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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkBlurMask.h"
#include "SkBlurMaskFilter.h"
#include "SkBlurDrawLooper.h"
#include "SkBlurPriv.h"
#include "SkCanvas.h"
#include "SkColorFilter.h"
#include "SkColorPriv.h"
#include "SkEmbossMaskFilter.h"
#include "SkLayerDrawLooper.h"
#include "SkMaskFilterBase.h"
#include "SkMath.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkPerlinNoiseShader.h"
#include "SkSurface.h"
#include "Test.h"
#if SK_SUPPORT_GPU
#include "GrContextFactory.h"
#include "SkGpuDevice.h"
#endif
#define WRITE_CSV 0
///////////////////////////////////////////////////////////////////////////////
#define ILLEGAL_MODE ((SkXfermode::Mode)-1)
static const int outset = 100;
static const SkColor bgColor = SK_ColorWHITE;
static const int strokeWidth = 4;
static void create(SkBitmap* bm, const SkIRect& bound) {
bm->allocN32Pixels(bound.width(), bound.height());
}
static void drawBG(SkCanvas* canvas) {
canvas->drawColor(bgColor);
}
struct BlurTest {
void (*addPath)(SkPath*);
int viewLen;
SkIRect views[9];
};
//Path Draw Procs
//Beware that paths themselves my draw differently depending on the clip.
static void draw50x50Rect(SkPath* path) {
path->addRect(0, 0, SkIntToScalar(50), SkIntToScalar(50));
}
//Tests
static BlurTest tests[] = {
{ draw50x50Rect, 3, {
//inner half of blur
{ 0, 0, 50, 50 },
//blur, but no path.
{ 50 + strokeWidth/2, 50 + strokeWidth/2, 100, 100 },
//just an edge
{ 40, strokeWidth, 60, 50 - strokeWidth },
}},
};
/** Assumes that the ref draw was completely inside ref canvas --
implies that everything outside is "bgColor".
Checks that all overlap is the same and that all non-overlap on the
ref is "bgColor".
*/
static bool compare(const SkBitmap& ref, const SkIRect& iref,
const SkBitmap& test, const SkIRect& itest)
{
const int xOff = itest.fLeft - iref.fLeft;
const int yOff = itest.fTop - iref.fTop;
for (int y = 0; y < test.height(); ++y) {
for (int x = 0; x < test.width(); ++x) {
SkColor testColor = test.getColor(x, y);
int refX = x + xOff;
int refY = y + yOff;
SkColor refColor;
if (refX >= 0 && refX < ref.width() &&
refY >= 0 && refY < ref.height())
{
refColor = ref.getColor(refX, refY);
} else {
refColor = bgColor;
}
if (refColor != testColor) {
return false;
}
}
}
return true;
}
DEF_TEST(BlurDrawing, reporter) {
SkPaint paint;
paint.setColor(SK_ColorGRAY);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(SkIntToScalar(strokeWidth));
SkScalar sigma = SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(5));
for (int style = 0; style <= kLastEnum_SkBlurStyle; ++style) {
SkBlurStyle blurStyle = static_cast<SkBlurStyle>(style);
const uint32_t flagPermutations = SkBlurMaskFilter::kAll_BlurFlag;
for (uint32_t flags = 0; flags < flagPermutations; ++flags) {
paint.setMaskFilter(SkBlurMaskFilter::Make(blurStyle, sigma, flags));
for (size_t test = 0; test < SK_ARRAY_COUNT(tests); ++test) {
SkPath path;
tests[test].addPath(&path);
SkPath strokedPath;
paint.getFillPath(path, &strokedPath);
SkRect refBound = strokedPath.getBounds();
SkIRect iref;
refBound.roundOut(&iref);
iref.inset(-outset, -outset);
SkBitmap refBitmap;
create(&refBitmap, iref);
SkCanvas refCanvas(refBitmap);
refCanvas.translate(SkIntToScalar(-iref.fLeft),
SkIntToScalar(-iref.fTop));
drawBG(&refCanvas);
refCanvas.drawPath(path, paint);
for (int view = 0; view < tests[test].viewLen; ++view) {
SkIRect itest = tests[test].views[view];
SkBitmap testBitmap;
create(&testBitmap, itest);
SkCanvas testCanvas(testBitmap);
testCanvas.translate(SkIntToScalar(-itest.fLeft),
SkIntToScalar(-itest.fTop));
drawBG(&testCanvas);
testCanvas.drawPath(path, paint);
REPORTER_ASSERT(reporter,
compare(refBitmap, iref, testBitmap, itest));
}
}
}
}
}
///////////////////////////////////////////////////////////////////////////////
// Use SkBlurMask::BlurGroundTruth to blur a 'width' x 'height' solid
// white rect. Return the right half of the middle row in 'result'.
static void ground_truth_2d(int width, int height,
SkScalar sigma,
int* result, int resultCount) {
SkMask src, dst;
src.fBounds.set(0, 0, width, height);
src.fFormat = SkMask::kA8_Format;
src.fRowBytes = src.fBounds.width();
src.fImage = SkMask::AllocImage(src.computeTotalImageSize());
memset(src.fImage, 0xff, src.computeTotalImageSize());
if (!SkBlurMask::BlurGroundTruth(sigma, &dst, src, kNormal_SkBlurStyle)) {
return;
}
int midX = dst.fBounds.centerX();
int midY = dst.fBounds.centerY();
uint8_t* bytes = dst.getAddr8(midX, midY);
int i;
for (i = 0; i < dst.fBounds.width()-(midX-dst.fBounds.fLeft); ++i) {
if (i < resultCount) {
result[i] = bytes[i];
}
}
for ( ; i < resultCount; ++i) {
result[i] = 0;
}
SkMask::FreeImage(src.fImage);
SkMask::FreeImage(dst.fImage);
}
// Implement a step function that is 255 between min and max; 0 elsewhere.
static int step(int x, SkScalar min, SkScalar max) {
if (min < x && x < max) {
return 255;
}
return 0;
}
// Implement a Gaussian function with 0 mean and std.dev. of 'sigma'.
static float gaussian(int x, SkScalar sigma) {
float k = SK_Scalar1/(sigma * sqrtf(2.0f*SK_ScalarPI));
float exponent = -(x * x) / (2 * sigma * sigma);
return k * expf(exponent);
}
// Perform a brute force convolution of a step function with a Gaussian.
// Return the right half in 'result'
static void brute_force_1d(SkScalar stepMin, SkScalar stepMax,
SkScalar gaussianSigma,
int* result, int resultCount) {
int gaussianRange = SkScalarCeilToInt(10 * gaussianSigma);
for (int i = 0; i < resultCount; ++i) {
SkScalar sum = 0.0f;
for (int j = -gaussianRange; j < gaussianRange; ++j) {
sum += gaussian(j, gaussianSigma) * step(i-j, stepMin, stepMax);
}
result[i] = SkClampMax(SkClampPos(int(sum + 0.5f)), 255);
}
}
static void blur_path(SkCanvas* canvas, const SkPath& path,
SkScalar gaussianSigma) {
SkScalar midX = path.getBounds().centerX();
SkScalar midY = path.getBounds().centerY();
canvas->translate(-midX, -midY);
SkPaint blurPaint;
blurPaint.setColor(SK_ColorWHITE);
blurPaint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, gaussianSigma,
SkBlurMaskFilter::kHighQuality_BlurFlag));
canvas->drawColor(SK_ColorBLACK);
canvas->drawPath(path, blurPaint);
}
// Readback the blurred draw results from the canvas
static void readback(const SkBitmap& src, int* result, int resultCount) {
SkBitmap readback;
readback.allocN32Pixels(resultCount, 30);
SkPixmap pm;
readback.peekPixels(&pm);
src.readPixels(pm, 0, 0);
const SkPMColor* pixels = pm.addr32(0, 15);
for (int i = 0; i < resultCount; ++i) {
result[i] = SkColorGetR(pixels[i]);
}
}
// Draw a blurred version of the provided path.
// Return the right half of the middle row in 'result'.
static void cpu_blur_path(const SkPath& path, SkScalar gaussianSigma,
int* result, int resultCount) {
SkBitmap bitmap;
bitmap.allocN32Pixels(resultCount, 30);
SkCanvas canvas(bitmap);
blur_path(&canvas, path, gaussianSigma);
readback(bitmap, result, resultCount);
}
#if WRITE_CSV
static void write_as_csv(const char* label, SkScalar scale, int* data, int count) {
SkDebugf("%s_%.2f,", label, scale);
for (int i = 0; i < count-1; ++i) {
SkDebugf("%d,", data[i]);
}
SkDebugf("%d\n", data[count-1]);
}
#endif
static bool match(int* first, int* second, int count, int tol) {
int delta;
for (int i = 0; i < count; ++i) {
delta = first[i] - second[i];
if (delta > tol || delta < -tol) {
return false;
}
}
return true;
}
// Test out the normal blur style with a wide range of sigmas
DEF_TEST(BlurSigmaRange, reporter) {
static const int kSize = 100;
// The geometry is offset a smidge to trigger:
// https://code.google.com/p/chromium/issues/detail?id=282418
SkPath rectPath;
rectPath.addRect(0.3f, 0.3f, 100.3f, 100.3f);
SkPoint polyPts[] = {
{ 0.3f, 0.3f },
{ 100.3f, 0.3f },
{ 100.3f, 100.3f },
{ 0.3f, 100.3f },
{ 2.3f, 50.3f } // a little divet to throw off the rect special case
};
SkPath polyPath;
polyPath.addPoly(polyPts, SK_ARRAY_COUNT(polyPts), true);
int rectSpecialCaseResult[kSize];
int generalCaseResult[kSize];
int groundTruthResult[kSize];
int bruteForce1DResult[kSize];
SkScalar sigma = 10.0f;
for (int i = 0; i < 4; ++i, sigma /= 10) {
cpu_blur_path(rectPath, sigma, rectSpecialCaseResult, kSize);
cpu_blur_path(polyPath, sigma, generalCaseResult, kSize);
ground_truth_2d(100, 100, sigma, groundTruthResult, kSize);
brute_force_1d(-50.0f, 50.0f, sigma, bruteForce1DResult, kSize);
REPORTER_ASSERT(reporter, match(rectSpecialCaseResult, bruteForce1DResult, kSize, 5));
REPORTER_ASSERT(reporter, match(generalCaseResult, bruteForce1DResult, kSize, 15));
REPORTER_ASSERT(reporter, match(groundTruthResult, bruteForce1DResult, kSize, 1));
#if WRITE_CSV
write_as_csv("RectSpecialCase", sigma, rectSpecialCaseResult, kSize);
write_as_csv("GeneralCase", sigma, generalCaseResult, kSize);
#if SK_SUPPORT_GPU
write_as_csv("GPU", sigma, gpuResult, kSize);
#endif
write_as_csv("GroundTruth2D", sigma, groundTruthResult, kSize);
write_as_csv("BruteForce1D", sigma, bruteForce1DResult, kSize);
#endif
}
}
///////////////////////////////////////////////////////////////////////////////////////////
static SkBlurQuality blurMaskFilterFlags_as_quality(uint32_t blurMaskFilterFlags) {
return (blurMaskFilterFlags & SkBlurMaskFilter::kHighQuality_BlurFlag) ?
kHigh_SkBlurQuality : kLow_SkBlurQuality;
}
static void test_blurDrawLooper(skiatest::Reporter* reporter, SkScalar sigma,
SkBlurStyle style, uint32_t blurMaskFilterFlags) {
if (kNormal_SkBlurStyle != style) {
return; // blurdrawlooper only supports normal
}
const SkColor color = 0xFF335577;
const SkScalar dx = 10;
const SkScalar dy = -5;
sk_sp<SkDrawLooper> lp(SkBlurDrawLooper::Make(color, sigma, dx, dy));
const bool expectSuccess = sigma > 0;
if (nullptr == lp) {
REPORTER_ASSERT(reporter, sigma <= 0);
} else {
SkDrawLooper::BlurShadowRec rec;
bool success = lp->asABlurShadow(&rec);
REPORTER_ASSERT(reporter, success == expectSuccess);
if (success) {
REPORTER_ASSERT(reporter, rec.fSigma == sigma);
REPORTER_ASSERT(reporter, rec.fOffset.x() == dx);
REPORTER_ASSERT(reporter, rec.fOffset.y() == dy);
REPORTER_ASSERT(reporter, rec.fColor == color);
REPORTER_ASSERT(reporter, rec.fStyle == style);
REPORTER_ASSERT(reporter, rec.fQuality == kLow_SkBlurQuality);
}
}
}
static void test_looper(skiatest::Reporter* reporter, sk_sp<SkDrawLooper> lp, SkScalar sigma,
SkBlurStyle style, SkBlurQuality quality, bool expectSuccess) {
SkDrawLooper::BlurShadowRec rec;
bool success = lp->asABlurShadow(&rec);
REPORTER_ASSERT(reporter, success == expectSuccess);
if (success != expectSuccess) {
lp->asABlurShadow(&rec);
}
if (success) {
REPORTER_ASSERT(reporter, rec.fSigma == sigma);
REPORTER_ASSERT(reporter, rec.fStyle == style);
REPORTER_ASSERT(reporter, rec.fQuality == quality);
}
}
static void make_noop_layer(SkLayerDrawLooper::Builder* builder) {
SkLayerDrawLooper::LayerInfo info;
info.fPaintBits = 0;
info.fColorMode = SkBlendMode::kDst;
builder->addLayer(info);
}
static void make_blur_layer(SkLayerDrawLooper::Builder* builder, sk_sp<SkMaskFilter> mf) {
SkLayerDrawLooper::LayerInfo info;
info.fPaintBits = SkLayerDrawLooper::kMaskFilter_Bit;
info.fColorMode = SkBlendMode::kSrc;
SkPaint* paint = builder->addLayer(info);
paint->setMaskFilter(std::move(mf));
}
static void test_layerDrawLooper(skiatest::Reporter* reporter, sk_sp<SkMaskFilter> mf,
SkScalar sigma, SkBlurStyle style, SkBlurQuality quality,
bool expectSuccess) {
SkLayerDrawLooper::LayerInfo info;
SkLayerDrawLooper::Builder builder;
// 1 layer is too few
make_noop_layer(&builder);
test_looper(reporter, builder.detach(), sigma, style, quality, false);
// 2 layers is good, but need blur
make_noop_layer(&builder);
make_noop_layer(&builder);
test_looper(reporter, builder.detach(), sigma, style, quality, false);
// 2 layers is just right
make_noop_layer(&builder);
make_blur_layer(&builder, mf);
test_looper(reporter, builder.detach(), sigma, style, quality, expectSuccess);
// 3 layers is too many
make_noop_layer(&builder);
make_blur_layer(&builder, mf);
make_noop_layer(&builder);
test_looper(reporter, builder.detach(), sigma, style, quality, false);
}
DEF_TEST(BlurAsABlur, reporter) {
const SkBlurStyle styles[] = {
kNormal_SkBlurStyle, kSolid_SkBlurStyle, kOuter_SkBlurStyle, kInner_SkBlurStyle
};
const SkScalar sigmas[] = {
// values <= 0 should not success for a blur
-1, 0, 0.5f, 2
};
// Test asABlur for SkBlurMaskFilter
//
for (size_t i = 0; i < SK_ARRAY_COUNT(styles); ++i) {
const SkBlurStyle style = styles[i];
for (size_t j = 0; j < SK_ARRAY_COUNT(sigmas); ++j) {
const SkScalar sigma = sigmas[j];
for (int flags = 0; flags <= SkBlurMaskFilter::kAll_BlurFlag; ++flags) {
const SkBlurQuality quality = blurMaskFilterFlags_as_quality(flags);
sk_sp<SkMaskFilter> mf(SkBlurMaskFilter::Make(style, sigma, flags));
if (nullptr == mf.get()) {
REPORTER_ASSERT(reporter, sigma <= 0);
} else {
REPORTER_ASSERT(reporter, sigma > 0);
SkMaskFilterBase::BlurRec rec;
bool success = as_MFB(mf)->asABlur(&rec);
if (flags & SkBlurMaskFilter::kIgnoreTransform_BlurFlag) {
REPORTER_ASSERT(reporter, !success);
} else {
REPORTER_ASSERT(reporter, success);
REPORTER_ASSERT(reporter, rec.fSigma == sigma);
REPORTER_ASSERT(reporter, rec.fStyle == style);
REPORTER_ASSERT(reporter, rec.fQuality == quality);
}
test_layerDrawLooper(reporter, std::move(mf), sigma, style, quality, success);
}
test_blurDrawLooper(reporter, sigma, style, flags);
}
}
}
// Test asABlur for SkEmbossMaskFilter -- should never succeed
//
{
SkEmbossMaskFilter::Light light = {
{ 1, 1, 1 }, 0, 127, 127
};
for (size_t j = 0; j < SK_ARRAY_COUNT(sigmas); ++j) {
const SkScalar sigma = sigmas[j];
auto mf(SkEmbossMaskFilter::Make(sigma, light));
if (mf) {
SkMaskFilterBase::BlurRec rec;
bool success = as_MFB(mf)->asABlur(&rec);
REPORTER_ASSERT(reporter, !success);
}
}
}
}
#if SK_SUPPORT_GPU
// This exercises the problem discovered in crbug.com/570232. The return value from
// SkBlurMask::BoxBlur wasn't being checked in SkBlurMaskFilter.cpp::GrRRectBlurEffect::Create
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SmallBoxBlurBug, reporter, ctxInfo) {
SkImageInfo info = SkImageInfo::MakeN32Premul(128, 128);
auto surface(SkSurface::MakeRenderTarget(ctxInfo.grContext(), SkBudgeted::kNo, info));
SkCanvas* canvas = surface->getCanvas();
SkRect r = SkRect::MakeXYWH(10, 10, 100, 100);
SkRRect rr = SkRRect::MakeRectXY(r, 10, 10);
SkPaint p;
p.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, 0.01f));
canvas->drawRRect(rr, p);
}
#endif
DEF_TEST(BlurredRRectNinePatchComputation, reporter) {
const SkRect r = SkRect::MakeXYWH(10, 10, 100, 100);
static const SkScalar kBlurRad = 3.0f;
bool ninePatchable;
SkRRect rrectToDraw;
SkISize size;
SkScalar rectXs[kSkBlurRRectMaxDivisions],
rectYs[kSkBlurRRectMaxDivisions];
SkScalar texXs[kSkBlurRRectMaxDivisions],
texYs[kSkBlurRRectMaxDivisions];
int numX, numY;
uint32_t skipMask;
// not nine-patchable
{
SkVector radii[4] = { { 100, 100 }, { 0, 0 }, { 100, 100 }, { 0, 0 } };
SkRRect rr;
rr.setRectRadii(r, radii);
ninePatchable = SkComputeBlurredRRectParams(rr, rr, SkRect::MakeEmpty(),
kBlurRad, kBlurRad,
&rrectToDraw, &size,
rectXs, rectYs, texXs, texYs,
&numX, &numY, &skipMask);
REPORTER_ASSERT(reporter, !ninePatchable);
}
// simple circular
{
static const SkScalar kCornerRad = 10.0f;
SkRRect rr;
rr.setRectXY(r, kCornerRad, kCornerRad);
ninePatchable = SkComputeBlurredRRectParams(rr, rr, SkRect::MakeEmpty(),
kBlurRad, kBlurRad,
&rrectToDraw, &size,
rectXs, rectYs, texXs, texYs,
&numX, &numY, &skipMask);
static const SkScalar kAns = 12.0f * kBlurRad + 2.0f * kCornerRad + 1.0f;
REPORTER_ASSERT(reporter, ninePatchable);
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SkIntToScalar(size.fWidth), kAns));
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SkIntToScalar(size.fHeight), kAns));
REPORTER_ASSERT(reporter, 4 == numX && 4 == numY);
REPORTER_ASSERT(reporter, !skipMask);
}
// simple elliptical
{
static const SkScalar kXCornerRad = 2.0f;
static const SkScalar kYCornerRad = 10.0f;
SkRRect rr;
rr.setRectXY(r, kXCornerRad, kYCornerRad);
ninePatchable = SkComputeBlurredRRectParams(rr, rr, SkRect::MakeEmpty(),
kBlurRad, kBlurRad,
&rrectToDraw, &size,
rectXs, rectYs, texXs, texYs,
&numX, &numY, &skipMask);
static const SkScalar kXAns = 12.0f * kBlurRad + 2.0f * kXCornerRad + 1.0f;
static const SkScalar kYAns = 12.0f * kBlurRad + 2.0f * kYCornerRad + 1.0f;
REPORTER_ASSERT(reporter, ninePatchable);
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SkIntToScalar(size.fWidth), kXAns));
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SkIntToScalar(size.fHeight), kYAns));
REPORTER_ASSERT(reporter, 4 == numX && 4 == numY);
REPORTER_ASSERT(reporter, !skipMask);
}
// test-out occlusion
{
static const SkScalar kCornerRad = 10.0f;
SkRRect rr;
rr.setRectXY(r, kCornerRad, kCornerRad);
// The rectXs & rectYs should be { 1, 29, 91, 119 }. Add two more points around each.
SkScalar testLocs[] = {
-18.0f, -9.0f,
1.0f,
9.0f, 18.0f,
29.0f,
39.0f, 49.0f,
91.0f,
109.0f, 118.0f,
119.0f,
139.0f, 149.0f
};
for (int minY = 0; minY < (int)SK_ARRAY_COUNT(testLocs); ++minY) {
for (int maxY = minY+1; maxY < (int)SK_ARRAY_COUNT(testLocs); ++maxY) {
for (int minX = 0; minX < (int)SK_ARRAY_COUNT(testLocs); ++minX) {
for (int maxX = minX+1; maxX < (int)SK_ARRAY_COUNT(testLocs); ++maxX) {
SkRect occluder = SkRect::MakeLTRB(testLocs[minX], testLocs[minY],
testLocs[maxX], testLocs[maxY]);
if (occluder.isEmpty()) {
continue;
}
ninePatchable = SkComputeBlurredRRectParams(rr, rr, occluder,
kBlurRad, kBlurRad,
&rrectToDraw, &size,
rectXs, rectYs, texXs, texYs,
&numX, &numY, &skipMask);
static const SkScalar kAns = 12.0f * kBlurRad + 2.0f * kCornerRad + 1.0f;
REPORTER_ASSERT(reporter, ninePatchable);
REPORTER_ASSERT(reporter,
SkScalarNearlyEqual(SkIntToScalar(size.fWidth), kAns));
REPORTER_ASSERT(reporter,
SkScalarNearlyEqual(SkIntToScalar(size.fHeight), kAns));
int checkBit = 0x1;
for (int y = 0; y < numY-1; ++y) {
for (int x = 0; x < numX-1; ++x) {
SkRect cell = SkRect::MakeLTRB(rectXs[x], rectYs[y],
rectXs[x+1], rectYs[y+1]);
REPORTER_ASSERT(reporter,
SkToBool(skipMask & checkBit) ==
(cell.isEmpty() || occluder.contains(cell)));
REPORTER_ASSERT(reporter, texXs[x] >= 0 &&
texXs[x] <= size.fWidth);
REPORTER_ASSERT(reporter, texYs[y] >= 0 &&
texXs[y] <= size.fHeight);
checkBit <<= 1;
}
}
}
}
}
}
}
}
// https://crbugs.com/787712
DEF_TEST(EmbossPerlinCrash, reporter) {
SkPaint p;
static constexpr SkEmbossMaskFilter::Light light = {
{ 1, 1, 1 }, 0, 127, 127
};
p.setMaskFilter(SkEmbossMaskFilter::Make(1, light));
p.setShader(SkPerlinNoiseShader::MakeFractalNoise(1.0f, 1.0f, 2, 0.0f));
sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(100, 100);
surface->getCanvas()->drawPaint(p);
}
///////////////////////////////////////////////////////////////////////////////////////////
#include "SkSurface.h"
#include "sk_pixel_iter.h"
DEF_TEST(BlurZeroSigma, reporter) {
auto surf = SkSurface::MakeRasterN32Premul(20, 20);
SkPaint paint;
paint.setAntiAlias(true);
const SkIRect ir = { 5, 5, 15, 15 };
const SkRect r = SkRect::Make(ir);
const SkScalar sigmas[] = { 0, SkBits2Float(1) };
// if sigma is zero (or nearly so), we need to draw correctly (unblurred) and not crash
// or assert.
for (auto sigma : sigmas) {
paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, sigma));
surf->getCanvas()->drawRect(r, paint);
sk_tool_utils::PixelIter iter(surf.get());
SkIPoint loc;
while (const SkPMColor* p = (const SkPMColor*)iter.next(&loc)) {
if (ir.contains(loc.fX, loc.fY)) {
// inside the rect we draw (opaque black)
REPORTER_ASSERT(reporter, *p == SkPackARGB32(0xFF, 0, 0, 0));
} else {
// outside the rect we didn't draw at all, no blurred edges
REPORTER_ASSERT(reporter, *p == 0);
}
}
}
}