diff options
Diffstat (limited to 'src/gdisp/gdisp.c')
| -rw-r--r-- | src/gdisp/gdisp.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/gdisp/gdisp.c b/src/gdisp/gdisp.c index 4c005079..b59b571d 100644 --- a/src/gdisp/gdisp.c +++ b/src/gdisp/gdisp.c @@ -990,6 +990,27 @@ void gdispDrawBox(coord_t x, coord_t y, coord_t cx, coord_t cy, color_t color) { } #endif +color_t gdispBlendColor(color_t fg, color_t bg, uint8_t alpha) +{ + uint16_t fg_ratio = alpha + 1; + uint16_t bg_ratio = 256 - alpha; + uint16_t r, g, b; + + r = RED_OF(fg) * fg_ratio; + g = GREEN_OF(fg) * fg_ratio; + b = BLUE_OF(fg) * fg_ratio; + + r += RED_OF(bg) * bg_ratio; + g += GREEN_OF(bg) * bg_ratio; + b += BLUE_OF(bg) * bg_ratio; + + r /= 256; + g /= 256; + b /= 256; + + return RGB2COLOR(r, g, b); +} + #if (!defined(gdispPackPixels) && !defined(GDISP_PIXELFORMAT_CUSTOM)) void gdispPackPixels(pixel_t *buf, coord_t cx, coord_t x, coord_t y, color_t color) { /* No mutex required as we only read static data */ |