diff options
| -rw-r--r-- | src/kern-linux.c | 90 |
1 files changed, 68 insertions, 22 deletions
diff --git a/src/kern-linux.c b/src/kern-linux.c index 071d3fc..8bbe0fd 100644 --- a/src/kern-linux.c +++ b/src/kern-linux.c @@ -30,11 +30,31 @@ */ const int alt_fbpath_limit = 2; +/** + * Addition metadata for the framebuffer. + */ struct data { + /** + * The number dead pixels at the beginning. + */ unsigned long start; + + /** + * The byte where the frame end. Zero if + * there is neither panning or padding. + */ unsigned long end; + + /** + * The number of dead pixels between lines. + */ long hblank; + + /** + * This variable is used to keep track of + * how many pixels have been read. + */ unsigned long position; }; @@ -92,15 +112,17 @@ measure (int fbno, int fbfd, long *restrict width, long *restrict height, void * struct fb_var_screeninfo varinfo; unsigned long int linelength; + /* Get configurations. */ if (ioctl (fbfd, FBIOGET_FSCREENINFO, &fixinfo)) goto fail; - if (ioctl (fbfd, FBIOGET_VSCREENINFO, &varinfo)) goto fail; + /* Get dimension. */ *width = varinfo.xres; *height = varinfo.yres; + /* Are the configurations supported? */ if (varinfo.bits_per_pixel & 7) { fprintf(stderr, _("%s: Unsupported framebuffer configurations: " @@ -108,10 +130,13 @@ measure (int fbno, int fbfd, long *restrict width, long *restrict height, void * exit(1); } + /* Get dead area information. */ linelength = fixinfo.line_length / (varinfo.bits_per_pixel / 8); d.start = varinfo.yoffset * linelength; d.start += varinfo.xoffset; d.end = d.start + linelength * varinfo.yres; + if ((d.start == 0) && (linelength == 0)) + d.end = 0; d.hblank = linelength - *width; d.position = 0; @@ -144,6 +169,24 @@ int convert_fb_to_png (png_struct *pngbuf, png_byte *restrict pixbuf, const char *restrict buf, size_t n, long width3, size_t *restrict adjustment, long *restrict state, void *restrict data) { +#define STORE(PADDING_AND_PANNING) \ + do \ + { \ + if (PADDING_AND_PANNING) \ + if ((pos < d.start) || (pos >= d.end)) \ + continue; \ + \ + if (PADDING_AND_PANNING ? (x3 < width3) : 1) \ + SAVE_PNG_PIXEL (pixbuf, x3, r, g, b); \ + x3 += 3; \ + if (x3 == lineend) \ + { \ + SAVE_PNG_ROW (pngbuf, pixbuf); \ + x3 = 0; \ + } \ + } \ + while (0) + const uint32_t *restrict pixel; int r, g, b; size_t off; @@ -152,27 +195,30 @@ convert_fb_to_png (png_struct *pngbuf, png_byte *restrict pixbuf, const char *re unsigned long pos = d.position; long lineend = width3 + d.hblank * 3; - for (off = 0; off < n; off += 4, pos++) - { - /* A pixel in the framebuffer is formatted as `%{blue}%{green}%{red}%{x}` - in big-endian binary, or `%{x}%{red}%{green}%{blue}` in little-endian binary. */ - pixel = (const uint32_t *)(buf + off); - r = (*pixel >> 16) & 255; - g = (*pixel >> 8) & 255; - b = (*pixel >> 0) & 255; - - if ((pos < d.start) || (pos >= d.end)) - continue; - - if (x3 < width3) - SAVE_PNG_PIXEL (pixbuf, x3, r, g, b); - x3 += 3; - if (x3 == lineend) - { - SAVE_PNG_ROW (pngbuf, pixbuf); - x3 = 0; - } - } + if ((d.start == 0) && (d.hblank == 0) && (d.end == 0)) /* Optimised version for customary settings. */ + for (off = 0; off < n; off += 4) + { + /* A pixel in the framebuffer is formatted as `%{blue}%{green}%{red}%{x}` + in big-endian binary, or `%{x}%{red}%{green}%{blue}` in little-endian binary. */ + pixel = (const uint32_t *)(buf + off); + r = (*pixel >> 16) & 255; + g = (*pixel >> 8) & 255; + b = (*pixel >> 0) & 255; + + STORE(0); + } + else + for (off = 0; off < n; off += 4, pos++) + { + /* A pixel in the framebuffer is formatted as `%{blue}%{green}%{red}%{x}` + in big-endian binary, or `%{x}%{red}%{green}%{blue}` in little-endian binary. */ + pixel = (const uint32_t *)(buf + off); + r = (*pixel >> 16) & 255; + g = (*pixel >> 8) & 255; + b = (*pixel >> 0) & 255; + + STORE(1); + } *adjustment = (off != n ? 4 : 0); *state = x3; |