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

[4fGradient] Relax interval checks

Browse Source 
We're currently considering intervals open at one extremity, in order to
ensure that a given value is always contained in a single interval.

This creates problems with synthetic clamp intervals [1, +inf), for
t == +inf (no interval can contain it).

Treat intervals as closed at both extremities instead.  This introduces
some ambiguitiy for overlapping values (contained in both adjacent
intervals), but solves the more serious problem above.

BUG=skia:6213

Change-Id: I33064f762fa9c2b914615e27977115d6654b12f4
Reviewed-on: https://skia-review.googlesource.com/8270
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
This commit is contained in:
Florin Malita 2017-02-09 13:46:55 -05:00 committed by Skia Commit-Bot
parent cf1bff945b
commit e659c7f36f
2 changed files with 64 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/effects/gradients/Sk4fLinearGradient.cpp
View File

@ -111,13 +111,13 @@ SkScalar pinFx<SkShader::kMirror_TileMode>(SkScalar fx) {
return f;
}
// true when x is in [k1,k2), or [k2, k1) when the interval is reversed.
// true when x is in [k1,k2], or [k2, k1] when the interval is reversed.
// TODO(fmalita): hoist the reversed interval check out of this helper.
bool in_range(SkScalar x, SkScalar k1, SkScalar k2) {
SkASSERT(k1 != k2);
return (k1 < k2)
? (x >= k1 && x < k2)
: (x >= k2 && x < k1);
? (x >= k1 && x <= k2)
: (x >= k2 && x <= k1);
}
} // anonymous namespace

63
tests/GradientTest.cpp
View File

@ -9,9 +9,11 @@
#include "SkColorPriv.h"
#include "SkColorShader.h"
#include "SkGradientShader.h"
#include "SkLinearGradient.h"
#include "SkShader.h"
#include "SkSurface.h"
#include "SkTemplates.h"
#include "SkTLazy.h"
#include "Test.h"
// https://code.google.com/p/chromium/issues/detail?id=448299
@ -350,7 +352,7 @@ static void test_clamping_overflow(skiatest::Reporter*) {
}
// http://crbug.com/636194
static void text_degenerate_linear(skiatest::Reporter*) {
static void test_degenerate_linear(skiatest::Reporter*) {
SkPaint p;
const SkColor colors[] = { SK_ColorRED, SK_ColorGREEN };
const SkPoint pts[] = {
@ -365,6 +367,62 @@ static void text_degenerate_linear(skiatest::Reporter*) {
// Passes if we don't trigger asserts.
}
// "Interesting" fuzzer values.
static void test_linear_fuzzer(skiatest::Reporter*) {
static const SkColor gColors0[] = { 0x30303030, 0x30303030 };
static const SkScalar gMatrix0[9] =
{ 6.40969056e-10f, 0, 6.40969056e-10f, 0, 4.42539023e-39f, 6.40969056e-10f, 0, 0, 1 };
static const struct {
SkPoint fPts[2];
const SkColor* fColors;
const SkScalar* fPos;
int fCount;
SkShader::TileMode fTileMode;
uint32_t fFlags;
const SkScalar* fLocalMatrix;
const SkScalar* fGlobalMatrix;
} gConfigs[] = {
{
{{0, -2.752941f}, {0, 0}},
gColors0,
nullptr,
SK_ARRAY_COUNT(gColors0),
SkShader::kClamp_TileMode,
0,
gMatrix0,
nullptr
},
};
static const uint32_t gForceFlags[] = { 0, SkLinearGradient::kForce4fContext_PrivateFlag };
sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(100, 100);
SkCanvas* canvas = surface->getCanvas();
SkPaint paint;
for (auto forceFlags : gForceFlags) {
for (const auto& config : gConfigs) {
SkAutoCanvasRestore acr(canvas, false);
SkTLazy<SkMatrix> localMatrix;
if (config.fLocalMatrix) {
localMatrix.init();
localMatrix.get()->set9(config.fLocalMatrix);
}
paint.setShader(SkGradientShader::MakeLinear(config.fPts,
config.fColors,
config.fPos,
config.fCount,
config.fTileMode,
config.fFlags | forceFlags,
localMatrix.getMaybeNull()));
canvas->drawPaint(paint);
}
}
}
DEF_TEST(Gradient, reporter) {
TestGradientShaders(reporter);
TestGradientOptimization(reporter);
@ -375,5 +433,6 @@ DEF_TEST(Gradient, reporter) {
test_linear_fuzz(reporter);
test_two_point_conical_zero_radius(reporter);
test_clamping_overflow(reporter);
text_degenerate_linear(reporter);
test_degenerate_linear(reporter);
test_linear_fuzzer(reporter);
}