editarmature_sketch.c

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/*
 * ***** 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.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <string.h>
#include <math.h>
#include <float.h>

#include "MEM_guardedalloc.h"

#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "DNA_armature_types.h"

#include "RNA_define.h"
#include "RNA_access.h"

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "BLI_graph.h"
#include "BLI_ghash.h"

#include "BKE_context.h"
#include "BKE_sketch.h"

#include "ED_view3d.h"
#include "ED_screen.h"

#include "BIF_gl.h"
//#include "BIF_screen.h"
//#include "BIF_space.h"
//#include "BIF_mywindow.h"
#include "ED_armature.h"
#include "armature_intern.h"
//#include "BIF_sketch.h"
#include "BIF_retarget.h"
#include "BIF_generate.h"
//#include "BIF_interface.h"

#include "ED_transform.h"

#include "WM_api.h"
#include "WM_types.h"

//#include "blendef.h"
//#include "mydevice.h"
#include "reeb.h"



typedef int  (*GestureDetectFct)(bContext*, SK_Gesture*, SK_Sketch *);
typedef void (*GestureApplyFct)(bContext*, SK_Gesture*, SK_Sketch *);

typedef struct SK_GestureAction {
    char name[64];
    GestureDetectFct    detect;
    GestureApplyFct     apply;
} SK_GestureAction;

#if 0 /* UNUSED 2.5 */
static SK_Point boneSnap;
#endif

static int    LAST_SNAP_POINT_VALID = 0;
static float  LAST_SNAP_POINT[3];


typedef struct SK_StrokeIterator {
    HeadFct     head;
    TailFct     tail;
    PeekFct     peek;
    NextFct     next;
    NextNFct    nextN;
    PreviousFct previous;
    StoppedFct  stopped;

    float *p, *no;
    float size;

    int length;
    int index;
    /*********************************/
    SK_Stroke *stroke;
    int start;
    int end;
    int stride;
} SK_StrokeIterator;

/******************** PROTOTYPES ******************************/

void initStrokeIterator(BArcIterator *iter, SK_Stroke *stk, int start, int end);

int sk_detectCutGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyCutGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
int sk_detectTrimGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyTrimGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
int sk_detectCommandGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyCommandGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
int sk_detectDeleteGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyDeleteGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
int sk_detectMergeGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyMergeGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
int sk_detectReverseGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyReverseGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
int sk_detectConvertGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);
void sk_applyConvertGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch);

SK_Sketch* contextSketch(const bContext *c, int create);
SK_Sketch* viewcontextSketch(ViewContext *vc, int create);

void sk_resetOverdraw(SK_Sketch *sketch);
int sk_hasOverdraw(SK_Sketch *sketch, SK_Stroke *stk);

/******************** GESTURE ACTIONS ******************************/

static SK_GestureAction GESTURE_ACTIONS[] =
    {
        {"Cut", sk_detectCutGesture, sk_applyCutGesture},
        {"Trim", sk_detectTrimGesture, sk_applyTrimGesture},
        {"Command", sk_detectCommandGesture, sk_applyCommandGesture},
        {"Delete", sk_detectDeleteGesture, sk_applyDeleteGesture},
        {"Merge", sk_detectMergeGesture, sk_applyMergeGesture},
        {"Reverse", sk_detectReverseGesture, sk_applyReverseGesture},
        {"Convert", sk_detectConvertGesture, sk_applyConvertGesture},
        {"", NULL, NULL}
    };

/******************** TEMPLATES UTILS *************************/

static char  *TEMPLATES_MENU = NULL;
static int    TEMPLATES_CURRENT = 0;
static GHash *TEMPLATES_HASH = NULL;
static RigGraph *TEMPLATE_RIGG = NULL;

void BIF_makeListTemplates(const bContext *C)
{
    Object *obedit = CTX_data_edit_object(C);
    Scene *scene = CTX_data_scene(C);
    ToolSettings *ts = CTX_data_tool_settings(C);
    Base *base;
    int index = 0;

    if (TEMPLATES_HASH != NULL)
    {
        BLI_ghash_free(TEMPLATES_HASH, NULL, NULL);
    }

    TEMPLATES_HASH = BLI_ghash_new(BLI_ghashutil_inthash, BLI_ghashutil_intcmp, "makeListTemplates gh");
    TEMPLATES_CURRENT = 0;

    for ( base = FIRSTBASE; base; base = base->next )
    {
        Object *ob = base->object;

        if (ob != obedit && ob->type == OB_ARMATURE)
        {
            index++;
            BLI_ghash_insert(TEMPLATES_HASH, SET_INT_IN_POINTER(index), ob);

            if (ob == ts->skgen_template)
            {
                TEMPLATES_CURRENT = index;
            }
        }
    }
}

const char *BIF_listTemplates(const bContext *UNUSED(C))
{
    GHashIterator ghi;
    char menu_header[] = "Template%t|None%x0|";
    char *p;

    if (TEMPLATES_MENU != NULL)
    {
        MEM_freeN(TEMPLATES_MENU);
    }

    TEMPLATES_MENU = MEM_callocN(sizeof(char) * (BLI_ghash_size(TEMPLATES_HASH) * 32 + 30), "skeleton template menu");

    p = TEMPLATES_MENU;

    p += sprintf(TEMPLATES_MENU, "%s", menu_header);

    BLI_ghashIterator_init(&ghi, TEMPLATES_HASH);

    while (!BLI_ghashIterator_isDone(&ghi))
    {
        Object *ob = BLI_ghashIterator_getValue(&ghi);
        int key = GET_INT_FROM_POINTER(BLI_ghashIterator_getKey(&ghi));

        p += sprintf(p, "|%s%%x%i", ob->id.name+2, key);

        BLI_ghashIterator_step(&ghi);
    }

    return TEMPLATES_MENU;
}

int   BIF_currentTemplate(const bContext *C)
{
    ToolSettings *ts = CTX_data_tool_settings(C);

    if (TEMPLATES_CURRENT == 0 && ts->skgen_template != NULL)
    {
        GHashIterator ghi;
        BLI_ghashIterator_init(&ghi, TEMPLATES_HASH);

        while (!BLI_ghashIterator_isDone(&ghi))
        {
            Object *ob = BLI_ghashIterator_getValue(&ghi);
            int key = GET_INT_FROM_POINTER(BLI_ghashIterator_getKey(&ghi));

            if (ob == ts->skgen_template)
            {
                TEMPLATES_CURRENT = key;
                break;
            }

            BLI_ghashIterator_step(&ghi);
        }
    }

    return TEMPLATES_CURRENT;
}

static RigGraph* sk_makeTemplateGraph(const bContext *C, Object *ob)
{
    Object *obedit = CTX_data_edit_object(C);
    if (ob == obedit)
    {
        return NULL;
    }

    if (ob != NULL)
    {
        if (TEMPLATE_RIGG && TEMPLATE_RIGG->ob != ob)
        {
            RIG_freeRigGraph((BGraph*)TEMPLATE_RIGG);
            TEMPLATE_RIGG = NULL;
        }

        if (TEMPLATE_RIGG == NULL)
        {
            bArmature *arm;

            arm = ob->data;

            TEMPLATE_RIGG = RIG_graphFromArmature(C, ob, arm);
        }
    }

    return TEMPLATE_RIGG;
}

int BIF_nbJointsTemplate(const bContext *C)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    RigGraph *rg = sk_makeTemplateGraph(C, ts->skgen_template);

    if (rg)
    {
        return RIG_nbJoints(rg);
    }
    else
    {
        return -1;
    }
}

const char * BIF_nameBoneTemplate(const bContext *C)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    SK_Sketch *stk = contextSketch(C, 1);
    RigGraph *rg;
    int index = 0;

    if (stk && stk->active_stroke != NULL)
    {
        index = stk->active_stroke->nb_points;
    }

    rg = sk_makeTemplateGraph(C, ts->skgen_template);

    if (rg == NULL)
    {
        return "";
    }

    return RIG_nameBone(rg, 0, index);
}

void  BIF_freeTemplates(bContext *UNUSED(C))
{
    if (TEMPLATES_MENU != NULL)
    {
        MEM_freeN(TEMPLATES_MENU);
        TEMPLATES_MENU = NULL;
    }

    if (TEMPLATES_HASH != NULL)
    {
        BLI_ghash_free(TEMPLATES_HASH, NULL, NULL);
        TEMPLATES_HASH = NULL;
    }

    if (TEMPLATE_RIGG != NULL)
    {
        RIG_freeRigGraph((BGraph*)TEMPLATE_RIGG);
        TEMPLATE_RIGG = NULL;
    }
}

void  BIF_setTemplate(bContext *C, int index)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    if (index > 0)
    {
        ts->skgen_template = BLI_ghash_lookup(TEMPLATES_HASH, SET_INT_IN_POINTER(index));
    }
    else
    {
        ts->skgen_template = NULL;

        if (TEMPLATE_RIGG != NULL)
        {
            RIG_freeRigGraph((BGraph*)TEMPLATE_RIGG);
        }
        TEMPLATE_RIGG = NULL;
    }
}

/*********************** CONVERSION ***************************/

static void sk_autoname(bContext *C, ReebArc *arc)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    if (ts->skgen_retarget_options & SK_RETARGET_AUTONAME)
    {
        if (arc == NULL)
        {
            char *num = ts->skgen_num_string;
            int i = atoi(num);
            i++;
            BLI_snprintf(num, 8, "%i", i);
        }
        else
        {
            char *side = ts->skgen_side_string;
            int valid = 0;
            int caps = 0;

            if (side[0] == '\0')
            {
                valid = 1;
            }
            else if (strcmp(side, "R")==0 || strcmp(side, "L")==0)
            {
                valid = 1;
                caps = 1;
            }
            else if (strcmp(side, "r")==0 || strcmp(side, "l")==0)
            {
                valid = 1;
                caps = 0;
            }

            if (valid)
            {
                if (arc->head->p[0] < 0)
                {
                    BLI_snprintf(side, 8, caps?"R":"r");
                }
                else
                {
                    BLI_snprintf(side, 8, caps?"L":"l");
                }
            }
        }
    }
}

static ReebNode *sk_pointToNode(SK_Point *pt, float imat[][4], float tmat[][3])
{
    ReebNode *node;

    node = MEM_callocN(sizeof(ReebNode), "reeb node");
    copy_v3_v3(node->p, pt->p);
    mul_m4_v3(imat, node->p);

    copy_v3_v3(node->no, pt->no);
    mul_m3_v3(tmat, node->no);

    return node;
}

static ReebArc *sk_strokeToArc(SK_Stroke *stk, float imat[][4], float tmat[][3])
{
    ReebArc *arc;
    int i;

    arc = MEM_callocN(sizeof(ReebArc), "reeb arc");
    arc->head = sk_pointToNode(stk->points, imat, tmat);
    arc->tail = sk_pointToNode(sk_lastStrokePoint(stk), imat, tmat);

    arc->bcount = stk->nb_points - 2; /* first and last are nodes, don't count */
    arc->buckets = MEM_callocN(sizeof(EmbedBucket) * arc->bcount, "Buckets");

    for (i = 0; i < arc->bcount; i++)
    {
        copy_v3_v3(arc->buckets[i].p, stk->points[i + 1].p);
        mul_m4_v3(imat, arc->buckets[i].p);

        copy_v3_v3(arc->buckets[i].no, stk->points[i + 1].no);
        mul_m3_v3(tmat, arc->buckets[i].no);
    }

    return arc;
}

static void sk_retargetStroke(bContext *C, SK_Stroke *stk)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    Object *obedit = CTX_data_edit_object(C);
    float imat[4][4];
    float tmat[3][3];
    ReebArc *arc;
    RigGraph *rg;

    invert_m4_m4(imat, obedit->obmat);

    copy_m3_m4(tmat, obedit->obmat);
    transpose_m3(tmat);

    arc = sk_strokeToArc(stk, imat, tmat);

    sk_autoname(C, arc);

    rg = sk_makeTemplateGraph(C, ts->skgen_template);

    BIF_retargetArc(C, arc, rg);

    sk_autoname(C, NULL);

    MEM_freeN(arc->head);
    MEM_freeN(arc->tail);
    REEB_freeArc((BArc*)arc);
}

/**************************************************************/

static void sk_cancelStroke(SK_Sketch *sketch)
{
    if (sketch->active_stroke != NULL)
    {
        sk_resetOverdraw(sketch);
        sk_removeStroke(sketch, sketch->active_stroke);
    }
}


static float sk_clampPointSize(SK_Point *pt, float size)
{
    return MAX2(size * pt->size, size / 2);
}

static void sk_drawPoint(GLUquadric *quad, SK_Point *pt, float size)
{
    glTranslatef(pt->p[0], pt->p[1], pt->p[2]);
    gluSphere(quad, sk_clampPointSize(pt, size), 8, 8);
}

static void sk_drawEdge(GLUquadric *quad, SK_Point *pt0, SK_Point *pt1, float size)
{
    float vec1[3], vec2[3] = {0, 0, 1}, axis[3];
    float angle, length;

    sub_v3_v3v3(vec1, pt1->p, pt0->p);
    length = normalize_v3(vec1);
    cross_v3_v3v3(axis, vec2, vec1);

    if (is_zero_v3(axis))
    {
        axis[1] = 1;
    }

    angle = angle_normalized_v3v3(vec2, vec1);

    glRotatef(angle * (float)(180.0/M_PI) + 180.0f, axis[0], axis[1], axis[2]);

    gluCylinder(quad, sk_clampPointSize(pt1, size), sk_clampPointSize(pt0, size), length, 8, 8);
}

static void sk_drawNormal(GLUquadric *quad, SK_Point *pt, float size, float height)
{
    float vec2[3] = {0, 0, 1}, axis[3];
    float angle;
    
    glPushMatrix();

    cross_v3_v3v3(axis, vec2, pt->no);

    if (is_zero_v3(axis))
    {
        axis[1] = 1;
    }

    angle = angle_normalized_v3v3(vec2, pt->no);

    glRotatef(angle * (float)(180.0/M_PI), axis[0], axis[1], axis[2]);

    glColor3f(0, 1, 1);
    gluCylinder(quad, sk_clampPointSize(pt, size), 0, sk_clampPointSize(pt, height), 10, 2);

    glPopMatrix();
}

static void sk_drawStroke(SK_Stroke *stk, int id, float color[3], int start, int end)
{
    float rgb[3];
    int i;
    GLUquadric *quad = gluNewQuadric();
    gluQuadricNormals(quad, GLU_SMOOTH);

    if (id != -1)
    {
        glLoadName(id);

        for (i = 0; i < stk->nb_points; i++)
        {
            glPushMatrix();

            sk_drawPoint(quad, stk->points + i, 0.1);

            if (i > 0)
            {
                sk_drawEdge(quad, stk->points + i - 1, stk->points + i, 0.1);
            }

            glPopMatrix();
        }

    }
    else
    {
        float d_rgb[3] = {1, 1, 1};

        copy_v3_v3(rgb, color);
        sub_v3_v3(d_rgb, rgb);
        mul_v3_fl(d_rgb, 1.0f / (float)stk->nb_points);

        for (i = 0; i < stk->nb_points; i++)
        {
            SK_Point *pt = stk->points + i;

            glPushMatrix();

            if (pt->type == PT_EXACT)
            {
                glColor3f(0, 0, 0);
                sk_drawPoint(quad, pt, 0.15);
                sk_drawNormal(quad, pt, 0.05, 0.9);
            }

            if (i >= start && i <= end)
            {
                glColor3f(0.3, 0.3, 0.3);
            }
            else
            {
                glColor3fv(rgb);
            }

            if (pt->type != PT_EXACT)
            {

                sk_drawPoint(quad, pt, 0.1);
            }

            if (i > 0)
            {
                sk_drawEdge(quad, pt - 1, pt, 0.1);
            }

            glPopMatrix();

            add_v3_v3(rgb, d_rgb);
        }
    }

    gluDeleteQuadric(quad);
}

static void drawSubdividedStrokeBy(ToolSettings *toolsettings, BArcIterator *iter, NextSubdivisionFunc next_subdividion)
{
    SK_Stroke *stk = ((SK_StrokeIterator*)iter)->stroke;
    float head[3], tail[3];
    int bone_start = 0;
    int end = iter->length;
    int index;
    GLUquadric *quad = gluNewQuadric();
    gluQuadricNormals(quad, GLU_SMOOTH);

    iter->head(iter);
    copy_v3_v3(head, iter->p);

    index = next_subdividion(toolsettings, iter, bone_start, end, head, tail);
    while (index != -1)
    {
        SK_Point *pt = stk->points + index;

        glPushMatrix();

        glColor3f(0, 1, 0);
        sk_drawPoint(quad, pt, 0.15);

        sk_drawNormal(quad, pt, 0.05, 0.9);

        glPopMatrix();

        copy_v3_v3(head, tail);
        bone_start = index; // start next bone from current index

        index = next_subdividion(toolsettings, iter, bone_start, end, head, tail);
    }

    gluDeleteQuadric(quad);
}

static void sk_drawStrokeSubdivision(ToolSettings *toolsettings, SK_Stroke *stk)
{
    int head_index = -1;
    int i;

    if (toolsettings->bone_sketching_convert == SK_CONVERT_RETARGET)
    {
        return;
    }


    for (i = 0; i < stk->nb_points; i++)
    {
        SK_Point *pt = stk->points + i;

        if (pt->type == PT_EXACT || i == stk->nb_points - 1) /* stop on exact or on last point */
        {
            if (head_index == -1)
            {
                head_index = i;
            }
            else
            {
                if (i - head_index > 1)
                {
                    SK_StrokeIterator sk_iter;
                    BArcIterator *iter = (BArcIterator*)&sk_iter;

                    initStrokeIterator(iter, stk, head_index, i);

                    if (toolsettings->bone_sketching_convert == SK_CONVERT_CUT_ADAPTATIVE)
                    {
                        drawSubdividedStrokeBy(toolsettings, iter, nextAdaptativeSubdivision);
                    }
                    else if (toolsettings->bone_sketching_convert == SK_CONVERT_CUT_LENGTH)
                    {
                        drawSubdividedStrokeBy(toolsettings, iter, nextLengthSubdivision);
                    }
                    else if (toolsettings->bone_sketching_convert == SK_CONVERT_CUT_FIXED)
                    {
                        drawSubdividedStrokeBy(toolsettings, iter, nextFixedSubdivision);
                    }

                }

                head_index = i;
            }
        }
    }
}

static SK_Point *sk_snapPointStroke(bContext *C, SK_Stroke *stk, int mval[2], int *dist, int *index, int all_pts)
{
    ARegion *ar = CTX_wm_region(C);
    SK_Point *pt = NULL;
    int i;

    for (i = 0; i < stk->nb_points; i++)
    {
        if (all_pts || stk->points[i].type == PT_EXACT)
        {
            short pval[2];
            int pdist;

            project_short_noclip(ar, stk->points[i].p, pval);

            pdist = ABS(pval[0] - mval[0]) + ABS(pval[1] - mval[1]);

            if (pdist < *dist)
            {
                *dist = pdist;
                pt = stk->points + i;

                if (index != NULL)
                {
                    *index = i;
                }
            }
        }
    }

    return pt;
}

#if 0 /* UNUSED 2.5 */
static SK_Point *sk_snapPointArmature(bContext *C, Object *ob, ListBase *ebones, int mval[2], int *dist)
{
    ARegion *ar = CTX_wm_region(C);
    SK_Point *pt = NULL;
    EditBone *bone;

    for (bone = ebones->first; bone; bone = bone->next)
    {
        float vec[3];
        short pval[2];
        int pdist;

        if ((bone->flag & BONE_CONNECTED) == 0)
        {
            copy_v3_v3(vec, bone->head);
            mul_m4_v3(ob->obmat, vec);
            project_short_noclip(ar, vec, pval);

            pdist = ABS(pval[0] - mval[0]) + ABS(pval[1] - mval[1]);

            if (pdist < *dist)
            {
                *dist = pdist;
                pt = &boneSnap;
                copy_v3_v3(pt->p, vec);
                pt->type = PT_EXACT;
            }
        }


        copy_v3_v3(vec, bone->tail);
        mul_m4_v3(ob->obmat, vec);
        project_short_noclip(ar, vec, pval);

        pdist = ABS(pval[0] - mval[0]) + ABS(pval[1] - mval[1]);

        if (pdist < *dist)
        {
            *dist = pdist;
            pt = &boneSnap;
            copy_v3_v3(pt->p, vec);
            pt->type = PT_EXACT;
        }
    }

    return pt;
}
#endif

void sk_resetOverdraw(SK_Sketch *sketch)
{
    sketch->over.target = NULL;
    sketch->over.start = -1;
    sketch->over.end = -1;
    sketch->over.count = 0;
}

int sk_hasOverdraw(SK_Sketch *sketch, SK_Stroke *stk)
{
    return  sketch->over.target &&
            sketch->over.count >= SK_OVERDRAW_LIMIT &&
            (sketch->over.target == stk || stk == NULL) &&
            (sketch->over.start != -1 || sketch->over.end != -1);
}

static void sk_updateOverdraw(bContext *C, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd)
{
    if (sketch->over.target == NULL)
    {
        SK_Stroke *target;
        int closest_index = -1;
        int dist = SNAP_MIN_DISTANCE * 2;

        for (target = sketch->strokes.first; target; target = target->next)
        {
            if (target != stk)
            {
                int index;

                SK_Point *spt = sk_snapPointStroke(C, target, dd->mval, &dist, &index, 1);

                if (spt != NULL)
                {
                    sketch->over.target = target;
                    closest_index = index;
                }
            }
        }

        if (sketch->over.target != NULL)
        {
            if (closest_index > -1)
            {
                if (sk_lastStrokePoint(stk)->type == PT_EXACT)
                {
                    sketch->over.count = SK_OVERDRAW_LIMIT;
                }
                else
                {
                    sketch->over.count++;
                }
            }

            if (stk->nb_points == 1)
            {
                sketch->over.start = closest_index;
            }
            else
            {
                sketch->over.end = closest_index;
            }
        }
    }
    else if (sketch->over.target != NULL)
    {
        SK_Point *closest_pt = NULL;
        int dist = SNAP_MIN_DISTANCE * 2;
        int index;

        closest_pt = sk_snapPointStroke(C, sketch->over.target, dd->mval, &dist, &index, 1);

        if (closest_pt != NULL)
        {
            if (sk_lastStrokePoint(stk)->type == PT_EXACT)
            {
                sketch->over.count = SK_OVERDRAW_LIMIT;
            }
            else
            {
                sketch->over.count++;
            }

            sketch->over.end = index;
        }
        else
        {
            sketch->over.end = -1;
        }
    }
}

/* return 1 on reverse needed */
static int sk_adjustIndexes(SK_Sketch *sketch, int *start, int *end)
{
    int retval = 0;

    *start = sketch->over.start;
    *end = sketch->over.end;

    if (*start == -1)
    {
        *start = 0;
    }

    if (*end == -1)
    {
        *end = sketch->over.target->nb_points - 1;
    }

    if (*end < *start)
    {
        int tmp = *start;
        *start = *end;
        *end = tmp;
        retval = 1;
    }

    return retval;
}

static void sk_endOverdraw(SK_Sketch *sketch)
{
    SK_Stroke *stk = sketch->active_stroke;

    if (sk_hasOverdraw(sketch, NULL))
    {
        int start;
        int end;

        if (sk_adjustIndexes(sketch, &start, &end))
        {
            sk_reverseStroke(stk);
        }

        if (stk->nb_points > 1)
        {
            stk->points->type = sketch->over.target->points[start].type;
            sk_lastStrokePoint(stk)->type = sketch->over.target->points[end].type;
        }

        sk_insertStrokePoints(sketch->over.target, stk->points, stk->nb_points, start, end);

        sk_removeStroke(sketch, stk);

        sk_resetOverdraw(sketch);
    }
}


static void sk_startStroke(SK_Sketch *sketch)
{
    SK_Stroke *stk = sk_createStroke();

    BLI_addtail(&sketch->strokes, stk);
    sketch->active_stroke = stk;

    sk_resetOverdraw(sketch);
}

static void sk_endStroke(bContext *C, SK_Sketch *sketch)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    sk_shrinkStrokeBuffer(sketch->active_stroke);

    if (ts->bone_sketching & BONE_SKETCHING_ADJUST)
    {
        sk_endOverdraw(sketch);
    }

    sketch->active_stroke = NULL;
}

static void sk_updateDrawData(SK_DrawData *dd)
{
    dd->type = PT_CONTINUOUS;

    dd->previous_mval[0] = dd->mval[0];
    dd->previous_mval[1] = dd->mval[1];
}

static float sk_distanceDepth(bContext *C, float p1[3], float p2[3])
{
    ARegion *ar = CTX_wm_region(C);
    RegionView3D *rv3d = ar->regiondata;
    float vec[3];
    float distance;

    sub_v3_v3v3(vec, p1, p2);

    project_v3_v3v3(vec, vec, rv3d->viewinv[2]);

    distance = len_v3(vec);

    if (dot_v3v3(rv3d->viewinv[2], vec) > 0)
    {
        distance *= -1;
    }

    return distance;
}

static void sk_interpolateDepth(bContext *C, SK_Stroke *stk, int start, int end, float length, float distance)
{
    ARegion *ar = CTX_wm_region(C);
    ScrArea *sa = CTX_wm_area(C);
    View3D *v3d = sa->spacedata.first;

    float progress = 0;
    int i;

    progress = len_v3v3(stk->points[start].p, stk->points[start - 1].p);

    for (i = start; i <= end; i++)
    {
        float ray_start[3], ray_normal[3];
        float delta = len_v3v3(stk->points[i].p, stk->points[i + 1].p);
        float pval[2];

        project_float(ar, stk->points[i].p, pval);
        ED_view3d_win_to_ray(ar, v3d, pval, ray_start, ray_normal);

        mul_v3_fl(ray_normal, distance * progress / length);
        add_v3_v3(stk->points[i].p, ray_normal);

        progress += delta ;
    }
}

static void sk_projectDrawPoint(bContext *C, float vec[3], SK_Stroke *stk, SK_DrawData *dd)
{
    ARegion *ar = CTX_wm_region(C);
    /* copied from grease pencil, need fixing */
    SK_Point *last = sk_lastStrokePoint(stk);
    short cval[2];
    float fp[3] = {0, 0, 0};
    float dvec[3];
    float mval_f[2];

    if (last != NULL)
    {
        copy_v3_v3(fp, last->p);
    }

    initgrabz(ar->regiondata, fp[0], fp[1], fp[2]);

    /* method taken from editview.c - mouse_cursor() */
    project_short_noclip(ar, fp, cval);
    VECSUB2D(mval_f, cval, dd->mval);
    ED_view3d_win_to_delta(ar, mval_f, dvec);
    sub_v3_v3v3(vec, fp, dvec);
}

static int sk_getStrokeDrawPoint(bContext *C, SK_Point *pt, SK_Sketch *UNUSED(sketch), SK_Stroke *stk, SK_DrawData *dd)
{
    pt->type = dd->type;
    pt->mode = PT_PROJECT;
    sk_projectDrawPoint(C, pt->p, stk, dd);

    return 1;
}

static int sk_addStrokeDrawPoint(bContext *C, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd)
{
    ARegion *ar = CTX_wm_region(C);
    RegionView3D *rv3d = ar->regiondata;
    SK_Point pt;

    sk_initPoint(&pt, dd, rv3d->viewinv[2]);

    sk_getStrokeDrawPoint(C, &pt, sketch, stk, dd);

    sk_appendStrokePoint(stk, &pt);

    return 1;
}

static int sk_getStrokeSnapPoint(bContext *C, SK_Point *pt, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    int point_added = 0;

    if (ts->snap_mode == SCE_SNAP_MODE_VOLUME)
    {
        DepthPeel *p1, *p2;
        float *last_p = NULL;
        float dist = FLT_MAX;
        float p[3] = {0};
        float size = 0;
        float mvalf[2];

        BLI_freelistN(&sketch->depth_peels);
        sketch->depth_peels.first = sketch->depth_peels.last = NULL;

        mvalf[0]= dd->mval[0];
        mvalf[1]= dd->mval[1];
        peelObjectsContext(C, &sketch->depth_peels, mvalf);

        if (stk->nb_points > 0 && stk->points[stk->nb_points - 1].type == PT_CONTINUOUS)
        {
            last_p = stk->points[stk->nb_points - 1].p;
        }
        else if (LAST_SNAP_POINT_VALID)
        {
            last_p = LAST_SNAP_POINT;
        }


        for (p1 = sketch->depth_peels.first; p1; p1 = p1->next)
        {
            if (p1->flag == 0)
            {
                float vec[3];
                float new_dist;
                float new_size = 0;

                p2 = NULL;
                p1->flag = 1;

                /* if peeling objects, take the first and last from each object */
                if (ts->snap_flag & SCE_SNAP_PEEL_OBJECT)
                {
                    DepthPeel *peel;
                    for (peel = p1->next; peel; peel = peel->next)
                    {
                        if (peel->ob == p1->ob)
                        {
                            peel->flag = 1;
                            p2 = peel;
                        }
                    }
                }
                /* otherwise, pair first with second and so on */
                else
                {
                    for (p2 = p1->next; p2 && p2->ob != p1->ob; p2 = p2->next)
                    {
                        /* nothing to do here */
                    }
                }

                if (p2)
                {
                    p2->flag = 1;

                    add_v3_v3v3(vec, p1->p, p2->p);
                    mul_v3_fl(vec, 0.5f);
                    new_size = len_v3v3(p1->p, p2->p);
                }
                else
                {
                    copy_v3_v3(vec, p1->p);
                }

                if (last_p == NULL)
                {
                    copy_v3_v3(p, vec);
                    size = new_size;
                    dist = 0;
                    break;
                }

                new_dist = len_v3v3(last_p, vec);

                if (new_dist < dist)
                {
                    copy_v3_v3(p, vec);
                    dist = new_dist;
                    size = new_size;
                }
            }
        }

        if (dist != FLT_MAX)
        {
            pt->type = dd->type;
            pt->mode = PT_SNAP;
            pt->size = size / 2;
            copy_v3_v3(pt->p, p);

            point_added = 1;
        }

        //BLI_freelistN(&depth_peels);
    }
    else
    {
        SK_Stroke *snap_stk;
        float vec[3];
        float no[3];
        float mval[2];
        int found = 0;
        int dist = SNAP_MIN_DISTANCE; // Use a user defined value here

        /* snap to strokes */
        // if (ts->snap_mode == SCE_SNAP_MODE_VERTEX) /* snap all the time to strokes */
        for (snap_stk = sketch->strokes.first; snap_stk; snap_stk = snap_stk->next)
        {
            SK_Point *spt = NULL;
            if (snap_stk == stk)
            {
                spt = sk_snapPointStroke(C, snap_stk, dd->mval, &dist, NULL, 0);
            }
            else
            {
                spt = sk_snapPointStroke(C, snap_stk, dd->mval, &dist, NULL, 1);
            }

            if (spt != NULL)
            {
                copy_v3_v3(pt->p, spt->p);
                point_added = 1;
            }
        }
        
        mval[0] = dd->mval[0];
        mval[1] = dd->mval[1];

        /* try to snap to closer object */
        found = snapObjectsContext(C, mval, &dist, vec, no, SNAP_NOT_SELECTED);
        if (found == 1)
        {
            pt->type = dd->type;
            pt->mode = PT_SNAP;
            copy_v3_v3(pt->p, vec);

            point_added = 1;
        }
    }

    return point_added;
}

static int sk_addStrokeSnapPoint(bContext *C, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd)
{
    int point_added;
    ARegion *ar = CTX_wm_region(C);
    RegionView3D *rv3d = ar->regiondata;
    SK_Point pt;

    sk_initPoint(&pt, dd, rv3d->viewinv[2]);

    point_added = sk_getStrokeSnapPoint(C, &pt, sketch, stk, dd);

    if (point_added)
    {
        float final_p[3];
        float length, distance;
        int total;
        int i;

        copy_v3_v3(final_p, pt.p);

        sk_projectDrawPoint(C, pt.p, stk, dd);
        sk_appendStrokePoint(stk, &pt);

        /* update all previous point to give smooth Z progresion */
        total = 0;
        length = 0;
        for (i = stk->nb_points - 2; i > 0; i--)
        {
            length += len_v3v3(stk->points[i].p, stk->points[i + 1].p);
            total++;
            if (stk->points[i].mode == PT_SNAP || stk->points[i].type == PT_EXACT)
            {
                break;
            }
        }

        if (total > 1)
        {
            distance = sk_distanceDepth(C, final_p, stk->points[i].p);

            sk_interpolateDepth(C, stk, i + 1, stk->nb_points - 2, length, distance);
        }

        copy_v3_v3(stk->points[stk->nb_points - 1].p, final_p);

        point_added = 1;
    }

    return point_added;
}

static void sk_addStrokePoint(bContext *C, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd, short snap)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    int point_added = 0;

    if (snap)
    {
        point_added = sk_addStrokeSnapPoint(C, sketch, stk, dd);
    }

    if (point_added == 0)
    {
        point_added = sk_addStrokeDrawPoint(C, sketch, stk, dd);
    }

    if (stk == sketch->active_stroke && ts->bone_sketching & BONE_SKETCHING_ADJUST)
    {
        sk_updateOverdraw(C, sketch, stk, dd);
    }
}

static void sk_getStrokePoint(bContext *C, SK_Point *pt, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd, short snap)
{
    int point_added = 0;

    if (snap)
    {
        point_added = sk_getStrokeSnapPoint(C, pt, sketch, stk, dd);
        LAST_SNAP_POINT_VALID = 1;
        copy_v3_v3(LAST_SNAP_POINT, pt->p);
    }
    else
    {
        LAST_SNAP_POINT_VALID = 0;
    }

    if (point_added == 0)
    {
        point_added = sk_getStrokeDrawPoint(C, pt, sketch, stk, dd);
    }
}

/********************************************/

static void* headPoint(void *arg);
static void* tailPoint(void *arg);
static void* nextPoint(void *arg);
static void* nextNPoint(void *arg, int n);
static void* peekPoint(void *arg, int n);
static void* previousPoint(void *arg);
static int   iteratorStopped(void *arg);

static void initIteratorFct(SK_StrokeIterator *iter)
{
    iter->head = headPoint;
    iter->tail = tailPoint;
    iter->peek = peekPoint;
    iter->next = nextPoint;
    iter->nextN = nextNPoint;
    iter->previous = previousPoint;
    iter->stopped = iteratorStopped;
}

static SK_Point* setIteratorValues(SK_StrokeIterator *iter, int index)
{
    SK_Point *pt = NULL;

    if (index >= 0 && index < iter->length)
    {
        pt = &(iter->stroke->points[iter->start + (iter->stride * index)]);
        iter->p = pt->p;
        iter->no = pt->no;
        iter->size = pt->size;
    }
    else
    {
        iter->p = NULL;
        iter->no = NULL;
        iter->size = 0;
    }

    return pt;
}

void initStrokeIterator(BArcIterator *arg, SK_Stroke *stk, int start, int end)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;

    initIteratorFct(iter);
    iter->stroke = stk;

    if (start < end)
    {
        iter->start = start + 1;
        iter->end = end - 1;
        iter->stride = 1;
    }
    else
    {
        iter->start = start - 1;
        iter->end = end + 1;
        iter->stride = -1;
    }

    iter->length = iter->stride * (iter->end - iter->start + 1);

    iter->index = -1;
}


static void* headPoint(void *arg)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;
    SK_Point *result = NULL;

    result = &(iter->stroke->points[iter->start - iter->stride]);
    iter->p = result->p;
    iter->no = result->no;
    iter->size = result->size;

    return result;
}

static void* tailPoint(void *arg)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;
    SK_Point *result = NULL;

    result = &(iter->stroke->points[iter->end + iter->stride]);
    iter->p = result->p;
    iter->no = result->no;
    iter->size = result->size;

    return result;
}

static void* nextPoint(void *arg)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;
    SK_Point *result = NULL;

    iter->index++;
    if (iter->index < iter->length)
    {
        result = setIteratorValues(iter, iter->index);
    }

    return result;
}

static void* nextNPoint(void *arg, int n)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;
    SK_Point *result = NULL;

    iter->index += n;

    /* check if passed end */
    if (iter->index < iter->length)
    {
        result = setIteratorValues(iter, iter->index);
    }

    return result;
}

static void* peekPoint(void *arg, int n)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;
    SK_Point *result = NULL;
    int index = iter->index + n;

    /* check if passed end */
    if (index < iter->length)
    {
        result = setIteratorValues(iter, index);
    }

    return result;
}

static void* previousPoint(void *arg)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;
    SK_Point *result = NULL;

    if (iter->index > 0)
    {
        iter->index--;
        result = setIteratorValues(iter, iter->index);
    }

    return result;
}

static int iteratorStopped(void *arg)
{
    SK_StrokeIterator *iter = (SK_StrokeIterator*)arg;

    if (iter->index >= iter->length)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

static void sk_convertStroke(bContext *C, SK_Stroke *stk)
{
    Object *obedit = CTX_data_edit_object(C);
    ToolSettings *ts = CTX_data_tool_settings(C);
    bArmature *arm = obedit->data;
    SK_Point *head;
    EditBone *parent = NULL;
    float invmat[4][4]; /* move in caller function */
    float tmat[3][3];
    int head_index = 0;
    int i;

    head = NULL;

    invert_m4_m4(invmat, obedit->obmat);

    copy_m3_m4(tmat, obedit->obmat);
    transpose_m3(tmat);

    for (i = 0; i < stk->nb_points; i++)
    {
        SK_Point *pt = stk->points + i;

        if (pt->type == PT_EXACT)
        {
            if (head == NULL)
            {
                head_index = i;
                head = pt;
            }
            else
            {
                EditBone *bone = NULL;
                EditBone *new_parent;

                if (i - head_index > 1)
                {
                    SK_StrokeIterator sk_iter;
                    BArcIterator *iter = (BArcIterator*)&sk_iter;

                    initStrokeIterator(iter, stk, head_index, i);

                    if (ts->bone_sketching_convert == SK_CONVERT_CUT_ADAPTATIVE)
                    {
                        bone = subdivideArcBy(ts, arm, arm->edbo, iter, invmat, tmat, nextAdaptativeSubdivision);
                    }
                    else if (ts->bone_sketching_convert == SK_CONVERT_CUT_LENGTH)
                    {
                        bone = subdivideArcBy(ts, arm, arm->edbo, iter, invmat, tmat, nextLengthSubdivision);
                    }
                    else if (ts->bone_sketching_convert == SK_CONVERT_CUT_FIXED)
                    {
                        bone = subdivideArcBy(ts, arm, arm->edbo, iter, invmat, tmat, nextFixedSubdivision);
                    }
                }

                if (bone == NULL)
                {
                    bone = ED_armature_edit_bone_add(arm, "Bone");

                    copy_v3_v3(bone->head, head->p);
                    copy_v3_v3(bone->tail, pt->p);

                    mul_m4_v3(invmat, bone->head);
                    mul_m4_v3(invmat, bone->tail);
                    setBoneRollFromNormal(bone, head->no, invmat, tmat);
                }

                new_parent = bone;
                bone->flag |= BONE_SELECTED|BONE_TIPSEL|BONE_ROOTSEL;

                /* move to end of chain */
                while (bone->parent != NULL)
                {
                    bone = bone->parent;
                    bone->flag |= BONE_SELECTED|BONE_TIPSEL|BONE_ROOTSEL;
                }

                if (parent != NULL)
                {
                    bone->parent = parent;
                    bone->flag |= BONE_CONNECTED;
                }

                parent = new_parent;
                head_index = i;
                head = pt;
            }
        }
    }
}

static void sk_convert(bContext *C, SK_Sketch *sketch)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    SK_Stroke *stk;

    for (stk = sketch->strokes.first; stk; stk = stk->next)
    {
        if (stk->selected == 1)
        {
            if (ts->bone_sketching_convert == SK_CONVERT_RETARGET)
            {
                sk_retargetStroke(C, stk);
            }
            else
            {
                sk_convertStroke(C, stk);
            }
//          XXX
//          allqueue(REDRAWBUTSEDIT, 0);
        }
    }
}
/******************* GESTURE *************************/


/* returns the number of self intersections */
static int sk_getSelfIntersections(bContext *C, ListBase *list, SK_Stroke *gesture)
{
    ARegion *ar = CTX_wm_region(C);
    int added = 0;
    int s_i;

    for (s_i = 0; s_i < gesture->nb_points - 1; s_i++)
    {
        float s_p1[3] = {0, 0, 0};
        float s_p2[3] = {0, 0, 0};
        int g_i;

        project_float(ar, gesture->points[s_i].p, s_p1);
        project_float(ar, gesture->points[s_i + 1].p, s_p2);

        /* start checking from second next, because two consecutive cannot intersect */
        for (g_i = s_i + 2; g_i < gesture->nb_points - 1; g_i++)
        {
            float g_p1[3] = {0, 0, 0};
            float g_p2[3] = {0, 0, 0};
            float vi[3];
            float lambda;

            project_float(ar, gesture->points[g_i].p, g_p1);
            project_float(ar, gesture->points[g_i + 1].p, g_p2);

            if (isect_line_line_strict_v3(s_p1, s_p2, g_p1, g_p2, vi, &lambda))
            {
                SK_Intersection *isect = MEM_callocN(sizeof(SK_Intersection), "Intersection");

                isect->gesture_index = g_i;
                isect->before = s_i;
                isect->after = s_i + 1;
                isect->stroke = gesture;

                sub_v3_v3v3(isect->p, gesture->points[s_i + 1].p, gesture->points[s_i].p);
                mul_v3_fl(isect->p, lambda);
                add_v3_v3(isect->p, gesture->points[s_i].p);

                BLI_addtail(list, isect);

                added++;
            }
        }
    }

    return added;
}

static int cmpIntersections(void *i1, void *i2)
{
    SK_Intersection *isect1 = i1, *isect2 = i2;

    if (isect1->stroke == isect2->stroke)
    {
        if (isect1->before < isect2->before)
        {
            return -1;
        }
        else if (isect1->before > isect2->before)
        {
            return 1;
        }
        else
        {
            if (isect1->lambda < isect2->lambda)
            {
                return -1;
            }
            else if (isect1->lambda > isect2->lambda)
            {
                return 1;
            }
        }
    }

    return 0;
}


/* returns the maximum number of intersections per stroke */
static int sk_getIntersections(bContext *C, ListBase *list, SK_Sketch *sketch, SK_Stroke *gesture)
{
    ARegion *ar = CTX_wm_region(C);
    ScrArea *sa = CTX_wm_area(C);
    View3D *v3d = sa->spacedata.first;
    SK_Stroke *stk;
    int added = 0;

    for (stk = sketch->strokes.first; stk; stk = stk->next)
    {
        int s_added = 0;
        int s_i;

        for (s_i = 0; s_i < stk->nb_points - 1; s_i++)
        {
            float s_p1[3] = {0, 0, 0};
            float s_p2[3] = {0, 0, 0};
            int g_i;

            project_float(ar, stk->points[s_i].p, s_p1);
            project_float(ar, stk->points[s_i + 1].p, s_p2);

            for (g_i = 0; g_i < gesture->nb_points - 1; g_i++)
            {
                float g_p1[3] = {0, 0, 0};
                float g_p2[3] = {0, 0, 0};
                float vi[3];
                float lambda;

                project_float(ar, gesture->points[g_i].p, g_p1);
                project_float(ar, gesture->points[g_i + 1].p, g_p2);

                if (isect_line_line_strict_v3(s_p1, s_p2, g_p1, g_p2, vi, &lambda))
                {
                    SK_Intersection *isect = MEM_callocN(sizeof(SK_Intersection), "Intersection");
                    float ray_start[3], ray_end[3];
                    float mval[2];

                    isect->gesture_index = g_i;
                    isect->before = s_i;
                    isect->after = s_i + 1;
                    isect->stroke = stk;
                    isect->lambda = lambda;

                    mval[0] = vi[0];
                    mval[1] = vi[1];
                    ED_view3d_win_to_segment_clip(ar, v3d, mval, ray_start, ray_end);

                    isect_line_line_v3( stk->points[s_i].p,
                                        stk->points[s_i + 1].p,
                                        ray_start,
                                        ray_end,
                                        isect->p,
                                        vi);

                    BLI_addtail(list, isect);

                    s_added++;
                }
            }
        }

        added = MAX2(s_added, added);
    }

    BLI_sortlist(list, cmpIntersections);

    return added;
}

static int sk_getSegments(SK_Stroke *segments, SK_Stroke *gesture)
{
    SK_StrokeIterator sk_iter;
    BArcIterator *iter = (BArcIterator*)&sk_iter;

    float CORRELATION_THRESHOLD = 0.99f;
    float *vec;
    int i, j;

    sk_appendStrokePoint(segments, &gesture->points[0]);
    vec = segments->points[segments->nb_points - 1].p;

    initStrokeIterator(iter, gesture, 0, gesture->nb_points - 1);

    for (i = 1, j = 0; i < gesture->nb_points; i++)
    {
        float n[3];

        /* Calculate normal */
        sub_v3_v3v3(n, gesture->points[i].p, vec);

        if (calcArcCorrelation(iter, j, i, vec, n) < CORRELATION_THRESHOLD)
        {
            j = i - 1;
            sk_appendStrokePoint(segments, &gesture->points[j]);
            vec = segments->points[segments->nb_points - 1].p;
            segments->points[segments->nb_points - 1].type = PT_EXACT;
        }
    }

    sk_appendStrokePoint(segments, &gesture->points[gesture->nb_points - 1]);

    return segments->nb_points - 1;
}

int sk_detectCutGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    if (gest->nb_segments == 1 && gest->nb_intersections == 1)
    {
        return 1;
    }

    return 0;
}

void sk_applyCutGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    SK_Intersection *isect;

    for (isect = gest->intersections.first; isect; isect = isect->next)
    {
        SK_Point pt;

        pt.type = PT_EXACT;
        pt.mode = PT_PROJECT; /* take mode from neighbouring points */
        copy_v3_v3(pt.p, isect->p);
        copy_v3_v3(pt.no, isect->stroke->points[isect->before].no);

        sk_insertStrokePoint(isect->stroke, &pt, isect->after);
    }
}

int sk_detectTrimGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    if (gest->nb_segments == 2 && gest->nb_intersections == 1 && gest->nb_self_intersections == 0)
    {
        float s1[3], s2[3];
        float angle;

        sub_v3_v3v3(s1, gest->segments->points[1].p, gest->segments->points[0].p);
        sub_v3_v3v3(s2, gest->segments->points[2].p, gest->segments->points[1].p);

        angle = RAD2DEGF(angle_v2v2(s1, s2));

        if (angle > 60 && angle < 120)
        {
            return 1;
        }
    }

    return 0;
}

void sk_applyTrimGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    SK_Intersection *isect;
    float trim_dir[3];

    sub_v3_v3v3(trim_dir, gest->segments->points[2].p, gest->segments->points[1].p);

    for (isect = gest->intersections.first; isect; isect = isect->next)
    {
        SK_Point pt;
        float stroke_dir[3];

        pt.type = PT_EXACT;
        pt.mode = PT_PROJECT; /* take mode from neighbouring points */
        copy_v3_v3(pt.p, isect->p);
        copy_v3_v3(pt.no, isect->stroke->points[isect->before].no);

        sub_v3_v3v3(stroke_dir, isect->stroke->points[isect->after].p, isect->stroke->points[isect->before].p);

        /* same direction, trim end */
        if (dot_v3v3(stroke_dir, trim_dir) > 0)
        {
            sk_replaceStrokePoint(isect->stroke, &pt, isect->after);
            sk_trimStroke(isect->stroke, 0, isect->after);
        }
        /* else, trim start */
        else
        {
            sk_replaceStrokePoint(isect->stroke, &pt, isect->before);
            sk_trimStroke(isect->stroke, isect->before, isect->stroke->nb_points - 1);
        }

    }
}

int sk_detectCommandGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    if (gest->nb_segments > 2 && gest->nb_intersections == 2 && gest->nb_self_intersections == 1)
    {
        SK_Intersection *isect, *self_isect;

        /* get the the last intersection of the first pair */
        for( isect = gest->intersections.first; isect; isect = isect->next )
        {
            if (isect->stroke == isect->next->stroke)
            {
                isect = isect->next;
                break;
            }
        }

        self_isect = gest->self_intersections.first;

        if (isect && isect->gesture_index < self_isect->gesture_index)
        {
            return 1;
        }
    }

    return 0;
}

void sk_applyCommandGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    SK_Intersection *isect;
    int command = 1;

//  XXX
//  command = pupmenu("Action %t|Flatten %x1|Straighten %x2|Polygonize %x3");
    if(command < 1) return;

    for (isect = gest->intersections.first; isect; isect = isect->next)
    {
        SK_Intersection *i2;

        i2 = isect->next;

        if (i2 && i2->stroke == isect->stroke)
        {
            switch (command)
            {
                case 1:
                    sk_flattenStroke(isect->stroke, isect->before, i2->after);
                    break;
                case 2:
                    sk_straightenStroke(isect->stroke, isect->before, i2->after, isect->p, i2->p);
                    break;
                case 3:
                    sk_polygonizeStroke(isect->stroke, isect->before, i2->after);
                    break;
            }

            isect = i2;
        }
    }
}

int sk_detectDeleteGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    if (gest->nb_segments == 2 && gest->nb_intersections == 2)
    {
        float s1[3], s2[3];
        float angle;

        sub_v3_v3v3(s1, gest->segments->points[1].p, gest->segments->points[0].p);
        sub_v3_v3v3(s2, gest->segments->points[2].p, gest->segments->points[1].p);

        angle = RAD2DEGF(angle_v2v2(s1, s2));

        if (angle > 120)
        {
            return 1;
        }
    }

    return 0;
}

void sk_applyDeleteGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *sketch)
{
    SK_Intersection *isect;

    for (isect = gest->intersections.first; isect; isect = isect->next)
    {
        /* only delete strokes that are crossed twice */
        if (isect->next && isect->next->stroke == isect->stroke)
        {
            isect = isect->next;

            sk_removeStroke(sketch, isect->stroke);
        }
    }
}

int sk_detectMergeGesture(bContext *C, SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    ARegion *ar = CTX_wm_region(C);
    if (gest->nb_segments > 2 && gest->nb_intersections == 2)
    {
        short start_val[2], end_val[2];
        short dist;

        project_short_noclip(ar, gest->stk->points[0].p, start_val);
        project_short_noclip(ar, sk_lastStrokePoint(gest->stk)->p, end_val);

        dist = MAX2(ABS(start_val[0] - end_val[0]), ABS(start_val[1] - end_val[1]));

        /* if gesture is a circle */
        if ( dist <= 20 )
        {
            SK_Intersection *isect;

            /* check if it circled around an exact point */
            for (isect = gest->intersections.first; isect; isect = isect->next)
            {
                /* only delete strokes that are crossed twice */
                if (isect->next && isect->next->stroke == isect->stroke)
                {
                    int start_index, end_index;
                    int i;

                    start_index = MIN2(isect->after, isect->next->after);
                    end_index = MAX2(isect->before, isect->next->before);

                    for (i = start_index; i <= end_index; i++)
                    {
                        if (isect->stroke->points[i].type == PT_EXACT)
                        {
                            return 1; /* at least one exact point found, stop detect here */
                        }
                    }

                    /* skip next */
                    isect = isect->next;
                }
            }
        }
    }

    return 0;
}

void sk_applyMergeGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    SK_Intersection *isect;

    /* check if it circled around an exact point */
    for (isect = gest->intersections.first; isect; isect = isect->next)
    {
        /* only merge strokes that are crossed twice */
        if (isect->next && isect->next->stroke == isect->stroke)
        {
            int start_index, end_index;
            int i;

            start_index = MIN2(isect->after, isect->next->after);
            end_index = MAX2(isect->before, isect->next->before);

            for (i = start_index; i <= end_index; i++)
            {
                /* if exact, switch to continuous */
                if (isect->stroke->points[i].type == PT_EXACT)
                {
                    isect->stroke->points[i].type = PT_CONTINUOUS;
                }
            }

            /* skip next */
            isect = isect->next;
        }
    }
}

int sk_detectReverseGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    if (gest->nb_segments > 2 && gest->nb_intersections == 2 && gest->nb_self_intersections == 0)
    {
        SK_Intersection *isect;

        /* check if it circled around an exact point */
        for (isect = gest->intersections.first; isect; isect = isect->next)
        {
            /* only delete strokes that are crossed twice */
            if (isect->next && isect->next->stroke == isect->stroke)
            {
                float start_v[3], end_v[3];
                float angle;

                if (isect->gesture_index < isect->next->gesture_index)
                {
                    sub_v3_v3v3(start_v, isect->p, gest->stk->points[0].p);
                    sub_v3_v3v3(end_v, sk_lastStrokePoint(gest->stk)->p, isect->next->p);
                }
                else
                {
                    sub_v3_v3v3(start_v, isect->next->p, gest->stk->points[0].p);
                    sub_v3_v3v3(end_v, sk_lastStrokePoint(gest->stk)->p, isect->p);
                }

                angle = RAD2DEGF(angle_v2v2(start_v, end_v));

                if (angle > 120)
                {
                    return 1;
                }

                /* skip next */
                isect = isect->next;
            }
        }
    }

    return 0;
}

void sk_applyReverseGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    SK_Intersection *isect;

    for (isect = gest->intersections.first; isect; isect = isect->next)
    {
        /* only reverse strokes that are crossed twice */
        if (isect->next && isect->next->stroke == isect->stroke)
        {
            sk_reverseStroke(isect->stroke);

            /* skip next */
            isect = isect->next;
        }
    }
}

int sk_detectConvertGesture(bContext *UNUSED(C), SK_Gesture *gest, SK_Sketch *UNUSED(sketch))
{
    if (gest->nb_segments == 3 && gest->nb_self_intersections == 1)
    {
        return 1;
    }
    return 0;
}

void sk_applyConvertGesture(bContext *C, SK_Gesture *UNUSED(gest), SK_Sketch *sketch)
{
    sk_convert(C, sketch);
}

static void sk_initGesture(bContext *C, SK_Gesture *gest, SK_Sketch *sketch)
{
    gest->intersections.first = gest->intersections.last = NULL;
    gest->self_intersections.first = gest->self_intersections.last = NULL;

    gest->segments = sk_createStroke();
    gest->stk = sketch->gesture;

    gest->nb_self_intersections = sk_getSelfIntersections(C, &gest->self_intersections, gest->stk);
    gest->nb_intersections = sk_getIntersections(C, &gest->intersections, sketch, gest->stk);
    gest->nb_segments = sk_getSegments(gest->segments, gest->stk);
}

static void sk_freeGesture(SK_Gesture *gest)
{
    sk_freeStroke(gest->segments);
    BLI_freelistN(&gest->intersections);
    BLI_freelistN(&gest->self_intersections);
}

static void sk_applyGesture(bContext *C, SK_Sketch *sketch)
{
    SK_Gesture gest;
    SK_GestureAction *act;

    sk_initGesture(C, &gest, sketch);

    /* detect and apply */
    for (act = GESTURE_ACTIONS; act->apply != NULL; act++)
    {
        if (act->detect(C, &gest, sketch))
        {
            act->apply(C, &gest, sketch);
            break;
        }
    }

    sk_freeGesture(&gest);
}

/********************************************/


static int sk_selectStroke(bContext *C, SK_Sketch *sketch, const int mval[2], int extend)
{
    ViewContext vc;
    rcti rect;
    unsigned int buffer[MAXPICKBUF];
    short hits;

    view3d_set_viewcontext(C, &vc);

    rect.xmin= mval[0]-5;
    rect.xmax= mval[0]+5;
    rect.ymin= mval[1]-5;
    rect.ymax= mval[1]+5;

    hits = view3d_opengl_select(&vc, buffer, MAXPICKBUF, &rect);

    if (hits>0)
    {
        int besthitresult = -1;

        if(hits == 1) {
            besthitresult = buffer[3];
        }
        else {
            besthitresult = buffer[3];
            /* loop and get best hit */
        }

        if (besthitresult > 0)
        {
            SK_Stroke *selected_stk = BLI_findlink(&sketch->strokes, besthitresult - 1);

            if (extend == 0)
            {
                sk_selectAllSketch(sketch, -1);

                selected_stk->selected = 1;
            }
            else
            {
                selected_stk->selected ^= 1;
            }


        }
        return 1;
    }

    return 0;
}

#if 0 /* UNUSED 2.5 */
static void sk_queueRedrawSketch(SK_Sketch *sketch)
{
    if (sketch->active_stroke != NULL)
    {
        SK_Point *last = sk_lastStrokePoint(sketch->active_stroke);

        if (last != NULL)
        {
//          XXX
//          allqueue(REDRAWVIEW3D, 0);
        }
    }
}
#endif

static void sk_drawSketch(Scene *scene, View3D *UNUSED(v3d), SK_Sketch *sketch, int with_names)
{
    ToolSettings *ts= scene->toolsettings;
    SK_Stroke *stk;

    glClear(GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);

    if (with_names)
    {
        int id;
        for (id = 1, stk = sketch->strokes.first; stk; id++, stk = stk->next)
        {
            sk_drawStroke(stk, id, NULL, -1, -1);
        }

        glLoadName(-1);
    }
    else
    {
        float selected_rgb[3] = {1, 0, 0};
        float unselected_rgb[3] = {1, 0.5, 0};

        for (stk = sketch->strokes.first; stk; stk = stk->next)
        {
            int start = -1;
            int end = -1;

            if (sk_hasOverdraw(sketch, stk))
            {
                sk_adjustIndexes(sketch, &start, &end);
            }

            sk_drawStroke(stk, -1, (stk->selected==1?selected_rgb:unselected_rgb), start, end);

            if (stk->selected == 1)
            {
                sk_drawStrokeSubdivision(ts, stk);
            }
        }

        if (sketch->active_stroke != NULL)
        {
            SK_Point *last = sk_lastStrokePoint(sketch->active_stroke);

            if (ts->bone_sketching & BONE_SKETCHING_QUICK)
            {
                sk_drawStrokeSubdivision(ts, sketch->active_stroke);
            }

            if (last != NULL)
            {
                GLUquadric *quad = gluNewQuadric();
                gluQuadricNormals(quad, GLU_SMOOTH);

                glPushMatrix();

                glEnable(GL_BLEND);
                glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

                switch (sketch->next_point.mode)
                {
                    case PT_SNAP:
                        glColor3f(0, 1, 0);
                        break;
                    case PT_PROJECT:
                        glColor3f(0, 0, 0);
                        break;
                }

                sk_drawPoint(quad, &sketch->next_point, 0.1);

                glColor4f(selected_rgb[0], selected_rgb[1], selected_rgb[2], 0.3);

                sk_drawEdge(quad, last, &sketch->next_point, 0.1);

                glDisable(GL_BLEND);

                glPopMatrix();

                gluDeleteQuadric(quad);
            }
        }
    }

#if 0
    if (sketch->depth_peels.first != NULL)
    {
        float colors[8][3] = {
                                {1, 0, 0},
                                {0, 1, 0},
                                {0, 0, 1},
                                {1, 1, 0},
                                {1, 0, 1},
                                {0, 1, 1},
                                {1, 1, 1},
                                {0, 0, 0}
                            };
        DepthPeel *p;
        GLUquadric *quad = gluNewQuadric();
        gluQuadricNormals(quad, GLU_SMOOTH);

        for (p = sketch->depth_peels.first; p; p = p->next)
        {
            int index = GET_INT_FROM_POINTER(p->ob);
            index = (index >> 5) & 7;

            glColor3fv(colors[index]);
            glPushMatrix();
            glTranslatef(p->p[0], p->p[1], p->p[2]);
            gluSphere(quad, 0.02, 8, 8);
            glPopMatrix();
        }

        gluDeleteQuadric(quad);
    }
#endif

    glDisable(GL_DEPTH_TEST);

    /* only draw gesture in active area */
    if (sketch->gesture != NULL /*&& area_is_active_area(G.vd->area)*/)
    {
        float gesture_rgb[3] = {0, 0.5, 1};
        sk_drawStroke(sketch->gesture, -1, gesture_rgb, -1, -1);
    }
}

static int sk_finish_stroke(bContext *C, SK_Sketch *sketch)
{
    ToolSettings *ts = CTX_data_tool_settings(C);

    if (sketch->active_stroke != NULL)
    {
        SK_Stroke *stk = sketch->active_stroke;

        sk_endStroke(C, sketch);

        if (ts->bone_sketching & BONE_SKETCHING_QUICK)
        {
            if (ts->bone_sketching_convert == SK_CONVERT_RETARGET)
            {
                sk_retargetStroke(C, stk);
            }
            else
            {
                sk_convertStroke(C, stk);
            }
//          XXX
//          BIF_undo_push("Convert Sketch");
            sk_removeStroke(sketch, stk);
//          XXX
//          allqueue(REDRAWBUTSEDIT, 0);
        }

//      XXX
//      allqueue(REDRAWVIEW3D, 0);
        return 1;
    }

    return 0;
}

static void sk_start_draw_stroke(SK_Sketch *sketch)
{
    if (sketch->active_stroke == NULL)
    {
        sk_startStroke(sketch);
        sk_selectAllSketch(sketch, -1);

        sketch->active_stroke->selected = 1;
    }
}

static void sk_start_draw_gesture(SK_Sketch *sketch)
{
    sketch->gesture = sk_createStroke();
}

static int sk_draw_stroke(bContext *C, SK_Sketch *sketch, SK_Stroke *stk, SK_DrawData *dd, short snap)
{
    if (sk_stroke_filtermval(dd))
    {
        sk_addStrokePoint(C, sketch, stk, dd, snap);
        sk_updateDrawData(dd);
        sk_updateNextPoint(sketch, stk);
        
        return 1;
    }

    return 0;
}

static int ValidSketchViewContext(ViewContext *vc)
{
    Object *obedit = vc->obedit;
    Scene *scene= vc->scene;

    if (obedit &&
        obedit->type == OB_ARMATURE &&
        scene->toolsettings->bone_sketching & BONE_SKETCHING)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

int BDR_drawSketchNames(ViewContext *vc)
{
    if (ValidSketchViewContext(vc))
    {
        SK_Sketch *sketch = viewcontextSketch(vc, 0);
        if (sketch)
        {
            sk_drawSketch(vc->scene, vc->v3d, sketch, 1);
            return 1;
        }
    }

    return 0;
}

void BDR_drawSketch(const bContext *C)
{
    if (ED_operator_sketch_mode(C))
    {
        SK_Sketch *sketch = contextSketch(C, 0);
        if (sketch)
        {
            sk_drawSketch(CTX_data_scene(C), CTX_wm_view3d(C), sketch, 0);
        }
    }
}

static int sketch_delete(bContext *C, wmOperator *UNUSED(op), wmEvent *UNUSED(event))
{
    SK_Sketch *sketch = contextSketch(C, 0);
    if (sketch)
    {
        sk_deleteSelectedStrokes(sketch);
//          allqueue(REDRAWVIEW3D, 0);
    }
    WM_event_add_notifier(C, NC_SCREEN|ND_SKETCH|NA_REMOVED, NULL);
    return OPERATOR_FINISHED;
}

void BIF_sk_selectStroke(bContext *C, const int mval[2], short extend)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    SK_Sketch *sketch = contextSketch(C, 0);

    if (sketch != NULL && ts->bone_sketching & BONE_SKETCHING)
    {
        if (sk_selectStroke(C, sketch, mval, extend))
            ED_area_tag_redraw(CTX_wm_area(C));
    }
}

void BIF_convertSketch(bContext *C)
{
    if (ED_operator_sketch_full_mode(C))
    {
        SK_Sketch *sketch = contextSketch(C, 0);
        if (sketch)
        {
            sk_convert(C, sketch);
//          BIF_undo_push("Convert Sketch");
//          allqueue(REDRAWVIEW3D, 0);
//          allqueue(REDRAWBUTSEDIT, 0);
        }
    }
}

void BIF_deleteSketch(bContext *C)
{
    if (ED_operator_sketch_full_mode(C))
    {
        SK_Sketch *sketch = contextSketch(C, 0);
        if (sketch)
        {
            sk_deleteSelectedStrokes(sketch);
//          BIF_undo_push("Convert Sketch");
//          allqueue(REDRAWVIEW3D, 0);
        }
    }
}

#if 0
void BIF_selectAllSketch(bContext *C, int mode)
{
    if (BIF_validSketchMode(C))
    {
        SK_Sketch *sketch = contextSketch(C, 0);
        if (sketch)
        {
            sk_selectAllSketch(sketch, mode);
//          XXX
//          allqueue(REDRAWVIEW3D, 0);
        }
    }
}
#endif

SK_Sketch* contextSketch(const bContext *C, int create)
{
    Object *obedit = CTX_data_edit_object(C);
    SK_Sketch *sketch = NULL;

    if (obedit && obedit->type == OB_ARMATURE)
    {
        bArmature *arm = obedit->data;
    
        if (arm->sketch == NULL && create)
        {
            arm->sketch = createSketch();
        }
        sketch = arm->sketch;
    }

    return sketch;
}

SK_Sketch* viewcontextSketch(ViewContext *vc, int create)
{
    Object *obedit = vc->obedit;
    SK_Sketch *sketch = NULL;

    if (obedit && obedit->type == OB_ARMATURE)
    {
        bArmature *arm = obedit->data;
    
        if (arm->sketch == NULL && create)
        {
            arm->sketch = createSketch();
        }
        sketch = arm->sketch;
    }

    return sketch;
}

static int sketch_convert(bContext *C, wmOperator *UNUSED(op), wmEvent *UNUSED(event))
{
    SK_Sketch *sketch = contextSketch(C, 0);
    if (sketch != NULL)
    {
        sk_convert(C, sketch);
        ED_area_tag_redraw(CTX_wm_area(C));
    }
    return OPERATOR_FINISHED;
}

static int sketch_cancel(bContext *C, wmOperator *UNUSED(op), wmEvent *UNUSED(event))
{
    SK_Sketch *sketch = contextSketch(C, 0);
    if (sketch != NULL)
    {
        sk_cancelStroke(sketch);
        ED_area_tag_redraw(CTX_wm_area(C));
        return OPERATOR_FINISHED;
    }
    return OPERATOR_PASS_THROUGH;
}

static int sketch_finish(bContext *C, wmOperator *UNUSED(op), wmEvent *UNUSED(event))
{
    SK_Sketch *sketch = contextSketch(C, 0);
    if (sketch != NULL)
    {
        if (sk_finish_stroke(C, sketch))
        {
            ED_area_tag_redraw(CTX_wm_area(C));
            return OPERATOR_FINISHED;
        }
    }
    return OPERATOR_PASS_THROUGH;
}

static int sketch_select(bContext *C, wmOperator *UNUSED(op), wmEvent *event)
{
    SK_Sketch *sketch = contextSketch(C, 0);
    if (sketch)
    {
        short extend = 0;
        if (sk_selectStroke(C, sketch, event->mval, extend))
            ED_area_tag_redraw(CTX_wm_area(C));
    }

    return OPERATOR_FINISHED;
}

static int sketch_draw_stroke_cancel(bContext *C, wmOperator *op)
{
    SK_Sketch *sketch = contextSketch(C, 1); /* create just to be sure */
    sk_cancelStroke(sketch);
    MEM_freeN(op->customdata);
    return OPERATOR_CANCELLED;
}

static int sketch_draw_stroke(bContext *C, wmOperator *op, wmEvent *event)
{
    short snap = RNA_boolean_get(op->ptr, "snap");
    SK_DrawData *dd;
    SK_Sketch *sketch = contextSketch(C, 1);

    op->customdata = dd = MEM_callocN(sizeof("SK_DrawData"), "SketchDrawData");
    sk_initDrawData(dd, event->mval);

    sk_start_draw_stroke(sketch);

    sk_draw_stroke(C, sketch, sketch->active_stroke, dd, snap);

    WM_event_add_modal_handler(C, op);

    return OPERATOR_RUNNING_MODAL;
}

static int sketch_draw_gesture_cancel(bContext *C, wmOperator *op)
{
    SK_Sketch *sketch = contextSketch(C, 1); /* create just to be sure */
    sk_cancelStroke(sketch);
    MEM_freeN(op->customdata);
    return OPERATOR_CANCELLED;
}

static int sketch_draw_gesture(bContext *C, wmOperator *op, wmEvent *event)
{
    short snap = RNA_boolean_get(op->ptr, "snap");
    SK_DrawData *dd;
    SK_Sketch *sketch = contextSketch(C, 1); /* create just to be sure */
    sk_cancelStroke(sketch);

    op->customdata = dd = MEM_callocN(sizeof("SK_DrawData"), "SketchDrawData");
    sk_initDrawData(dd, event->mval);

    sk_start_draw_gesture(sketch);
    sk_draw_stroke(C, sketch, sketch->gesture, dd, snap);

    WM_event_add_modal_handler(C, op);

    return OPERATOR_RUNNING_MODAL;
}

static int sketch_draw_modal(bContext *C, wmOperator *op, wmEvent *event, short gesture, SK_Stroke *stk)
{
    short snap = RNA_boolean_get(op->ptr, "snap");
    SK_DrawData *dd = op->customdata;
    SK_Sketch *sketch = contextSketch(C, 1); /* create just to be sure */
    int retval = OPERATOR_RUNNING_MODAL;

    switch (event->type)
    {
    case LEFTCTRLKEY:
    case RIGHTCTRLKEY:
        snap = event->ctrl;
        RNA_boolean_set(op->ptr, "snap", snap);
        break;
    case MOUSEMOVE:
    case INBETWEEN_MOUSEMOVE:
        dd->mval[0] = event->mval[0];
        dd->mval[1] = event->mval[1];
        sk_draw_stroke(C, sketch, stk, dd, snap);
        ED_area_tag_redraw(CTX_wm_area(C));
        break;
    case ESCKEY:
        op->type->cancel(C, op);
        ED_area_tag_redraw(CTX_wm_area(C));
        retval = OPERATOR_CANCELLED;
        break;
    case LEFTMOUSE:
        if (event->val == KM_RELEASE)
        {
            if (gesture == 0)
            {
                sk_endContinuousStroke(stk);
                sk_filterLastContinuousStroke(stk);
                sk_updateNextPoint(sketch, stk);
                ED_area_tag_redraw(CTX_wm_area(C));
                MEM_freeN(op->customdata);
                retval = OPERATOR_FINISHED;
            }
            else
            {
                sk_endContinuousStroke(stk);
                sk_filterLastContinuousStroke(stk);

                if (stk->nb_points > 1)
                {
                    /* apply gesture here */
                    sk_applyGesture(C, sketch);
                }

                sk_freeStroke(stk);
                sketch->gesture = NULL;

                ED_area_tag_redraw(CTX_wm_area(C));
                MEM_freeN(op->customdata);
                retval = OPERATOR_FINISHED;
            }
        }
        break;
    }

    return retval;
}

static int sketch_draw_stroke_modal(bContext *C, wmOperator *op, wmEvent *event)
{
    SK_Sketch *sketch = contextSketch(C, 1); /* create just to be sure */
    return sketch_draw_modal(C, op, event, 0, sketch->active_stroke);
}

static int sketch_draw_gesture_modal(bContext *C, wmOperator *op, wmEvent *event)
{
    SK_Sketch *sketch = contextSketch(C, 1); /* create just to be sure */
    return sketch_draw_modal(C, op, event, 1, sketch->gesture);
}

static int sketch_draw_preview(bContext *C, wmOperator *op, wmEvent *event)
{
    short snap = RNA_boolean_get(op->ptr, "snap");
    SK_Sketch *sketch = contextSketch(C, 0);

    if (sketch)
    {
        SK_DrawData dd;

        sk_initDrawData(&dd, event->mval);
        sk_getStrokePoint(C, &sketch->next_point, sketch, sketch->active_stroke, &dd, snap);
        ED_area_tag_redraw(CTX_wm_area(C));
    }

    return OPERATOR_FINISHED|OPERATOR_PASS_THROUGH;
}

/* ============================================== Poll Functions ============================================= */

int ED_operator_sketch_mode_active_stroke(bContext *C)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    SK_Sketch *sketch = contextSketch(C, 0);

    if (ts->bone_sketching & BONE_SKETCHING &&
        sketch != NULL &&
        sketch->active_stroke != NULL)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

static int ED_operator_sketch_mode_gesture(bContext *C)
{
    ToolSettings *ts = CTX_data_tool_settings(C);
    SK_Sketch *sketch = contextSketch(C, 0);

    if (ts->bone_sketching & BONE_SKETCHING &&
        (ts->bone_sketching & BONE_SKETCHING_QUICK) == 0 &&
        sketch != NULL &&
        sketch->active_stroke == NULL)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

int ED_operator_sketch_full_mode(bContext *C)
{
    Object *obedit = CTX_data_edit_object(C);
    ToolSettings *ts = CTX_data_tool_settings(C);

    if (obedit &&
        obedit->type == OB_ARMATURE &&
        ts->bone_sketching & BONE_SKETCHING &&
        (ts->bone_sketching & BONE_SKETCHING_QUICK) == 0)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

int ED_operator_sketch_mode(const bContext *C)
{
    Object *obedit = CTX_data_edit_object(C);
    ToolSettings *ts = CTX_data_tool_settings(C);

    if (obedit &&
        obedit->type == OB_ARMATURE &&
        ts->bone_sketching & BONE_SKETCHING)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

/* ================================================ Operators ================================================ */

void SKETCH_OT_delete(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "delete";
    ot->idname= "SKETCH_OT_delete";

    /* api callbacks */
    ot->invoke= sketch_delete;

    ot->poll= ED_operator_sketch_full_mode;

    /* flags */
//  ot->flag= OPTYPE_UNDO;
}

void SKETCH_OT_select(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "select";
    ot->idname= "SKETCH_OT_select";

    /* api callbacks */
    ot->invoke= sketch_select;

    ot->poll= ED_operator_sketch_full_mode;

    /* flags */
//  ot->flag= OPTYPE_UNDO;
}

void SKETCH_OT_cancel_stroke(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "cancel stroke";
    ot->idname= "SKETCH_OT_cancel_stroke";

    /* api callbacks */
    ot->invoke= sketch_cancel;

    ot->poll= ED_operator_sketch_mode_active_stroke;

    /* flags */
//  ot->flag= OPTYPE_UNDO;
}

void SKETCH_OT_convert(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "convert";
    ot->idname= "SKETCH_OT_convert";

    /* api callbacks */
    ot->invoke= sketch_convert;

    ot->poll= ED_operator_sketch_full_mode;

    /* flags */
    ot->flag= OPTYPE_UNDO;
}

void SKETCH_OT_finish_stroke(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "end stroke";
    ot->idname= "SKETCH_OT_finish_stroke";

    /* api callbacks */
    ot->invoke= sketch_finish;

    ot->poll= ED_operator_sketch_mode_active_stroke;

    /* flags */
//  ot->flag= OPTYPE_UNDO;
}

void SKETCH_OT_draw_preview(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "draw preview";
    ot->idname= "SKETCH_OT_draw_preview";

    /* api callbacks */
    ot->invoke= sketch_draw_preview;

    ot->poll= ED_operator_sketch_mode_active_stroke;

    RNA_def_boolean(ot->srna, "snap", 0, "Snap", "");

    /* flags */
//  ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
}

void SKETCH_OT_draw_stroke(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "draw stroke";
    ot->idname= "SKETCH_OT_draw_stroke";

    /* api callbacks */
    ot->invoke = sketch_draw_stroke;
    ot->modal  = sketch_draw_stroke_modal;
    ot->cancel = sketch_draw_stroke_cancel;

    ot->poll= (int (*)(bContext *))ED_operator_sketch_mode;

    RNA_def_boolean(ot->srna, "snap", 0, "Snap", "");

    /* flags */
    ot->flag= OPTYPE_BLOCKING; // OPTYPE_REGISTER|OPTYPE_UNDO
}

void SKETCH_OT_gesture(wmOperatorType *ot)
{
    /* identifiers */
    ot->name= "gesture";
    ot->idname= "SKETCH_OT_gesture";

    /* api callbacks */
    ot->invoke = sketch_draw_gesture;
    ot->modal  = sketch_draw_gesture_modal;
    ot->cancel = sketch_draw_gesture_cancel;

    ot->poll= ED_operator_sketch_mode_gesture;

    RNA_def_boolean(ot->srna, "snap", 0, "Snap", "");

    /* flags */
    ot->flag= OPTYPE_BLOCKING; // OPTYPE_UNDO
}