rt-thread/components/gui/src/dc_buffer.c

/*
 * File      : dc_buffer.c
 * This file is part of RT-Thread GUI Engine
 * COPYRIGHT (C) 2006 - 2017, RT-Thread Development Team
 *
 *  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.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2009-10-16     Bernard      first version
 */
#include <rtgui/rtgui.h>
#include <rtgui/dc.h>
#include <rtgui/blit.h>
#include <rtgui/color.h>
#include <rtgui/rtgui_system.h>
#include <rtgui/dc_draw.h>
#include <rtgui/image_container.h>
#include <string.h>

static rt_bool_t rtgui_dc_buffer_fini(struct rtgui_dc *dc);
static void rtgui_dc_buffer_draw_point(struct rtgui_dc *dc, int x, int y);
static void rtgui_dc_buffer_draw_color_point(struct rtgui_dc *dc, int x, int y, rtgui_color_t color);
static void rtgui_dc_buffer_draw_vline(struct rtgui_dc *dc, int x, int y1, int y2);
static void rtgui_dc_buffer_draw_hline(struct rtgui_dc *dc, int x1, int x2, int y);
static void rtgui_dc_buffer_fill_rect(struct rtgui_dc *dc, struct rtgui_rect *rect);
static void rtgui_dc_buffer_blit_line(struct rtgui_dc *self, int x1, int x2, int y, rt_uint8_t *line_data);
static void rtgui_dc_buffer_blit(struct rtgui_dc *self, struct rtgui_point *dc_point,
                                 struct rtgui_dc *dest, rtgui_rect_t *rect);

const struct rtgui_dc_engine dc_buffer_engine =
{
    rtgui_dc_buffer_draw_point,
    rtgui_dc_buffer_draw_color_point,
    rtgui_dc_buffer_draw_vline,
    rtgui_dc_buffer_draw_hline,
    rtgui_dc_buffer_fill_rect,
    rtgui_dc_buffer_blit_line,
    rtgui_dc_buffer_blit,

    rtgui_dc_buffer_fini,
};

#define _dc_get_pitch(dc)           \
    (dc->pitch)
#define _dc_get_pixel(dc, x, y)     \
    ((dc)->pixel + (y) * (dc)->pitch + (x) * rtgui_color_get_bpp((dc)->pixel_format))
#define _dc_get_bits_per_pixel(dc)  \
    rtgui_color_get_bits(dc->pixel_format)

#define _hw_get_pixel(dst, x, y, type)  \
        (type *)((rt_uint8_t*)((dst)->framebuffer) + (y) * (dst)->pitch + (x) * _UI_BITBYTES((dst)->bits_per_pixel))

struct rtgui_dc *rtgui_dc_buffer_create(int w, int h)
{
    rt_uint8_t pixel_format;

    pixel_format = rtgui_graphic_driver_get_default()->pixel_format;

    /* create a dc_buffer with hardware driver pixel format */
    return rtgui_dc_buffer_create_pixformat(pixel_format, w, h);
}
RTM_EXPORT(rtgui_dc_buffer_create);

struct rtgui_dc *rtgui_dc_buffer_create_pixformat(rt_uint8_t pixel_format, int w, int h)
{
    struct rtgui_dc_buffer *dc;

    dc = (struct rtgui_dc_buffer *)rtgui_malloc(sizeof(struct rtgui_dc_buffer));
    if (dc)
    {
        dc->parent.type = RTGUI_DC_BUFFER;
        dc->parent.engine = &dc_buffer_engine;
        dc->gc.foreground = default_foreground;
        dc->gc.background = default_background;
        dc->gc.font = rtgui_font_default();
        dc->gc.textalign = RTGUI_ALIGN_LEFT | RTGUI_ALIGN_TOP;
        dc->pixel_format = pixel_format;

        dc->width = w;
        dc->height = h;
        dc->pitch = w * rtgui_color_get_bpp(pixel_format);

#ifdef RTGUI_IMAGE_CONTAINER
        dc->image_item = RT_NULL;
#endif
        dc->pixel = rtgui_malloc(h * dc->pitch);
        if (!dc->pixel)
        {
            rtgui_free(dc);
            return RT_NULL;
        }
        rt_memset(dc->pixel, 0, h * dc->pitch);

        return &(dc->parent);
    }

    return RT_NULL;
}
RTM_EXPORT(rtgui_dc_buffer_create_pixformat);

#ifdef RTGUI_IMAGE_CONTAINER
struct rtgui_dc *rtgui_img_dc_create_pixformat(rt_uint8_t pixel_format, 
    rt_uint8_t *pixel, struct rtgui_image_item *image_item)
{
    struct rtgui_dc_buffer *dc;

    dc = (struct rtgui_dc_buffer *)rtgui_malloc(sizeof(struct rtgui_dc_buffer));
    if (dc)
    {
        dc->parent.type = RTGUI_DC_BUFFER;
        dc->parent.engine = &dc_buffer_engine;
        dc->gc.foreground = default_foreground;
        dc->gc.background = default_background;
        dc->gc.font = rtgui_font_default();
        dc->gc.textalign = RTGUI_ALIGN_LEFT | RTGUI_ALIGN_TOP;
        dc->pixel_format = pixel_format;

        dc->width = image_item->image->w;
        dc->height = image_item->image->h;
        dc->pitch = image_item->image->w * rtgui_color_get_bpp(pixel_format);

        dc->image_item = image_item;
        dc->pixel = pixel;

        return &(dc->parent);
    }

    return RT_NULL;
}
RTM_EXPORT(rtgui_img_dc_create_pixformat);
#endif

struct rtgui_dc *rtgui_dc_buffer_create_from_dc(struct rtgui_dc* dc)
{
    struct rtgui_dc_buffer *buffer;

    if (dc == RT_NULL)
        return RT_NULL;

    if (dc->type == RTGUI_DC_BUFFER)
    {
        struct rtgui_dc_buffer *d = (struct rtgui_dc_buffer*) dc;

        /* buffer clone */
        buffer = (struct rtgui_dc_buffer*)rtgui_dc_buffer_create_pixformat(d->pixel_format,
                 d->width,
                 d->height);
        if (buffer != RT_NULL)
        {
            rt_memcpy(buffer->pixel, d->pixel, d->pitch * d->height);

            return RTGUI_DC(buffer);
        }
    }

    return RT_NULL;
}
RTM_EXPORT(rtgui_dc_buffer_create_from_dc);

rt_uint8_t *rtgui_dc_buffer_get_pixel(struct rtgui_dc *dc)
{
    struct rtgui_dc_buffer *dc_buffer;

    dc_buffer = (struct rtgui_dc_buffer *)dc;

    return dc_buffer->pixel;
}
RTM_EXPORT(rtgui_dc_buffer_get_pixel);

static rt_bool_t rtgui_dc_buffer_fini(struct rtgui_dc *dc)
{
    struct rtgui_dc_buffer *buffer = (struct rtgui_dc_buffer *)dc;

    if (dc->type != RTGUI_DC_BUFFER) return RT_FALSE;

#ifdef RTGUI_IMAGE_CONTAINER
    if (buffer->image_item)
    {
        rtgui_image_container_put(buffer->image_item);
        buffer->pixel = RT_NULL;
    }
#endif

    if (buffer->pixel)
        rtgui_free(buffer->pixel);

    return RT_TRUE;
}

static void rtgui_dc_buffer_draw_point(struct rtgui_dc *self, int x, int y)
{
    struct rtgui_dc_buffer *dst;
    unsigned r, g, b, a;

    dst = (struct rtgui_dc_buffer *)self;

    /* does not draw point out of dc */
    if ((x >= dst->width) || (y >= dst->height)) return;
    if (x < 0 || y < 0) return;

    r = RTGUI_RGB_R(dst->gc.foreground);
    g = RTGUI_RGB_G(dst->gc.foreground);
    b = RTGUI_RGB_B(dst->gc.foreground);
    a = RTGUI_RGB_A(dst->gc.foreground);

    switch (dst->pixel_format)
    {
    case RTGRAPHIC_PIXEL_FORMAT_RGB565:
        DRAW_SETPIXELXY_RGB565(x, y);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_BGR565:
        DRAW_SETPIXELXY_BGR565(x, y);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_RGB888:
        DRAW_SETPIXELXY_RGB888(x, y);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_ARGB888:
        DRAW_SETPIXELXY_ARGB8888(x, y);
        break;
    }
}

static void rtgui_dc_buffer_draw_color_point(struct rtgui_dc *self, int x, int y, rtgui_color_t color)
{
    struct rtgui_dc_buffer *dst;
    unsigned r, g, b, a;

    dst = (struct rtgui_dc_buffer *)self;

    /* does not draw point out of dc */
    if ((x >= dst->width) || (y >= dst->height)) return;
    if (x < 0 || y < 0) return;

    r = RTGUI_RGB_R(color);
    g = RTGUI_RGB_G(color);
    b = RTGUI_RGB_B(color);
    a = RTGUI_RGB_A(color);

    switch (dst->pixel_format)
    {
    case RTGRAPHIC_PIXEL_FORMAT_RGB565:
        DRAW_SETPIXELXY_RGB565(x, y);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_BGR565:
        DRAW_SETPIXELXY_BGR565(x, y);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_RGB888:
        DRAW_SETPIXELXY_RGB888(x, y);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_ARGB888:
        DRAW_SETPIXELXY_ARGB8888(x, y);
        break;
    }
}

static void rtgui_dc_buffer_draw_vline(struct rtgui_dc *self, int x1, int y1, int y2)
{
    struct rtgui_dc_buffer *dst;
    unsigned r, g, b, a;

    dst = (struct rtgui_dc_buffer *)self;

    if (x1 < 0 || x1 >= dst->width) return;
    if (y1 >= dst->height) return;

    if (y1 < 0) y1 = 0;
    if (y2 > dst->height) y2 = dst->height;

    r = RTGUI_RGB_R(dst->gc.foreground);
    g = RTGUI_RGB_G(dst->gc.foreground);
    b = RTGUI_RGB_B(dst->gc.foreground);
    a = RTGUI_RGB_A(dst->gc.foreground);

    switch (dst->pixel_format)
    {
    case RTGRAPHIC_PIXEL_FORMAT_RGB565:
        VLINE(rt_uint16_t, DRAW_SETPIXEL_RGB565, 0);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_BGR565:
        VLINE(rt_uint16_t, DRAW_SETPIXEL_BGR565, 0);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_RGB888:
        VLINE(rt_uint16_t, DRAW_SETPIXEL_RGB888, 0);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_ARGB888:
        VLINE(rt_uint32_t, DRAW_SETPIXEL_ARGB8888, 0);
        break;
    }
}

static void rtgui_dc_buffer_draw_hline(struct rtgui_dc *self, int x1, int x2, int y1)
{
    struct rtgui_dc_buffer *dst;
    unsigned r, g, b, a;

    dst = (struct rtgui_dc_buffer *)self;

    /* parameter checking */
    if (y1 < 0 || y1 >= dst->height) return;
    if (x1 >= dst->width) return;

    if (x1 < 0) x1 = 0;
    if (x2 > dst->width) x2 = dst->width;

    r = RTGUI_RGB_R(dst->gc.foreground);
    g = RTGUI_RGB_G(dst->gc.foreground);
    b = RTGUI_RGB_B(dst->gc.foreground);
    a = RTGUI_RGB_A(dst->gc.foreground);

    switch (dst->pixel_format)
    {
    case RTGRAPHIC_PIXEL_FORMAT_RGB565:
        HLINE(rt_uint16_t, DRAW_SETPIXEL_RGB565, 0);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_BGR565:
        HLINE(rt_uint16_t, DRAW_SETPIXEL_BGR565, 0);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_RGB888:
        HLINE(rt_uint16_t, DRAW_SETPIXEL_RGB888, 0);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_ARGB888:
        HLINE(rt_uint32_t, DRAW_SETPIXEL_ARGB8888, 0);
        break;
    }
}

static void rtgui_dc_buffer_fill_rect(struct rtgui_dc *self, struct rtgui_rect *dst_rect)
{
    struct rtgui_dc_buffer *dst;
    unsigned r, g, b, a;
    rtgui_rect_t _r, *rect;

    RT_ASSERT(self);
    if (dst_rect == RT_NULL) rtgui_dc_get_rect(self, &_r);
    else _r = *dst_rect;

    dst = (struct rtgui_dc_buffer *)self;

    if (_r.x2 < 0 || _r.y2 < 0) return; /* out of rect */

    /* parameter checking */
    if (_r.x1 >= dst->width)
        return;
    else if (_r.x1 < 0)
        _r.x1 = 0;
    if (_r.x2 > dst->width)
        _r.x2 = dst->width;

    if (_r.y1 >= dst->height)
        return;
    else if (_r.y1 < 0)
        _r.y1 = 0;
    if (_r.y2 > dst->height)
        _r.y2 = dst->height;
    rect = &_r;

    r = RTGUI_RGB_R(dst->gc.background);
    g = RTGUI_RGB_G(dst->gc.background);
    b = RTGUI_RGB_B(dst->gc.background);
    a = RTGUI_RGB_A(dst->gc.background);

    switch (dst->pixel_format)
    {
    case RTGRAPHIC_PIXEL_FORMAT_RGB565:
        FILLRECT(rt_uint16_t, DRAW_SETPIXEL_RGB565);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_BGR565:
        FILLRECT(rt_uint16_t, DRAW_SETPIXEL_BGR565);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_RGB888:
        FILLRECT(rt_uint32_t, DRAW_SETPIXEL_RGB888);
        break;
    case RTGRAPHIC_PIXEL_FORMAT_ARGB888:
        FILLRECT(rt_uint32_t, DRAW_SETPIXEL_ARGB8888);
        break;
    }
}

/* blit a dc to another dc */
static void rtgui_dc_buffer_blit(struct rtgui_dc *self,
                                 struct rtgui_point *dc_pt,
                                 struct rtgui_dc *dest,
                                 rtgui_rect_t *rect)
{
    int pitch;
    rt_uint16_t rect_width, rect_height;
    struct rtgui_rect _rect, *dest_rect;
    struct rtgui_point dc_point;
    struct rtgui_dc_buffer *dc = (struct rtgui_dc_buffer *)self;

    if (rtgui_dc_get_visible(dest) == RT_FALSE)
        return;

    /* use the (0,0) origin point */
    if (dc_pt == RT_NULL)
        dc_point = rtgui_empty_point;
    else
    {
        dc_point = *dc_pt;
    }

    rtgui_dc_get_rect(dest, &_rect);
    /* use the rect of dest dc */
    if (rect == RT_NULL)
    {
        dest_rect = &_rect;
    }
    else
    {
        dest_rect = rect;
        if (dest_rect->x1 >= _rect.x2 || dest_rect->y1 >= _rect.y2)
            return;
        if (dest_rect->x1 < 0)
        {
            if (-dest_rect->x1 >= dc->width)
                return;
            dc_point.x += -dest_rect->x1;
            dest_rect->x1 = 0;
        }
        if (dest_rect->y1 < 0)
        {
            if (-dest_rect->y1 >= dc->height)
                return;
            dc_point.y += -dest_rect->y1;
            dest_rect->y1 = 0;
        }
        if (dest_rect->x2 > _rect.x2)
            dest_rect->x2 = _rect.x2;
        if (dest_rect->y2 > _rect.y2)
            dest_rect->y2 = _rect.y2;
    }

    if (dest_rect->x2 < dest_rect->x1 || dest_rect->y2 < dest_rect->y1) return;
    if (dc_point.x >= dc->width || dc_point.y >= dc->height) return;

    /* get the minimal width and height */
    rect_width  = _UI_MIN(rtgui_rect_width(*dest_rect), dc->width - dc_point.x);
    rect_height = _UI_MIN(rtgui_rect_height(*dest_rect), dc->height - dc_point.y);

    if ((dest->type == RTGUI_DC_HW) || (dest->type == RTGUI_DC_CLIENT))
    {
        int index;
        rt_uint8_t *line_ptr, *pixels;
        rtgui_blit_line_func blit_line;
        struct rtgui_graphic_driver *hw_driver;

        hw_driver = rtgui_graphic_driver_get_default();
        /* prepare pixel line */
        pixels = _dc_get_pixel(dc, dc_point.x, dc_point.y);

        if (dest->type == RTGUI_DC_HW && hw_driver->framebuffer != RT_NULL)
        {
            /* use rtgui_blit */

            struct rtgui_blit_info info;
            struct rtgui_widget *owner;

            info.a = 255;

            /* blit source */
            info.src = _dc_get_pixel(dc, dc_point.x, dc_point.y);
            info.src_fmt = dc->pixel_format;
            info.src_h = rect_height;
            info.src_w = rect_width;
            info.src_pitch = dc->pitch;
            info.src_skip = info.src_pitch - info.src_w * rtgui_color_get_bpp(dc->pixel_format);

            owner = ((struct rtgui_dc_hw*)dest)->owner;

            /* blit destination */
            info.dst = (rt_uint8_t*)hw_driver->framebuffer;
            info.dst = info.dst + (owner->extent.y1 + dest_rect->y1) * hw_driver->pitch +
                       (owner->extent.x1 + dest_rect->x1) * rtgui_color_get_bpp(hw_driver->pixel_format);
            info.dst_fmt = hw_driver->pixel_format;
            info.dst_h = rect_height;
            info.dst_w = rect_width;
            info.dst_pitch = hw_driver->pitch;
            info.dst_skip = info.dst_pitch - info.dst_w * rtgui_color_get_bpp(hw_driver->pixel_format);

            rtgui_blit(&info);
        }
        else if (dest->type == RTGUI_DC_CLIENT&& hw_driver->framebuffer != RT_NULL)
        {
            /* use rtgui_blit */
            rt_uint8_t bpp, hw_bpp;
            struct rtgui_blit_info info;
            struct rtgui_widget *owner;
            struct rtgui_region dest_region;
            struct rtgui_rect dest_extent;
            int num_rects;
            struct rtgui_rect *rects;

            /* get owner */
            owner = RTGUI_CONTAINER_OF(dest, struct rtgui_widget, dc_type);

            dest_extent = *dest_rect;
            rtgui_widget_rect_to_device(owner, &dest_extent);

            rtgui_region_init_with_extents(&dest_region, &dest_extent);
            rtgui_region_intersect_rect(&dest_region, &(owner->clip), &dest_extent);
            bpp = rtgui_color_get_bpp(dc->pixel_format);
            hw_bpp = rtgui_color_get_bpp(hw_driver->pixel_format);

            num_rects = rtgui_region_num_rects(&dest_region);
            rects = rtgui_region_rects(&dest_region);

            /* common info */
            info.a = 255;
            info.src_fmt = dc->pixel_format;
            info.src_pitch = dc->pitch;

            info.dst_fmt = hw_driver->pixel_format;
            info.dst_pitch = hw_driver->pitch;

            for (index = 0; index < num_rects; index ++)
            {
                struct rtgui_rect *r = &rects[index];

                /* blit source */
                info.src = _dc_get_pixel(dc, dc_point.x + (r->x1 - dest_extent.x1),
                                         dc_point.y + (r->y1 - dest_extent.y1));
                info.src_h = rtgui_rect_height(*r);
                info.src_w = rtgui_rect_width(*r);
                info.src_skip = info.src_pitch - info.src_w * bpp;

                /* blit destination */
                info.dst = (rt_uint8_t*)hw_driver->framebuffer + r->y1 * hw_driver->pitch +
                           r->x1 * hw_bpp;
                info.dst_h = rtgui_rect_height(*r);
                info.dst_w = rtgui_rect_width(*r);
                info.dst_skip = info.dst_pitch - info.dst_w * hw_bpp;

                rtgui_blit(&info);
            }

            rtgui_region_fini(&dest_region);
        }
        else
        {
            /* calculate pitch */
            pitch = rect_width * rtgui_color_get_bpp(dc->pixel_format);

            /* get blit line function */
            blit_line = rtgui_blit_line_get(_UI_BITBYTES(hw_driver->bits_per_pixel),
                                            rtgui_color_get_bpp(dc->pixel_format));
            if (hw_driver->framebuffer != RT_NULL)
            {
                struct rtgui_widget* owner;
                if (dest->type == RTGUI_DC_HW) owner = ((struct rtgui_dc_hw*) dest)->owner;
                else if (dest->type == RTGUI_DC_CLIENT) owner = RTGUI_CONTAINER_OF(dest, struct rtgui_widget, dc_type);
                else RT_ASSERT(0);

                /* change the logic coordinate to the device coordinate */
                rtgui_rect_moveto(dest_rect, owner->extent.x1, owner->extent.y1);

                for (index = dest_rect->y1; index < dest_rect->y1 + rect_height; index ++)
                {
                    line_ptr = _hw_get_pixel(hw_driver, dest_rect->x1, index, rt_uint8_t);
                    blit_line(line_ptr, (rt_uint8_t*)pixels, pitch);
                    pixels += dc->pitch;
                }
            }
            else
            {
                /* calculate pitch */
                pitch = rect_width * rtgui_color_get_bpp(dc->pixel_format);
                /* create line buffer */
                line_ptr = (rt_uint8_t *) rtgui_malloc(rect_width * _UI_BITBYTES(hw_driver->bits_per_pixel));

                /* draw each line */
                for (index = dest_rect->y1; index < dest_rect->y1 + rect_height; index ++)
                {
                    /* blit on line buffer */
                    blit_line(line_ptr, (rt_uint8_t *)pixels, pitch);
                    pixels += dc->pitch;

                    /* draw on hardware dc */
                    dest->engine->blit_line(dest, dest_rect->x1, dest_rect->x1 + rect_width,
                                            index, line_ptr);
                }

                /* release line buffer */
                rtgui_free(line_ptr);
            }
        }
    }
    else if (dest->type == RTGUI_DC_BUFFER)
    {
        struct rtgui_dc_buffer *dest_dc = (struct rtgui_dc_buffer*)dest;

        /* use rtgui_blit to handle buffer blit */
        struct rtgui_blit_info info;

        info.a = 255;

        /* blit source */
        info.src = _dc_get_pixel(dc, dc_point.x, dc_point.y);
        info.src_fmt = dc->pixel_format;
        info.src_h = rect_height;
        info.src_w = rect_width;
        info.src_pitch = dc->pitch;
        info.src_skip = info.src_pitch - info.src_w * rtgui_color_get_bpp(dc->pixel_format);

        /* blit destination */
        info.dst = _dc_get_pixel(dest_dc, dest_rect->x1, dest_rect->y1);
        info.dst_fmt = dest_dc->pixel_format;
        info.dst_h = rect_height;
        info.dst_w = rect_width;
        info.dst_pitch = dest_dc->pitch;
        info.dst_skip = info.dst_pitch - info.dst_w * rtgui_color_get_bpp(dest_dc->pixel_format);

        rtgui_blit(&info);
    }
}

static void rtgui_dc_buffer_blit_line(struct rtgui_dc *self, int x1, int x2, int y, rt_uint8_t *line_data)
{
    rt_uint8_t *pixel;
    struct rtgui_dc_buffer *dc = (struct rtgui_dc_buffer *)self;

    RT_ASSERT(dc != RT_NULL);
    RT_ASSERT(line_data != RT_NULL);

    /* out of range */
    if ((x1 >= dc->width) || (y >= dc->height) || y < 0 || x1 == x2)
        return;

    /* check range */
    if (x1 < 0)
        x1 = 0;
    if (x2 >= dc->width)
        x2 = dc->width-1;

    pixel = _dc_get_pixel(dc,x1,y);
    rt_memcpy(pixel, line_data, (x2 - x1) * rtgui_color_get_bpp(dc->pixel_format));
}

#ifdef RT_USING_DFS
#include <dfs_posix.h>
void rtgui_dc_buffer_dump(struct rtgui_dc *self, char *fn)
{
    struct dc_file_header
    {
        int w, h;
        int format;
    } header;
    struct rtgui_dc_buffer *buffer;
    int fd;

    if (self->type != RTGUI_DC_BUFFER) return; /* only support DC buffer */
    buffer = (struct rtgui_dc_buffer*)self;

    header.w = buffer->width;
    header.h = buffer->height;
    header.format = buffer->pixel_format;

    fd = open(fn, O_RDWR | O_CREAT | O_TRUNC, 0);
    if (fd >= 0)
    {
        write(fd, &header, sizeof(header));
        write(fd, buffer->pixel, header.w * header.h * rtgui_color_get_bpp(header.format));
        close(fd);
    }
}
#endif