ThreadX GUIX加载JPEG图片，并将其绘制到内存设备方法

eric2013

代码：

1. /******************************************************************************************/
   
2. /* Decode main screen background jpeg.                                                    */
   
3. /* The background jpeg is saved in the resource data in "raw" format, meaning it is still */
   
4. /* a jpeg encoded graphic image. We need to decode and color space convert the raw jpeg   */
   
5. /* data to create a GUIX pixelmap before we can draw the image.                           */
   
6. /******************************************************************************************/
   
7. static VOID decode_main_screen_jpeg()
   
8. {
   
9.     GX_IMAGE_READER reader;
   
10.     GX_PIXELMAP *map;
    
11. 
    
12.     /* get a pointer to the raw jpeg data */
    
13.     gx_context_pixelmap_get(GX_PIXELMAP_ID_HOME_BG, &map);
    
14. 
    
15.     /* create an image reader object */
    
16.     gx_image_reader_create(&reader, map->gx_pixelmap_data, map->gx_pixelmap_data_size, GX_COLOR_FORMAT_24XRGB, 0);
    
17. 
    
18.     /* decode and color space convert the jpeg to produce a GUIX compatible pixelmap image */
    
19.     gx_image_reader_start(&reader, &main_screen_bg);
    
20. }
    
21. 
    
22. /******************************************************************************************/
    
23. /* Override the default draw function of "main_screen".                                   */
    
24. /******************************************************************************************/
    
25. VOID main_screen_draw(GX_WINDOW *window)
    
26. {
    
27.     gx_window_background_draw(window);
    
28. 
    
29.     /* If this is the first time drawing, then we need to decompress the raw jpeg
    
30.        image we use to paint the screen background
    
31.     */
    
32.     if (!main_screen_bg.gx_pixelmap_data)
    
33.     {
    
34.         decode_main_screen_jpeg();
    
35.     }
    
36. 
    
37.     /* unless something went wrong, the pixelmap data should now be populated in
    
38.        GUIX pixelmap format
    
39.     */
    
40.     if (main_screen_bg.gx_pixelmap_data)
    
41.     {
    
42.         /* Draw background map. */
    
43.         gx_canvas_pixelmap_draw(window->gx_widget_size.gx_rectangle_left,
    
44.             window->gx_widget_size.gx_rectangle_top, &main_screen_bg);
    
45.     }
    
46.     gx_widget_children_draw(window);
    
47. }
    

复制代码

hpdell

yklstudent

虽然暂时用不上，但是还是要mark下的