text: #include <rtthread.h>
  #include <rtgui/dc_hw.h>
  #include <rtgui/image.h>
  #include <rtgui/rtgui_system.h>
  #include <rtgui/image_hdc.h>
  #include <rtgui/blit.h>
  
  #define HDC_MAGIC_LEN       4
  
  extern int fastlz_decompress(const void *input, int length, void *output, int maxout);
  
  struct rtgui_image_hdc
  {
      rt_bool_t is_loaded;
  
      /* hdc image information */
      rt_uint16_t byte_per_pixel;
      rt_uint16_t pitch;
      rt_uint8_t  pixel_format;
  
      rt_size_t   pixel_offset;
      rt_uint8_t *pixels;
  
      struct rtgui_filerw *filerw;
  };
  
  static rt_bool_t rtgui_image_hdc_check(struct rtgui_filerw *file);
  static rt_bool_t rtgui_image_hdc_load(struct rtgui_image *image, struct rtgui_filerw *file, rt_bool_t load);
  static void rtgui_image_hdc_unload(struct rtgui_image *image);
  static void rtgui_image_hdc_blit(struct rtgui_image *image, struct rtgui_dc *dc, struct rtgui_rect *rect);
  static void rtgui_image_hdcmm_blit(struct rtgui_image *image, struct rtgui_dc *dc, struct rtgui_rect *dst_rect);
  
  struct rtgui_image_engine rtgui_image_hdc_engine =
  {
      "hdc",
      { RT_NULL },
      rtgui_image_hdc_check,
      rtgui_image_hdc_load,
      rtgui_image_hdc_unload,
      rtgui_image_hdc_blit,
  };
  
  const struct rtgui_image_engine rtgui_image_hdcmm_engine =
  {
      "hdcmm",
      {RT_NULL},
      RT_NULL,
      RT_NULL,
      RT_NULL,
      rtgui_image_hdcmm_blit,
  };
  
  static rt_bool_t rtgui_image_hdc_check(struct rtgui_filerw *file)
  {
      int start;
      rt_bool_t is_HDC;
      rt_uint8_t magic[4];
  
      if (!file) return 0;
  
      start = rtgui_filerw_tell(file);
  
      /* move to the beginning of file */
      rtgui_filerw_seek(file, 0, RTGUI_FILE_SEEK_SET);
  
      is_HDC = RT_FALSE;
      if (rtgui_filerw_read(file, magic, 1, sizeof(magic)) == sizeof(magic))
      {
          if (magic[0] == 'H' &&
                  magic[1] == 'D' &&
                  magic[2] == 'C' &&
                  magic[3] == '\0')
          {
              is_HDC = RT_TRUE;
          }
      }
      rtgui_filerw_seek(file, start, RTGUI_FILE_SEEK_SET);
  
      return (is_HDC);
  }
  
  static rt_bool_t rtgui_image_hdc_load(struct rtgui_image *image, struct rtgui_filerw *file, rt_bool_t load)
  {
      rt_uint32_t header[5];
      struct rtgui_image_hdc *hdc;
  
      hdc = (struct rtgui_image_hdc *) rtgui_malloc(sizeof(struct rtgui_image_hdc));
      if (hdc == RT_NULL) return RT_FALSE;
  
      rtgui_filerw_read(file, (char *)&header, 1, sizeof(header));
  
      /* set image information */
      image->w = (rt_uint16_t)header[1];
      image->h = (rt_uint16_t)header[2];
      image->engine = &rtgui_image_hdc_engine;
      image->data = hdc;
      hdc->pixel_format = header[3];
      hdc->filerw = file;
      if (header[3] == 0)
      {
          /* 0.x version */
          hdc->pixel_format = rtgui_graphic_driver_get_default()->pixel_format;
      }
      else if (header[3] == 1)
      {
          /* 1.x version */
          hdc->pixel_format = header[4];
      }
      else if (header[3] == 2)
      {
          /* 2.x version */
          hdc->pixel_format = header[4];
      }
  
      hdc->byte_per_pixel = rtgui_color_get_bpp(hdc->pixel_format);
      hdc->pitch = image->w * hdc->byte_per_pixel;
      hdc->pixel_offset = rtgui_filerw_tell(file);
  
      if (load == RT_TRUE)
      {
          if (header[3] == 2)
          {
  #if 0   /* TODO: add HDC with fastlz compressed */
              int data_length, dec_length;
              rt_uint8_t *data;
  
              data_length = rtgui_filerw_seek(hdc->filerw, 0, SEEK_END) - sizeof(header);
              rtgui_filerw_seek(hdc->filerw, sizeof(header), SEEK_SET);
  
              data = (rt_uint8_t *)rtgui_malloc(data_length);
              if (data == RT_NULL)
              {
                  /* release data */
                  rtgui_free(hdc);
                  return RT_FALSE;
              }
  
              if (rtgui_filerw_read(hdc->filerw, data, 1, data_length) != data_length)
              {
                  rtgui_filerw_close(hdc->filerw);
                  /* release data */
                  rtgui_free(hdc);
                  return RT_FALSE;
              }
              rtgui_filerw_close(hdc->filerw);
              hdc->filerw = RT_NULL;
  
              hdc->pixels = (rt_uint8_t *)rtgui_malloc(image->h * hdc->pitch);
              if (hdc->pixels == RT_NULL)
              {
                  /* release data */
                  rtgui_free(hdc);
                  rtgui_free(data);
                  return RT_FALSE;
              }
  
              dec_length = fastlz_decompress(data, data_length, hdc->pixels, image->h * hdc->pitch);
              if (dec_length != image->h * hdc->pitch)
              {
                  /* release data */
                  rtgui_free(hdc->pixels);
                  rtgui_free(hdc);
                  rtgui_free(data);
                  return RT_FALSE;
              }
              hdc->pixel_offset = 0;
              rtgui_free(data);
  #endif
          }
          else
          {
              /* load all pixels */
              hdc->pixels = rtgui_malloc(image->h * hdc->pitch);
              if (hdc->pixels == RT_NULL)
              {
                  /* release data */
                  rtgui_free(hdc);
                  return RT_FALSE;
              }
  
              rtgui_filerw_read(hdc->filerw, hdc->pixels, 1, image->h * hdc->pitch);
              rtgui_filerw_close(hdc->filerw);
              hdc->filerw = RT_NULL;
              hdc->pixel_offset = 0;
          }
      }
      else
      {
          hdc->pixels = RT_NULL;
      }
  
      return RT_TRUE;
  }
  
  static void rtgui_image_hdc_unload(struct rtgui_image *image)
  {
      struct rtgui_image_hdc *hdc;
  
      if (image != RT_NULL)
      {
          hdc = (struct rtgui_image_hdc *) image->data;
  
          if (hdc->pixels != RT_NULL)
              rtgui_free(hdc->pixels);
          if (hdc->filerw != RT_NULL)
              rtgui_filerw_close(hdc->filerw);
  
          /* release data */
          rtgui_free(hdc);
      }
  }
  
  static void rtgui_image_hdc_blit(struct rtgui_image *image,
                                   struct rtgui_dc *dc,
                                   struct rtgui_rect *dst_rect)
  {
      rt_int16_t y, w, h, xoff, yoff;
      struct rtgui_image_hdc *hdc;
  
      RT_ASSERT(image != RT_NULL || dc != RT_NULL || dst_rect != RT_NULL);
  
      /* this dc is not visible */
      if (rtgui_dc_get_visible(dc) != RT_TRUE)
          return;
  
      if (!image)
          return;
  
      hdc = (struct rtgui_image_hdc *) image->data;
      RT_ASSERT(hdc != RT_NULL);
  
      xoff = 0;
      if (dst_rect->x1 < 0)
      {
          xoff = -dst_rect->x1;
          dst_rect->x1 = 0;
      }
      yoff = 0;
      if (dst_rect->y1 < 0)
      {
          yoff = -dst_rect->y1;
          dst_rect->y1 = 0;
      }
  
      if (dst_rect->x2 <= 0 || dst_rect->y2 <= 0)
          return;
  
      if (xoff >= image->w || yoff >= image->h)
          return;
  
      /* the minimum rect */
      w = _UI_MIN(image->w - xoff, rtgui_rect_width(*dst_rect));
      h = _UI_MIN(image->h - yoff, rtgui_rect_height(*dst_rect));
  
      if (w == 0 || h == 0)
          return;
  
      if (hdc->pixels != RT_NULL)
      {
          rt_uint8_t *ptr;
  
          /* get pixel pointer */
          ptr = hdc->pixels + hdc->pitch * yoff + hdc->byte_per_pixel * xoff;
  
          if (hdc->pixel_format == rtgui_dc_get_pixel_format(dc) &&
                  hdc->pixel_format != RTGRAPHIC_PIXEL_FORMAT_ARGB888)
          {
              for (y = 0; y < h; y ++)
              {
                  dc->engine->blit_line(dc,
                                        dst_rect->x1,
                                        dst_rect->x1 + w,
                                        dst_rect->y1 + y,
                                        ptr);
                  ptr += hdc->pitch;
              }
          }
          else if (dc->type == RTGUI_DC_CLIENT)
          {
              const struct rtgui_graphic_driver *hw_driver;
              struct rtgui_widget *owner = RTGUI_CONTAINER_OF(dc, struct rtgui_widget, dc_type);
  
              hw_driver = rtgui_graphic_driver_get_default();
              if (hdc->pixel_format == RTGRAPHIC_PIXEL_FORMAT_ARGB888)
              {
                  rt_uint8_t alpha;
  
                  for (y = 0; y < h; y ++)
                  {
                      int x;
  
                      rtgui_color_t *pixel = (rtgui_color_t *)(hdc->pixels + hdc->pitch * (yoff + y) + hdc->byte_per_pixel * xoff);
  
                      for (x = 0; x < w; x ++)
                      {
                          alpha = RTGUI_RGB_A(*pixel);
  
                          if (alpha == 0) { }
                          if (alpha == 0xff)
                          {
                              rtgui_dc_draw_color_point(dc, dst_rect->x1 + x, dst_rect->y1 + y, *pixel);
                          }
                          else
                          {
                              /* draw an alpha blending point */
                              if (hw_driver->framebuffer != RT_NULL)
                                  rtgui_dc_blend_point(dc, dst_rect->x1 + x, dst_rect->y1 + y, RTGUI_BLENDMODE_BLEND,
                                                       RTGUI_RGB_R(*pixel), RTGUI_RGB_G(*pixel), RTGUI_RGB_B(*pixel), RTGUI_RGB_A(*pixel));
                          }
  
                          pixel ++;
                      }
                  }
              }
          }
          else
          {
              struct rtgui_blit_info info;
              info.a = 0;
  
              /* initialize source blit information */
              info.src = ptr;
              info.src_h = h;
              info.src_w = w;
              info.src_fmt = hdc->pixel_format;
              info.src_pitch = hdc->pitch;
              info.src_skip = hdc->pitch - w * rtgui_color_get_bpp(hdc->pixel_format);
  
              /* initialize destination blit information */
              if (dc->type == RTGUI_DC_BUFFER)
              {
                  struct rtgui_dc_buffer *buffer;
                  buffer = (struct rtgui_dc_buffer *)dc;
  
                  info.dst = rtgui_dc_buffer_get_pixel(RTGUI_DC(buffer)) + dst_rect->y1 * buffer->pitch +
                             dst_rect->x1 * rtgui_color_get_bpp(buffer->pixel_format);
                  info.dst_h = h;
                  info.dst_w = w;
                  info.dst_fmt = buffer->pixel_format;
                  info.dst_pitch = buffer->pitch;
                  info.dst_skip = info.dst_pitch - info.dst_w * rtgui_color_get_bpp(buffer->pixel_format);
              }
              else if (dc->type == RTGUI_DC_HW)
              {
                  struct rtgui_widget *owner;
                  struct rtgui_rect r;
                  struct rtgui_dc_hw *ddc = (struct rtgui_dc_hw *)dc;
  
                  owner = ((struct rtgui_dc_hw *)dc)->owner;
  
                  rtgui_graphic_driver_get_rect(RT_NULL, &r);
  
                  /* blit destination */
                  info.dst = (rt_uint8_t *)ddc->hw_driver->framebuffer;
                  info.dst = info.dst + (owner->extent.y1 + dst_rect->y1) * ddc->hw_driver->pitch +
                             (owner->extent.x1 + dst_rect->x1) * rtgui_color_get_bpp(ddc->hw_driver->pixel_format);
                  info.dst_fmt = ddc->hw_driver->pixel_format;
                  info.dst_h = h;
                  info.dst_w = w;
                  info.dst_pitch = ddc->hw_driver->pitch;
                  info.dst_skip = info.dst_pitch - info.dst_w * rtgui_color_get_bpp(ddc->hw_driver->pixel_format);
              }
  
              rtgui_blit(&info);
          }
      }
      else
      {
          rt_uint8_t *ptr;
          ptr = rtgui_malloc(hdc->byte_per_pixel * w);
          if (ptr == RT_NULL)
              return; /* no memory */
  
          /* seek to the begin of pixel data */
          rtgui_filerw_seek(hdc->filerw,
                            hdc->pixel_offset + hdc->pitch * yoff + hdc->byte_per_pixel * xoff,
                            RTGUI_FILE_SEEK_SET);
  
          for (y = 0; y < h; y ++)
          {
              /* read pixel data */
              if (rtgui_filerw_read(hdc->filerw, ptr, 1,
                                    hdc->byte_per_pixel * w) != hdc->byte_per_pixel * w)
                  break; /* read data failed */
  
              dc->engine->blit_line(dc,
                                    dst_rect->x1,
                                    dst_rect->x1 + w,
                                    dst_rect->y1 + y,
                                    ptr);
              rtgui_filerw_seek(hdc->filerw, hdc->byte_per_pixel * xoff, RTGUI_FILE_SEEK_CUR);
          }
  
          rtgui_free(ptr);
      }
  }
  
  static void rtgui_image_hdcmm_blit(struct rtgui_image *image, struct rtgui_dc *dc, struct rtgui_rect *dst_rect)
  {
      rt_uint8_t *ptr;
      rt_uint16_t y, w, h, xoff, yoff;
      struct rtgui_image_hdcmm *hdc;
  
      RT_ASSERT(image != RT_NULL && dc != RT_NULL && dst_rect != RT_NULL);
  
      /* this dc is not visible */
      if (rtgui_dc_get_visible(dc) != RT_TRUE)
          return;
  
      hdc = (struct rtgui_image_hdcmm *) image;
      if (!hdc->pixels)
          return;
  
      xoff = 0;
      if (dst_rect->x1 < 0)
      {
          xoff = -dst_rect->x1;
          dst_rect->x1 = 0;
      }
      yoff = 0;
      if (dst_rect->y1 < 0)
      {
          yoff = -dst_rect->y1;
          dst_rect->y1 = 0;
      }
  
      if (xoff >= image->w || yoff >= image->h)
          return;
  
      /* the minimum rect */
      w = _UI_MIN(image->w - xoff, rtgui_rect_width(*dst_rect));
      h = _UI_MIN(image->h - yoff, rtgui_rect_height(*dst_rect));
  
      /* get pixel pointer */
      ptr = hdc->pixels + hdc->pitch * yoff + hdc->byte_per_pixel * xoff;
  
      for (y = 0; y < h; y++)
      {
          dc->engine->blit_line(dc, dst_rect->x1, dst_rect->x1 + w, dst_rect->y1 + y, ptr);
          ptr += hdc->pitch;
      }
  }
  
  void rtgui_image_hdc_init()
  {
      /* register hdc on image system */
      rtgui_image_register_engine(&rtgui_image_hdc_engine);
  }
  
  