Fix T46851: Crash on multires more than million

yet another bug introduced by recent shadowing changes -- q and r CCG arrays
were overwritten by the temporary evaluation because the code was changed to
use global pointers instead of the local ones.

Naming of the variables could be changed to be a bit more accurate.

1 files changed, 22 insertions, 20 deletions

diff --git a/source/blender/blenkernel/intern/CCGSubSurf_legacy.c b/source/blender/blenkernel/intern/CCGSubSurf_legacy.c
index afa44048317..e9002af19b1 100644
--- a/source/blender/blenkernel/intern/CCGSubSurf_legacy.c
+++ b/source/blender/blenkernel/intern/CCGSubSurf_legacy.c
@@ -684,10 +684,12 @@ static void ccgSubSurf__calcSubdivLevel(
 
 #pragma omp parallel private(ptrIdx) if (numEffectedF * edgeSize * edgeSize * 4 >= CCG_OMP_LIMIT)
 	{
+		float *q_thread, *r_thread;
+
 #pragma omp critical
 		{
-			q = MEM_mallocN(ss->meshIFC.vertDataSize, "CCGSubsurf q");
-			r = MEM_mallocN(ss->meshIFC.vertDataSize, "CCGSubsurf r");
+			q_thread = MEM_mallocN(ss->meshIFC.vertDataSize, "CCGSubsurf q");
+			r_thread = MEM_mallocN(ss->meshIFC.vertDataSize, "CCGSubsurf r");
 		}
 
 #pragma omp for schedule(static)
@@ -700,20 +702,20 @@ static void ccgSubSurf__calcSubdivLevel(
 			 * - old interior edge points
 			 * - new interior face midpoints
 			 */
-			VertDataZero(q, ss);
+			VertDataZero(q_thread, ss);
 			for (S = 0; S < f->numVerts; S++) {
-				VertDataAdd(q, FACE_getIFCo(f, nextLvl, S, 1, 1), ss);
+				VertDataAdd(q_thread, FACE_getIFCo(f, nextLvl, S, 1, 1), ss);
 			}
-			VertDataMulN(q, 1.0f / f->numVerts, ss);
-			VertDataZero(r, ss);
+			VertDataMulN(q_thread, 1.0f / f->numVerts, ss);
+			VertDataZero(r_thread, ss);
 			for (S = 0; S < f->numVerts; S++) {
-				VertDataAdd(r, FACE_getIECo(f, curLvl, S, 1), ss);
+				VertDataAdd(r_thread, FACE_getIECo(f, curLvl, S, 1), ss);
 			}
-			VertDataMulN(r, 1.0f / f->numVerts, ss);
+			VertDataMulN(r_thread, 1.0f / f->numVerts, ss);
 
 			VertDataMulN((float *)FACE_getCenterData(f), f->numVerts - 2.0f, ss);
-			VertDataAdd((float *)FACE_getCenterData(f), q, ss);
-			VertDataAdd((float *)FACE_getCenterData(f), r, ss);
+			VertDataAdd((float *)FACE_getCenterData(f), q_thread, ss);
+			VertDataAdd((float *)FACE_getCenterData(f), r_thread, ss);
 			VertDataMulN((float *)FACE_getCenterData(f), 1.0f / f->numVerts, ss);
 
 			for (S = 0; S < f->numVerts; S++) {
@@ -729,14 +731,14 @@ static void ccgSubSurf__calcSubdivLevel(
 						const float *co = FACE_getIFCo(f, curLvl, S, x, y);
 						float *nCo = FACE_getIFCo(f, nextLvl, S, fx, fy);
 						
-						VertDataAvg4(q,
+						VertDataAvg4(q_thread,
 						             FACE_getIFCo(f, nextLvl, S, fx - 1, fy - 1),
 						             FACE_getIFCo(f, nextLvl, S, fx + 1, fy - 1),
 						             FACE_getIFCo(f, nextLvl, S, fx + 1, fy + 1),
 						             FACE_getIFCo(f, nextLvl, S, fx - 1, fy + 1),
 						             ss);
 
-						VertDataAvg4(r,
+						VertDataAvg4(r_thread,
 						             FACE_getIFCo(f, nextLvl, S, fx - 1, fy + 0),
 						             FACE_getIFCo(f, nextLvl, S, fx + 1, fy + 0),
 						             FACE_getIFCo(f, nextLvl, S, fx + 0, fy - 1),
@@ -744,9 +746,9 @@ static void ccgSubSurf__calcSubdivLevel(
 						             ss);
 
 						VertDataCopy(nCo, co, ss);
-						VertDataSub(nCo, q, ss);
+						VertDataSub(nCo, q_thread, ss);
 						VertDataMulN(nCo, 0.25f, ss);
-						VertDataAdd(nCo, r, ss);
+						VertDataAdd(nCo, r_thread, ss);
 					}
 				}
 
@@ -760,13 +762,13 @@ static void ccgSubSurf__calcSubdivLevel(
 					const float *co = FACE_getIECo(f, curLvl, S, x);
 					float *nCo = FACE_getIECo(f, nextLvl, S, fx);
 					
-					VertDataAvg4(q,
+					VertDataAvg4(q_thread,
 					             FACE_getIFCo(f, nextLvl, (S + 1) % f->numVerts, 1, fx - 1),
 					             FACE_getIFCo(f, nextLvl, (S + 1) % f->numVerts, 1, fx + 1),
 					             FACE_getIFCo(f, nextLvl, S, fx + 1, +1),
 					             FACE_getIFCo(f, nextLvl, S, fx - 1, +1), ss);
 
-					VertDataAvg4(r,
+					VertDataAvg4(r_thread,
 					             FACE_getIECo(f, nextLvl, S, fx - 1),
 					             FACE_getIECo(f, nextLvl, S, fx + 1),
 					             FACE_getIFCo(f, nextLvl, (S + 1) % f->numVerts, 1, fx),
@@ -774,17 +776,17 @@ static void ccgSubSurf__calcSubdivLevel(
 					             ss);
 
 					VertDataCopy(nCo, co, ss);
-					VertDataSub(nCo, q, ss);
+					VertDataSub(nCo, q_thread, ss);
 					VertDataMulN(nCo, 0.25f, ss);
-					VertDataAdd(nCo, r, ss);
+					VertDataAdd(nCo, r_thread, ss);
 				}
 			}
 		}
 
 #pragma omp critical
 		{
-			MEM_freeN(q);
-			MEM_freeN(r);
+			MEM_freeN(q_thread);
+			MEM_freeN(r_thread);
 		}
 	}