brush.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.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

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

#include "MEM_guardedalloc.h"

#include "DNA_brush_types.h"
#include "DNA_color_types.h"
#include "DNA_scene_types.h"
#include "DNA_object_types.h"
#include "DNA_windowmanager_types.h"

#include "WM_types.h"

#include "RNA_access.h"

#include "BLI_bpath.h"
#include "BLI_math.h"
#include "BLI_blenlib.h"
#include "BLI_rand.h"
#include "BLI_utildefines.h"

#include "BKE_brush.h"
#include "BKE_colortools.h"
#include "BKE_global.h"
#include "BKE_image.h"
#include "BKE_library.h"
#include "BKE_main.h"
#include "BKE_paint.h"
#include "BKE_texture.h"
#include "BKE_icons.h"

#include "IMB_imbuf.h"
#include "IMB_imbuf_types.h"

#include "RE_render_ext.h" /* externtex */
#include "RE_shader_ext.h"

static void brush_set_defaults(Brush *brush)
{
    brush->blend = 0;
    brush->flag = 0;

    brush->ob_mode = OB_MODE_ALL_PAINT;

    /* BRUSH SCULPT TOOL SETTINGS */
    brush->size= 35; /* radius of the brush in pixels */
    brush->alpha= 0.5f; /* brush strength/intensity probably variable should be renamed? */
    brush->autosmooth_factor= 0.0f;
    brush->crease_pinch_factor= 0.5f;
    brush->sculpt_plane = SCULPT_DISP_DIR_AREA;
    brush->plane_offset= 0.0f; /* how far above or below the plane that is found by averaging the faces */
    brush->plane_trim= 0.5f;
    brush->clone.alpha= 0.5f;
    brush->normal_weight= 0.0f;
    brush->flag |= BRUSH_ALPHA_PRESSURE;

    /* BRUSH PAINT TOOL SETTINGS */
    brush->rgb[0]= 1.0f; /* default rgb color of the brush when painting - white */
    brush->rgb[1]= 1.0f;
    brush->rgb[2]= 1.0f;

    /* BRUSH STROKE SETTINGS */
    brush->flag |= (BRUSH_SPACE|BRUSH_SPACE_ATTEN);
    brush->spacing= 10; /* how far each brush dot should be spaced as a percentage of brush diameter */

    brush->smooth_stroke_radius= 75;
    brush->smooth_stroke_factor= 0.9f;

    brush->rate= 0.1f; /* time delay between dots of paint or sculpting when doing airbrush mode */

    brush->jitter= 0.0f;

    /* BRUSH TEXTURE SETTINGS */
    default_mtex(&brush->mtex);

    brush->texture_sample_bias= 0; /* value to added to texture samples */
    brush->texture_overlay_alpha= 33;

    /* brush appearance  */

    brush->add_col[0]= 1.00; /* add mode color is light red */
    brush->add_col[1]= 0.39;
    brush->add_col[2]= 0.39;

    brush->sub_col[0]= 0.39; /* subtract mode color is light blue */
    brush->sub_col[1]= 0.39;
    brush->sub_col[2]= 1.00;
}

/* Datablock add/copy/free/make_local */

Brush *add_brush(const char *name)
{
    Brush *brush;

    brush= alloc_libblock(&G.main->brush, ID_BR, name);

    /* enable fake user by default */
    brush->id.flag |= LIB_FAKEUSER;

    brush_set_defaults(brush);

    brush->sculpt_tool = SCULPT_TOOL_DRAW; /* sculpting defaults to the draw tool for new brushes */

     /* the default alpha falloff curve */
    brush_curve_preset(brush, CURVE_PRESET_SMOOTH);

    return brush;
}

Brush *copy_brush(Brush *brush)
{
    Brush *brushn;
    
    brushn= copy_libblock(&brush->id);

    if (brush->mtex.tex)
        id_us_plus((ID*)brush->mtex.tex);

    if (brush->icon_imbuf)
        brushn->icon_imbuf= IMB_dupImBuf(brush->icon_imbuf);

    brushn->preview = NULL;

    brushn->curve= curvemapping_copy(brush->curve);

    /* enable fake user by default */
    if (!(brushn->id.flag & LIB_FAKEUSER)) {
        brushn->id.flag |= LIB_FAKEUSER;
        brushn->id.us++;
    }
    
    return brushn;
}

/* not brush itself */
void free_brush(Brush *brush)
{
    if (brush->mtex.tex)
        brush->mtex.tex->id.us--;

    if (brush->icon_imbuf)
        IMB_freeImBuf(brush->icon_imbuf);

    BKE_previewimg_free(&(brush->preview));

    curvemapping_free(brush->curve);
}

static void extern_local_brush(Brush *brush)
{
    id_lib_extern((ID *)brush->mtex.tex);
    id_lib_extern((ID *)brush->clone.image);
}

void make_local_brush(Brush *brush)
{

    /* - only lib users: do nothing
     * - only local users: set flag
     * - mixed: make copy
     */

    Main *bmain= G.main;
    Scene *scene;
    int is_local= FALSE, is_lib= FALSE;

    if(brush->id.lib==NULL) return;

    if(brush->clone.image) {
        /* special case: ima always local immediately. Clone image should only
           have one user anyway. */
        id_clear_lib_data(bmain, &brush->clone.image->id);
        extern_local_brush(brush);
    }

    for(scene= bmain->scene.first; scene && ELEM(0, is_lib, is_local); scene=scene->id.next) {
        if(paint_brush(&scene->toolsettings->imapaint.paint)==brush) {
            if(scene->id.lib) is_lib= TRUE;
            else is_local= TRUE;
        }
    }

    if(is_local && is_lib == FALSE) {
        id_clear_lib_data(bmain, &brush->id);
        extern_local_brush(brush);

        /* enable fake user by default */
        if (!(brush->id.flag & LIB_FAKEUSER)) {
            brush->id.flag |= LIB_FAKEUSER;
            brush->id.us++;
        }
    }
    else if(is_local && is_lib) {
        Brush *brush_new= copy_brush(brush);
        brush_new->id.us= 1; /* only keep fake user */
        brush_new->id.flag |= LIB_FAKEUSER;

        /* Remap paths of new ID using old library as base. */
        BKE_id_lib_local_paths(bmain, brush->id.lib, &brush_new->id);
        
        for(scene= bmain->scene.first; scene; scene=scene->id.next) {
            if(paint_brush(&scene->toolsettings->imapaint.paint)==brush) {
                if(scene->id.lib==NULL) {
                    paint_brush_set(&scene->toolsettings->imapaint.paint, brush_new);
                }
            }
        }
    }
}

void brush_debug_print_state(Brush *br)
{
    /* create a fake brush and set it to the defaults */
    Brush def= {{NULL}};
    brush_set_defaults(&def);
    
#define BR_TEST(field, t)                   \
    if(br->field != def.field)              \
        printf("br->" #field " = %" #t ";\n", br->field)

#define BR_TEST_FLAG(_f)                \
    if((br->flag & _f) && !(def.flag & _f))     \
        printf("br->flag |= " #_f ";\n");   \
    else if(!(br->flag & _f) && (def.flag & _f))    \
        printf("br->flag &= ~" #_f ";\n")
    

    /* print out any non-default brush state */
    BR_TEST(normal_weight, f);

    BR_TEST(blend, d);
    BR_TEST(size, d);

    /* br->flag */
    BR_TEST_FLAG(BRUSH_AIRBRUSH);
    BR_TEST_FLAG(BRUSH_TORUS);
    BR_TEST_FLAG(BRUSH_ALPHA_PRESSURE);
    BR_TEST_FLAG(BRUSH_SIZE_PRESSURE);
    BR_TEST_FLAG(BRUSH_JITTER_PRESSURE);
    BR_TEST_FLAG(BRUSH_SPACING_PRESSURE);
    BR_TEST_FLAG(BRUSH_FIXED_TEX);
    BR_TEST_FLAG(BRUSH_RAKE);
    BR_TEST_FLAG(BRUSH_ANCHORED);
    BR_TEST_FLAG(BRUSH_DIR_IN);
    BR_TEST_FLAG(BRUSH_SPACE);
    BR_TEST_FLAG(BRUSH_SMOOTH_STROKE);
    BR_TEST_FLAG(BRUSH_PERSISTENT);
    BR_TEST_FLAG(BRUSH_ACCUMULATE);
    BR_TEST_FLAG(BRUSH_LOCK_ALPHA);
    BR_TEST_FLAG(BRUSH_ORIGINAL_NORMAL);
    BR_TEST_FLAG(BRUSH_OFFSET_PRESSURE);
    BR_TEST_FLAG(BRUSH_SPACE_ATTEN);
    BR_TEST_FLAG(BRUSH_ADAPTIVE_SPACE);
    BR_TEST_FLAG(BRUSH_LOCK_SIZE);
    BR_TEST_FLAG(BRUSH_TEXTURE_OVERLAY);
    BR_TEST_FLAG(BRUSH_EDGE_TO_EDGE);
    BR_TEST_FLAG(BRUSH_RESTORE_MESH);
    BR_TEST_FLAG(BRUSH_INVERSE_SMOOTH_PRESSURE);
    BR_TEST_FLAG(BRUSH_RANDOM_ROTATION);
    BR_TEST_FLAG(BRUSH_PLANE_TRIM);
    BR_TEST_FLAG(BRUSH_FRONTFACE);
    BR_TEST_FLAG(BRUSH_CUSTOM_ICON);

    BR_TEST(jitter, f);
    BR_TEST(spacing, d);
    BR_TEST(smooth_stroke_radius, d);
    BR_TEST(smooth_stroke_factor, f);
    BR_TEST(rate, f);

    BR_TEST(alpha, f);

    BR_TEST(sculpt_plane, d);

    BR_TEST(plane_offset, f);

    BR_TEST(autosmooth_factor, f);

    BR_TEST(crease_pinch_factor, f);

    BR_TEST(plane_trim, f);

    BR_TEST(texture_sample_bias, f);
    BR_TEST(texture_overlay_alpha, d);

    BR_TEST(add_col[0], f);
    BR_TEST(add_col[1], f);
    BR_TEST(add_col[2], f);
    BR_TEST(sub_col[0], f);
    BR_TEST(sub_col[1], f);
    BR_TEST(sub_col[2], f);

    printf("\n");
    
#undef BR_TEST
#undef BR_TEST_FLAG
}

void brush_reset_sculpt(Brush *br)
{
    /* enable this to see any non-default
       settings used by a brush:

    brush_debug_print_state(br);
    */

    brush_set_defaults(br);
    brush_curve_preset(br, CURVE_PRESET_SMOOTH);

    switch(br->sculpt_tool) {
    case SCULPT_TOOL_CLAY:
        br->flag |= BRUSH_FRONTFACE;
        break;
    case SCULPT_TOOL_CREASE:
        br->flag |= BRUSH_DIR_IN;
        br->alpha = 0.25;
        break;
    case SCULPT_TOOL_FILL:
        br->add_col[1] = 1;
        br->sub_col[0] = 0.25;
        br->sub_col[1] = 1;
        break;
    case SCULPT_TOOL_FLATTEN:
        br->add_col[1] = 1;
        br->sub_col[0] = 0.25;
        br->sub_col[1] = 1;
        break;
    case SCULPT_TOOL_INFLATE:
        br->add_col[0] = 0.750000;
        br->add_col[1] = 0.750000;
        br->add_col[2] = 0.750000;
        br->sub_col[0] = 0.250000;
        br->sub_col[1] = 0.250000;
        br->sub_col[2] = 0.250000;
        break;
    case SCULPT_TOOL_NUDGE:
        br->add_col[0] = 0.250000;
        br->add_col[1] = 1.000000;
        br->add_col[2] = 0.250000;
        break;
    case SCULPT_TOOL_PINCH:
        br->add_col[0] = 0.750000;
        br->add_col[1] = 0.750000;
        br->add_col[2] = 0.750000;
        br->sub_col[0] = 0.250000;
        br->sub_col[1] = 0.250000;
        br->sub_col[2] = 0.250000;
        break;
    case SCULPT_TOOL_SCRAPE:
        br->add_col[1] = 1.000000;
        br->sub_col[0] = 0.250000;
        br->sub_col[1] = 1.000000;
        break;
    case SCULPT_TOOL_ROTATE:
        br->alpha = 1.0;
        break;
    case SCULPT_TOOL_SMOOTH:
        br->flag &= ~BRUSH_SPACE_ATTEN;
        br->spacing = 5;
        br->add_col[0] = 0.750000;
        br->add_col[1] = 0.750000;
        br->add_col[2] = 0.750000;
        break;
    case SCULPT_TOOL_GRAB:
    case SCULPT_TOOL_SNAKE_HOOK:
    case SCULPT_TOOL_THUMB:
        br->size = 75;
        br->flag &= ~BRUSH_ALPHA_PRESSURE;
        br->flag &= ~BRUSH_SPACE;
        br->flag &= ~BRUSH_SPACE_ATTEN;
        br->add_col[0] = 0.250000;
        br->add_col[1] = 1.000000;
        br->add_col[2] = 0.250000;
        break;
    default:
        break;
    }
}

/* Library Operations */
void brush_curve_preset(Brush *b, /*CurveMappingPreset*/int preset)
{
    CurveMap *cm = NULL;

    if(!b->curve)
        b->curve = curvemapping_add(1, 0, 0, 1, 1);

    cm = b->curve->cm;
    cm->flag &= ~CUMA_EXTEND_EXTRAPOLATE;

    b->curve->preset = preset;
    curvemap_reset(cm, &b->curve->clipr, b->curve->preset, CURVEMAP_SLOPE_NEGATIVE);
    curvemapping_changed(b->curve, 0);
}

int brush_texture_set_nr(Brush *brush, int nr)
{
    ID *idtest, *id=NULL;

    id= (ID *)brush->mtex.tex;

    idtest= (ID*)BLI_findlink(&G.main->tex, nr-1);
    if(idtest==NULL) { /* new tex */
        if(id) idtest= (ID *)copy_texture((Tex *)id);
        else idtest= (ID *)add_texture("Tex");
        idtest->us--;
    }
    if(idtest!=id) {
        brush_texture_delete(brush);

        brush->mtex.tex= (Tex*)idtest;
        id_us_plus(idtest);

        return 1;
    }

    return 0;
}

int brush_texture_delete(Brush *brush)
{
    if(brush->mtex.tex)
        brush->mtex.tex->id.us--;

    return 1;
}

int brush_clone_image_set_nr(Brush *brush, int nr)
{
    if(brush && nr > 0) {
        Image *ima= (Image*)BLI_findlink(&G.main->image, nr-1);

        if(ima) {
            brush_clone_image_delete(brush);
            brush->clone.image= ima;
            id_us_plus(&ima->id);
            brush->clone.offset[0]= brush->clone.offset[1]= 0.0f;

            return 1;
        }
    }

    return 0;
}

int brush_clone_image_delete(Brush *brush)
{
    if (brush && brush->clone.image) {
        brush->clone.image->id.us--;
        brush->clone.image= NULL;
        return 1;
    }

    return 0;
}

/* Brush Sampling */
void brush_sample_tex(const Scene *scene, Brush *brush, const float xy[2], float rgba[4], const int thread)
{
    MTex *mtex= &brush->mtex;

    if (mtex && mtex->tex) {
        float co[3], tin, tr, tg, tb, ta;
        int hasrgb;
        const int radius= brush_size(scene, brush);

        co[0]= xy[0]/radius;
        co[1]= xy[1]/radius;
        co[2]= 0.0f;

        hasrgb= externtex(mtex, co, &tin, &tr, &tg, &tb, &ta, thread);

        if (hasrgb) {
            rgba[0]= tr;
            rgba[1]= tg;
            rgba[2]= tb;
            rgba[3]= ta;
        }
        else {
            rgba[0]= tin;
            rgba[1]= tin;
            rgba[2]= tin;
            rgba[3]= 1.0f;
        }
    }
    else {
        rgba[0]= rgba[1]= rgba[2]= rgba[3]= 1.0f;
    }
}

/* TODO, use define for 'texfall' arg */
void brush_imbuf_new(const Scene *scene, Brush *brush, short flt, short texfall, int bufsize, ImBuf **outbuf, int use_color_correction)
{
    ImBuf *ibuf;
    float xy[2], rgba[4], *dstf;
    int x, y, rowbytes, xoff, yoff, imbflag;
    const int radius= brush_size(scene, brush);
    char *dst, crgb[3];
    const float alpha= brush_alpha(scene, brush);
    float brush_rgb[3];
    
    imbflag= (flt)? IB_rectfloat: IB_rect;
    xoff = -bufsize/2.0f + 0.5f;
    yoff = -bufsize/2.0f + 0.5f;
    rowbytes= bufsize*4;

    if (*outbuf)
        ibuf= *outbuf;
    else
        ibuf= IMB_allocImBuf(bufsize, bufsize, 32, imbflag);

    if (flt) {
        copy_v3_v3(brush_rgb, brush->rgb);
        if(use_color_correction){
            srgb_to_linearrgb_v3_v3(brush_rgb, brush_rgb);
        }

        for (y=0; y < ibuf->y; y++) {
            dstf = ibuf->rect_float + y*rowbytes;

            for (x=0; x < ibuf->x; x++, dstf+=4) {
                xy[0] = x + xoff;
                xy[1] = y + yoff;

                if (texfall == 0) {
                    copy_v3_v3(dstf, brush_rgb);
                    dstf[3]= alpha*brush_curve_strength_clamp(brush, len_v2(xy), radius);
                }
                else if (texfall == 1) {
                    brush_sample_tex(scene, brush, xy, dstf, 0);
                }
                else {
                    brush_sample_tex(scene, brush, xy, rgba, 0);
                    mul_v3_v3v3(dstf, rgba, brush_rgb);
                    dstf[3] = rgba[3]*alpha*brush_curve_strength_clamp(brush, len_v2(xy), radius);
                }
            }
        }
    }
    else {
        float alpha_f; /* final float alpha to convert to char */
        F3TOCHAR3(brush->rgb, crgb);

        for (y=0; y < ibuf->y; y++) {
            dst = (char*)ibuf->rect + y*rowbytes;

            for (x=0; x < ibuf->x; x++, dst+=4) {
                xy[0] = x + xoff;
                xy[1] = y + yoff;

                if (texfall == 0) {
                    alpha_f = alpha * brush_curve_strength(brush, len_v2(xy), radius);

                    dst[0] = crgb[0];
                    dst[1] = crgb[1];
                    dst[2] = crgb[2];
                    dst[3] = FTOCHAR(alpha_f);
                }
                else if (texfall == 1) {
                    brush_sample_tex(scene, brush, xy, rgba, 0);
                    dst[0] = FTOCHAR(rgba[0]);
                    dst[1] = FTOCHAR(rgba[1]);
                    dst[2] = FTOCHAR(rgba[2]);
                    dst[3] = FTOCHAR(rgba[3]);
                }
                else if (texfall == 2) {
                    brush_sample_tex(scene, brush, xy, rgba, 0);
                    mul_v3_v3(rgba, brush->rgb);
                    alpha_f = rgba[3] * alpha * brush_curve_strength_clamp(brush, len_v2(xy), radius);

                    dst[0] = FTOCHAR(rgba[0]);
                    dst[1] = FTOCHAR(rgba[1]);
                    dst[2] = FTOCHAR(rgba[2]);
                    dst[3] = FTOCHAR(alpha_f);
                }
                else {
                    brush_sample_tex(scene, brush, xy, rgba, 0);
                    alpha_f = rgba[3] * alpha * brush_curve_strength_clamp(brush, len_v2(xy), radius);

                    dst[0] = crgb[0];
                    dst[1] = crgb[1];
                    dst[2] = crgb[2];
                    dst[3] = FTOCHAR(alpha_f);
                }
            }
        }
    }

    *outbuf= ibuf;
}

/* Unified Size and Strength */

// XXX: be careful about setting size and unprojected radius
// because they depend on one another
// these functions do not set the other corresponding value
// this can lead to odd behavior if size and unprojected
// radius become inconsistent.
// the biggest problem is that it isn't possible to change
// unprojected radius because a view context is not
// available.  my ussual solution to this is to use the
// ratio of change of the size to change the unprojected
// radius.  Not completely convinced that is correct.
// In anycase, a better solution is needed to prevent
// inconsistency.

void brush_set_size(Scene *scene, Brush *brush, int size)
{
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;

    if (ups->flag & UNIFIED_PAINT_SIZE)
        ups->size= size;
    else
        brush->size= size;
}

int brush_size(const Scene *scene, Brush *brush)
{
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;

    return (ups->flag & UNIFIED_PAINT_SIZE) ? ups->size : brush->size;
}

int brush_use_locked_size(const Scene *scene, Brush *brush)
{
    const short us_flag = scene->toolsettings->unified_paint_settings.flag;

    return (us_flag & UNIFIED_PAINT_SIZE) ?
            (us_flag & UNIFIED_PAINT_BRUSH_LOCK_SIZE) :
            (brush->flag & BRUSH_LOCK_SIZE);
}

int brush_use_size_pressure(const Scene *scene, Brush *brush)
{
    const short us_flag = scene->toolsettings->unified_paint_settings.flag;

    return (us_flag & UNIFIED_PAINT_SIZE) ?
            (us_flag & UNIFIED_PAINT_BRUSH_SIZE_PRESSURE) :
            (brush->flag & BRUSH_SIZE_PRESSURE);
}

int brush_use_alpha_pressure(const Scene *scene, Brush *brush)
{
    const short us_flag = scene->toolsettings->unified_paint_settings.flag;

    return (us_flag & UNIFIED_PAINT_ALPHA) ?
            (us_flag & UNIFIED_PAINT_BRUSH_ALPHA_PRESSURE) :
            (brush->flag & BRUSH_ALPHA_PRESSURE);
}

void brush_set_unprojected_radius(Scene *scene, Brush *brush, float unprojected_radius)
{
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;

    if (ups->flag & UNIFIED_PAINT_SIZE)
        ups->unprojected_radius= unprojected_radius;
    else
        brush->unprojected_radius= unprojected_radius;
}

float brush_unprojected_radius(const Scene *scene, Brush *brush)
{
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;

    return (ups->flag & UNIFIED_PAINT_SIZE) ?
            ups->unprojected_radius :
            brush->unprojected_radius;
}

static void brush_set_alpha(Scene *scene, Brush *brush, float alpha)
{
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;

    if (ups->flag & UNIFIED_PAINT_ALPHA)
        ups->alpha= alpha;
    else
        brush->alpha= alpha;
}

float brush_alpha(const Scene *scene, Brush *brush)
{
    UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;

    return (ups->flag & UNIFIED_PAINT_ALPHA) ? ups->alpha : brush->alpha;
}

/* scale unprojected radius to reflect a change in the brush's 2D size */
void brush_scale_unprojected_radius(float *unprojected_radius,
                                    int new_brush_size,
                                    int old_brush_size)
{
    float scale = new_brush_size;
    /* avoid division by zero */
    if(old_brush_size != 0)
        scale /= (float)old_brush_size;
    (*unprojected_radius) *= scale;
}

/* scale brush size to reflect a change in the brush's unprojected radius */
void brush_scale_size(int *brush_size,
                      float new_unprojected_radius,
                      float old_unprojected_radius)
{
    float scale = new_unprojected_radius;
    /* avoid division by zero */
    if(old_unprojected_radius != 0)
        scale /= new_unprojected_radius;
    (*brush_size)= (int)((float)(*brush_size) * scale);
}

/* Brush Painting */

typedef struct BrushPainterCache {
    short enabled;

    int size;           /* size override, if 0 uses 2*brush_size(brush) */
    short flt;          /* need float imbuf? */
    short texonly;      /* no alpha, color or fallof, only texture in imbuf */

    int lastsize;
    float lastalpha;
    float lastjitter;

    ImBuf *ibuf;
    ImBuf *texibuf;
    ImBuf *maskibuf;
} BrushPainterCache;

struct BrushPainter {
    Scene *scene;
    Brush *brush;

    float lastmousepos[2];  /* mouse position of last paint call */

    float accumdistance;    /* accumulated distance of brush since last paint op */
    float lastpaintpos[2];  /* position of last paint op */
    float startpaintpos[2]; /* position of first paint */

    double accumtime;       /* accumulated time since last paint op (airbrush) */
    double lasttime;        /* time of last update */

    float lastpressure;

    short firsttouch;       /* first paint op */

    float startsize;
    float startalpha;
    float startjitter;
    float startspacing;

    BrushPainterCache cache;
};

BrushPainter *brush_painter_new(Scene *scene, Brush *brush)
{
    BrushPainter *painter= MEM_callocN(sizeof(BrushPainter), "BrushPainter");

    painter->brush= brush;
    painter->scene= scene;
    painter->firsttouch= 1;
    painter->cache.lastsize= -1; /* force ibuf create in refresh */

    painter->startsize = brush_size(scene, brush);
    painter->startalpha = brush_alpha(scene, brush);
    painter->startjitter = brush->jitter;
    painter->startspacing = brush->spacing;

    return painter;
}

void brush_painter_require_imbuf(BrushPainter *painter, short flt, short texonly, int size)
{
    if ((painter->cache.flt != flt) || (painter->cache.size != size) ||
        ((painter->cache.texonly != texonly) && texonly)) {
        if (painter->cache.ibuf) IMB_freeImBuf(painter->cache.ibuf);
        if (painter->cache.maskibuf) IMB_freeImBuf(painter->cache.maskibuf);
        painter->cache.ibuf= painter->cache.maskibuf= NULL;
        painter->cache.lastsize= -1; /* force ibuf create in refresh */
    }

    if (painter->cache.flt != flt) {
        if (painter->cache.texibuf) IMB_freeImBuf(painter->cache.texibuf);
        painter->cache.texibuf= NULL;
        painter->cache.lastsize= -1; /* force ibuf create in refresh */
    }

    painter->cache.size= size;
    painter->cache.flt= flt;
    painter->cache.texonly= texonly;
    painter->cache.enabled= 1;
}

void brush_painter_free(BrushPainter *painter)
{
    Brush *brush = painter->brush;

    brush_set_size(painter->scene, brush, painter->startsize);
    brush_set_alpha(painter->scene, brush, painter->startalpha);
    brush->jitter = painter->startjitter;
    brush->spacing = painter->startspacing;

    if (painter->cache.ibuf) IMB_freeImBuf(painter->cache.ibuf);
    if (painter->cache.texibuf) IMB_freeImBuf(painter->cache.texibuf);
    if (painter->cache.maskibuf) IMB_freeImBuf(painter->cache.maskibuf);
    MEM_freeN(painter);
}

static void brush_painter_do_partial(BrushPainter *painter, ImBuf *oldtexibuf, int x, int y, int w, int h, int xt, int yt, float *pos)
{
    Scene *scene= painter->scene;
    Brush *brush= painter->brush;
    ImBuf *ibuf, *maskibuf, *texibuf;
    float *bf, *mf, *tf, *otf=NULL, xoff, yoff, xy[2], rgba[4];
    char *b, *m, *t, *ot= NULL;
    int dotexold, origx= x, origy= y;
    const int radius= brush_size(painter->scene, brush);

    xoff = -radius + 0.5f;
    yoff = -radius + 0.5f;
    xoff += (int)pos[0] - (int)painter->startpaintpos[0];
    yoff += (int)pos[1] - (int)painter->startpaintpos[1];

    ibuf = painter->cache.ibuf;
    texibuf = painter->cache.texibuf;
    maskibuf = painter->cache.maskibuf;

    dotexold = (oldtexibuf != NULL);

    /* not sure if it's actually needed or it's a mistake in coords/sizes
       calculation in brush_painter_fixed_tex_partial_update(), but without this
       limitation memory gets corrupted at fast strokes with quite big spacing (sergey) */
    w = MIN2(w, ibuf->x);
    h = MIN2(h, ibuf->y);

    if (painter->cache.flt) {
        for (; y < h; y++) {
            bf = ibuf->rect_float + (y*ibuf->x + origx)*4;
            tf = texibuf->rect_float + (y*texibuf->x + origx)*4;
            mf = maskibuf->rect_float + (y*maskibuf->x + origx)*4;

            if (dotexold)
                otf = oldtexibuf->rect_float + ((y - origy + yt)*oldtexibuf->x + xt)*4;

            for (x=origx; x < w; x++, bf+=4, mf+=4, tf+=4) {
                if (dotexold) {
                    copy_v3_v3(tf, otf);
                    tf[3] = otf[3];
                    otf += 4;
                }
                else {
                    xy[0] = x + xoff;
                    xy[1] = y + yoff;

                    brush_sample_tex(scene, brush, xy, tf, 0);
                }

                bf[0] = tf[0]*mf[0];
                bf[1] = tf[1]*mf[1];
                bf[2] = tf[2]*mf[2];
                bf[3] = tf[3]*mf[3];
            }
        }
    }
    else {
        for (; y < h; y++) {
            b = (char*)ibuf->rect + (y*ibuf->x + origx)*4;
            t = (char*)texibuf->rect + (y*texibuf->x + origx)*4;
            m = (char*)maskibuf->rect + (y*maskibuf->x + origx)*4;

            if (dotexold)
                ot = (char*)oldtexibuf->rect + ((y - origy + yt)*oldtexibuf->x + xt)*4;

            for (x=origx; x < w; x++, b+=4, m+=4, t+=4) {
                if (dotexold) {
                    t[0] = ot[0];
                    t[1] = ot[1];
                    t[2] = ot[2];
                    t[3] = ot[3];
                    ot += 4;
                }
                else {
                    xy[0] = x + xoff;
                    xy[1] = y + yoff;

                    brush_sample_tex(scene, brush, xy, rgba, 0);
                    t[0]= FTOCHAR(rgba[0]);
                    t[1]= FTOCHAR(rgba[1]);
                    t[2]= FTOCHAR(rgba[2]);
                    t[3]= FTOCHAR(rgba[3]);
                }

                b[0] = t[0]*m[0]/255;
                b[1] = t[1]*m[1]/255;
                b[2] = t[2]*m[2]/255;
                b[3] = t[3]*m[3]/255;
            }
        }
    }
}

static void brush_painter_fixed_tex_partial_update(BrushPainter *painter, float *pos)
{
    const Scene *scene= painter->scene;
    Brush *brush= painter->brush;
    BrushPainterCache *cache= &painter->cache;
    ImBuf *oldtexibuf, *ibuf;
    int imbflag, destx, desty, srcx, srcy, w, h, x1, y1, x2, y2;
    const int diameter= 2*brush_size(scene, brush);

    imbflag= (cache->flt)? IB_rectfloat: IB_rect;
    if (!cache->ibuf)
        cache->ibuf= IMB_allocImBuf(diameter, diameter, 32, imbflag);
    ibuf= cache->ibuf;

    oldtexibuf= cache->texibuf;
    cache->texibuf= IMB_allocImBuf(diameter, diameter, 32, imbflag);

    if (oldtexibuf) {
        srcx= srcy= 0;
        destx= (int)painter->lastpaintpos[0] - (int)pos[0];
        desty= (int)painter->lastpaintpos[1] - (int)pos[1];
        w= oldtexibuf->x;
        h= oldtexibuf->y;

        IMB_rectclip(cache->texibuf, oldtexibuf, &destx, &desty, &srcx, &srcy, &w, &h);
    }
    else {
        srcx= srcy= 0;
        destx= desty= 0;
        w= h= 0;
    }
    
    x1= destx;
    y1= desty;
    x2= destx+w;
    y2= desty+h;

    /* blend existing texture in new position */
    if ((x1 < x2) && (y1 < y2))
        brush_painter_do_partial(painter, oldtexibuf, x1, y1, x2, y2, srcx, srcy, pos);

    if (oldtexibuf)
        IMB_freeImBuf(oldtexibuf);

    /* sample texture in new areas */
    if ((0 < x1) && (0 < ibuf->y))
        brush_painter_do_partial(painter, NULL, 0, 0, x1, ibuf->y, 0, 0, pos);
    if ((x2 < ibuf->x) && (0 < ibuf->y))
        brush_painter_do_partial(painter, NULL, x2, 0, ibuf->x, ibuf->y, 0, 0, pos);
    if ((x1 < x2) && (0 < y1))
        brush_painter_do_partial(painter, NULL, x1, 0, x2, y1, 0, 0, pos);
    if ((x1 < x2) && (y2 < ibuf->y))
        brush_painter_do_partial(painter, NULL, x1, y2, x2, ibuf->y, 0, 0, pos);
}

static void brush_painter_refresh_cache(BrushPainter *painter, float *pos, int use_color_correction)
{
    const Scene *scene= painter->scene;
    Brush *brush= painter->brush;
    BrushPainterCache *cache= &painter->cache;
    MTex *mtex= &brush->mtex;
    int size;
    short flt;
    const int diameter= 2*brush_size(scene, brush);
    const float alpha= brush_alpha(scene, brush);

    if (diameter != cache->lastsize ||
        alpha != cache->lastalpha ||
        brush->jitter != cache->lastjitter)
    {
        if (cache->ibuf) {
            IMB_freeImBuf(cache->ibuf);
            cache->ibuf= NULL;
        }
        if (cache->maskibuf) {
            IMB_freeImBuf(cache->maskibuf);
            cache->maskibuf= NULL;
        }

        flt= cache->flt;
        size= (cache->size)? cache->size: diameter;

        if (brush->flag & BRUSH_FIXED_TEX) {
            brush_imbuf_new(scene, brush, flt, 3, size, &cache->maskibuf, use_color_correction);
            brush_painter_fixed_tex_partial_update(painter, pos);
        }
        else
            brush_imbuf_new(scene, brush, flt, 2, size, &cache->ibuf, use_color_correction);

        cache->lastsize= diameter;
        cache->lastalpha= alpha;
        cache->lastjitter= brush->jitter;
    }
    else if ((brush->flag & BRUSH_FIXED_TEX) && mtex && mtex->tex) {
        int dx = (int)painter->lastpaintpos[0] - (int)pos[0];
        int dy = (int)painter->lastpaintpos[1] - (int)pos[1];

        if ((dx != 0) || (dy != 0))
            brush_painter_fixed_tex_partial_update(painter, pos);
    }
}

void brush_painter_break_stroke(BrushPainter *painter)
{
    painter->firsttouch= 1;
}

static void brush_apply_pressure(BrushPainter *painter, Brush *brush, float pressure)
{
    if (brush_use_alpha_pressure(painter->scene, brush)) 
        brush_set_alpha(painter->scene, brush, MAX2(0.0f, painter->startalpha*pressure));
    if (brush_use_size_pressure(painter->scene, brush))
        brush_set_size(painter->scene, brush, MAX2(1.0f, painter->startsize*pressure));
    if (brush->flag & BRUSH_JITTER_PRESSURE)
        brush->jitter = MAX2(0.0f, painter->startjitter*pressure);
    if (brush->flag & BRUSH_SPACING_PRESSURE)
        brush->spacing = MAX2(1.0f, painter->startspacing*(1.5f-pressure));
}

void brush_jitter_pos(const Scene *scene, Brush *brush, float pos[2], float jitterpos[2])
{
    int use_jitter= brush->jitter != 0;

    /* jitter-ed brush gives weird and unpredictable result for this
       kinds of stroke, so manyally disable jitter usage (sergey) */
    use_jitter&= (brush->flag & (BRUSH_RESTORE_MESH|BRUSH_ANCHORED)) == 0;

    if(use_jitter){
        float rand_pos[2];
        const int radius= brush_size(scene, brush);
        const int diameter= 2*radius;

        // find random position within a circle of diameter 1
        do {
            rand_pos[0] = BLI_frand()-0.5f;
            rand_pos[1] = BLI_frand()-0.5f;
        } while (len_v2(rand_pos) > 0.5f);

        jitterpos[0] = pos[0] + 2*rand_pos[0]*diameter*brush->jitter;
        jitterpos[1] = pos[1] + 2*rand_pos[1]*diameter*brush->jitter;
    }
    else {
        copy_v2_v2(jitterpos, pos);
    }
}

int brush_painter_paint(BrushPainter *painter, BrushFunc func, float *pos, double time, float pressure, void *user, int use_color_correction)
{
    Scene *scene= painter->scene;
    Brush *brush= painter->brush;
    int totpaintops= 0;

    if (pressure == 0.0f) {
        if(painter->lastpressure) // XXX - hack, operator misses
            pressure= painter->lastpressure;
        else
            pressure = 1.0f;    /* zero pressure == not using tablet */
    }
    if (painter->firsttouch) {
        /* paint exactly once on first touch */
        painter->startpaintpos[0]= pos[0];
        painter->startpaintpos[1]= pos[1];

        brush_apply_pressure(painter, brush, pressure);
        if (painter->cache.enabled)
            brush_painter_refresh_cache(painter, pos, use_color_correction);
        totpaintops += func(user, painter->cache.ibuf, pos, pos);
        
        painter->lasttime= time;
        painter->firsttouch= 0;
        painter->lastpaintpos[0]= pos[0];
        painter->lastpaintpos[1]= pos[1];
    }
#if 0
    else if (painter->brush->flag & BRUSH_AIRBRUSH) {
        float spacing, step, paintpos[2], dmousepos[2], len;
        double starttime, curtime= time;

        /* compute brush spacing adapted to brush size */
        spacing= brush->rate; //radius*brush->spacing*0.01f;

        /* setup starting time, direction vector and accumulated time */
        starttime= painter->accumtime;
        sub_v2_v2v2(dmousepos, pos, painter->lastmousepos);
        len= normalize_v2(dmousepos);
        painter->accumtime += curtime - painter->lasttime;

        /* do paint op over unpainted time distance */
        while (painter->accumtime >= spacing) {
            step= (spacing - starttime)*len;
            paintpos[0]= painter->lastmousepos[0] + dmousepos[0]*step;
            paintpos[1]= painter->lastmousepos[1] + dmousepos[1]*step;

            if (painter->cache.enabled)
                brush_painter_refresh_cache(painter);
            totpaintops += func(user, painter->cache.ibuf,
                painter->lastpaintpos, paintpos);

            painter->lastpaintpos[0]= paintpos[0];
            painter->lastpaintpos[1]= paintpos[1];
            painter->accumtime -= spacing;
            starttime -= spacing;
        }
        
        painter->lasttime= curtime;
    }
#endif
    else {
        float startdistance, spacing, step, paintpos[2], dmousepos[2], finalpos[2];
        float t, len, press;
        const int radius= brush_size(scene, brush);

        /* compute brush spacing adapted to brush radius, spacing may depend
           on pressure, so update it */
        brush_apply_pressure(painter, brush, painter->lastpressure);
        spacing= MAX2(1.0f, radius)*brush->spacing*0.01f;

        /* setup starting distance, direction vector and accumulated distance */
        startdistance= painter->accumdistance;
        sub_v2_v2v2(dmousepos, pos, painter->lastmousepos);
        len= normalize_v2(dmousepos);
        painter->accumdistance += len;

        if (brush->flag & BRUSH_SPACE) {
            /* do paint op over unpainted distance */
            while ((len > 0.0f) && (painter->accumdistance >= spacing)) {
                step= spacing - startdistance;
                paintpos[0]= painter->lastmousepos[0] + dmousepos[0]*step;
                paintpos[1]= painter->lastmousepos[1] + dmousepos[1]*step;

                t = step/len;
                press= (1.0f-t)*painter->lastpressure + t*pressure;
                brush_apply_pressure(painter, brush, press);
                spacing= MAX2(1.0f, radius)*brush->spacing*0.01f;

                brush_jitter_pos(scene, brush, paintpos, finalpos);

                if (painter->cache.enabled)
                    brush_painter_refresh_cache(painter, finalpos, use_color_correction);

                totpaintops +=
                    func(user, painter->cache.ibuf, painter->lastpaintpos, finalpos);

                painter->lastpaintpos[0]= paintpos[0];
                painter->lastpaintpos[1]= paintpos[1];
                painter->accumdistance -= spacing;
                startdistance -= spacing;
            }
        } else {
            brush_jitter_pos(scene, brush, pos, finalpos);

            if (painter->cache.enabled)
                brush_painter_refresh_cache(painter, finalpos, use_color_correction);

            totpaintops += func(user, painter->cache.ibuf, pos, finalpos);

            painter->lastpaintpos[0]= pos[0];
            painter->lastpaintpos[1]= pos[1];
            painter->accumdistance= 0;
        }

        /* do airbrush paint ops, based on the number of paint ops left over
           from regular painting. this is a temporary solution until we have
           accurate time stamps for mouse move events */
        if (brush->flag & BRUSH_AIRBRUSH) {
            double curtime= time;
            double painttime= brush->rate*totpaintops;

            painter->accumtime += curtime - painter->lasttime;
            if (painter->accumtime <= painttime)
                painter->accumtime= 0.0;
            else
                painter->accumtime -= painttime;

            while (painter->accumtime >= (double)brush->rate) {
                brush_apply_pressure(painter, brush, pressure);

                brush_jitter_pos(scene, brush, pos, finalpos);

                if (painter->cache.enabled)
                    brush_painter_refresh_cache(painter, finalpos, use_color_correction);

                totpaintops +=
                    func(user, painter->cache.ibuf, painter->lastmousepos, finalpos);
                painter->accumtime -= (double)brush->rate;
            }

            painter->lasttime= curtime;
        }
    }

    painter->lastmousepos[0]= pos[0];
    painter->lastmousepos[1]= pos[1];
    painter->lastpressure= pressure;

    brush_set_alpha(scene, brush, painter->startalpha);
    brush_set_size(scene, brush, painter->startsize);
    brush->jitter = painter->startjitter;
    brush->spacing = painter->startspacing;

    return totpaintops;
}

/* Uses the brush curve control to find a strength value between 0 and 1 */
float brush_curve_strength_clamp(Brush *br, float p, const float len)
{
    if(p >= len)    return 0;
    else            p= p/len;

    p= curvemapping_evaluateF(br->curve, 0, p);
    if(p < 0.0f)        p= 0.0f;
    else if(p > 1.0f)   p= 1.0f;
    return p;
}
/* same as above but can return negative values if the curve enables
 * used for sculpt only */
float brush_curve_strength(Brush *br, float p, const float len)
{
    if(p >= len)
        p= 1.0f;
    else
        p= p/len;

    return curvemapping_evaluateF(br->curve, 0, p);
}

/* TODO: should probably be unified with BrushPainter stuff? */
unsigned int *brush_gen_texture_cache(Brush *br, int half_side)
{
    unsigned int *texcache = NULL;
    MTex *mtex = &br->mtex;
    TexResult texres= {0};
    int hasrgb, ix, iy;
    int side = half_side * 2;
    
    if(mtex->tex) {
        float x, y, step = 2.0 / side, co[3];

        texcache = MEM_callocN(sizeof(int) * side * side, "Brush texture cache");

        BKE_image_get_ibuf(mtex->tex->ima, NULL);
        
        /*do normalized cannonical view coords for texture*/
        for (y=-1.0, iy=0; iy<side; iy++, y += step) {
            for (x=-1.0, ix=0; ix<side; ix++, x += step) {
                co[0]= x;
                co[1]= y;
                co[2]= 0.0f;
                
                /* This is copied from displace modifier code */
                hasrgb = multitex_ext(mtex->tex, co, NULL, NULL, 0, &texres);
            
                /* if the texture gave an RGB value, we assume it didn't give a valid
                 * intensity, so calculate one (formula from do_material_tex).
                 * if the texture didn't give an RGB value, copy the intensity across
                 */
                if(hasrgb & TEX_RGB)
                    texres.tin = (0.35f * texres.tr + 0.45f *
                                  texres.tg + 0.2f * texres.tb);

                texres.tin = texres.tin * 255.0f;
                ((char*)texcache)[(iy*side+ix)*4] = (char)texres.tin;
                ((char*)texcache)[(iy*side+ix)*4+1] = (char)texres.tin;
                ((char*)texcache)[(iy*side+ix)*4+2] = (char)texres.tin;
                ((char*)texcache)[(iy*side+ix)*4+3] = (char)texres.tin;
            }
        }
    }

    return texcache;
}

/**** Radial Control ****/
struct ImBuf *brush_gen_radial_control_imbuf(Brush *br)
{
    ImBuf *im = MEM_callocN(sizeof(ImBuf), "radial control texture");
    unsigned int *texcache;
    int side = 128;
    int half = side / 2;
    int i, j;

    texcache = brush_gen_texture_cache(br, half);
    im->rect_float = MEM_callocN(sizeof(float) * side * side, "radial control rect");
    im->x = im->y = side;

    for(i=0; i<side; ++i) {
        for(j=0; j<side; ++j) {
            float magn= sqrt(pow(i - half, 2) + pow(j - half, 2));
            im->rect_float[i*side + j]= brush_curve_strength_clamp(br, magn, half);
        }
    }

    /* Modulate curve with texture */
    if(texcache) {
        for(i=0; i<side; ++i) {
            for(j=0; j<side; ++j) {
                const int col= texcache[i*side+j];
                im->rect_float[i*side+j]*= (((char*)&col)[0]+((char*)&col)[1]+((char*)&col)[2])/3.0f/255.0f;
            }
        }

        MEM_freeN(texcache);
    }

    return im;
}