Subdiv: Cleanup, de-duplicate tangent matrix calculation

4 files changed, 88 insertions, 65 deletions

diff --git a/source/blender/blenkernel/BKE_multires.h b/source/blender/blenkernel/BKE_multires.h
index 28a98768a06..d4e0dbb72cd 100644
--- a/source/blender/blenkernel/BKE_multires.h
+++ b/source/blender/blenkernel/BKE_multires.h
@@ -32,6 +32,8 @@
  *  \ingroup bke
  */
 
+#include "BLI_compiler_compat.h"
+
 enum MultiresModifiedFlags;
 
 struct Depsgraph;
@@ -151,4 +153,18 @@ void BKE_multires_subdiv_mesh_settings_init(
         const bool use_render_params,
         const bool ignore_simplify);
 
+/* General helpers. */
+
+/* For a given partial derivatives of a ptex face get tangent matrix for
+ * displacement.
+ * Corner needs to be known to properly "rotate" partial derivatives.
+ */
+BLI_INLINE void BKE_multires_construct_tangent_matrix(
+        float tangent_matrix[3][3],
+        const float dPdu[3],
+        const float dPdv[3],
+        const int corner);
+
 #endif  /* __BKE_MULTIRES_H__ */
+
+#include "intern/multires_inline.h"
diff --git a/source/blender/blenkernel/intern/multires_inline.h b/source/blender/blenkernel/intern/multires_inline.h
new file mode 100644
index 00000000000..fe01fb6e221
--- /dev/null
+++ b/source/blender/blenkernel/intern/multires_inline.h
@@ -0,0 +1,68 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2018 by Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Sergey Sharybin.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/blenkernel/intern/multires_inline.h
+ *  \ingroup bke
+ */
+
+#ifndef __BKE_MULTIRES_INLINE_H__
+#define __BKE_MULTIRES_INLINE_H__
+
+#include "BKE_multires.h"
+#include "BLI_math_vector.h"
+
+BLI_INLINE void BKE_multires_construct_tangent_matrix(
+        float tangent_matrix[3][3],
+        const float dPdu[3],
+        const float dPdv[3],
+        const int corner)
+{
+	if (corner == 0) {
+		copy_v3_v3(tangent_matrix[0], dPdv);
+		copy_v3_v3(tangent_matrix[1], dPdu);
+		mul_v3_fl(tangent_matrix[0], -1.0f);
+		mul_v3_fl(tangent_matrix[1], -1.0f);
+	}
+	else if (corner == 1) {
+		copy_v3_v3(tangent_matrix[0], dPdu);
+		copy_v3_v3(tangent_matrix[1], dPdv);
+		mul_v3_fl(tangent_matrix[1], -1.0f);
+	}
+	else if (corner == 2) {
+		copy_v3_v3(tangent_matrix[0], dPdv);
+		copy_v3_v3(tangent_matrix[1], dPdu);
+	}
+	else if (corner == 3) {
+		copy_v3_v3(tangent_matrix[0], dPdu);
+		copy_v3_v3(tangent_matrix[1], dPdv);
+		mul_v3_fl(tangent_matrix[0], -1.0f);
+	}
+	cross_v3_v3v3(tangent_matrix[2], dPdu, dPdv);
+	normalize_v3(tangent_matrix[0]);
+	normalize_v3(tangent_matrix[1]);
+	normalize_v3(tangent_matrix[2]);
+}
+
+#endif  /* __BKE_MULTIRES_INLINE_H__ */
diff --git a/source/blender/blenkernel/intern/multires_reshape.c b/source/blender/blenkernel/intern/multires_reshape.c
index d99e8486738..22605eb510a 100644
--- a/source/blender/blenkernel/intern/multires_reshape.c
+++ b/source/blender/blenkernel/intern/multires_reshape.c
@@ -86,37 +86,6 @@ BLI_INLINE int rotate_quad_to_corner(const float u, const float v,
 	return corner;
 }
 
-BLI_INLINE void construct_tangent_matrix(float tangent_matrix[3][3],
-                                         const float dPdu[3],
-                                         const float dPdv[3],
-                                         const int corner)
-{
-	if (corner == 0) {
-		copy_v3_v3(tangent_matrix[0], dPdv);
-		copy_v3_v3(tangent_matrix[1], dPdu);
-		mul_v3_fl(tangent_matrix[0], -1.0f);
-		mul_v3_fl(tangent_matrix[1], -1.0f);
-	}
-	else if (corner == 1) {
-		copy_v3_v3(tangent_matrix[0], dPdu);
-		copy_v3_v3(tangent_matrix[1], dPdv);
-		mul_v3_fl(tangent_matrix[1], -1.0f);
-	}
-	else if (corner == 2) {
-		copy_v3_v3(tangent_matrix[0], dPdv);
-		copy_v3_v3(tangent_matrix[1], dPdu);
-	}
-	else if (corner == 3) {
-		copy_v3_v3(tangent_matrix[0], dPdu);
-		copy_v3_v3(tangent_matrix[1], dPdv);
-		mul_v3_fl(tangent_matrix[0], -1.0f);
-	}
-	cross_v3_v3v3(tangent_matrix[2], dPdu, dPdv);
-	normalize_v3(tangent_matrix[0]);
-	normalize_v3(tangent_matrix[1]);
-	normalize_v3(tangent_matrix[2]);
-}
-
 static void multires_reshape_init_mmd(
         MultiresModifierData *reshape_mmd,
         const MultiresModifierData *mmd)
@@ -364,7 +333,8 @@ static void multires_reshape_vertex_from_final_data(
 	float D[3];
 	sub_v3_v3v3(D, final_P, P);
 	float tangent_matrix[3][3];
-	construct_tangent_matrix(tangent_matrix, dPdu, dPdv, grid_corner);
+	BKE_multires_construct_tangent_matrix(
+	        tangent_matrix, dPdu, dPdv, grid_corner);
 	float inv_tangent_matrix[3][3];
 	invert_m3_m3(inv_tangent_matrix, tangent_matrix);
 	float tangent_D[3];
diff --git a/source/blender/blenkernel/intern/subdiv_displacement_multires.c b/source/blender/blenkernel/intern/subdiv_displacement_multires.c
index aea02c5f9c9..bcb96ce8a66 100644
--- a/source/blender/blenkernel/intern/subdiv_displacement_multires.c
+++ b/source/blender/blenkernel/intern/subdiv_displacement_multires.c
@@ -38,6 +38,7 @@
 #include "BLI_math_vector.h"
 
 #include "BKE_customdata.h"
+#include "BKE_multires.h"
 
 #include "MEM_guardedalloc.h"
 
@@ -156,38 +157,6 @@ static const MDisps *displacement_get_prev_grid(
 	return &data->mdisps[poly->loopstart + prev_corner];
 }
 
-/* NOTE: Derivatives are in ptex face space. */
-BLI_INLINE void construct_tangent_matrix(float tangent_matrix[3][3],
-                                         const float dPdu[3],
-                                         const float dPdv[3],
-                                         const int corner)
-{
-	if (corner == 0) {
-		copy_v3_v3(tangent_matrix[0], dPdv);
-		copy_v3_v3(tangent_matrix[1], dPdu);
-		mul_v3_fl(tangent_matrix[0], -1.0f);
-		mul_v3_fl(tangent_matrix[1], -1.0f);
-	}
-	else if (corner == 1) {
-		copy_v3_v3(tangent_matrix[0], dPdu);
-		copy_v3_v3(tangent_matrix[1], dPdv);
-		mul_v3_fl(tangent_matrix[1], -1.0f);
-	}
-	else if (corner == 2) {
-		copy_v3_v3(tangent_matrix[0], dPdv);
-		copy_v3_v3(tangent_matrix[1], dPdu);
-	}
-	else if (corner == 3) {
-		copy_v3_v3(tangent_matrix[0], dPdu);
-		copy_v3_v3(tangent_matrix[1], dPdv);
-		mul_v3_fl(tangent_matrix[0], -1.0f);
-	}
-	cross_v3_v3v3(tangent_matrix[2], dPdu, dPdv);
-	normalize_v3(tangent_matrix[0]);
-	normalize_v3(tangent_matrix[1]);
-	normalize_v3(tangent_matrix[2]);
-}
-
 BLI_INLINE eAverageWith read_displacement_grid(
         const MDisps *displacement_grid,
         const int grid_size,
@@ -331,7 +300,7 @@ static void eval_displacement(SubdivDisplacement *displacement,
 	                     tangent_D);
 	/* Convert it to the object space. */
 	float tangent_matrix[3][3];
-	construct_tangent_matrix(tangent_matrix, dPdu, dPdv, corner);
+	BKE_multires_construct_tangent_matrix(tangent_matrix, dPdu, dPdv, corner);
 	mul_v3_m3v3(r_D, tangent_matrix, tangent_D);
 }