demo/wayland_rawfb/nuklear_raw_wayland.h

#ifndef NK_RAW_WAYLAND_H_
#define NK_RAW_WAYLAND_H_

#define WIDTH 800
#define HEIGHT 600

#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif
#ifndef MAX
#define MAX(a,b) ((a) < (b) ? (b) : (a))
#endif

typedef enum wayland_pixel_layout {
    PIXEL_LAYOUT_XRGB_8888,
    PIXEL_LAYOUT_RGBX_8888,
} wayland_pl;

struct wayland_img {
    void *pixels;
    int w, h, pitch;
    wayland_pl pl;
    enum nk_font_atlas_format format;
};

struct nk_wayland{
    /*wayland vars*/
    struct wl_display *display;
    struct wl_compositor *compositor;
    struct xdg_wm_base *xdg_wm_base;
    struct wl_shm *wl_shm;
    struct wl_seat* seat;
    struct wl_callback *frame_callback;
    struct wl_surface *surface;
	struct xdg_surface *xdg_surface;
	struct xdg_toplevel *xdg_toplevel;
	struct wl_buffer *front_buffer;


    /*nuklear vars*/
    struct nk_context ctx;
    struct nk_rect scissors;
    struct nk_font_atlas atlas;
    struct wayland_img font_tex;
	int32_t width, height;
	int32_t *data;
    int mouse_pointer_x;
    int mouse_pointer_y;
    uint8_t tex_scratch[512 * 512];

};

static uint32_t nk_color_to_xrgb8888(struct nk_color col)
{
    return (col.a << 24) + (col.r << 16) + (col.g << 8) + col.b;
}

static struct nk_color nk_wayland_int2color(const unsigned int i, wayland_pl pl)
{
    struct nk_color col = {0,0,0,0};

    switch (pl) {
    case PIXEL_LAYOUT_RGBX_8888:
        col.r = (i >> 24) & 0xff;
        col.g = (i >> 16) & 0xff;
        col.b = (i >> 8) & 0xff;
        col.a = i & 0xff;
        break;
    case PIXEL_LAYOUT_XRGB_8888:
        col.a = (i >> 24) & 0xff;
        col.r = (i >> 16) & 0xff;
        col.g = (i >> 8) & 0xff;
        col.b = i & 0xff;
        break;

    default:
        perror("nk_rawfb_int2color(): Unsupported pixel layout.\n");
        break;
    }
    return col;
}

static unsigned int nk_wayland_color2int(const struct nk_color c, wayland_pl pl)
{
    unsigned int res = 0;

    switch (pl) {
    case PIXEL_LAYOUT_RGBX_8888:
        res |= c.r << 24;
        res |= c.g << 16;
        res |= c.b << 8;
        res |= c.a;
        break;

    case PIXEL_LAYOUT_XRGB_8888:
        res |= c.a << 24;
        res |= c.r << 16;
        res |= c.g << 8;
        res |= c.b;
        break;

    default:
        perror("nk_rawfb_color2int(): Unsupported pixel layout.\n");
        break;
    }
    return (res);
}

static void nk_wayland_ctx_setpixel(const struct nk_wayland* win,
    const short x0, const short y0, const struct nk_color col)
{
    uint32_t c = nk_color_to_xrgb8888(col);
    uint32_t *pixels = (uint32_t *)win->data;
    unsigned int *ptr;

    pixels += (y0 * win->width);
    ptr = (unsigned int *)pixels + x0;

    if (y0 < win->scissors.h && y0 >= win->scissors.y && x0 >= win->scissors.x && x0 < win->scissors.w){
        *ptr = c;
    }else {
        printf("out of bound! \n");
    }
}

static void nk_wayland_fill_polygon(const struct nk_wayland* win, const struct nk_vec2i *pnts, int count, const struct nk_color col)
{
    int i = 0;
    //#define MAX_POINTS 64
    int left = 10000, top = 10000, bottom = 0, right = 0;
    int nodes, nodeX[1024], pixelX, pixelY, j, swap ;

    if (count == 0) return;
    if (count > 1024)
        count = 1024;

    /* Get polygon dimensions */
    for (i = 0; i < count; i++) {
        if (left > pnts[i].x)
            left = pnts[i].x;
        if (right < pnts[i].x)
            right = pnts[i].x;
        if (top > pnts[i].y)
            top = pnts[i].y;
        if (bottom < pnts[i].y)
            bottom = pnts[i].y;
    } bottom++; right++;

    /* Polygon scanline algorithm released under public-domain by Darel Rex Finley, 2007 */
    /*  Loop through the rows of the image. */
    for (pixelY = top; pixelY < bottom; pixelY ++) {
        nodes = 0; /*  Build a list of nodes. */
        j = count - 1;
        for (i = 0; i < count; i++) {
            if (((pnts[i].y < pixelY) && (pnts[j].y >= pixelY)) ||
                ((pnts[j].y < pixelY) && (pnts[i].y >= pixelY))) {
                nodeX[nodes++]= (int)((float)pnts[i].x
                     + ((float)pixelY - (float)pnts[i].y) / ((float)pnts[j].y - (float)pnts[i].y)
                     * ((float)pnts[j].x - (float)pnts[i].x));
            } j = i;
        }

        /*  Sort the nodes, via a simple “Bubble” sort. */
        i = 0;
        while (i < nodes - 1) {
            if (nodeX[i] > nodeX[i+1]) {
                swap = nodeX[i];
                nodeX[i] = nodeX[i+1];
                nodeX[i+1] = swap;
                if (i) i--;
            } else i++;
        }
        /*  Fill the pixels between node pairs. */
        for (i = 0; i < nodes; i += 2) {
            if (nodeX[i+0] >= right) break;
            if (nodeX[i+1] > left) {
                if (nodeX[i+0] < left) nodeX[i+0] = left ;
                if (nodeX[i+1] > right) nodeX[i+1] = right;
                for (pixelX = nodeX[i]; pixelX < nodeX[i + 1]; pixelX++)
                    nk_wayland_ctx_setpixel(win, pixelX, pixelY, col);
            }
        }
    }
}

static void nk_wayland_fill_arc(const struct nk_wayland* win, short x0, short y0, short w, short h, const short s, const struct nk_color col)
{
    /* Bresenham's ellipses - modified to fill one quarter */
    const int a2 = (w * w) / 4;
    const int b2 = (h * h) / 4;
    const int fa2 = 4 * a2, fb2 = 4 * b2;
    int x, y, sigma;
    struct nk_vec2i pnts[3];
    if (w < 1 || h < 1) return;
    if (s != 0 && s != 90 && s != 180 && s != 270)
        return;

    /* Convert upper left to center */
    h = (h + 1) / 2;
    w = (w + 1) / 2;
    x0 += w;
    y0 += h;

    pnts[0].x = x0;
    pnts[0].y = y0;
    pnts[2].x = x0;
    pnts[2].y = y0;

    /* First half */
    for (x = 0, y = h, sigma = 2*b2+a2*(1-2*h); b2*x <= a2*y; x++) {
        if (s == 180) {
            pnts[1].x = x0 + x; pnts[1].y = y0 + y;
        } else if (s == 270) {
            pnts[1].x = x0 - x; pnts[1].y = y0 + y;
        } else if (s == 0) {
            pnts[1].x = x0 + x; pnts[1].y = y0 - y;
        } else if (s == 90) {
            pnts[1].x = x0 - x; pnts[1].y = y0 - y;
        }
        nk_wayland_fill_polygon(win, pnts, 3, col);
        pnts[2] = pnts[1];
        if (sigma >= 0) {
            sigma += fa2 * (1 - y);
            y--;
        } sigma += b2 * ((4 * x) + 6);
    }

    /* Second half */
    for (x = w, y = 0, sigma = 2*a2+b2*(1-2*w); a2*y <= b2*x; y++) {
        if (s == 180) {
            pnts[1].x = x0 + x; pnts[1].y = y0 + y;
        } else if (s == 270) {
            pnts[1].x = x0 - x; pnts[1].y = y0 + y;
        } else if (s == 0) {
            pnts[1].x = x0 + x; pnts[1].y = y0 - y;
        } else if (s == 90) {
            pnts[1].x = x0 - x; pnts[1].y = y0 - y;
        }
        nk_wayland_fill_polygon(win, pnts, 3, col);
        pnts[2] = pnts[1];
        if (sigma >= 0) {
            sigma += fb2 * (1 - x);
            x--;
        } sigma += a2 * ((4 * y) + 6);
    }
}

static void nk_wayland_img_setpixel(const struct wayland_img *img, const int x0, const int y0, const struct nk_color col)
{
    unsigned int c = nk_wayland_color2int(col, img->pl);
    unsigned char *ptr;
    unsigned int *pixel;
    NK_ASSERT(img);
    if (y0 < img->h && y0 >= 0 && x0 >= 0 && x0 < img->w) {
        ptr = (unsigned char *)img->pixels + (img->pitch * y0);
	pixel = (unsigned int *)ptr;

        if (img->format == NK_FONT_ATLAS_ALPHA8) {
            ptr[x0] = col.a;
        } else {
	    pixel[x0] = c;
        }
    }
}

static struct nk_color nk_wayland_getpixel(const struct nk_wayland* win, const int x0, const int y0)
{
    struct nk_color col = {0, 0, 0, 0};
    uint32_t *ptr;

    if (y0 < win->height && y0 >= 0 && x0 >= 0 && x0 < win->width) {
        ptr = (uint32_t *)win->data + (y0 * win->width);

        col = nk_wayland_int2color(*ptr, PIXEL_LAYOUT_XRGB_8888);
    }

    return col;
}

static struct nk_color nk_wayland_img_getpixel(const struct wayland_img *img, const int x0, const int y0)
{
    struct nk_color col = {0, 0, 0, 0};
    unsigned char *ptr;
    unsigned int pixel;
    NK_ASSERT(img);
    if (y0 < img->h && y0 >= 0 && x0 >= 0 && x0 < img->w) {
        ptr = (unsigned char *)img->pixels + (img->pitch * y0);

        if (img->format == NK_FONT_ATLAS_ALPHA8) {
            col.a = ptr[x0];
            col.b = col.g = col.r = 0xff;
        } else {
            pixel = ((unsigned int *)ptr)[x0];
            col = nk_wayland_int2color(pixel, img->pl);
        }
    } return col;
}

static void nk_wayland_blendpixel(const struct nk_wayland* win, const int x0, const int y0, struct nk_color col)
{
    struct nk_color col2;
    unsigned char inv_a;
    if (col.a == 0)
        return;

    inv_a = 0xff - col.a;
    col2 = nk_wayland_getpixel(win, x0, y0);
    col.r = (col.r * col.a + col2.r * inv_a) >> 8;
    col.g = (col.g * col.a + col2.g * inv_a) >> 8;
    col.b = (col.b * col.a + col2.b * inv_a) >> 8;
    nk_wayland_ctx_setpixel(win, x0, y0, col);
}

static void nk_wayland_img_blendpixel(const struct wayland_img *img, const int x0, const int y0, struct nk_color col)
{
    struct nk_color col2;
    unsigned char inv_a;
    if (col.a == 0)
        return;

    inv_a = 0xff - col.a;
    col2 = nk_wayland_img_getpixel(img, x0, y0);
    col.r = (col.r * col.a + col2.r * inv_a) >> 8;
    col.g = (col.g * col.a + col2.g * inv_a) >> 8;
    col.b = (col.b * col.a + col2.b * inv_a) >> 8;
    nk_wayland_img_setpixel(img, x0, y0, col);
}

static void nk_wayland_line_horizontal(const struct nk_wayland* win, const short x0, const short y, const short x1, const struct nk_color col)
{
    /* This function is called the most. Try to optimize it a bit...
     * It does not check for scissors or image borders.
     * The caller has to make sure it does no exceed bounds. */
    unsigned int i, n;
    unsigned int c[16];
    unsigned char *pixels = (uint8_t*)win->data;
    unsigned int *ptr;

    pixels += (y * (win->width * 4));
    ptr = (unsigned int *)pixels + x0;

    n = x1 - x0;
    for (i = 0; i < sizeof(c) / sizeof(c[0]); i++)
        c[i] = nk_color_to_xrgb8888(col);

    while (n > 16) {
        memcpy((void *)ptr, c, sizeof(c));
        n -= 16; ptr += 16;
    } for (i = 0; i < n; i++)
        ptr[i] = c[i];
}


static void nk_wayland_scissor(struct nk_wayland* win, const float x, const float y, const float w, const float h)
{
    win->scissors.x = MIN(MAX(x, 0), WIDTH);
    win->scissors.y = MIN(MAX(y, 0), HEIGHT);
    win->scissors.w = MIN(MAX(w + x, 0), WIDTH);
    win->scissors.h = MIN(MAX(h + y, 0), HEIGHT);
}

static void nk_wayland_stroke_line(const struct nk_wayland* win, short x0, short y0, short x1, short y1, const unsigned int line_thickness, const struct nk_color col)
{
    short tmp;
    int dy, dx, stepx, stepy;

    NK_UNUSED(line_thickness);

    dy = y1 - y0;
    dx = x1 - x0;

    //printf("\n\n\n\n");
    // fast path
    if (dy == 0) {
        if (dx == 0 || y0 >= win->scissors.h || y0 < win->scissors.y){
            return;
        }

        if (dx < 0) {
            // swap x0 and x1
            tmp = x1;
            x1 = x0;
            x0 = tmp;
        }
        x1 = MIN(win->scissors.w, x1);
        x0 = MIN(win->scissors.w, x0);
        x1 = MAX(win->scissors.x, x1);
        x0 = MAX(win->scissors.x, x0);
        nk_wayland_line_horizontal(win, x0, y0, x1, col);
        return;
    }
    if (dy < 0) {
        dy = -dy;
        stepy = -1;
    } else stepy = 1;

    if (dx < 0) {
        dx = -dx;
        stepx = -1;
    } else stepx = 1;

    dy <<= 1;
    dx <<= 1;

    nk_wayland_ctx_setpixel(win, x0, y0, col);
    if (dx > dy) {
        int fraction = dy - (dx >> 1);
        while (x0 != x1) {
            if (fraction >= 0) {
                y0 += stepy;
                fraction -= dx;
            }
            x0 += stepx;
            fraction += dy;
            nk_wayland_ctx_setpixel(win, x0, y0, col);
        }
    } else {
        int fraction = dx - (dy >> 1);
        while (y0 != y1) {
            if (fraction >= 0) {
                x0 += stepx;
                fraction -= dy;
            }
            y0 += stepy;
            fraction += dx;
            nk_wayland_ctx_setpixel(win, x0, y0, col);
        }
    }
}

static void
nk_wayland_fill_rect(const struct nk_wayland* win,
    const short x, const short y, const short w, const short h,
    const short r, const struct nk_color col)
{
    int i;
    if (r == 0) {
        for (i = 0; i < h; i++)
            nk_wayland_stroke_line(win, x, y + i, x + w, y + i, 1, col);
    } else {
        const short xc = x + r;
        const short yc = y + r;
        const short wc = (short)(w - 2 * r);
        const short hc = (short)(h - 2 * r);

        struct nk_vec2i pnts[12];
        pnts[0].x = x;
        pnts[0].y = yc;
        pnts[1].x = xc;
        pnts[1].y = yc;
        pnts[2].x = xc;
        pnts[2].y = y;

        pnts[3].x = xc + wc;
        pnts[3].y = y;
        pnts[4].x = xc + wc;
        pnts[4].y = yc;
        pnts[5].x = x + w;
        pnts[5].y = yc;

        pnts[6].x = x + w;
        pnts[6].y = yc + hc;
        pnts[7].x = xc + wc;
        pnts[7].y = yc + hc;
        pnts[8].x = xc + wc;
        pnts[8].y = y + h;

        pnts[9].x = xc;
        pnts[9].y = y + h;
        pnts[10].x = xc;
        pnts[10].y = yc + hc;
        pnts[11].x = x;
        pnts[11].y = yc + hc;

        nk_wayland_fill_polygon(win, pnts, 12, col);

        nk_wayland_fill_arc(win, xc + wc - r, y,
                (unsigned)r*2, (unsigned)r*2, 0 , col);
        nk_wayland_fill_arc(win, x, y,
                (unsigned)r*2, (unsigned)r*2, 90 , col);
        nk_wayland_fill_arc(win, x, yc + hc - r,
                (unsigned)r*2, (unsigned)r*2, 270 , col);
        nk_wayland_fill_arc(win, xc + wc - r, yc + hc - r,
                (unsigned)r*2, (unsigned)r*2, 180 , col);
    }
}

static void nk_wayland_stroke_arc(const struct nk_wayland* win,
    short x0, short y0, short w, short h, const short s,
    const short line_thickness, const struct nk_color col)
{
    /* Bresenham's ellipses - modified to draw one quarter */
    const int a2 = (w * w) / 4;
    const int b2 = (h * h) / 4;
    const int fa2 = 4 * a2, fb2 = 4 * b2;
    int x, y, sigma;

    NK_UNUSED(line_thickness);

    if (s != 0 && s != 90 && s != 180 && s != 270) return;
    if (w < 1 || h < 1) return;

    /* Convert upper left to center */
    h = (h + 1) / 2;
    w = (w + 1) / 2;
    x0 += w; y0 += h;

    /* First half */
    for (x = 0, y = h, sigma = 2*b2+a2*(1-2*h); b2*x <= a2*y; x++) {
        if (s == 180)
            nk_wayland_ctx_setpixel(win, x0 + x, y0 + y, col);
        else if (s == 270)
            nk_wayland_ctx_setpixel(win, x0 - x, y0 + y, col);
        else if (s == 0)
            nk_wayland_ctx_setpixel(win, x0 + x, y0 - y, col);
        else if (s == 90)
            nk_wayland_ctx_setpixel(win, x0 - x, y0 - y, col);
        if (sigma >= 0) {
            sigma += fa2 * (1 - y);
            y--;
        } sigma += b2 * ((4 * x) + 6);
    }

    /* Second half */
    for (x = w, y = 0, sigma = 2*a2+b2*(1-2*w); a2*y <= b2*x; y++) {
        if (s == 180)
            nk_wayland_ctx_setpixel(win, x0 + x, y0 + y, col);
        else if (s == 270)
            nk_wayland_ctx_setpixel(win, x0 - x, y0 + y, col);
        else if (s == 0)
            nk_wayland_ctx_setpixel(win, x0 + x, y0 - y, col);
        else if (s == 90)
            nk_wayland_ctx_setpixel(win, x0 - x, y0 - y, col);
        if (sigma >= 0) {
            sigma += fb2 * (1 - x);
            x--;
        } sigma += a2 * ((4 * y) + 6);
    }
}


static void nk_wayland_stroke_rect(const struct nk_wayland* win,
    const short x, const short y, const short w, const short h,
    const short r, const short line_thickness, const struct nk_color col)
{
    if (r == 0) {
        nk_wayland_stroke_line(win, x, y, x + w, y, line_thickness, col);
        nk_wayland_stroke_line(win, x, y + h, x + w, y + h, line_thickness, col);
        nk_wayland_stroke_line(win, x, y, x, y + h, line_thickness, col);
        nk_wayland_stroke_line(win, x + w, y, x + w, y + h, line_thickness, col);
    } else {
        const short xc = x + r;
        const short yc = y + r;
        const short wc = (short)(w - 2 * r);
        const short hc = (short)(h - 2 * r);

        nk_wayland_stroke_line(win, xc, y, xc + wc, y, line_thickness, col);
        nk_wayland_stroke_line(win, x + w, yc, x + w, yc + hc, line_thickness, col);
        nk_wayland_stroke_line(win, xc, y + h, xc + wc, y + h, line_thickness, col);
        nk_wayland_stroke_line(win, x, yc, x, yc + hc, line_thickness, col);

        nk_wayland_stroke_arc(win, xc + wc - r, y,
                (unsigned)r*2, (unsigned)r*2, 0 , line_thickness, col);
        nk_wayland_stroke_arc(win, x, y,
                (unsigned)r*2, (unsigned)r*2, 90 , line_thickness, col);
        nk_wayland_stroke_arc(win, x, yc + hc - r,
                (unsigned)r*2, (unsigned)r*2, 270 , line_thickness, col);
        nk_wayland_stroke_arc(win, xc + wc - r, yc + hc - r,
                (unsigned)r*2, (unsigned)r*2, 180 , line_thickness, col);
    }
}

static void nk_wayland_fill_triangle(const struct nk_wayland *win,
    const short x0, const short y0, const short x1, const short y1,
    const short x2, const short y2, const struct nk_color col)
{
    struct nk_vec2i pnts[3];
    pnts[0].x = x0;
    pnts[0].y = y0;
    pnts[1].x = x1;
    pnts[1].y = y1;
    pnts[2].x = x2;
    pnts[2].y = y2;
    nk_wayland_fill_polygon(win, pnts, 3, col);
}

static void nk_wayland_clear(const struct nk_wayland *win, const struct nk_color col)
{
    nk_wayland_fill_rect(win, 0, 0, win->width, win->height, 0, col);
}

static void nk_wayland_fill_circle(struct nk_wayland* win, short x0, short y0, short w, short h, const struct nk_color col)
{
    /* Bresenham's ellipses */
    const int a2 = (w * w) / 4;
    const int b2 = (h * h) / 4;
    const int fa2 = 4 * a2, fb2 = 4 * b2;
    int x, y, sigma;

    /* Convert upper left to center */
    h = (h + 1) / 2;
    w = (w + 1) / 2;
    x0 += w;
    y0 += h;

    /* First half */
    for (x = 0, y = h, sigma = 2*b2+a2*(1-2*h); b2*x <= a2*y; x++) {
        nk_wayland_stroke_line(win, x0 - x, y0 + y, x0 + x, y0 + y, 1, col);
        nk_wayland_stroke_line(win, x0 - x, y0 - y, x0 + x, y0 - y, 1, col);
        if (sigma >= 0) {
            sigma += fa2 * (1 - y);
            y--;
        } sigma += b2 * ((4 * x) + 6);
    }
    /* Second half */
    for (x = w, y = 0, sigma = 2*a2+b2*(1-2*w); a2*y <= b2*x; y++) {
        nk_wayland_stroke_line(win, x0 - x, y0 + y, x0 + x, y0 + y, 1, col);
        nk_wayland_stroke_line(win, x0 - x, y0 - y, x0 + x, y0 - y, 1, col);
        if (sigma >= 0) {
            sigma += fb2 * (1 - x);
            x--;
        } sigma += a2 * ((4 * y) + 6);
    }
}
/**
 * Copy wayland_img into nk_wayland with scissor & stretch
 */
static void nk_wayland_copy_image(const struct nk_wayland *win, const struct wayland_img *src,
    const struct nk_rect *dst_rect,
    const struct nk_rect *src_rect,
    const struct nk_rect *dst_scissors,
    const struct nk_color *fg)
{
    short i, j;
    struct nk_color col;
    float xinc = src_rect->w / dst_rect->w;
    float yinc = src_rect->h / dst_rect->h;
    float xoff = src_rect->x, yoff = src_rect->y;

    // Simple nearest filtering rescaling
    // TODO: use bilinear filter
    for (j = 0; j < (short)dst_rect->h; j++) {
        for (i = 0; i < (short)dst_rect->w; i++) {
            if (dst_scissors) {
                if (i + (int)(dst_rect->x + 0.5f) < dst_scissors->x || i + (int)(dst_rect->x + 0.5f) >= dst_scissors->w)
                    continue;
                if (j + (int)(dst_rect->y + 0.5f) < dst_scissors->y || j + (int)(dst_rect->y + 0.5f) >= dst_scissors->h)
                    continue;
            }
            col = nk_wayland_img_getpixel(src, (int)xoff, (int) yoff);
	    if (col.r || col.g || col.b)
	    {
		col.r = fg->r;
		col.g = fg->g;
		col.b = fg->b;
	    }
            nk_wayland_blendpixel(win, i + (int)(dst_rect->x + 0.5f), j + (int)(dst_rect->y + 0.5f), col);
            xoff += xinc;
        }
        xoff = src_rect->x;
        yoff += yinc;
    }
}

static void nk_wayland_font_query_font_glyph(nk_handle handle, const float height, struct nk_user_font_glyph *glyph, const nk_rune codepoint, const nk_rune next_codepoint)
{
    float scale;
    const struct nk_font_glyph *g;
    struct nk_font *font;
    NK_ASSERT(glyph);
    NK_UNUSED(next_codepoint);

    font = (struct nk_font*)handle.ptr;
    NK_ASSERT(font);
    NK_ASSERT(font->glyphs);
    if (!font || !glyph)
        return;

    scale = height/font->info.height;
    g = nk_font_find_glyph(font, codepoint);
    glyph->width = (g->x1 - g->x0) * scale;
    glyph->height = (g->y1 - g->y0) * scale;
    glyph->offset = nk_vec2(g->x0 * scale, g->y0 * scale);
    glyph->xadvance = (g->xadvance * scale);
    glyph->uv[0] = nk_vec2(g->u0, g->v0);
    glyph->uv[1] = nk_vec2(g->u1, g->v1);
}

void nk_wayland_draw_text(const struct nk_wayland *win, const struct nk_user_font *font, const struct nk_rect rect, const char *text, const int len, const float font_height, const struct nk_color fg)
{
    float x = 0;
    int text_len = 0;
    nk_rune unicode = 0;
    nk_rune next = 0;
    int glyph_len = 0;
    int next_glyph_len = 0;
    struct nk_user_font_glyph g;
    if (!len || !text) return;

    x = 0;
    glyph_len = nk_utf_decode(text, &unicode, len);
    if (!glyph_len) return;

    // draw every glyph image
    while (text_len < len && glyph_len) {
        struct nk_rect src_rect;
        struct nk_rect dst_rect;
        float char_width = 0;
        if (unicode == NK_UTF_INVALID) break;

        // query currently drawn glyph information
        next_glyph_len = nk_utf_decode(text + text_len + glyph_len, &next, (int)len - text_len);
        nk_wayland_font_query_font_glyph(font->userdata, font_height, &g, unicode,
                    (next == NK_UTF_INVALID) ? '\0' : next);

        //calculate and draw glyph drawing rectangle and image
        char_width = g.xadvance;
        src_rect.x = g.uv[0].x * win->font_tex.w;
        src_rect.y = g.uv[0].y * win->font_tex.h;
        src_rect.w = g.uv[1].x * win->font_tex.w - g.uv[0].x * win->font_tex.w;
        src_rect.h = g.uv[1].y * win->font_tex.h - g.uv[0].y * win->font_tex.h;

        dst_rect.x = x + g.offset.x + rect.x;
        dst_rect.y = g.offset.y + rect.y;
        dst_rect.w = ceilf(g.width);
        dst_rect.h = ceilf(g.height);

        // Use software rescaling to blit glyph from font_text to framebuffer
        nk_wayland_copy_image(win, &(win->font_tex), &dst_rect, &src_rect, &(win->scissors), &fg);

        // offset next glyph
        text_len += glyph_len;
        x += char_width;
        glyph_len = next_glyph_len;
        unicode = next;
    }
}

static void nk_wayland_render(struct nk_wayland *win, const struct nk_color clear, const unsigned char enable_clear)
{
    const struct nk_command *cmd;
    const struct nk_command_text *tx;
    const struct nk_command_scissor *s;
    const struct nk_command_rect_filled *rf;
    const struct nk_command_rect *r;
    const struct nk_command_circle_filled *c;
    const struct nk_command_triangle_filled *t;
    const struct nk_command_line *l;
    const struct nk_command_polygon_filled *p;

    if (enable_clear)
        nk_wayland_clear(win, clear);

    nk_foreach(cmd, (struct nk_context*)&(win->ctx)) {
        switch (cmd->type) {
        case NK_COMMAND_NOP:
            //printf("NK_COMMAND_NOP \n");
            break;

        case NK_COMMAND_SCISSOR:
            s = (const struct nk_command_scissor*)cmd;
            nk_wayland_scissor(win, s->x, s->y, s->w, s->h);
            break;

        case NK_COMMAND_LINE:
            l = (const struct nk_command_line *)cmd;
            nk_wayland_stroke_line(win, l->begin.x, l->begin.y, l->end.x, l->end.y, l->line_thickness, l->color);
            break;

        case NK_COMMAND_RECT:
            r = (const struct nk_command_rect *)cmd;
            nk_wayland_stroke_rect(win, r->x, r->y, r->w, r->h, (unsigned short)r->rounding, r->line_thickness, r->color);
            break;

        case NK_COMMAND_RECT_FILLED:
            rf = (const struct nk_command_rect_filled *)cmd;
            nk_wayland_fill_rect(win, rf->x, rf->y, rf->w, rf->h, (unsigned short)rf->rounding, rf->color);
            break;

        case NK_COMMAND_CIRCLE:
          //  printf("NK_COMMAND_CIRCLE \n");
            //const struct nk_command_circle *c = (const struct nk_command_circle *)cmd;
            //nk_rawfb_stroke_circle(rawfb, c->x, c->y, c->w, c->h, c->line_thickness, c->color);
            break;

        case NK_COMMAND_CIRCLE_FILLED:
            c = (const struct nk_command_circle_filled *)cmd;
            nk_wayland_fill_circle(win, c->x, c->y, c->w, c->h, c->color);

            //const struct nk_command_circle_filled *c = (const struct nk_command_circle_filled *)cmd;
            //nk_rawfb_fill_circle(rawfb, c->x, c->y, c->w, c->h, c->color);
            break;

        case NK_COMMAND_TRIANGLE:
            //printf("NK_COMMAND_TRIANGLE \n");
            //const struct nk_command_triangle*t = (const struct nk_command_triangle*)cmd;
            //nk_rawfb_stroke_triangle(rawfb, t->a.x, t->a.y, t->b.x, t->b.y, t->c.x, t->c.y, t->line_thickness, t->color);
            break;

        case NK_COMMAND_TRIANGLE_FILLED:
            t = (const struct nk_command_triangle_filled *)cmd;
            nk_wayland_fill_triangle(win, t->a.x, t->a.y, t->b.x, t->b.y, t->c.x, t->c.y, t->color);
            break;

        case NK_COMMAND_POLYGON:
          //  printf("NK_COMMAND_POLYGON \n");
            //const struct nk_command_polygon *p =(const struct nk_command_polygon*)cmd;
            //nk_rawfb_stroke_polygon(rawfb, p->points, p->point_count, p->line_thickness,p->color);
            break;

        case NK_COMMAND_POLYGON_FILLED:
           // printf("NK_COMMAND_POLYGON_FILLED \n");
            p = (const struct nk_command_polygon_filled *)cmd;
            nk_wayland_fill_polygon(win, p->points, p->point_count, p->color);
            break;

        case NK_COMMAND_POLYLINE:
           // printf("NK_COMMAND_POLYLINE \n");
            //const struct nk_command_polyline *p = (const struct nk_command_polyline *)cmd;
            //nk_rawfb_stroke_polyline(rawfb, p->points, p->point_count, p->line_thickness, p->color);
            break;

        case NK_COMMAND_TEXT:
            tx = (const struct nk_command_text*)cmd;
            nk_wayland_draw_text(win, tx->font, nk_rect(tx->x, tx->y, tx->w, tx->h), tx->string, tx->length, tx->height, tx->foreground);
            break;

        case NK_COMMAND_CURVE:
         //    printf("NK_COMMAND_CURVE \n");
            //const struct nk_command_curve *q = (const struct nk_command_curve *)cmd;
            //nk_rawfb_stroke_curve(rawfb, q->begin, q->ctrl[0], q->ctrl[1], q->end, 22, q->line_thickness, q->color);
            break;

        case NK_COMMAND_RECT_MULTI_COLOR:
          //  printf("NK_COMMAND_RECT_MULTI_COLOR \n");
            //const struct nk_command_rect_multi_color *q = (const struct nk_command_rect_multi_color *)cmd;
            //nk_rawfb_draw_rect_multi_color(rawfb, q->x, q->y, q->w, q->h, q->left, q->top, q->right, q->bottom);
            break;

        case NK_COMMAND_IMAGE:
            //printf("NK_COMMAND_IMAGE \n");
           // const struct nk_command_image *q = (const struct nk_command_image *)cmd;
           // nk_rawfb_drawimage(rawfb, q->x, q->y, q->w, q->h, &q->img, &q->col);
            break;

        case NK_COMMAND_ARC:
            printf("NK_COMMAND_ARC \n");
            assert(0 && "NK_COMMAND_ARC not implemented\n");
            break;

        case NK_COMMAND_ARC_FILLED:
            printf("NK_COMMAND_ARC \n");
            assert(0 && "NK_COMMAND_ARC_FILLED not implemented\n");
            break;

        default:
            printf("unhandled OP: %d \n", cmd->type);
            break;
        }
    } nk_clear(&(win->ctx));
}

#endif