
+    case CD_PROP_INT8:
     case CD_PROP_INT32:
     case CD_PROP_FLOAT: {
       /* TODO(@kevindietrich): should be 1 when scalar attributes conversion is handled by us. See
@@ -326,6 +327,10 @@ static void extract_attr_init(const MeshRenderData *mr,
       extract_attr_generic<bool, float3>(mr, vbo, request);
       break;
     }
+    case CD_PROP_INT8: {
+      extract_attr_generic<int8_t, float3>(mr, vbo, request);
+      break;
+    }
     case CD_PROP_INT32: {
       extract_attr_generic<int32_t, float3>(mr, vbo, request);
       break;
@@ -378,6 +383,10 @@ static void extract_attr_init_subdiv(const DRWSubdivCache *subdiv_cache,
       extract_attr_generic<bool, float3>(mr, src_data, request);
       break;
     }
+    case CD_PROP_INT8: {
+      extract_attr_generic<int8_t, float3>(mr, src_data, request);
+      break;
+    }
     case CD_PROP_INT32: {
       extract_attr_generic<int32_t, float3>(mr, src_data, request);
       break;