Avoid more needless copying in mesh processing

Apply the same optimisations to mesh type 6 as were just applied to
mesh type 7.

1 files changed, 20 insertions, 33 deletions

diff --git a/fitz/res_shade.c b/fitz/res_shade.c
index 0369830d..732855ed 100644
--- a/fitz/res_shade.c
+++ b/fitz/res_shade.c
@@ -646,9 +646,9 @@ static void
 fz_mesh_type6_process(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz_mesh_processor *painter)
 {
 	fz_stream *stream = fz_open_compressed_buffer(ctx, shade->buffer);
-	int haspatch, hasprevpatch;
-	float prevc[4][FZ_MAX_COLORS];
-	fz_point prevp[12];
+	float color_storage[2][4][FZ_MAX_COLORS];
+	fz_point point_storage[2][12];
+	int store = 0;
 	int ncomp = painter->ncomp;
 	int i, k;
 	int bpflag = shade->u.m.bpflag;
@@ -663,14 +663,16 @@ fz_mesh_type6_process(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz
 
 	fz_try(ctx)
 	{
-		hasprevpatch = 0;
+		float (*prevc)[FZ_MAX_COLORS] = NULL;
+		fz_point *prevp = NULL;
 		while (!fz_is_eof_bits(stream))
 		{
-			float c[4][FZ_MAX_COLORS];
-			fz_point v[12];
+			float (*c)[FZ_MAX_COLORS] = color_storage[store];
+			fz_point *v = point_storage[store];
 			int startcolor;
 			int startpt;
 			int flag;
+			tensor_patch patch;
 
 			flag = fz_read_bits(stream, bpflag);
 
@@ -698,13 +700,10 @@ fz_mesh_type6_process(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz
 					c[i][k] = read_sample(stream, bpcomp, c0[k], c1[k]);
 			}
 
-			haspatch = 0;
-
 			if (flag == 0)
 			{
-				haspatch = 1;
 			}
-			else if (flag == 1 && hasprevpatch)
+			else if (flag == 1 && prevc)
 			{
 				v[0] = prevp[3];
 				v[1] = prevp[4];
@@ -712,10 +711,8 @@ fz_mesh_type6_process(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz
 				v[3] = prevp[6];
 				memcpy(c[0], prevc[1], ncomp * sizeof(float));
 				memcpy(c[1], prevc[2], ncomp * sizeof(float));
-
-				haspatch = 1;
 			}
-			else if (flag == 2 && hasprevpatch)
+			else if (flag == 2 && prevc)
 			{
 				v[0] = prevp[6];
 				v[1] = prevp[7];
@@ -723,10 +720,8 @@ fz_mesh_type6_process(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz
 				v[3] = prevp[9];
 				memcpy(c[0], prevc[2], ncomp * sizeof(float));
 				memcpy(c[1], prevc[3], ncomp * sizeof(float));
-
-				haspatch = 1;
 			}
-			else if (flag == 3 && hasprevpatch)
+			else if (flag == 3 && prevc)
 			{
 				v[0] = prevp[ 9];
 				v[1] = prevp[10];
@@ -734,29 +729,21 @@ fz_mesh_type6_process(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz
 				v[3] = prevp[ 0];
 				memcpy(c[0], prevc[3], ncomp * sizeof(float));
 				memcpy(c[1], prevc[0], ncomp * sizeof(float));
-
-				haspatch = 1;
 			}
+			else
+				continue;
 
-			if (haspatch)
-			{
-				tensor_patch patch;
-
-				make_tensor_patch(&patch, 6, v);
-
-				for (i = 0; i < 4; i++)
-					memcpy(patch.color[i], c[i], ncomp * sizeof(float));
 
-				draw_patch(painter, &patch, SUBDIV, SUBDIV);
+			make_tensor_patch(&patch, 6, v);
 
-				for (i = 0; i < 12; i++)
-					prevp[i] = v[i];
+			for (i = 0; i < 4; i++)
+				memcpy(patch.color[i], c[i], ncomp * sizeof(float));
 
-				for (i = 0; i < 4; i++)
-					memcpy(prevc[i], c[i], ncomp * sizeof(float));
+			draw_patch(painter, &patch, SUBDIV, SUBDIV);
 
-				hasprevpatch = 1;
-			}
+			prevp = v;
+			prevc = c;
+			store ^= 1;
 		}
 	}
 	fz_always(ctx)