#include "dryos.h"
#include "vram.h"

#include "bmp.h"
#include "version.h"
#include "config.h"
#include "lens.h"
#include "math.h"
#include "raw.h"
#include "menu.h"

#include "imgconv.h"

#include "histogram.h"
#include "module.h"

#include "zebra.h"
#include "falsecolor.h"


#if defined(FEATURE_HISTOGRAM)

extern int FAST get_y_skip_offset_for_overlays();
extern int nondigic_zoom_overlay_enabled();


CONFIG_INT( "hist.draw", hist_draw,  1 );
#ifdef FEATURE_RAW_HISTOGRAM
CONFIG_INT( "hist.type", hist_type,  2 );
#else
CONFIG_INT( "hist.type", hist_type,  1 );
#endif
CONFIG_INT( "hist.warn", hist_warn,  1 );
CONFIG_INT( "hist.log",  hist_log,   1 );
CONFIG_INT( "hist.meter", hist_meter,  2);

struct Histogram histogram;

#ifdef FEATURE_RAW_HISTOGRAM

#define HIST_METER_DYNAMIC_RANGE 1
#define HIST_METER_ETTR_HINT 2

static void histobar_refresh();

void FAST hist_build_raw()
{
    if (!raw_update_params()) return;

    memset(&histogram, 0, sizeof(histogram));
    histogram.is_raw = 1;

    int step = lv ? 4 : 2;

    /* mapping from 14-bit RAW to EV on the 12-bit histogram:
     * above raw_info.white_level: last bin (HIST_WIDTH-1)
     * 12 stops below that: first bin (0)
     * raw_to_ev returns 0 at white level or above,
     * and negative floating point values below */
    char r2ev[16384];
    for (int i = 0; i < 16384; i++)
    {
        r2ev[i] = COERCE((raw_to_ev(i) + 12) * (HIST_WIDTH-1) / 12, 0, HIST_WIDTH-1);
        qprintf("[HIST] RAW %d => %d (white=%d)\n", i, r2ev[i], raw_info.white_level);
    }

    for (int i = os.y0; i < os.y_max; i += step)
    {
        int y = BM2RAW_Y(i);
        if (y < raw_info.active_area.y1+8 || y > raw_info.active_area.y2-8) continue;

        for (int j = os.x0; j < os.x_max; j += 8)
        {
            int x = BM2RAW_X(j);
            if (x < raw_info.active_area.x1+8 || x > raw_info.active_area.x2-8) continue;

            int r = raw_red_pixel_dark(x, y);
            int g = raw_green_pixel_dark(x, y);
            int b = raw_blue_pixel_dark(x, y);

            /* ignore bad pixels */
            if (r == 0 || g == 0 || b == 0) continue;

            int ir = r2ev[r];
            int ig = r2ev[g];
            int ib = r2ev[b];
            
            histogram.hist_r[ir]++;
            histogram.hist_g[ig]++;
            histogram.hist_b[ib]++;
            histogram.total_px++;
        }
    }
    
    /* in dark areas, spread the histogram count to show solid histogram instead of isolated bars */
    for (int i = 0; i < 5000; i++)
    {
        int ev0 = r2ev[i];
        int evplus = r2ev[i+1];
        int evminus = r2ev[i-1];
        if (evplus - evminus > 2) /* will there be a gap? fill it */
        {
            int num_bins = evplus - evminus - 1;
            int delta_r = histogram.hist_r[ev0] / num_bins;
            int delta_g = histogram.hist_g[ev0] / num_bins;
            int delta_b = histogram.hist_b[ev0] / num_bins;
            for (int e = evminus+1; e <= evplus-1; e++)
            {
                histogram.hist_r[e] += delta_r;
                histogram.hist_g[e] += delta_g;
                histogram.hist_b[e] += delta_b;
                histogram.hist_r[ev0] -= delta_r;
                histogram.hist_g[ev0] -= delta_g;
                histogram.hist_b[ev0] -= delta_b;
            }
        }
    }
    
    for (int i = 0; i < HIST_WIDTH; i++)
    {
        histogram.max = MAX(histogram.max, histogram.hist_r[i]);
        histogram.max = MAX(histogram.max, histogram.hist_g[i]);
        histogram.max = MAX(histogram.max, histogram.hist_b[i]);
    }

    histobar_refresh();
}

MENU_UPDATE_FUNC(raw_histo_update)
{
    if (RAW_HISTOGRAM_ENABLED)
    {
        menu_checkdep_raw(entry, info);
    }

    if (RAW_HISTOBAR_ENABLED)
    {
        MENU_SET_WARNING(MENU_WARN_INFO, "Will use Histobar in LiveView, RAW histogram after taking a pic.");
    }
    else if (RAW_HISTOGRAM_ENABLED)
    {
        MENU_SET_WARNING(MENU_WARN_INFO, "Will use RAW histogram in LiveView and after taking a pic.");
    }
}
#endif

static int hist_rgb_color(int y, int sizeR, int sizeG, int sizeB)
{
    switch ((y > sizeR ? 0 : 1) |
            (y > sizeG ? 0 : 2) |
            (y > sizeB ? 0 : 4))
    {
        case 0b000: return COLOR_ALMOST_BLACK;
        case 0b001: return COLOR_RED;
        case 0b010: return COLOR_GREEN2;
        case 0b100: return COLOR_LIGHT_BLUE;
        case 0b011: return COLOR_YELLOW;
        case 0b110: return COLOR_CYAN;
        case 0b101: return COLOR_MAGENTA;
        case 0b111: return COLOR_WHITE;
    }
    return 0;
}

static void hist_dot(int x, int y, int fg_color, int bg_color, int radius, int label)
{
    x &= ~3;
    y &= ~3;
    for (int r = 0; r < radius; r++)
    {
        draw_circle(x, y, r, fg_color);
        draw_circle(x + 1, y, r, fg_color);
    }
    draw_circle(x, y, radius, bg_color);

    if (label)
    {
        if (label < 10)
            bmp_printf(
                SHADOW_FONT(FONT(FONT_MED, COLOR_WHITE, fg_color)),
                x - 4,
                y - font_med.height/2,
                "%d", label
            );
        else
            bmp_printf(
                SHADOW_FONT(FONT(FONT_SMALL, COLOR_WHITE, fg_color)),
                x - 8,
                y - font_small.height/2,
                "%d", label
            );
    }
}

static int hist_dot_radius(int over, int hist_total_px)
{
    // overexposures stronger than 1% are displayed at max radius (10)
    int p = 100 * over / hist_total_px;
    if (p > 1) return 10;

    // for smaller overexposure percentages, use dot radius to suggest the amount
    unsigned p1000 = 100 * 1000 * over / hist_total_px;
    int plog = p1000 ? (int)log2f(p1000) : 0;
    return MIN(plog, 10);
}

static int hist_dot_label(int over, int hist_total_px)
{
    return 100 * over / hist_total_px;
}

static int (*auto_ettr_export_correction)(int* out) = MODULE_FUNCTION(auto_ettr_export_correction);

/** Draw the histogram image into the bitmap framebuffer.
 *
 * Draw one pixel at a time; it seems to be ok with err70.
 * Since there is plenty of math per pixel this doesn't
 * swamp the bitmap framebuffer hardware.
 */
void hist_draw_image(
    unsigned        x_origin,
    unsigned        y_origin
)
{
    #ifdef FEATURE_RAW_HISTOGRAM
    if (RAW_HISTOBAR_ENABLED && lv && can_use_raw_overlays_menu())
        return;
    #endif
    
    if (!PLAY_OR_QR_MODE)
    {
        if (!lv_luma_is_accurate()) return;
    }
    uint8_t * const bvram = bmp_vram();
    if (!bvram) return;

    // Align the x origin, just in case
    x_origin &= ~3;

    uint8_t * row = bvram + x_origin + y_origin * BMPPITCH;
    if( histogram.max == 0 )
        histogram.max = 1;

    unsigned i, y;

    int log_max = log_length(histogram.max);

    #ifdef FEATURE_RAW_HISTOGRAM
    const int v = (1200 - raw_info.dynamic_range) * HIST_WIDTH / 1200;
    int underexposed_level = COERCE(v, 0, HIST_WIDTH-1);
    int stops_until_overexposure = 0;
    #endif

    for( i=0 ; i < HIST_WIDTH ; i++ )
    {
        // Scale by the maximum bin value
        const uint32_t size  = hist_log ? log_length(histogram.hist[i])   * hist_height / log_max : (histogram.hist[i]   * hist_height) / histogram.max;
        const uint32_t sizeR = hist_log ? log_length(histogram.hist_r[i]) * hist_height / log_max : (histogram.hist_r[i] * hist_height) / histogram.max;
        const uint32_t sizeG = hist_log ? log_length(histogram.hist_g[i]) * hist_height / log_max : (histogram.hist_g[i] * hist_height) / histogram.max;
        const uint32_t sizeB = hist_log ? log_length(histogram.hist_b[i]) * hist_height / log_max : (histogram.hist_b[i] * hist_height) / histogram.max;

        uint8_t * col = row + i;
        // vertical line up to the hist size
        for( y=hist_height ; y>0 ; y-- , col += BMPPITCH )
        {
            if (histogram.is_rgb)
                *col = hist_rgb_color(y, sizeR, sizeG, sizeB);
            else
                *col = y > size ? COLOR_BG :
#if defined(FEATURE_FALSE_COLOR)
                                             falsecolor_fordraw(((i << 8) / HIST_WIDTH) & 0xFF);
#else
                                             COLOR_WHITE;
#endif /* defined(FEATURE_FALSE_COLOR) */
        }

#if defined(FEATURE_HISTOGRAM)
        /* draw clip warnings */
        if (hist_warn && i == HIST_WIDTH - 1)
        {
            unsigned int thr = histogram.total_px / 100000; // start at 0.0001 with a tiny dot
            thr = MAX(thr, 1);
            int yw = y_origin + 12 + (hist_log ? hist_height - 24 : 0);
            int bg = (hist_log ? COLOR_WHITE : COLOR_BLACK);
            if (histogram.is_rgb)
            {
                unsigned int over_r = histogram.hist_r[i];
                unsigned int over_g = histogram.hist_g[i];
                unsigned int over_b = histogram.hist_b[i];

                if (over_r > thr) hist_dot(x_origin + HIST_WIDTH/2 - 25, yw, COLOR_RED,        bg, hist_dot_radius(over_r, histogram.total_px), hist_dot_label(over_r, histogram.total_px));
                if (over_g > thr) hist_dot(x_origin + HIST_WIDTH/2     , yw, COLOR_GREEN1,     bg, hist_dot_radius(over_g, histogram.total_px), hist_dot_label(over_g, histogram.total_px));
                if (over_b > thr) hist_dot(x_origin + HIST_WIDTH/2 + 25, yw, COLOR_LIGHT_BLUE, bg, hist_dot_radius(over_b, histogram.total_px), hist_dot_label(over_b, histogram.total_px));
            }
            else
            {
                unsigned int over = histogram.hist[i] + histogram.hist[i-1];
                if (over > thr) hist_dot(x_origin + HIST_WIDTH/2, yw, COLOR_RED, bg, hist_dot_radius(over, histogram.total_px), hist_dot_label(over, histogram.total_px));
            }
        }
#endif
        #ifdef FEATURE_RAW_HISTOGRAM
        /* divide the histogram in 12 equal slices - each slice is 1 EV */
        if (histogram.is_raw)
        {
            static unsigned bar_pos;
            if (i == 0) bar_pos = 0;
            int H = hist_height - MAX(MAX(sizeR, sizeG), sizeB) - 1;
            int h = hist_height - MIN(MIN(sizeR, sizeG), sizeB) - 1;

            /* mark what's below the noise floor with... noise */
            if ((int)i <= underexposed_level && i%2==0)
            {
                for (int y = y_origin + ((i/2)%2)*2; y < (int)y_origin + hist_height; y += 4)
                {
                    int noise_color = 
                        (y < (int)y_origin + H) ? COLOR_GRAY(60) :      /* noise color on top of histogram */
                        (y < (int)y_origin + h) ? COLOR_WHITE    :      /* noise color where histogram has a solid color, but not white */
                                                  COLOR_BLACK    ;      /* noise color where histogram is white */
                    bmp_putpixel(x_origin + i, y, noise_color);
                }
            }

            /* draw full-stop (EV) bars */
            if (i == bar_pos)
            {
                int dy = (i < font_med.width * 4) ? font_med.height : 0;
                draw_line(x_origin + i, y_origin + dy, x_origin + i, y_origin + h, COLOR_GRAY(50));
                bar_pos = (((bar_pos+1)*12/HIST_WIDTH) + 1) * HIST_WIDTH/12;
            }

            /* compute a basic ETTR hint */
            unsigned int thr = histogram.total_px / 10000;
            if (histogram.hist_r[i] > thr || histogram.hist_g[i] > thr || histogram.hist_b[i] > thr)
                stops_until_overexposure = 120 - (i * 120 / (HIST_WIDTH-1));
        }
        #endif

    }

    /* draw histogram border */
    bmp_draw_rect(60, x_origin-1, y_origin-1, HIST_WIDTH+2, hist_height+2);

    #ifdef FEATURE_RAW_HISTOGRAM
    if (histogram.is_raw)
    {
        char msg[10];
        switch (hist_meter)
        {
            case HIST_METER_DYNAMIC_RANGE:
            {
                int dr = (raw_info.dynamic_range + 5) / 10;
                snprintf(msg, sizeof(msg), "D%d.%d", dr/10, dr%10);
                break;
            }

            case HIST_METER_ETTR_HINT:
            {
                if (!stops_until_overexposure)
                    stops_until_overexposure = INT_MIN;

                #ifdef CONFIG_MODULES
                int ettr_stops = INT_MIN;

                if (auto_ettr_export_correction(&ettr_stops) == 1)
                    if (ettr_stops != INT_MIN)
                        stops_until_overexposure = (ettr_stops+5)/10;
                #endif

                if (stops_until_overexposure != INT_MIN)
                    snprintf(msg, sizeof(msg), "E%s%d.%d", FMT_FIXEDPOINT1(stops_until_overexposure));
                else
                    snprintf(msg, sizeof(msg), "OVER");
                break;
            }

            default:
                snprintf(msg, sizeof(msg), "RAW");
                break;
        }
        bmp_printf(SHADOW_FONT(FONT_MED), x_origin+4, y_origin, msg);
    }
    #endif
}

MENU_UPDATE_FUNC(hist_print)
{
#if defined(FEATURE_HISTOGRAM)
    if (hist_draw)
    {
        int raw = 0;
        #ifdef FEATURE_RAW_HISTOGRAM
        raw = RAW_HISTOGRAM_ENABLED && can_use_raw_overlays_menu();
        #endif
        
        MENU_SET_VALUE(
            "%s%s",
            raw ? (RAW_HISTOBAR_ENABLED ? "RAW HistoBar" : "RAW RGB") :
            hist_type == 0 ? "Luma (YUV)" :
            hist_type == 1 ? "RGB (YUV)" : "RAW N/A",
            hist_log ? ", Log" : (raw && RAW_HISTOBAR_ENABLED) ? "" : ", Linear"
        );
    }
#endif
}

#endif /* defined(FEATURE_HISTOGRAM) */

MENU_UPDATE_FUNC(hist_warn_display)
{
#if defined(FEATURE_HISTOGRAM)
    MENU_SET_VALUE(
        "Clip warning  : %s",
        hist_warn == 0 ? "OFF" :
        hist_warn == 1 ? "0.001% px" :
        hist_warn == 2 ? "0.01% px" :
        hist_warn == 3 ? "0.1% px" :
        hist_warn == 4 ? "1% px" :
                         "Gradual"
    );
#endif /* defined(FEATURE_HISTOGRAM) */
}

#ifdef FEATURE_RAW_HISTOGRAM

/* speed:
 * 0 = slowest, but 100% accurate (only for GRAY_PROJECTION_GREEN for now)
 * 1 = sample at LiveView resolution (720x480)
 * 2 = LiveView resolution downsampled by 2 on each axis
 * 3 = LiveView resolution downsampled by 3 on each axis
 * and so on, until 16
 */

int FAST raw_hist_get_percentile_levels(int* percentiles_x10, int* output_raw_values, int n, int gray_projection, int speed)
{
    if (!raw_update_params()) goto err;
    get_yuv422_vram();

    int* hist = malloc(16384*4);
    if (!hist) goto err;
    memset(hist, 0, 16384*4);

    int off = get_y_skip_offset_for_histogram();
    if (speed == 0 && gray_projection == GRAY_PROJECTION_GREEN)
    {
        /* time: 1-2 seconds on full raw 5D3 */
        //~ int t0 = get_ms_clock();
        for (struct raw_pixblock * row = (struct raw_pixblock *) raw_info.buffer + raw_info.active_area.y1 * raw_info.width / 8 + (raw_info.active_area.x1 + 7) / 8; (void*)row < (void*)raw_info.buffer + raw_info.pitch * raw_info.active_area.y2; row += 2 * raw_info.width / 8)
        {
            struct raw_pixblock * row2 = row + raw_info.pitch / sizeof(struct raw_pixblock);

            struct raw_pixblock * p;
            struct raw_pixblock * q;
            for (p = row, q = row2; (void*)p < (void*)row + raw_info.jpeg.width * 14/8; p++, q++)
            {

                /**
                 *  p: abcdefgh abcdefgh
                 *  q: abcdefgh abcdefgh
                 *
                 *     rgrgrgrg rgrgrgrg
                 *     gbgbgbgb gbgbgbgb
                 */

                //~ int pa = ((int)(p->a));
                int pb = ((int)(p->b_lo | (p->b_hi << 12)));
                //~ int pc = ((int)(p->c_lo | (p->c_hi << 10)));
                int pd = ((int)(p->d_lo | (p->d_hi << 8)));
                //~ int pe = ((int)(p->e_lo | (p->e_hi << 6)));
                int pf = ((int)(p->f_lo | (p->f_hi << 4)));
                //~ int pg = ((int)(p->g_lo | (p->g_hi << 2)));
                int ph = ((int)(p->h));
                int qa = ((int)(q->a));
                //~ int qb = ((int)(q->b_lo | (q->b_hi << 12)));
                int qc = ((int)(q->c_lo | (q->c_hi << 10)));
                //~ int qd = ((int)(q->d_lo | (q->d_hi << 8)));
                int qe = ((int)(q->e_lo | (q->e_hi << 6)));
                //~ int qf = ((int)(q->f_lo | (q->f_hi << 4)));
                int qg = ((int)(q->g_lo | (q->g_hi << 2)));
                //~ int qh = ((int)(q->h));

                hist[pb]++;
                hist[pd]++;
                hist[pf]++;
                hist[ph]++;
                hist[qa]++;
                hist[qc]++;
                hist[qe]++;
                hist[qg]++;

                /* to check if we sample only the active area */
                //~ p->a = rand();
            }
        }
        //~ int t1 = get_ms_clock();
        //~ NotifyBox(5000, "%d ", t1 - t0);
        //~ save_dng("A:/foo.dng");
    }
    else
    {
        speed = COERCE(speed, 1, 16);
        for (int i = os.y0 + off; i < os.y_max - off; i += speed)
        {
            int y = BM2RAW_Y(i);
            for (int j = os.x0; j < os.x_max; j += speed)
            {
                int x = BM2RAW_X(j);
                int px = raw_get_gray_pixel(x, y, gray_projection);
                hist[px & 16383]++;
            }
        }
    }

    int total = 0;
    int i;
    for( i=0 ; i < 16384 ; i++ )
        total += hist[i];

    for (int k = 0; k < n; k++)
    {
        int thr = (uint64_t)total * percentiles_x10[k] / 1000 - 2;  // 50% => median; allow up to 2 stuck pixels
        int n = 0;
        int ans = -1;

        for( i=0 ; i < 16384; i++ )
        {
            n += hist[i];
            if (n >= thr)
            {
                ans = i;
                break;
            }
        }

        output_raw_values[k] = ans;
    }

    free(hist);
    return 1;

err:
    for (int k = 0; k < n; k++)
    {
        output_raw_values[k] = -1;
    }
    return -1;
}

int raw_hist_get_percentile_level(int percentile_x10, int gray_projection, int speed)
{
    int ans;
    raw_hist_get_percentile_levels(&percentile_x10, &ans, 1, gray_projection, speed);
    return ans;
}


int raw_hist_get_overexposure_percentage(int gray_projection)
{
    if (!raw_update_params()) return -1;
    get_yuv422_vram();

    /* use some tolerance when checking for overexposure, because white level might vary a little */
    int white = raw_info.white_level * 80 / 100;
    int over = 0;
    int total = 0;

    int step = lv ? 4 : 2;

    for (int i = os.y0; i < os.y_max; i += step)
    {
        int y = BM2RAW_Y(i);
        for (int j = os.x0; j < os.x_max; j += step)
        {
            int x = BM2RAW_X(j);
            int px = raw_get_gray_pixel(x, y, gray_projection);
            if (px >= white) over++;
            total++;
        }
    }

    /* percentage x100 */
    return over * 10000 / total;
}

#include "lvinfo.h"

static int histobar_ev[15];
static int histobar_stops;
static int histobar_clipped;
static int histobar_stops_until_overexposure;
static int histobar_midtone_level;  /* median */
static int histobar_shadow_level;   /* at 5th percentile, as in ETTR */

static void histobar_refresh()
{
    int stops = COERCE((raw_info.dynamic_range + 50) / 100, 0, 14);

    int i_prev = 0;
    for(int ev = 0 ; ev < stops ; ev++ )
    {
        int evh = COERCE(ev - stops + 12, 0, 12);
        int i = evh * HIST_WIDTH / 12;
        
        int pixels_in_this_stop = 0;
        for (int j = i_prev; j < i; j++)
        {
            int max = MAX(MAX(histogram.hist_r[i], histogram.hist_g[i]), histogram.hist_b[i]);
            pixels_in_this_stop += max;
        }
        histobar_ev[ev] = pixels_in_this_stop;
        i_prev = i;
    }
    histobar_stops = stops;
    
    int i = HIST_WIDTH-1;
    histobar_clipped = histogram.hist_r[i] + histogram.hist_g[i] + histogram.hist_b[i];

    int stops_until_overexposure = INT_MIN;
    int acc = 0;
    int shadow_px = histogram.total_px / 20;
    int midtone_px = histogram.total_px / 2;
    for( i=0 ; i < HIST_WIDTH ; i++ )
    {
        int thr = histogram.total_px / 10000;
        int max = MAX(MAX(histogram.hist_r[i], histogram.hist_g[i]), histogram.hist_b[i]);
        int ev_till_right_x10 = 120 - (i * 120 / (HIST_WIDTH-1));
        int ev_till_right = ev_till_right_x10 / 10;
        int ev_from_left = histobar_stops - ev_till_right;
        if (max > thr)
        {
            stops_until_overexposure = ev_till_right_x10;
        }
        
        if (acc < midtone_px && acc + max >= midtone_px)
        {
            histobar_midtone_level = ev_from_left;
        }

        if (acc < shadow_px && acc + max >= shadow_px)
        {
            histobar_shadow_level = ev_from_left;
        }

        acc += max;
    }

    #ifdef CONFIG_MODULES
    int ettr_stops = INT_MIN;

    if (auto_ettr_export_correction(&ettr_stops) == 1)
        if (ettr_stops != INT_MIN)
            stops_until_overexposure = (ettr_stops+5)/10;
    #endif

    histobar_stops_until_overexposure = stops_until_overexposure;

    #ifdef CONFIG_QEMU
    /* double-check median and shadow levels (compare with histobar readings) */
    int prctiles[2] = {500, 50};
    int raw_levels[2];
    int ev_levels[2];
    raw_hist_get_percentile_levels(prctiles, raw_levels, 2, GRAY_PROJECTION_MAX_RGB, 0);
    ev_levels[0] = (int)roundf(raw_to_ev(raw_levels[0]) * 10);
    ev_levels[1] = (int)roundf(raw_to_ev(raw_levels[1]) * 10);
    printf("Median   : %d = %s%d.%d EV\n", raw_levels[0], FMT_FIXEDPOINT1(ev_levels[0]));
    printf("Shadow 5%%: %d = %s%d.%d EV\n", 0, raw_levels[1], FMT_FIXEDPOINT1(ev_levels[1]));
    #endif

    lens_display_set_dirty();
}

static LVINFO_UPDATE_FUNC(histobar_update)
{
#ifdef FEATURE_RAW_HISTOGRAM
    if (!RAW_HISTOBAR_ENABLED)
        return;
#endif    
    if (!lv_luma_is_accurate())
        return;
    
    if (!can_use_raw_overlays())
        return;
    
    int w = fontspec_font(item->fontspec)->width - 4;
    int h = fontspec_font(item->fontspec)->height - 4;
    item->width = histobar_stops * w;
    item->height = h;
    item->custom_drawing = 1;
    
    if (can_draw)
    {
        for(int ev = 0 ; ev < histobar_stops ; ev++ )
        {
            int pixels_in_this_stop = histobar_ev[ev];
            int thr = histogram.total_px / 10000;
            int full = (pixels_in_this_stop > thr);
            
            int x = item->x - item->width/2 + ev * w + 1;
            int y = item->y-2;
            int h = item->height;
            int fh = h;                 /* fill height */
            int fg = item->color_fg;    /* outline color */
            int bg0 = item->color_bg;   /* background color */
            int bg = bg0;               /* fill color */

            if (full)
            {
                bg = fg;
            }

            if (ev == histobar_midtone_level)
            {
                fg = bg = COLOR_YELLOW;
            }
            
            if (ev < histobar_shadow_level && full)
            {
                fh = h/3;
            }

            if (ev == histobar_stops-1 && histobar_clipped > thr)
            {
                fg = bg = COLOR_RED;
                fh = h;
            }
            else if (ev == 0 && full)
            {
                fg = bg = COLOR_LIGHT_BLUE;
            }
            
            bmp_fill(bg0, x, y, w-2, h-fh);
            bmp_fill(bg, x, y+h-fh, w-2, fh);
            bmp_draw_rect(fg, x, y, w-2, h);
        }
    }
}

static LVINFO_UPDATE_FUNC(histobar_indic_update)
{
    LVINFO_BUFFER(10);

    if (!hist_meter)
        return;
    
#ifdef FEATURE_RAW_HISTOGRAM
    if (!RAW_HISTOBAR_ENABLED)
        return;
#endif
    if (!lv_luma_is_accurate())
        return;
    
    if (!can_use_raw_overlays())
        return;
    
    switch (hist_meter)
    {
        case HIST_METER_DYNAMIC_RANGE:
        {
            int dr = (raw_info.dynamic_range + 5) / 10;
            snprintf(buffer, sizeof(buffer), SYM_DR"%d.%d", dr/10, dr%10);
            break;
        }

        case HIST_METER_ETTR_HINT:
        {
            int stops_until_overexposure = histobar_stops_until_overexposure;

            if (stops_until_overexposure != INT_MIN)
                snprintf(buffer, sizeof(buffer), SYM_ETTR"%s%d.%d", FMT_FIXEDPOINT1(stops_until_overexposure));
            else
                snprintf(buffer, sizeof(buffer), "OVER");
            break;
        }
    }
}

static struct lvinfo_item info_items[] = {
    {
        .name = "HistoBar",
        .which_bar = LV_PREFER_TOP_BAR,
        .update = histobar_update,
        .preferred_position = -1,
    },
    {
        .name = "EV indic",
        .which_bar = LV_PREFER_TOP_BAR,
        .update = histobar_indic_update,
        .preferred_position = -1,
    },
};

static void hist_init()
{
    lvinfo_add_items(info_items, COUNT(info_items));
}

INIT_FUNC("hist", hist_init);

#endif