AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Make cross_prod used in SkPath::cheapComputeDirection fallback to double computation when result is 0. Verbal LGTM from reed.

Browse Source 
git-svn-id: http://skia.googlecode.com/svn/trunk@3216 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
bsalomon@google.com 2012-02-17 13:38:26 +00:00
parent c2c80c42e2
commit f0ed80a7eb
2 changed files with 47 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/core/SkPath.cpp
View File

@ -1909,8 +1909,26 @@ CONTOUR_END:
SkDEBUGCODE(++fContourCounter;)
}
// returns cross product of (p1 - p0) and (p2 - p0)
static SkScalar cross_prod(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2) {
return SkPoint::CrossProduct(p1 - p0, p2 - p0);
SkScalar cross = SkPoint::CrossProduct(p1 - p0, p2 - p0);
// We may get 0 when the above subtracts underflow. We expect this to be
// very rare and lazily promote to double.
if (0 == cross) {
double p0x = SkScalarToDouble(p0.fX);
double p0y = SkScalarToDouble(p0.fY);
double p1x = SkScalarToDouble(p1.fX);
double p1y = SkScalarToDouble(p1.fY);
double p2x = SkScalarToDouble(p2.fX);
double p2y = SkScalarToDouble(p2.fY);
cross = SkDoubleToScalar((p1x - p0x) * (p2y - p0y) -
(p1y - p0y) * (p2x - p0x));
}
return cross;
}
// Returns the first pt with the maximum Y coordinate

33
tests/PathTest.cpp
View File

@ -15,6 +15,21 @@
#include "SkSize.h"
#include "SkWriter32.h"
/**
* cheapIsDirection can take a shortcut when a path is marked convex.
* This function ensures that we always test cheapIsDirection when the path
* is flagged with unknown convexity status.
*/
static void check_direction(SkPath* path,
SkPath::Direction expectedDir,
skiatest::Reporter* reporter) {
if (SkPath::kConvex_Convexity == path->getConvexity()) {
REPORTER_ASSERT(reporter, path->cheapIsDirection(expectedDir));
path->setConvexity(SkPath::kUnknown_Convexity);
}
REPORTER_ASSERT(reporter, path->cheapIsDirection(expectedDir));
}
static void test_direction(skiatest::Reporter* reporter) {
size_t i;
SkPath path;
@ -46,7 +61,7 @@ static void test_direction(skiatest::Reporter* reporter) {
path.reset();
bool valid = SkParsePath::FromSVGString(gCW[i], &path);
REPORTER_ASSERT(reporter, valid);
REPORTER_ASSERT(reporter, path.cheapIsDirection(SkPath::kCW_Direction));
check_direction(&path, SkPath::kCW_Direction, reporter);
}
static const char* gCCW[] = {
@ -58,7 +73,7 @@ static void test_direction(skiatest::Reporter* reporter) {
path.reset();
bool valid = SkParsePath::FromSVGString(gCCW[i], &path);
REPORTER_ASSERT(reporter, valid);
REPORTER_ASSERT(reporter, path.cheapIsDirection(SkPath::kCCW_Direction));
check_direction(&path, SkPath::kCCW_Direction, reporter);
}
// Test two donuts, each wound a different direction. Only the outer contour
@ -66,12 +81,20 @@ static void test_direction(skiatest::Reporter* reporter) {
path.reset();
path.addCircle(0, 0, SkIntToScalar(2), SkPath::kCW_Direction);
path.addCircle(0, 0, SkIntToScalar(1), SkPath::kCCW_Direction);
REPORTER_ASSERT(reporter, path.cheapIsDirection(SkPath::kCW_Direction));
check_direction(&path, SkPath::kCW_Direction, reporter);
path.reset();
path.addCircle(0, 0, SkIntToScalar(1), SkPath::kCW_Direction);
path.addCircle(0, 0, SkIntToScalar(2), SkPath::kCCW_Direction);
REPORTER_ASSERT(reporter, path.cheapIsDirection(SkPath::kCCW_Direction));
check_direction(&path, SkPath::kCCW_Direction, reporter);
// triangle with one point really far from the origin.
path.reset();
// the first point is roughly 1.05e10, 1.05e10
path.moveTo(SkFloatToScalar(SkBits2Float(0x501c7652)), SkFloatToScalar(SkBits2Float(0x501c7652)));
path.lineTo(110 * SK_Scalar1, -10 * SK_Scalar1);
path.lineTo(-10 * SK_Scalar1, 60 * SK_Scalar1);
check_direction(&path, SkPath::kCCW_Direction, reporter);
}
static void add_rect(SkPath* path, const SkRect& r) {