DeformMod: Performance by reusing buffers

The Deform modifiers was reallocating buffers that only fit the vertices
of the inner loop. This patch first counts the maximum needed buffer and
allocates one.

When using the daily dweebs animation file the playback performance went
from 0.66 fps to 0.93 fps.

Reviewed By: sybren

Differential Revision: https://developer.blender.org/D7132

1 files changed, 13 insertions, 9 deletions

diff --git a/source/blender/modifiers/intern/MOD_surfacedeform.c b/source/blender/modifiers/intern/MOD_surfacedeform.c
index 605919662f7..743c2227981 100644
--- a/source/blender/modifiers/intern/MOD_surfacedeform.c
+++ b/source/blender/modifiers/intern/MOD_surfacedeform.c
@@ -1121,20 +1121,25 @@ static void deformVert(void *__restrict userdata,
 {
   const SDefDeformData *const data = (SDefDeformData *)userdata;
   const SDefBind *sdbind = data->bind_verts[index].binds;
+  const int num_binds = data->bind_verts[index].numbinds;
   float *const vertexCos = data->vertexCos[index];
   float norm[3], temp[3];
 
   zero_v3(vertexCos);
 
-  for (int j = 0; j < data->bind_verts[index].numbinds; j++, sdbind++) {
-    /* Mode-generic operations (allocate poly coordinates) */
-    float(*coords)[3] = MEM_malloc_arrayN(sdbind->numverts, sizeof(*coords), "SDefDoPolyCoords");
+  /* Allocate a `coords_buffer` that fits all the temp-data. */
+  int max_verts = 0;
+  for (int j = 0; j < num_binds; j++) {
+    max_verts = MAX2(max_verts, sdbind[j].numverts);
+  }
+  float(*coords_buffer)[3] = MEM_malloc_arrayN(max_verts, sizeof(*coords_buffer), __func__);
 
+  for (int j = 0; j < num_binds; j++, sdbind++) {
     for (int k = 0; k < sdbind->numverts; k++) {
-      copy_v3_v3(coords[k], data->targetCos[sdbind->vert_inds[k]]);
+      copy_v3_v3(coords_buffer[k], data->targetCos[sdbind->vert_inds[k]]);
     }
 
-    normal_poly_v3(norm, coords, sdbind->numverts);
+    normal_poly_v3(norm, coords_buffer, sdbind->numverts);
     zero_v3(temp);
 
     /* ---------- looptri mode ---------- */
@@ -1147,14 +1152,14 @@ static void deformVert(void *__restrict userdata,
       /* ---------- ngon mode ---------- */
       if (sdbind->mode == MOD_SDEF_MODE_NGON) {
         for (int k = 0; k < sdbind->numverts; k++) {
-          madd_v3_v3fl(temp, coords[k], sdbind->vert_weights[k]);
+          madd_v3_v3fl(temp, coords_buffer[k], sdbind->vert_weights[k]);
         }
       }
 
       /* ---------- centroid mode ---------- */
       else if (sdbind->mode == MOD_SDEF_MODE_CENTROID) {
         float cent[3];
-        mid_v3_v3_array(cent, coords, sdbind->numverts);
+        mid_v3_v3_array(cent, coords_buffer, sdbind->numverts);
 
         madd_v3_v3fl(temp, data->targetCos[sdbind->vert_inds[0]], sdbind->vert_weights[0]);
         madd_v3_v3fl(temp, data->targetCos[sdbind->vert_inds[1]], sdbind->vert_weights[1]);
@@ -1162,13 +1167,12 @@ static void deformVert(void *__restrict userdata,
       }
     }
 
-    MEM_freeN(coords);
-
     /* Apply normal offset (generic for all modes) */
     madd_v3_v3fl(temp, norm, sdbind->normal_dist);
 
     madd_v3_v3fl(vertexCos, temp, sdbind->influence);
   }
+  MEM_freeN(coords_buffer);
 }
 
 static void surfacedeformModifier_do(ModifierData *md,