[U-Boot] [PATCH 20/24] lcd: Support colour lookup table on 16bpp display in BMP images

[Joe Hershberger]

Hi Simon,

On Mon, May 4, 2015 at 12:31 PM, Simon Glass <sjg at chromium.org> wrote:
> For 16-bit-per-pixel displays it is useful to support 8 bit-per-pixel
> images to reduce image size. Add support for this when drawing BMP images.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  common/lcd.c         | 23 ++++++++++++++++++++---
>  include/bmp_layout.h |  4 ++--
>  2 files changed, 22 insertions(+), 5 deletions(-)
>
> diff --git a/common/lcd.c b/common/lcd.c
> index 055c366..2d11578 100644
> --- a/common/lcd.c
> +++ b/common/lcd.c
> @@ -578,6 +578,8 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>         unsigned long width, height, byte_width;
>         unsigned long pwidth = panel_info.vl_col;
>         unsigned colors, bpix, bmp_bpix;
> +       int hdr_size;
> +       bmp_color_table_entry_t *palette = bmp->color_table;
>
>         if (!bmp || !(bmp->header.signature[0] == 'B' &&
>                 bmp->header.signature[1] == 'M')) {
> @@ -589,6 +591,8 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>         width = get_unaligned_le32(&bmp->header.width);
>         height = get_unaligned_le32(&bmp->header.height);
>         bmp_bpix = get_unaligned_le16(&bmp->header.bit_count);
> +       hdr_size = get_unaligned_le16(&bmp->header.size);
> +       debug("hdr_size=%d, bmp_bpix=%d\n", hdr_size, bmp_bpix);
>
>         colors = 1 << bmp_bpix;
>
> @@ -613,8 +617,8 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>                 return 1;
>         }
>
> -       debug("Display-bmp: %d x %d  with %d colors\n",
> -               (int)width, (int)height, (int)colors);
> +       debug("Display-bmp: %d x %d  with %d colors, display %d\n",
> +             (int)width, (int)height, (int)colors, 1 << bpix);
>
>         if (bmp_bpix == 8)
>                 lcd_set_cmap(bmp, colors);
> @@ -641,6 +645,7 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>                 cmap_base = configuration_get_cmap();
>  #ifdef CONFIG_LCD_BMP_RLE8
>                 u32 compression = get_unaligned_le32(&bmp->header.compression);
> +               debug("compressed %d %d\n", compression, BMP_BI_RLE8);
>                 if (compression == BMP_BI_RLE8) {
>                         if (bpix != 16) {
>                                 /* TODO implement render code for bpix != 16 */
> @@ -663,7 +668,19 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
>                                 if (bpix != 16) {
>                                         fb_put_byte(&fb, &bmap);
>                                 } else {
> -                                       *(uint16_t *)fb = cmap_base[*(bmap++)];
> +                                       struct bmp_color_table_entry *entry;
> +                                       uint val;
> +
> +                                       if (cmap_base) {
> +                                               val = cmap_base[*bmap];
> +                                       } else {
> +                                               entry = &palette[*bmap];
> +                                               val = entry->blue >> 3 |
> +                                                       entry->green >> 2 << 5 |
> +                                                       entry->red >> 3 << 11;
> +                                       }
> +                                       *(uint16_t *)fb = val;
> +                                       bmap++;
>                                         fb += sizeof(uint16_t) / sizeof(*fb);
>                                 }
>                         }
> diff --git a/include/bmp_layout.h b/include/bmp_layout.h
> index 22b1fbc..47f505c 100644
> --- a/include/bmp_layout.h
> +++ b/include/bmp_layout.h
> @@ -11,12 +11,12 @@
>  #ifndef _BMP_H_
>  #define _BMP_H_
>
> -typedef struct bmp_color_table_entry {
> +typedef struct __packed bmp_color_table_entry {

It would be great to drop the typedef here.

>         __u8    blue;
>         __u8    green;
>         __u8    red;
>         __u8    reserved;
> -} __attribute__ ((packed)) bmp_color_table_entry_t;
> +} bmp_color_table_entry_t;
>
>  /* When accessing these fields, remember that they are stored in little
>     endian format, so use linux macros, e.g. le32_to_cpu(width)          */
> --

Cheers,
-Joe