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

1 files changed, 16 insertions, 16 deletions

diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index c72bbe2fd08..72733349087 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -750,10 +750,10 @@ void psys_get_birth_coords(
   /* particles live in global space so    */
   /* let's convert:                       */
   /* -location                            */
-  mul_m4_v3(ob->obmat, loc);
+  mul_m4_v3(ob->object_to_world, loc);
 
   /* -normal                              */
-  mul_mat3_m4_v3(ob->obmat, nor);
+  mul_mat3_m4_v3(ob->object_to_world, nor);
   normalize_v3(nor);
 
   /* -tangent                             */
@@ -771,7 +771,7 @@ void psys_get_birth_coords(
     fac = -sinf((float)M_PI * (part->tanphase + phase));
     madd_v3_v3fl(vtan, utan, fac);
 
-    mul_mat3_m4_v3(ob->obmat, vtan);
+    mul_mat3_m4_v3(ob->object_to_world, vtan);
 
     copy_v3_v3(utan, nor);
     mul_v3_fl(utan, dot_v3v3(vtan, nor));
@@ -786,7 +786,7 @@ void psys_get_birth_coords(
     r_vel[1] = 2.0f * (psys_frand(psys, p + 11) - 0.5f);
     r_vel[2] = 2.0f * (psys_frand(psys, p + 12) - 0.5f);
 
-    mul_mat3_m4_v3(ob->obmat, r_vel);
+    mul_mat3_m4_v3(ob->object_to_world, r_vel);
     normalize_v3(r_vel);
   }
 
@@ -796,7 +796,7 @@ void psys_get_birth_coords(
     r_ave[1] = 2.0f * (psys_frand(psys, p + 14) - 0.5f);
     r_ave[2] = 2.0f * (psys_frand(psys, p + 15) - 0.5f);
 
-    mul_mat3_m4_v3(ob->obmat, r_ave);
+    mul_mat3_m4_v3(ob->object_to_world, r_ave);
     normalize_v3(r_ave);
   }
 
@@ -808,7 +808,7 @@ void psys_get_birth_coords(
     r_rot[3] = 2.0f * (psys_frand(psys, p + 19) - 0.5f);
     normalize_qt(r_rot);
 
-    mat4_to_quat(rot, ob->obmat);
+    mat4_to_quat(rot, ob->object_to_world);
     mul_qt_qtqt(r_rot, r_rot, rot);
   }
 
@@ -822,7 +822,7 @@ void psys_get_birth_coords(
 
     /* boids store direction in ave */
     if (fabsf(nor[2]) == 1.0f) {
-      sub_v3_v3v3(state->ave, loc, ob->obmat[3]);
+      sub_v3_v3v3(state->ave, loc, ob->object_to_world[3]);
       normalize_v3(state->ave);
     }
     else {
@@ -868,15 +868,15 @@ void psys_get_birth_coords(
 
     /*      *emitter object orientation     */
     if (part->ob_vel[0] != 0.0f) {
-      normalize_v3_v3(vec, ob->obmat[0]);
+      normalize_v3_v3(vec, ob->object_to_world[0]);
       madd_v3_v3fl(vel, vec, part->ob_vel[0]);
     }
     if (part->ob_vel[1] != 0.0f) {
-      normalize_v3_v3(vec, ob->obmat[1]);
+      normalize_v3_v3(vec, ob->object_to_world[1]);
       madd_v3_v3fl(vel, vec, part->ob_vel[1]);
     }
     if (part->ob_vel[2] != 0.0f) {
-      normalize_v3_v3(vec, ob->obmat[2]);
+      normalize_v3_v3(vec, ob->object_to_world[2]);
       madd_v3_v3fl(vel, vec, part->ob_vel[2]);
     }
 
@@ -924,7 +924,7 @@ void psys_get_birth_coords(
         case PART_ROT_OB_X:
         case PART_ROT_OB_Y:
         case PART_ROT_OB_Z:
-          copy_v3_v3(rot_vec, ob->obmat[part->rotmode - PART_ROT_OB_X]);
+          copy_v3_v3(rot_vec, ob->object_to_world[part->rotmode - PART_ROT_OB_X]);
           use_global_space = false;
           break;
         default:
@@ -951,7 +951,7 @@ void psys_get_birth_coords(
         float q_obmat[4];
         float q_imat[4];
 
-        mat4_to_quat(q_obmat, ob->obmat);
+        mat4_to_quat(q_obmat, ob->object_to_world);
         invert_qt_qt_normalized(q_imat, q_obmat);
 
         if (part->rotmode != PART_ROT_NOR_TAN) {
@@ -3364,7 +3364,7 @@ static void hair_create_input_mesh(ParticleSimulationData *sim,
       use_hair = psys_hair_use_simulation(pa, max_length);
 
       psys_mat_hair_to_object(sim->ob, sim->psmd->mesh_final, psys->part->from, pa, hairmat);
-      mul_m4_m4m4(root_mat, sim->ob->obmat, hairmat);
+      mul_m4_m4m4(root_mat, sim->ob->object_to_world, hairmat);
       normalize_m4(root_mat);
 
       bending_stiffness = CLAMPIS(
@@ -3555,7 +3555,7 @@ static void save_hair(ParticleSimulationData *sim, float UNUSED(cfra))
   HairKey *key, *root;
   PARTICLE_P;
 
-  invert_m4_m4(ob->imat, ob->obmat);
+  invert_m4_m4(ob->imat, ob->object_to_world);
 
   psys->lattice_deform_data = psys_create_lattice_deform_data(sim);
 
@@ -4380,7 +4380,7 @@ static void particles_fluid_step(ParticleSimulationData *sim,
           mul_v3_v3(pa->state.co, scaleAbs);
 
           /* Match domain scale. */
-          mul_m4_v3(ob->obmat, pa->state.co);
+          mul_m4_v3(ob->object_to_world, pa->state.co);
 
           /* Add origin offset to particle position. */
           zero_v3(tmp);
@@ -4963,7 +4963,7 @@ void particle_system_update(struct Depsgraph *depsgraph,
 
   /* Save matrix for duplicators,
    * at render-time the actual dupli-object's matrix is used so don't update! */
-  invert_m4_m4(psys->imat, ob->obmat);
+  invert_m4_m4(psys->imat, ob->object_to_world);
 
   BKE_particle_batch_cache_dirty_tag(psys, BKE_PARTICLE_BATCH_DIRTY_ALL);
 }