multi-threaded sequencer buffer calculation for masks.

1 files changed, 9 insertions, 8 deletions

diff --git a/source/blender/blenkernel/intern/mask_rasterize.c b/source/blender/blenkernel/intern/mask_rasterize.c
index ce04ad31a33..ba0d738409c 100644
--- a/source/blender/blenkernel/intern/mask_rasterize.c
+++ b/source/blender/blenkernel/intern/mask_rasterize.c
@@ -1291,27 +1291,28 @@ float BKE_maskrasterize_handle_sample(MaskRasterHandle *mr_handle, const float x
  * \brief Rasterize a buffer from a single mask
  *
  * We could get some speedup by inlining #BKE_maskrasterize_handle_sample
- * and calcilating each layer then blending buffers, but this function is only
+ * and calculating each layer then blending buffers, but this function is only
  * used by the sequencer - so better have the caller thread.
  *
- * If we wanted to this function could be threaded with OpenMP easily.
+ * Since #BKE_maskrasterize_handle_sample is used threaded elsewhere,
+ * we can simply use openmp here for some speedup.
  */
 void BKE_maskrasterize_buffer(MaskRasterHandle *mr_handle,
                               const unsigned int width, const unsigned int height,
                               float *buffer)
 {
-	unsigned int x;
 	unsigned int y;
-	float *fp = buffer;
-
-	float xy[2];
 
+#pragma omp parallel for private(y)
 	for (y = 0; y < height; y++) {
+		unsigned int i = y * width;
+		unsigned int x;
+		float xy[2];
 		xy[1] = (float)y / (float)height;
-		for (x = 0; x < width; x++) {
+		for (x = 0; x < width; x++, i++) {
 			xy[0] = (float)x / (float)width;
 
-			*fp++ = BKE_maskrasterize_handle_sample(mr_handle, xy);
+			buffer[i] = BKE_maskrasterize_handle_sample(mr_handle, xy);
 		}
 	}
 }