diff options
| author |  reed@google.com <reed@google.com@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2011-06-09 15:54:38 +0000 |
|---|---|---|
| committer | reed@google.com <reed@google.com@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2011-06-09 15:54:38 +0000 |
| commit | 2f3567c0003b948ad90528e597ea1e8326f644ae (patch) | |
| tree | b76b6005c6f03fbf35dd44839ade046fb1bc3c69 /src/core/SkScan_AntiPath.cpp | |
| parent | 9dc527bebfaca7c87a39302510399bb0d0fe770d (diff) | |
check-point for unifying results between runs and mask backends for aa
git-svn-id: http://skia.googlecode.com/svn/trunk@1554 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'src/core/SkScan_AntiPath.cpp')
| -rw-r--r-- | src/core/SkScan_AntiPath.cpp | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/core/SkScan_AntiPath.cpp b/src/core/SkScan_AntiPath.cpp index 398f786c95..4dc2cd346c 100644 --- a/src/core/SkScan_AntiPath.cpp +++ b/src/core/SkScan_AntiPath.cpp @@ -26,8 +26,20 @@ #define SCALE (1 << SHIFT) #define MASK (SCALE - 1) +/* + We have two techniques for capturing the output of the supersampler: + - SUPERMASK, which records a large mask-bitmap + this is often faster for small, complex objects + - RLE, which records a rle-encoded scanline + this is often faster for large objects with big spans + + NEW_AA is a set of code-changes to try to make both paths produce identical + results. Its not quite there yet, though the remaining differences may be + in the subsequent blits, and not in the different masks/runs... + */ //#define FORCE_SUPERMASK //#define FORCE_RLE +//#define SK_SUPPORT_NEW_AA /////////////////////////////////////////////////////////////////////////////// @@ -281,9 +293,17 @@ static void add_aa_span(uint8_t* alpha, U8CPU startAlpha, int middleCount, edge of the current span round to the same super-sampled x value, I might overflow to 256 with this add, hence the funny subtract. */ +#ifdef SK_SUPPORT_NEW_AA + if (startAlpha) { + unsigned tmp = *alpha + startAlpha; + SkASSERT(tmp <= 256); + *alpha++ = SkToU8(tmp - (tmp >> 8)); + } +#else unsigned tmp = *alpha + startAlpha; SkASSERT(tmp <= 256); *alpha++ = SkToU8(tmp - (tmp >> 8)); +#endif if (middleCount >= MIN_COUNT_FOR_QUAD_LOOP) { // loop until we're quad-byte aligned @@ -365,7 +385,15 @@ void MaskSuperBlitter::blitH(int x, int y, int width) { SkASSERT(row < fMask.fImage + kMAX_STORAGE + 1); add_aa_span(row, coverage_to_alpha(fe - fb)); } else { +#ifdef SK_SUPPORT_NEW_AA + if (0 == fb) { + n += 1; + } else { + fb = (1 << SHIFT) - fb; + } +#else fb = (1 << SHIFT) - fb; +#endif SkASSERT(row >= fMask.fImage); SkASSERT(row + n + 1 < fMask.fImage + kMAX_STORAGE + 1); add_aa_span(row, coverage_to_alpha(fb), n, coverage_to_alpha(fe), |