diff options
Diffstat (limited to 'src/display')
| -rw-r--r-- | src/display/nr-arena-item.cpp | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/src/display/nr-arena-item.cpp b/src/display/nr-arena-item.cpp index 9b3a6214c..5598efa32 100644 --- a/src/display/nr-arena-item.cpp +++ b/src/display/nr-arena-item.cpp @@ -514,11 +514,12 @@ nr_arena_item_invoke_render (cairo_t *ct, NRArenaItem *item, NRRectL const *area d = NR_PIXBLOCK_PX (&mpb) + (y - carea.y0) * mpb.rs; for (x = carea.x0; x < carea.x1; x++) { + // See below for calculation unsigned int m; - m = NR_PREMUL_112 (s[0] + s[1] + s[2], s[3]); - d[0] = - FAST_DIV_ROUND < 3 * 255 * 255 > - (NR_PREMUL_123 (d[0], m)); + m = NR_PREMUL_112 ( (NR_PREMUL_112 (s[0], 54) + + NR_PREMUL_112 (s[1], 183) + + NR_PREMUL_112 (s[2], 19) ) >> 8, s[3]); + d[0] = FAST_DIV_ROUND < 255 * 255 > ( NR_PREMUL_123 (d[0], m)); s += 4; d += 1; } @@ -533,8 +534,17 @@ nr_arena_item_invoke_render (cairo_t *ct, NRArenaItem *item, NRRectL const *area carea.y0) * mpb.rs; for (x = carea.x0; x < carea.x1; x++) { unsigned int m; - m = NR_PREMUL_112 (s[0] + s[1] + s[2], s[3]); - d[0] = FAST_DIV_ROUND < 3 * 255 > (m); + // m = NR_PREMUL_112 (s[0] + s[1] + s[2], s[3]); + // d[0] = FAST_DIV_ROUND < 3 * 255 > (m); + // Must use luminance to alpha from feColorMatrix. + // This is an approximation, optimized(?) for speed. + // 0.2125 * 256 = 54.4000 + // 0.7154 * 256 = 183.1424 + // 0.0721 * 256 = 18.4576 + m = NR_PREMUL_112 ( (NR_PREMUL_112 (s[0], 54) + + NR_PREMUL_112 (s[1], 183) + + NR_PREMUL_112 (s[2], 19) ) >> 8, s[3]); + d[0] = FAST_DIV_ROUND < 255 > (m); s += 4; d += 1; } |