Refactor: Rename Object->obmat to Object->object_to_world

Motivation is to disambiguate on the naming level what the matrix
actually means. It is very easy to understand the meaning backwards,
especially since in Python the name goes the opposite way (it is
called `world_matrix` in the Python API).

It is important to disambiguate the naming without making developers
to look into the comment in the header file (which is also not super
clear either). Additionally, more clear naming facilitates the unit
verification (or, in this case, space validation) when reading an
expression.

This patch calls the matrix `object_to_world` which makes it clear
from the local code what is it exactly going on. This is only done
on DNA level, and a lot of local variables still follow the old
naming.

A DNA rename is setup in a way that there is no change on the file
level, so there should be no regressions at all.

The possibility is to add `_matrix` or `_mat` suffix to the name
to make it explicit that it is a matrix. Although, not sure if it
really helps the readability, or is it something redundant.

Differential Revision: https://developer.blender.org/D16328

8 files changed, 39 insertions, 39 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_mesh.cc b/source/blender/draw/intern/draw_cache_impl_mesh.cc
index 5ce658abfe4..031de3e4ef2 100644
--- a/source/blender/draw/intern/draw_cache_impl_mesh.cc
+++ b/source/blender/draw/intern/draw_cache_impl_mesh.cc
@@ -1889,7 +1889,7 @@ void DRW_mesh_batch_cache_create_requested(struct TaskGraph *task_graph,
                                                       is_editmode,
                                                       is_paint_mode,
                                                       is_mode_active,
-                                                      ob->obmat,
+                                                      ob->object_to_world,
                                                       false,
                                                       true,
                                                       scene,
@@ -1906,7 +1906,7 @@ void DRW_mesh_batch_cache_create_requested(struct TaskGraph *task_graph,
                                                       is_editmode,
                                                       is_paint_mode,
                                                       is_mode_active,
-                                                      ob->obmat,
+                                                      ob->object_to_world,
                                                       false,
                                                       false,
                                                       scene,
@@ -1922,7 +1922,7 @@ void DRW_mesh_batch_cache_create_requested(struct TaskGraph *task_graph,
                            is_editmode,
                            is_paint_mode,
                            is_mode_active,
-                           ob->obmat,
+                           ob->object_to_world,
                            true,
                            false,
                            do_cage,
@@ -1943,7 +1943,7 @@ void DRW_mesh_batch_cache_create_requested(struct TaskGraph *task_graph,
                                                     is_editmode,
                                                     is_paint_mode,
                                                     is_mode_active,
-                                                    ob->obmat,
+                                                    ob->object_to_world,
                                                     true,
                                                     false,
                                                     scene,
diff --git a/source/blender/draw/intern/draw_curves.cc b/source/blender/draw/intern/draw_curves.cc
index ee9045696be..ee9ed4666e0 100644
--- a/source/blender/draw/intern/draw_curves.cc
+++ b/source/blender/draw/intern/draw_curves.cc
@@ -390,7 +390,7 @@ DRWShadingGroup *DRW_shgroup_curves_create_sub(Object *object,
   DRW_shgroup_uniform_int(shgrp, "hairStrandsRes", &curves_cache->final[subdiv].strands_res, 1);
   DRW_shgroup_uniform_int_copy(shgrp, "hairThicknessRes", thickness_res);
   DRW_shgroup_uniform_float_copy(shgrp, "hairRadShape", hair_rad_shape);
-  DRW_shgroup_uniform_mat4_copy(shgrp, "hairDupliMatrix", object->obmat);
+  DRW_shgroup_uniform_mat4_copy(shgrp, "hairDupliMatrix", object->object_to_world);
   DRW_shgroup_uniform_float_copy(shgrp, "hairRadRoot", hair_rad_root);
   DRW_shgroup_uniform_float_copy(shgrp, "hairRadTip", hair_rad_tip);
   DRW_shgroup_uniform_bool_copy(shgrp, "hairCloseTip", hair_close_tip);
diff --git a/source/blender/draw/intern/draw_hair.cc b/source/blender/draw/intern/draw_hair.cc
index 08e5d780cba..c5261f26f76 100644
--- a/source/blender/draw/intern/draw_hair.cc
+++ b/source/blender/draw/intern/draw_hair.cc
@@ -216,12 +216,12 @@ void DRW_hair_duplimat_get(Object *object,
       if (collection != nullptr) {
         sub_v3_v3(dupli_mat[3], collection->instance_offset);
       }
-      mul_m4_m4m4(dupli_mat, dupli_parent->obmat, dupli_mat);
+      mul_m4_m4m4(dupli_mat, dupli_parent->object_to_world, dupli_mat);
     }
     else {
-      copy_m4_m4(dupli_mat, dupli_object->ob->obmat);
+      copy_m4_m4(dupli_mat, dupli_object->ob->object_to_world);
       invert_m4(dupli_mat);
-      mul_m4_m4m4(dupli_mat, object->obmat, dupli_mat);
+      mul_m4_m4m4(dupli_mat, object->object_to_world, dupli_mat);
     }
   }
   else {
diff --git a/source/blender/draw/intern/draw_manager.c b/source/blender/draw/intern/draw_manager.c
index d0290426af3..4fcfec833eb 100644
--- a/source/blender/draw/intern/draw_manager.c
+++ b/source/blender/draw/intern/draw_manager.c
@@ -2801,7 +2801,7 @@ void DRW_draw_depth_object(
 
   GPU_matrix_projection_set(rv3d->winmat);
   GPU_matrix_set(rv3d->viewmat);
-  GPU_matrix_mul(object->obmat);
+  GPU_matrix_mul(object->object_to_world);
 
   /* Setup frame-buffer. */
   GPUTexture *depth_tx = GPU_viewport_depth_texture(viewport);
@@ -2821,11 +2821,11 @@ void DRW_draw_depth_object(
   const bool use_clipping_planes = RV3D_CLIPPING_ENABLED(v3d, rv3d);
   if (use_clipping_planes) {
     GPU_clip_distances(6);
-    ED_view3d_clipping_local(rv3d, object->obmat);
+    ED_view3d_clipping_local(rv3d, object->object_to_world);
     for (int i = 0; i < 6; i++) {
       copy_v4_v4(planes.world[i], rv3d->clip_local[i]);
     }
-    copy_m4_m4(planes.ModelMatrix, object->obmat);
+    copy_m4_m4(planes.ModelMatrix, object->object_to_world);
   }
 
   drw_batch_cache_validate(object);
diff --git a/source/blender/draw/intern/draw_manager_data.cc b/source/blender/draw/intern/draw_manager_data.cc
index 792db9d0a6b..4aa27e2288c 100644
--- a/source/blender/draw/intern/draw_manager_data.cc
+++ b/source/blender/draw/intern/draw_manager_data.cc
@@ -724,8 +724,8 @@ static void drw_call_culling_init(DRWCullingState *cull, Object *ob)
     float corner[3];
     /* Get BoundSphere center and radius from the BoundBox. */
     mid_v3_v3v3(cull->bsphere.center, bbox->vec[0], bbox->vec[6]);
-    mul_v3_m4v3(corner, ob->obmat, bbox->vec[0]);
-    mul_m4_v3(ob->obmat, cull->bsphere.center);
+    mul_v3_m4v3(corner, ob->object_to_world, bbox->vec[0]);
+    mul_m4_v3(ob->object_to_world, cull->bsphere.center);
     cull->bsphere.radius = len_v3v3(cull->bsphere.center, corner);
 
     /* Bypass test for very large objects (see T67319). */
@@ -1017,7 +1017,7 @@ void DRW_shgroup_call_ex(DRWShadingGroup *shgroup,
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : obmat, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : obmat, ob);
   drw_command_draw(shgroup, geom, handle);
 
   /* Culling data. */
@@ -1042,7 +1042,7 @@ void DRW_shgroup_call_range(
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : nullptr, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : nullptr, ob);
   drw_command_draw_range(shgroup, geom, handle, v_sta, v_num);
 }
 
@@ -1053,7 +1053,7 @@ void DRW_shgroup_call_instance_range(
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : nullptr, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : nullptr, ob);
   drw_command_draw_intance_range(shgroup, geom, handle, i_sta, i_num);
 }
 
@@ -1099,7 +1099,7 @@ static void drw_shgroup_call_procedural_add_ex(DRWShadingGroup *shgroup,
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : nullptr, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : nullptr, ob);
   drw_command_draw_procedural(shgroup, geom, handle, vert_count);
 }
 
@@ -1149,7 +1149,7 @@ void DRW_shgroup_call_procedural_indirect(DRWShadingGroup *shgroup,
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : nullptr, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : nullptr, ob);
   drw_command_draw_indirect(shgroup, geom, handle, indirect_buf);
 }
 
@@ -1159,7 +1159,7 @@ void DRW_shgroup_call_instances(DRWShadingGroup *shgroup, Object *ob, GPUBatch *
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : nullptr, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : nullptr, ob);
   drw_command_draw_instance(shgroup, geom, handle, count, false);
 }
 
@@ -1173,7 +1173,7 @@ void DRW_shgroup_call_instances_with_attrs(DRWShadingGroup *shgroup,
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, nullptr, DST.select_id);
   }
-  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : nullptr, ob);
+  DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->object_to_world : nullptr, ob);
   GPUBatch *batch = DRW_temp_batch_instance_request(
       DST.vmempool->idatalist, nullptr, inst_attributes, geom);
   drw_command_draw_instance(shgroup, batch, handle, 0, true);
@@ -1283,7 +1283,7 @@ static void drw_sculpt_get_frustum_planes(Object *ob, float planes[6][4])
    * 4x4 matrix is done by multiplying with the transpose inverse.
    * The inverse cancels out here since we transform by inverse(obmat). */
   float tmat[4][4];
-  transpose_m4_m4(tmat, ob->obmat);
+  transpose_m4_m4(tmat, ob->object_to_world);
   for (int i = 0; i < 6; i++) {
     mul_m4_v4(tmat, planes[i]);
   }
@@ -1361,7 +1361,7 @@ static void drw_sculpt_generate_calls(DRWSculptCallbackData *scd)
 
   if (SCULPT_DEBUG_BUFFERS) {
     int debug_node_nr = 0;
-    DRW_debug_modelmat(scd->ob->obmat);
+    DRW_debug_modelmat(scd->ob->object_to_world);
     BKE_pbvh_draw_debug_cb(
         pbvh,
         (void (*)(PBVHNode * n, void *d, const float min[3], const float max[3], PBVHNodeFlags f))
diff --git a/source/blender/draw/intern/draw_manager_text.cc b/source/blender/draw/intern/draw_manager_text.cc
index 100ef528bc8..239f6fcca73 100644
--- a/source/blender/draw/intern/draw_manager_text.cc
+++ b/source/blender/draw/intern/draw_manager_text.cc
@@ -305,11 +305,11 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
         if (clip_segment_v3_plane_n(v1, v2, clip_planes, 4, v1_clip, v2_clip)) {
 
           mid_v3_v3v3(vmid, v1_clip, v2_clip);
-          mul_m4_v3(ob->obmat, vmid);
+          mul_m4_v3(ob->object_to_world, vmid);
 
           if (do_global) {
-            mul_mat3_m4_v3(ob->obmat, v1);
-            mul_mat3_m4_v3(ob->obmat, v2);
+            mul_mat3_m4_v3(ob->object_to_world, v1);
+            mul_mat3_m4_v3(ob->object_to_world, v2);
           }
 
           if (unit->system) {
@@ -373,7 +373,7 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
             float angle;
 
             mid_v3_v3v3(vmid, v1_clip, v2_clip);
-            mul_m4_v3(ob->obmat, vmid);
+            mul_m4_v3(ob->object_to_world, vmid);
 
             if (use_coords) {
               copy_v3_v3(no_a, poly_normals[BM_elem_index_get(l_a->f)]);
@@ -443,16 +443,16 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
           n += 3;
 
           if (do_global) {
-            mul_mat3_m4_v3(ob->obmat, v1);
-            mul_mat3_m4_v3(ob->obmat, v2);
-            mul_mat3_m4_v3(ob->obmat, v3);
+            mul_mat3_m4_v3(ob->object_to_world, v1);
+            mul_mat3_m4_v3(ob->object_to_world, v2);
+            mul_mat3_m4_v3(ob->object_to_world, v3);
           }
 
           area += area_tri_v3(v1, v2, v3);
         }
 
         mul_v3_fl(vmid, 1.0f / float(n));
-        mul_m4_v3(ob->obmat, vmid);
+        mul_m4_v3(ob->object_to_world, vmid);
 
         if (unit->system) {
           numstr_len = BKE_unit_value_as_string(
@@ -522,9 +522,9 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
             copy_v3_v3(v2_local, v2);
 
             if (do_global) {
-              mul_mat3_m4_v3(ob->obmat, v1);
-              mul_mat3_m4_v3(ob->obmat, v2);
-              mul_mat3_m4_v3(ob->obmat, v3);
+              mul_mat3_m4_v3(ob->object_to_world, v1);
+              mul_mat3_m4_v3(ob->object_to_world, v2);
+              mul_mat3_m4_v3(ob->object_to_world, v3);
             }
 
             float angle = angle_v3v3v3(v1, v2, v3);
@@ -535,7 +535,7 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
                                            (is_rad) ? angle : RAD2DEGF(angle),
                                            (is_rad) ? "r" : "°");
             interp_v3_v3v3(fvec, vmid, v2_local, 0.8f);
-            mul_m4_v3(ob->obmat, fvec);
+            mul_m4_v3(ob->object_to_world, fvec);
             DRW_text_cache_add(dt, fvec, numstr, numstr_len, 0, 0, txt_flag, col);
           }
         }
@@ -566,7 +566,7 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
             copy_v3_v3(v1, v->co);
           }
 
-          mul_m4_v3(ob->obmat, v1);
+          mul_m4_v3(ob->object_to_world, v1);
 
           numstr_len = BLI_snprintf_rlen(numstr, sizeof(numstr), "%d", i);
           DRW_text_cache_add(dt, v1, numstr, numstr_len, 0, 0, txt_flag, col);
@@ -595,7 +595,7 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
 
           if (clip_segment_v3_plane_n(v1, v2, clip_planes, 4, v1_clip, v2_clip)) {
             mid_v3_v3v3(vmid, v1_clip, v2_clip);
-            mul_m4_v3(ob->obmat, vmid);
+            mul_m4_v3(ob->object_to_world, vmid);
 
             numstr_len = BLI_snprintf_rlen(numstr, sizeof(numstr), "%d", i);
             DRW_text_cache_add(
@@ -629,7 +629,7 @@ void DRW_text_edit_mesh_measure_stats(ARegion *region,
             BM_face_calc_center_median(f, v1);
           }
 
-          mul_m4_v3(ob->obmat, v1);
+          mul_m4_v3(ob->object_to_world, v1);
 
           numstr_len = BLI_snprintf_rlen(numstr, sizeof(numstr), "%d", i);
           DRW_text_cache_add(dt, v1, numstr, numstr_len, 0, 0, txt_flag, col);
diff --git a/source/blender/draw/intern/draw_resource.hh b/source/blender/draw/intern/draw_resource.hh
index 2df38e32ed2..b116d7fe183 100644
--- a/source/blender/draw/intern/draw_resource.hh
+++ b/source/blender/draw/intern/draw_resource.hh
@@ -31,7 +31,7 @@
 
 inline void ObjectMatrices::sync(const Object &object)
 {
-  model = object.obmat;
+  model = object.object_to_world;
   model_inverse = object.imat;
 }
 
diff --git a/source/blender/draw/intern/draw_volume.cc b/source/blender/draw/intern/draw_volume.cc
index 2b4b0e3c089..5c1ce7c3111 100644
--- a/source/blender/draw/intern/draw_volume.cc
+++ b/source/blender/draw/intern/draw_volume.cc
@@ -127,7 +127,7 @@ static DRWShadingGroup *drw_volume_object_grids_init(Object *ob,
 
   grp = DRW_shgroup_create_sub(grp);
 
-  volume_infos.density_scale = BKE_volume_density_scale(volume, ob->obmat);
+  volume_infos.density_scale = BKE_volume_density_scale(volume, ob->object_to_world);
   volume_infos.color_mul = float4(1.0f);
   volume_infos.temperature_mul = 1.0f;
   volume_infos.temperature_bias = 0.0f;