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

2 files changed, 15 insertions, 15 deletions

diff --git a/source/blender/editors/uvedit/uvedit_select.c b/source/blender/editors/uvedit/uvedit_select.c
index 7dd223a9252..777cc1d97e4 100644
--- a/source/blender/editors/uvedit/uvedit_select.c
+++ b/source/blender/editors/uvedit/uvedit_select.c
@@ -4705,7 +4705,7 @@ static int uv_select_similar_vert_exec(bContext *C, wmOperator *op)
 
     const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, ob->obmat);
+    copy_m3_m4(ob_m3, ob->object_to_world);
 
     BMFace *face;
     BMIter iter;
@@ -4742,7 +4742,7 @@ static int uv_select_similar_vert_exec(bContext *C, wmOperator *op)
     bool changed = false;
     const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, ob->obmat);
+    copy_m3_m4(ob_m3, ob->object_to_world);
 
     BMFace *face;
     BMIter iter;
@@ -4818,7 +4818,7 @@ static int uv_select_similar_edge_exec(bContext *C, wmOperator *op)
 
     const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, ob->obmat);
+    copy_m3_m4(ob_m3, ob->object_to_world);
 
     BMFace *face;
     BMIter iter;
@@ -4859,7 +4859,7 @@ static int uv_select_similar_edge_exec(bContext *C, wmOperator *op)
     bool changed = false;
     const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, ob->obmat);
+    copy_m3_m4(ob_m3, ob->object_to_world);
 
     BMFace *face;
     BMIter iter;
@@ -4927,7 +4927,7 @@ static int uv_select_similar_face_exec(bContext *C, wmOperator *op)
     BMesh *bm = em->bm;
 
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, ob->obmat);
+    copy_m3_m4(ob_m3, ob->object_to_world);
 
     const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
 
@@ -4963,7 +4963,7 @@ static int uv_select_similar_face_exec(bContext *C, wmOperator *op)
     const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
 
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, ob->obmat);
+    copy_m3_m4(ob_m3, ob->object_to_world);
 
     BMFace *face;
     BMIter iter;
@@ -5053,7 +5053,7 @@ static int uv_select_similar_island_exec(bContext *C, wmOperator *op)
     }
 
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, obedit->obmat);
+    copy_m3_m4(ob_m3, obedit->object_to_world);
 
     int index;
     LISTBASE_FOREACH_INDEX (struct FaceIsland *, island, &island_list_ptr[ob_index], index) {
@@ -5082,7 +5082,7 @@ static int uv_select_similar_island_exec(bContext *C, wmOperator *op)
       continue;
     }
     float ob_m3[3][3];
-    copy_m3_m4(ob_m3, obedit->obmat);
+    copy_m3_m4(ob_m3, obedit->object_to_world);
 
     bool changed = false;
     int index;
diff --git a/source/blender/editors/uvedit/uvedit_unwrap_ops.c b/source/blender/editors/uvedit/uvedit_unwrap_ops.c
index 92efaf79de7..de1c88fe896 100644
--- a/source/blender/editors/uvedit/uvedit_unwrap_ops.c
+++ b/source/blender/editors/uvedit/uvedit_unwrap_ops.c
@@ -1388,7 +1388,7 @@ static void uv_map_transform_center(const Scene *scene,
     }
     case V3D_AROUND_CURSOR: /* cursor center */
     {
-      invert_m4_m4(ob->imat, ob->obmat);
+      invert_m4_m4(ob->imat, ob->object_to_world);
       mul_v3_m4v3(r_center, ob->imat, scene->cursor.location);
       break;
     }
@@ -1439,7 +1439,7 @@ static void uv_map_rotation_matrix_ex(float result[4][4],
   zero_v3(viewmatrix[3]);
 
   /* get rotation of the current object matrix */
-  copy_m4_m4(rotobj, ob->obmat);
+  copy_m4_m4(rotobj, ob->object_to_world);
   zero_v3(rotobj[3]);
 
   /* but shifting */
@@ -1948,7 +1948,7 @@ static int unwrap_exec(bContext *C, wmOperator *op)
       continue;
     }
 
-    mat4_to_size(obsize, obedit->obmat);
+    mat4_to_size(obsize, obedit->object_to_world);
     if (!(fabsf(obsize[0] - obsize[1]) < 1e-4f && fabsf(obsize[1] - obsize[2]) < 1e-4f)) {
       if ((reported_errors & UNWRAP_ERROR_NONUNIFORM) == 0) {
         BKE_report(op->reports,
@@ -1958,7 +1958,7 @@ static int unwrap_exec(bContext *C, wmOperator *op)
         reported_errors |= UNWRAP_ERROR_NONUNIFORM;
       }
     }
-    else if (is_negative_m4(obedit->obmat)) {
+    else if (is_negative_m4(obedit->object_to_world)) {
       if ((reported_errors & UNWRAP_ERROR_NEGATIVE) == 0) {
         BKE_report(
             op->reports,
@@ -2538,7 +2538,7 @@ static int uv_from_view_exec(bContext *C, wmOperator *op)
     float objects_pos_avg[4] = {0};
 
     for (uint ob_index = 0; ob_index < objects_len; ob_index++) {
-      add_v4_v4(objects_pos_avg, objects[ob_index]->obmat[3]);
+      add_v4_v4(objects_pos_avg, objects[ob_index]->object_to_world[3]);
     }
 
     mul_v4_fl(objects_pos_avg, 1.0f / objects_len);
@@ -2576,7 +2576,7 @@ static int uv_from_view_exec(bContext *C, wmOperator *op)
       const bool camera_bounds = RNA_boolean_get(op->ptr, "camera_bounds");
       struct ProjCameraInfo *uci = BLI_uvproject_camera_info(
           v3d->camera,
-          obedit->obmat,
+          obedit->object_to_world,
           camera_bounds ? (scene->r.xsch * scene->r.xasp) : 1.0f,
           camera_bounds ? (scene->r.ysch * scene->r.yasp) : 1.0f);
 
@@ -2597,7 +2597,7 @@ static int uv_from_view_exec(bContext *C, wmOperator *op)
       }
     }
     else {
-      copy_m4_m4(rotmat, obedit->obmat);
+      copy_m4_m4(rotmat, obedit->object_to_world);
 
       BM_ITER_MESH (efa, &iter, em->bm, BM_FACES_OF_MESH) {
         if (!BM_elem_flag_test(efa, BM_ELEM_SELECT)) {