Alembic: removed a lot of unnecessary & duplicate code from abc_util.cc

create_transform_matrix(float[4][4]) did mostly the same as
create_transform_matrix(Object *, float[4][4]), but more elegant.
However, the former has some inconsistencies with the latter (which
are now merged and made explicit, turned out one was for z-up→y-up
while the other was for y-up→z-up), and was renamed to
copy_m44_axis_swap(...) to convey its purpose more clearly.

Furthermore, "loc" has been renamed to "trans", as matrices don't
store locations but translations; and more variables now have a src_
or dst_ prefix to denote whether they contain a matrix/vector in the
source or destination axis orientation.

1 files changed, 59 insertions, 215 deletions

diff --git a/source/blender/alembic/intern/abc_util.cc b/source/blender/alembic/intern/abc_util.cc
index 68306af1e42..8b6b2a47e4a 100644
--- a/source/blender/alembic/intern/abc_util.cc
+++ b/source/blender/alembic/intern/abc_util.cc
@@ -162,57 +162,68 @@ static void create_rotation_matrix(
 	rot_z_mat[1][1] = cos(rz);
 }
 
-/* Recompute transform matrix of object in new coordinate system
- * (from Y-Up to Z-Up).
- *
- * Note that r_mat is used as both input and output parameter.
- */
-void create_transform_matrix(float r_mat[4][4])
+/* Convert matrix from Z=up to Y=up or vice versa. Use yup_mat = zup_mat for in-place conversion. */
+void copy_m44_axis_swap(float dst_mat[4][4], float src_mat[4][4], AbcAxisSwapMode mode)
 {
-	float rot_mat[3][3], rot[3][3], scale_mat[4][4], invmat[4][4], transform_mat[4][4];
+	float dst_rot[3][3], src_rot[3][3], dst_scale_mat[4][4];
 	float rot_x_mat[3][3], rot_y_mat[3][3], rot_z_mat[3][3];
-	float loc[3], scale[3], euler[3];
+	float src_trans[3], dst_scale[3], src_scale[3], euler[3];
 
-	zero_v3(loc);
-	zero_v3(scale);
+	zero_v3(src_trans);
+	zero_v3(dst_scale);
+	zero_v3(src_scale);
 	zero_v3(euler);
-	unit_m3(rot);
-	unit_m3(rot_mat);
-	unit_m4(scale_mat);
-	unit_m4(transform_mat);
-	unit_m4(invmat);
+	unit_m3(src_rot);
+	unit_m3(dst_rot);
+	unit_m4(dst_scale_mat);
 
-	/* Compute rotation matrix. */
+	/* We assume there is no sheer component and no homogeneous scaling component. */
+	BLI_assert(src_mat[0][3] == 0.0);
+	BLI_assert(src_mat[1][3] == 0.0);
+	BLI_assert(src_mat[2][3] == 0.0);
+	BLI_assert(src_mat[3][3] == 1.0);
 
-	/* Extract location, rotation, and scale from matrix. */
-	mat4_to_loc_rot_size(loc, rot, scale, r_mat);
+	/* Extract translation, rotation, and scale form matrix. */
+	mat4_to_loc_rot_size(src_trans, src_rot, src_scale, src_mat);
 
 	/* Get euler angles from rotation matrix. */
-	mat3_to_eulO(euler, ROT_MODE_XYZ, rot);
+	mat3_to_eulO(euler, ROT_MODE_XYZ, src_rot);
 
 	/* Create X, Y, Z rotation matrices from euler angles. */
-	create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, false);
+	create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler,
+	                       mode == ABC_YUP_FROM_ZUP);
 
 	/* Concatenate rotation matrices. */
-	mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-	mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-	mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-
-	/* Add rotation matrix to transformation matrix. */
-	copy_m4_m3(transform_mat, rot_mat);
-
-	/* Add translation to transformation matrix. */
-	copy_zup_from_yup(transform_mat[3], loc);
-
-	/* Create scale matrix. */
-	scale_mat[0][0] = scale[0];
-	scale_mat[1][1] = scale[2];
-	scale_mat[2][2] = scale[1];
+	mul_m3_m3m3(dst_rot, dst_rot, rot_y_mat);
+	mul_m3_m3m3(dst_rot, dst_rot, rot_z_mat);
+	mul_m3_m3m3(dst_rot, dst_rot, rot_x_mat);
+
+	mat3_to_eulO(euler, ROT_MODE_XYZ, dst_rot);
+
+	/* Start construction of dst_mat from rotation matrix */
+	unit_m4(dst_mat);
+	copy_m4_m3(dst_mat, dst_rot);
+
+	/* Apply translation */
+	switch(mode) {
+	case ABC_ZUP_FROM_YUP:
+		copy_zup_from_yup(dst_mat[3], src_trans);
+		break;
+	case ABC_YUP_FROM_ZUP:
+		copy_yup_from_zup(dst_mat[3], src_trans);
+		break;
+	default:
+		BLI_assert(false);
+	}
 
-	/* Add scale to transformation matrix. */
-	mul_m4_m4m4(transform_mat, transform_mat, scale_mat);
+	/* Apply scale matrix. Swaps y and z, but does not
+	 * negate like translation does. */
+	dst_scale[0] = src_scale[0];
+	dst_scale[1] = src_scale[2];
+	dst_scale[2] = src_scale[1];
 
-	copy_m4_m4(r_mat, transform_mat);
+	size_to_mat4(dst_scale_mat, dst_scale);
+	mul_m4_m4m4(dst_mat, dst_mat, dst_scale_mat);
 }
 
 void convert_matrix(const Imath::M44d &xform, Object *ob,
@@ -230,7 +241,7 @@ void convert_matrix(const Imath::M44d &xform, Object *ob,
 		mul_m4_m4m4(r_mat, r_mat, cam_to_yup);
 	}
 
-	create_transform_matrix(r_mat);
+	copy_m44_axis_swap(r_mat, r_mat, ABC_ZUP_FROM_YUP);
 
 	if (!has_alembic_parent) {
 		/* Only apply scaling to root objects, parenting will propagate it. */
@@ -241,195 +252,28 @@ void convert_matrix(const Imath::M44d &xform, Object *ob,
 	}
 }
 
-/* Recompute transform matrix of object in new coordinate system (from Z-Up to Y-Up). */
-void create_transform_matrix(Object *obj, float transform_mat[4][4])
+/* Recompute transform matrix of object in new coordinate system
+ * (from Z-Up to Y-Up). */
+void create_transform_matrix(Object *obj, float yup_mat[4][4])
 {
-	float rot_mat[3][3], rot[3][3], scale_mat[4][4], invmat[4][4], mat[4][4];
-	float rot_x_mat[3][3], rot_y_mat[3][3], rot_z_mat[3][3];
-	float loc[3], scale[3], euler[3];
-
-	zero_v3(loc);
-	zero_v3(scale);
-	zero_v3(euler);
-	unit_m3(rot);
-	unit_m3(rot_mat);
-	unit_m4(scale_mat);
-	unit_m4(transform_mat);
-	unit_m4(invmat);
-	unit_m4(mat);
+	float zup_mat[4][4];
 
 	/* get local matrix. */
 	/* TODO Sybren: when we're exporting as "flat", i.e. non-hierarchial,
 	 * we should export the world matrix even when the object has a parent
 	 * Blender Object. */
 	if (obj->parent) {
-		invert_m4_m4(invmat, obj->parent->obmat);
-		mul_m4_m4m4(mat, invmat, obj->obmat);
+		/* Note that this produces another matrix than the local matrix, due to
+		 * constraints and modifiers as well as the obj->parentinv matrix. */
+		invert_m4_m4(obj->parent->imat, obj->parent->obmat);
+		mul_m4_m4m4(zup_mat, obj->parent->imat, obj->obmat);
 	}
 	else {
-		copy_m4_m4(mat, obj->obmat);
+		copy_m4_m4(zup_mat, obj->obmat);
 	}
 
-	/* Compute rotation matrix. */
-	switch (obj->rotmode) {
-		case ROT_MODE_AXISANGLE:
-		{
-			/* Get euler angles from axis angle rotation. */
-			axis_angle_to_eulO(euler, ROT_MODE_XYZ, obj->rotAxis, obj->rotAngle);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-
-			/* Extract location and scale from matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			break;
-		}
-		case ROT_MODE_QUAT:
-		{
-			float q[4];
-			copy_v4_v4(q, obj->quat);
-
-			/* Swap axis. */
-			q[2] = obj->quat[3];
-			q[3] = -obj->quat[2];
-
-			/* Compute rotation matrix from quaternion. */
-			quat_to_mat3(rot_mat, q);
-
-			/* Extract location and scale from matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			break;
-		}
-		case ROT_MODE_XYZ:
-		{
-			/* Extract location, rotation, and scale form matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			/* Get euler angles from rotation matrix. */
-			mat3_to_eulO(euler, ROT_MODE_XYZ, rot);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-
-			break;
-		}
-		case ROT_MODE_XZY:
-		{
-			/* Extract location, rotation, and scale form matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			/* Get euler angles from rotation matrix. */
-			mat3_to_eulO(euler, ROT_MODE_XZY, rot);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-
-			break;
-		}
-		case ROT_MODE_YXZ:
-		{
-			/* Extract location, rotation, and scale form matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			/* Get euler angles from rotation matrix. */
-			mat3_to_eulO(euler, ROT_MODE_YXZ, rot);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-
-			break;
-		}
-		case ROT_MODE_YZX:
-		{
-			/* Extract location, rotation, and scale form matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			/* Get euler angles from rotation matrix. */
-			mat3_to_eulO(euler, ROT_MODE_YZX, rot);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-
-			break;
-		}
-		case ROT_MODE_ZXY:
-		{
-			/* Extract location, rotation, and scale form matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			/* Get euler angles from rotation matrix. */
-			mat3_to_eulO(euler, ROT_MODE_ZXY, rot);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-
-			break;
-		}
-		case ROT_MODE_ZYX:
-		{
-			/* Extract location, rotation, and scale form matrix. */
-			mat4_to_loc_rot_size(loc, rot, scale, mat);
-
-			/* Get euler angles from rotation matrix. */
-			mat3_to_eulO(euler, ROT_MODE_ZYX, rot);
-
-			/* Create X, Y, Z rotation matrices from euler angles. */
-			create_rotation_matrix(rot_x_mat, rot_y_mat, rot_z_mat, euler, true);
-
-			/* Concatenate rotation matrices. */
-			mul_m3_m3m3(rot_mat, rot_mat, rot_x_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_z_mat);
-			mul_m3_m3m3(rot_mat, rot_mat, rot_y_mat);
-
-			break;
-		}
-	}
-
-	/* Add rotation matrix to transformation matrix. */
-	copy_m4_m3(transform_mat, rot_mat);
-
-	/* Add translation to transformation matrix. */
-	copy_yup_from_zup(transform_mat[3], loc);
-
-	/* Create scale matrix. */
-	scale_mat[0][0] = scale[0];
-	scale_mat[1][1] = scale[2];
-	scale_mat[2][2] = scale[1];
 
-	/* Add scale to transformation matrix. */
-	mul_m4_m4m4(transform_mat, transform_mat, scale_mat);
+	copy_m44_axis_swap(yup_mat, zup_mat, ABC_YUP_FROM_ZUP);
 }
 
 bool has_property(const Alembic::Abc::ICompoundProperty &prop, const std::string &name)