diff options
Diffstat (limited to 'splash/SplashMath.h')
| -rw-r--r-- | splash/SplashMath.h | 93 |
1 files changed, 78 insertions, 15 deletions
diff --git a/splash/SplashMath.h b/splash/SplashMath.h index 3b82e7a..4b7ab1f 100644 --- a/splash/SplashMath.h +++ b/splash/SplashMath.h @@ -2,6 +2,8 @@ // // SplashMath.h // +// Copyright 2003-2013 Glyph & Cog, LLC +// //======================================================================== #ifndef SPLASHMATH_H @@ -35,19 +37,18 @@ static inline int splashFloor(SplashCoord x) { Gushort oldCW, newCW, t; int result; - __asm__ volatile("fldl %4\n" - "fnstcw %0\n" + __asm__ volatile("fnstcw %0\n" "movw %0, %3\n" "andw $0xf3ff, %3\n" "orw $0x0400, %3\n" "movw %3, %1\n" // round down "fldcw %1\n" - "fistpl %2\n" + "fistl %2\n" "fldcw %0\n" : "=m" (oldCW), "=m" (newCW), "=m" (result), "=r" (t) - : "m" (x)); + : "t" (x)); return result; -#elif defined(WIN32) && defined(_M_IX86) +#elif defined(_WIN32) && defined(_M_IX86) // floor() and (int)() are implemented separately, which results // in changing the FPCW multiple times - so we optimize it with // some inline assembly @@ -81,19 +82,18 @@ static inline int splashCeil(SplashCoord x) { Gushort oldCW, newCW, t; int result; - __asm__ volatile("fldl %4\n" - "fnstcw %0\n" + __asm__ volatile("fnstcw %0\n" "movw %0, %3\n" "andw $0xf3ff, %3\n" "orw $0x0800, %3\n" "movw %3, %1\n" // round up "fldcw %1\n" - "fistpl %2\n" + "fistl %2\n" "fldcw %0\n" : "=m" (oldCW), "=m" (newCW), "=m" (result), "=r" (t) - : "m" (x)); + : "t" (x)); return result; -#elif defined(WIN32) && defined(_M_IX86) +#elif defined(_WIN32) && defined(_M_IX86) // ceil() and (int)() are implemented separately, which results // in changing the FPCW multiple times - so we optimize it with // some inline assembly @@ -128,19 +128,18 @@ static inline int splashRound(SplashCoord x) { int result; x += 0.5; - __asm__ volatile("fldl %4\n" - "fnstcw %0\n" + __asm__ volatile("fnstcw %0\n" "movw %0, %3\n" "andw $0xf3ff, %3\n" "orw $0x0400, %3\n" "movw %3, %1\n" // round down "fldcw %1\n" - "fistpl %2\n" + "fistl %2\n" "fldcw %0\n" : "=m" (oldCW), "=m" (newCW), "=m" (result), "=r" (t) - : "m" (x)); + : "t" (x)); return result; -#elif defined(WIN32) && defined(_M_IX86) +#elif defined(_WIN32) && defined(_M_IX86) // this could use round-to-nearest mode and avoid the "+0.5", // but that produces slightly different results (because i+0.5 // sometimes rounds up and sometimes down using the even rule) @@ -223,4 +222,68 @@ static inline GBool splashCheckDet(SplashCoord m11, SplashCoord m12, #endif } +// Perform stroke adjustment on a SplashCoord range [xMin, xMax), +// resulting in an int range [*xMinI, *xMaxI). +// +// There are several options: +// +// 1. Round both edge coordinates. +// Pro: adjacent strokes/fills line up without any gaps or +// overlaps +// Con: lines with the same original floating point width can +// end up with different integer widths, e.g.: +// xMin = 10.1 xMax = 11.3 (width = 1.2) +// --> xMinI = 10 xMaxI = 11 (width = 1) +// but +// xMin = 10.4 xMax = 11.6 (width = 1.2) +// --> xMinI = 10 xMaxI = 12 (width = 2) +// +// 2. Round the min coordinate; add the ceiling of the width. +// Pro: lines with the same original floating point width will +// always end up with the same integer width +// Con: adjacent strokes/fills can have overlaps (which is +// problematic with transparency) +// (This could use floor on the min coordinate, instead of +// rounding, with similar results.) +// (If the width is rounded instead of using ceiling, the results +// Are similar, except that adjacent strokes/fills can have gaps +// as well as overlaps.) +// +// 3. Use floor on the min coordinate and ceiling on the max +// coordinate. +// Pro: lines always end up at least as wide as the original +// floating point width +// Con: adjacent strokes/fills can have overlaps, and lines with +// the same original floating point width can end up with +// different integer widths; the integer width can be more +// than one pixel wider than the original width, e.g.: +// xMin = 10.9 xMax = 12.1 (width = 1.2) +// --> xMinI = 10 xMaxI = 13 (width = 3) +// but +// xMin = 10.1 xMax = 11.3 (width = 1.2) +// --> xMinI = 10 xMaxI = 12 (width = 2) +static inline void splashStrokeAdjust(SplashCoord xMin, SplashCoord xMax, + int *xMinI, int *xMaxI) { + int x0, x1; + + // NB: enable exactly one of these. +#if 1 // 1. Round both edge coordinates. + x0 = splashRound(xMin); + x1 = splashRound(xMax); +#endif +#if 0 // 2. Round the min coordinate; add the ceiling of the width. + x0 = splashRound(xMin); + x1 = x0 + splashCeil(xMax - xMin); +#endif +#if 0 // 3. Use floor on the min coord and ceiling on the max coord. + x0 = splashFloor(xMin); + x1 = splashCeil(xMax); +#endif + if (x1 == x0) { + ++x1; + } + *xMinI = x0; + *xMaxI = x1; +} + #endif |