Basic Add tool for creating new strands in hair edit mode.

11 files changed, 207 insertions, 37 deletions

diff --git a/source/blender/blenkernel/BKE_edithair.h b/source/blender/blenkernel/BKE_edithair.h
index 070f8df2c8d..7d39ff691a8 100644
--- a/source/blender/blenkernel/BKE_edithair.h
+++ b/source/blender/blenkernel/BKE_edithair.h
@@ -54,11 +54,18 @@ typedef struct BMEditStrands {
 	struct Object *ob;
 	struct DerivedMesh *root_dm;
 	
+	int flag;
+	
 	unsigned int vertex_glbuf;
 	unsigned int elem_glbuf;
 	unsigned int dot_glbuf;
 } BMEditStrands;
 
+/* BMEditStrands->flag */
+typedef enum BMEditStrandsFlag {
+	BM_STRANDS_DIRTY_SEGLEN     = 1,
+} BMEditStrandsFlag;
+
 struct BMEditStrands *BKE_editstrands_create(struct BMesh *bm, struct DerivedMesh *root_dm);
 struct BMEditStrands *BKE_editstrands_copy(struct BMEditStrands *es);
 struct BMEditStrands *BKE_editstrands_from_object(struct Object *ob);
@@ -67,9 +74,8 @@ void BKE_editstrands_free(struct BMEditStrands *es);
 
 /* === constraints === */
 
-void BKE_editstrands_calc_segment_lengths(struct BMesh *bm);
-
 void BKE_editstrands_solve_constraints(struct BMEditStrands *es);
+void BKE_editstrands_ensure(struct BMEditStrands *es);
 
 /* === particle conversion === */
 
diff --git a/source/blender/blenkernel/BKE_mesh_sample.h b/source/blender/blenkernel/BKE_mesh_sample.h
index e43b162a7b8..6b489550847 100644
--- a/source/blender/blenkernel/BKE_mesh_sample.h
+++ b/source/blender/blenkernel/BKE_mesh_sample.h
@@ -33,7 +33,7 @@ struct MSurfaceSample;
 
 /* ==== Evaluate ==== */
 
-bool BKE_mesh_sample_eval(struct DerivedMesh *dm, const struct MSurfaceSample *sample, float loc[3], float nor[3]);
+bool BKE_mesh_sample_eval(struct DerivedMesh *dm, const struct MSurfaceSample *sample, float loc[3], float nor[3], float tang[3]);
 bool BKE_mesh_sample_shapekey(struct Key *key, struct KeyBlock *kb, const struct MSurfaceSample *sample, float loc[3]);
 
 
diff --git a/source/blender/blenkernel/intern/edithair.c b/source/blender/blenkernel/intern/edithair.c
index e1064d95946..2da64f18dc0 100644
--- a/source/blender/blenkernel/intern/edithair.c
+++ b/source/blender/blenkernel/intern/edithair.c
@@ -101,7 +101,7 @@ void BKE_editstrands_free(BMEditStrands *es)
 
 /* === constraints === */
 
-void BKE_editstrands_calc_segment_lengths(BMesh *bm)
+static void editstrands_calc_segment_lengths(BMesh *bm)
 {
 	BMVert *root, *v, *vprev;
 	BMIter iter, iter_strand;
@@ -128,10 +128,10 @@ static void editstrands_apply_root_locations(BMesh *bm, DerivedMesh *root_dm)
 	
 	BM_ITER_STRANDS(root, &iter, bm, BM_STRANDS_OF_MESH) {
 		MSurfaceSample root_sample;
-		float loc[3], nor[3];
+		float loc[3], nor[3], tang[3];
 		
 		BM_elem_meshsample_data_named_get(&bm->vdata, root, CD_MSURFACE_SAMPLE, CD_HAIR_ROOT_LOCATION, &root_sample);
-		if (BKE_mesh_sample_eval(root_dm, &root_sample, loc, nor)) {
+		if (BKE_mesh_sample_eval(root_dm, &root_sample, loc, nor, tang)) {
 			copy_v3_v3(root->co, loc);
 		}
 	}
@@ -167,10 +167,23 @@ static void editstrands_solve_segment_lengths(BMesh *bm)
 
 void BKE_editstrands_solve_constraints(BMEditStrands *es)
 {
+	BKE_editstrands_ensure(es);
+	
 	editstrands_apply_root_locations(es->bm, es->root_dm);
 	editstrands_solve_segment_lengths(es->bm);
 }
 
+void BKE_editstrands_ensure(BMEditStrands *es)
+{
+	BM_strands_cd_flag_ensure(es->bm, 0);
+	
+	if (es->flag & BM_STRANDS_DIRTY_SEGLEN) {
+		editstrands_calc_segment_lengths(es->bm);
+		
+		es->flag &= ~BM_STRANDS_DIRTY_SEGLEN;
+	}
+}
+
 
 /* === particle conversion === */
 
@@ -188,7 +201,7 @@ BMesh *BKE_particles_to_bmesh(Object *ob, ParticleSystem *psys)
 		
 		BM_strands_bm_from_psys(bm, ob, psys, psmd->dm, true, psys->shapenr);
 		
-		BKE_editstrands_calc_segment_lengths(bm);
+		editstrands_calc_segment_lengths(bm);
 	}
 
 	return bm;
diff --git a/source/blender/blenkernel/intern/mesh_sample.c b/source/blender/blenkernel/intern/mesh_sample.c
index b4c59037f88..c36d2adde8b 100644
--- a/source/blender/blenkernel/intern/mesh_sample.c
+++ b/source/blender/blenkernel/intern/mesh_sample.c
@@ -43,15 +43,15 @@
 
 /* ==== Evaluate ==== */
 
-bool BKE_mesh_sample_eval(DerivedMesh *dm, const MSurfaceSample *sample, float loc[3], float nor[3])
+bool BKE_mesh_sample_eval(DerivedMesh *dm, const MSurfaceSample *sample, float loc[3], float nor[3], float tang[3])
 {
 	MVert *mverts = dm->getVertArray(dm);
 	unsigned int totverts = (unsigned int)dm->getNumVerts(dm);
 	MVert *v1, *v2, *v3;
-	float vnor[3];
 	
 	zero_v3(loc);
 	zero_v3(nor);
+	zero_v3(tang);
 	
 	if (sample->orig_verts[0] >= totverts ||
 	    sample->orig_verts[1] >= totverts ||
@@ -62,18 +62,39 @@ bool BKE_mesh_sample_eval(DerivedMesh *dm, const MSurfaceSample *sample, float l
 	v2 = &mverts[sample->orig_verts[1]];
 	v3 = &mverts[sample->orig_verts[2]];
 	
-	madd_v3_v3fl(loc, v1->co, sample->orig_weights[0]);
-	madd_v3_v3fl(loc, v2->co, sample->orig_weights[1]);
-	madd_v3_v3fl(loc, v3->co, sample->orig_weights[2]);
+	{ /* location */
+		madd_v3_v3fl(loc, v1->co, sample->orig_weights[0]);
+		madd_v3_v3fl(loc, v2->co, sample->orig_weights[1]);
+		madd_v3_v3fl(loc, v3->co, sample->orig_weights[2]);
+	}
 	
-	normal_short_to_float_v3(vnor, v1->no);
-	madd_v3_v3fl(nor, vnor, sample->orig_weights[0]);
-	normal_short_to_float_v3(vnor, v2->no);
-	madd_v3_v3fl(nor, vnor, sample->orig_weights[1]);
-	normal_short_to_float_v3(vnor, v3->no);
-	madd_v3_v3fl(nor, vnor, sample->orig_weights[2]);
+	{ /* normal */
+		float vnor[3];
+		
+		normal_short_to_float_v3(vnor, v1->no);
+		madd_v3_v3fl(nor, vnor, sample->orig_weights[0]);
+		normal_short_to_float_v3(vnor, v2->no);
+		madd_v3_v3fl(nor, vnor, sample->orig_weights[1]);
+		normal_short_to_float_v3(vnor, v3->no);
+		madd_v3_v3fl(nor, vnor, sample->orig_weights[2]);
+		
+		normalize_v3(nor);
+	}
 	
-	normalize_v3(nor);
+	{ /* tangent */
+		float edge[3];
+		
+		/* XXX simply using the v1-v2 edge as a tangent vector for now ...
+		 * Eventually mikktspace generated tangents (CD_TANGENT tessface layer)
+		 * should be used for consistency, but requires well-defined tessface
+		 * indices for the mesh surface samples.
+		 */
+		
+		sub_v3_v3v3(edge, v2->co, v1->co);
+		/* make edge orthogonal to nor */
+		madd_v3_v3fl(edge, nor, -dot_v3v3(edge, nor));
+		normalize_v3_v3(tang, edge);
+	}
 	
 	return true;
 }
@@ -329,9 +350,9 @@ bool BKE_mesh_sample_from_particle(MSurfaceSample *sample, ParticleSystem *psys,
 bool BKE_mesh_sample_to_particle(MSurfaceSample *sample, ParticleSystem *UNUSED(psys), DerivedMesh *dm, BVHTreeFromMesh *bvhtree, ParticleData *pa)
 {
 	BVHTreeNearest nearest;
-	float vec[3], nor[3];
+	float vec[3], nor[3], tang[3];
 	
-	BKE_mesh_sample_eval(dm, sample, vec, nor);
+	BKE_mesh_sample_eval(dm, sample, vec, nor, tang);
 	
 	nearest.index = -1;
 	nearest.dist_sq = FLT_MAX;
diff --git a/source/blender/bmesh/intern/bmesh_strands.c b/source/blender/bmesh/intern/bmesh_strands.c
index ae8fd7ae4f1..ec1b7781dd6 100644
--- a/source/blender/bmesh/intern/bmesh_strands.c
+++ b/source/blender/bmesh/intern/bmesh_strands.c
@@ -27,6 +27,7 @@
 #include "MEM_guardedalloc.h"
 
 #include "BLI_utildefines.h"
+#include "BLI_math.h"
 #include "BLI_mempool.h"
 
 #include "bmesh.h"
@@ -115,3 +116,30 @@ int BM_strands_keys_count(BMVert *root)
 	return count;
 }
 
+/* ------------------------------------------------------------------------- */
+
+/* Create a new strand */
+BMVert *BM_strands_create(BMesh *bm, int len, bool set_defaults)
+{
+	float co[3] = {0.0f, 0.0f, 0.0f};
+	
+	BMVert *root, *v, *vprev;
+	int k;
+	
+	for (k = 0; k < len; ++k) {
+		vprev = v;
+		v = BM_vert_create(bm, co, NULL, set_defaults ? BM_CREATE_NOP : BM_CREATE_SKIP_CD);
+		
+		zero_v3(v->no);
+		
+		/* root */
+		if (k == 0) {
+			root = v;
+		}
+		else {
+			/*BMEdge *e =*/ BM_edge_create(bm, vprev, v, NULL, set_defaults ? BM_CREATE_NOP : BM_CREATE_SKIP_CD);
+		}
+	}
+	
+	return root;
+}
diff --git a/source/blender/bmesh/intern/bmesh_strands.h b/source/blender/bmesh/intern/bmesh_strands.h
index 8410bfd8443..66284ee62f8 100644
--- a/source/blender/bmesh/intern/bmesh_strands.h
+++ b/source/blender/bmesh/intern/bmesh_strands.h
@@ -72,6 +72,9 @@ BLI_INLINE bool BM_strands_vert_is_tip(BMVert *v)
 int BM_strands_count(BMesh *bm);
 int BM_strands_keys_count(BMVert *root);
 
+/* Create a new strand */
+struct BMVert *BM_strands_create(struct BMesh *bm, int len, bool set_defaults);
+
 /* ==== Iterators ==== */
 
 typedef enum BMStrandsIterType {
diff --git a/source/blender/bmesh/intern/bmesh_strands_conv.c b/source/blender/bmesh/intern/bmesh_strands_conv.c
index 786b35b486a..b23dbbdf1fe 100644
--- a/source/blender/bmesh/intern/bmesh_strands_conv.c
+++ b/source/blender/bmesh/intern/bmesh_strands_conv.c
@@ -76,13 +76,10 @@ void BM_strands_cd_validate(BMesh *UNUSED(bm))
 {
 }
 
-void BM_strands_cd_flag_ensure(BMesh *bm, ParticleSystem *psys, const char cd_flag)
+void BM_strands_cd_flag_ensure(BMesh *bm, const char cd_flag)
 {
 	const char cd_flag_all = BM_strands_cd_flag_from_bmesh(bm) | cd_flag;
 	BM_strands_cd_flag_apply(bm, cd_flag_all);
-	if (psys) {
-//		psys->cd_flag = cd_flag_all;
-	}
 }
 
 void BM_strands_cd_flag_apply(BMesh *bm, const char UNUSED(cd_flag))
diff --git a/source/blender/bmesh/intern/bmesh_strands_conv.h b/source/blender/bmesh/intern/bmesh_strands_conv.h
index 30bf139c4de..683c1e998ad 100644
--- a/source/blender/bmesh/intern/bmesh_strands_conv.h
+++ b/source/blender/bmesh/intern/bmesh_strands_conv.h
@@ -45,7 +45,7 @@ extern const char *CD_HAIR_WEIGHT;
 extern const char *CD_HAIR_ROOT_LOCATION;
 
 void BM_strands_cd_validate(struct BMesh *bm);
-void BM_strands_cd_flag_ensure(struct BMesh *bm, struct ParticleSystem *psys, const char cd_flag);
+void BM_strands_cd_flag_ensure(struct BMesh *bm, const char cd_flag);
 void BM_strands_cd_flag_apply(struct BMesh *bm, const char cd_flag);
 char BM_strands_cd_flag_from_bmesh(struct BMesh *bm);
 
diff --git a/source/blender/editors/hair/hair_edit.c b/source/blender/editors/hair/hair_edit.c
index fa7e914b5ee..4912adde524 100644
--- a/source/blender/editors/hair/hair_edit.c
+++ b/source/blender/editors/hair/hair_edit.c
@@ -308,7 +308,6 @@ static bool hair_stroke_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
 	HairEditSettings *settings = &scene->toolsettings->hair_edit;
 	ARegion *ar = CTX_wm_region(C);
 	
-	float imat[4][4];
 	float mouse[2], mdelta[2], zvec[3], delta_max;
 	int totsteps, step;
 	HairToolData tool_data;
@@ -316,8 +315,6 @@ static bool hair_stroke_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
 	
 	RNA_float_get_array(itemptr, "mouse", mouse);
 	
-	invert_m4_m4(imat, ob->obmat);
-	
 	if (stroke->first) {
 		copy_v2_v2(stroke->lastmouse, mouse);
 		stroke->first = false;
@@ -338,6 +335,7 @@ static bool hair_stroke_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
 	tool_data.edit = edit;
 	tool_data.settings = settings;
 	
+	invert_m4_m4(tool_data.imat, ob->obmat);
 	copy_v2_v2(tool_data.mval, mouse);
 	tool_data.mdepth = stroke->zfac;
 	
@@ -345,8 +343,8 @@ static bool hair_stroke_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
 	ED_view3d_win_to_3d(ar, zvec, mouse, tool_data.loc);
 	ED_view3d_win_to_delta(ar, mdelta, tool_data.delta, stroke->zfac);
 	/* tools work in object space */
-	mul_m4_v3(imat, tool_data.loc);
-	mul_mat3_m4_v3(imat, tool_data.delta);
+	mul_m4_v3(tool_data.imat, tool_data.loc);
+	mul_mat3_m4_v3(tool_data.imat, tool_data.delta);
 
 	for (step = 0; step < totsteps; ++step) {
 		bool step_updated = hair_brush_step(&tool_data);
diff --git a/source/blender/editors/hair/hair_intern.h b/source/blender/editors/hair/hair_intern.h
index 7218fa08483..92b40fd083f 100644
--- a/source/blender/editors/hair/hair_intern.h
+++ b/source/blender/editors/hair/hair_intern.h
@@ -73,6 +73,7 @@ typedef struct HairToolData {
 	float mdepth;       /* mouse z depth */
 	
 	/* object space */
+	float imat[4][4];   /* obmat inverse */
 	float loc[3];       /* start location */
 	float delta[3];     /* stroke step */
 } HairToolData;
diff --git a/source/blender/editors/hair/hair_stroke.c b/source/blender/editors/hair/hair_stroke.c
index e7b095e9c85..ec34475fc94 100644
--- a/source/blender/editors/hair/hair_stroke.c
+++ b/source/blender/editors/hair/hair_stroke.c
@@ -37,12 +37,15 @@
 #include "BLI_math.h"
 
 #include "DNA_brush_types.h"
+#include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_view3d_types.h"
 
 #include "BKE_brush.h"
+#include "BKE_DerivedMesh.h"
 #include "BKE_edithair.h"
+#include "BKE_mesh_sample.h"
 
 #include "bmesh.h"
 
@@ -163,10 +166,102 @@ static void hair_vertex_comb(HairToolData *data, void *userdata, BMVert *v, floa
 	madd_v3_v3fl(v->co, data->delta, combfactor);
 }
 
+
+BLI_INLINE void construct_m4_loc_nor_tan(float mat[4][4], const float loc[3], const float nor[3], const float tang[3])
+{
+	float cotang[3];
+	
+	cross_v3_v3v3(cotang, nor, tang);
+	
+	copy_v3_v3(mat[0], tang);
+	copy_v3_v3(mat[1], cotang);
+	copy_v3_v3(mat[2], nor);
+	copy_v3_v3(mat[3], loc);
+	mat[0][3] = 0.0f;
+	mat[1][3] = 0.0f;
+	mat[2][3] = 0.0f;
+	mat[3][3] = 1.0f;
+}
+
+static void grow_hair(BMEditStrands *edit, MSurfaceSample *sample)
+{
+	DerivedMesh *dm = edit->root_dm;
+	const float len = 1.5f;
+	
+	float root_mat[4][4];
+	BMVert *root, *v;
+	BMIter iter;
+	int i;
+	
+	{
+		float co[3], nor[3], tang[3];
+		BKE_mesh_sample_eval(dm, sample, co, nor, tang);
+		construct_m4_loc_nor_tan(root_mat, co, nor, tang);
+	}
+	
+	root = BM_strands_create(edit->bm, 5, true);
+	
+	BM_elem_meshsample_data_named_set(&edit->bm->vdata, root, CD_MSURFACE_SAMPLE, CD_HAIR_ROOT_LOCATION, sample);
+	
+	BM_ITER_STRANDS_ELEM_INDEX(v, &iter, root, BM_VERTS_OF_STRAND, i) {
+		float co[3];
+		
+		co[0] = co[1] = 0.0f;
+		co[2] = len * (float)i / (float)(len - 1);
+		
+		mul_m4_v3(root_mat, co);
+		
+		copy_v3_v3(v->co, co);
+	}
+	
+	BM_mesh_elem_index_ensure(edit->bm, BM_ALL);
+}
+
+static bool hair_add_ray_cb(void *vdata, float ray_start[3], float ray_end[3])
+{
+	HairToolData *data = vdata;
+	ViewContext *vc = &data->viewdata.vc;
+	
+	ED_view3d_win_to_segment(vc->ar, vc->v3d, data->mval, ray_start, ray_end, true);
+	
+	mul_m4_v3(data->imat, ray_start);
+	mul_m4_v3(data->imat, ray_end);
+	
+	return true;
+}
+
+static bool hair_get_surface_sample(HairToolData *data, MSurfaceSample *sample)
+{
+	DerivedMesh *dm = data->edit->root_dm;
+	
+	MSurfaceSampleStorage dst;
+	int tot;
+	
+	BKE_mesh_sample_storage_single(&dst, sample);
+	tot = BKE_mesh_sample_generate_raycast(&dst, dm, hair_add_ray_cb, data, 1);
+	BKE_mesh_sample_storage_release(&dst);
+	
+	return tot > 0;
+}
+
+static bool hair_add(HairToolData *data)
+{
+	MSurfaceSample sample;
+	
+	if (!hair_get_surface_sample(data, &sample))
+		return false;
+	
+	grow_hair(data->edit, &sample);
+	
+	return true;
+}
+
+
 bool hair_brush_step(HairToolData *data)
 {
 	Brush *brush = data->settings->brush;
 	BrushHairTool hair_tool = brush->hair_tool;
+	BMEditStrands *edit = data->edit;
 	int tot = 0;
 	
 	switch (hair_tool) {
@@ -181,12 +276,20 @@ bool hair_brush_step(HairToolData *data)
 			tot = hair_tool_apply_vertex(data, hair_vertex_comb, &combdata);
 			break;
 		}
-		case HAIR_TOOL_CUT:     break;
-		case HAIR_TOOL_LENGTH:  break;
-		case HAIR_TOOL_PUFF:    break;
-		case HAIR_TOOL_ADD:     break;
-		case HAIR_TOOL_SMOOTH:  break;
-		case HAIR_TOOL_WEIGHT:  break;
+		case HAIR_TOOL_CUT:
+			break;
+		case HAIR_TOOL_LENGTH:
+			break;
+		case HAIR_TOOL_PUFF:
+			break;
+		case HAIR_TOOL_ADD:
+			if (hair_add(data))
+				edit->flag |= BM_STRANDS_DIRTY_SEGLEN;
+			break;
+		case HAIR_TOOL_SMOOTH:
+			break;
+		case HAIR_TOOL_WEIGHT:
+			break;
 	}
 	
 	return tot > 0;