skia2/tests/RectTest.cpp
Michael Ludwig 9e1e913c81 Add rect subtraction utility function+tests
This operation came when updating aggregate inner and outer bounds
for Ganesh' new clip stack (particularly when accounting for the effect
of a difference operation). This geometric operation is theoretically
more general purpose so I moved it out to SkRectPriv.

Change-Id: Ibd76f9b95efc1790ecda1038779c124155031d8f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/283756
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
2020-04-15 21:44:36 +00:00

260 lines
9.5 KiB
C++

/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/core/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkPath.h"
#include "include/core/SkRect.h"
#include "src/core/SkRectPriv.h"
#include "tests/Test.h"
static bool has_green_pixels(const SkBitmap& bm) {
for (int j = 0; j < bm.height(); ++j) {
for (int i = 0; i < bm.width(); ++i) {
if (SkColorGetG(bm.getColor(i, j))) {
return true;
}
}
}
return false;
}
static void test_stroke_width_clipping(skiatest::Reporter* reporter) {
SkBitmap bm;
bm.allocN32Pixels(100, 10);
bm.eraseColor(SK_ColorTRANSPARENT);
SkCanvas canvas(bm);
SkPaint paint;
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(10);
paint.setColor(0xff00ff00);
// clip out the left half of our canvas
canvas.clipRect(SkRect::MakeXYWH(51, 0, 49, 100));
// no stroke bleed should be visible
canvas.drawRect(SkRect::MakeWH(44, 100), paint);
REPORTER_ASSERT(reporter, !has_green_pixels(bm));
// right stroke edge should bleed into the visible area
canvas.scale(2, 2);
canvas.drawRect(SkRect::MakeWH(22, 50), paint);
REPORTER_ASSERT(reporter, has_green_pixels(bm));
}
static void test_skbug4406(skiatest::Reporter* reporter) {
SkBitmap bm;
bm.allocN32Pixels(10, 10);
bm.eraseColor(SK_ColorTRANSPARENT);
SkCanvas canvas(bm);
const SkRect r = { 1.5f, 1, 3.5f, 3 };
// draw filled green rect first
SkPaint paint;
paint.setStyle(SkPaint::kFill_Style);
paint.setColor(0xff00ff00);
paint.setStrokeWidth(1);
paint.setAntiAlias(true);
canvas.drawRect(r, paint);
// paint black with stroke rect (that asserts in bug 4406)
// over the filled rect, it should cover it
paint.setStyle(SkPaint::kStroke_Style);
paint.setColor(0xff000000);
paint.setStrokeWidth(1);
canvas.drawRect(r, paint);
REPORTER_ASSERT(reporter, !has_green_pixels(bm));
// do it again with thinner stroke
paint.setStyle(SkPaint::kFill_Style);
paint.setColor(0xff00ff00);
paint.setStrokeWidth(1);
paint.setAntiAlias(true);
canvas.drawRect(r, paint);
// paint black with stroke rect (that asserts in bug 4406)
// over the filled rect, it doesnt cover it completelly with thinner stroke
paint.setStyle(SkPaint::kStroke_Style);
paint.setColor(0xff000000);
paint.setStrokeWidth(0.99f);
canvas.drawRect(r, paint);
REPORTER_ASSERT(reporter, has_green_pixels(bm));
}
DEF_TEST(Rect, reporter) {
test_stroke_width_clipping(reporter);
test_skbug4406(reporter);
}
DEF_TEST(Rect_grow, reporter) {
test_stroke_width_clipping(reporter);
test_skbug4406(reporter);
}
DEF_TEST(Rect_path_nan, reporter) {
SkRect r = { 0, 0, SK_ScalarNaN, 100 };
SkPath p;
p.addRect(r);
// path normally just jams its bounds to be r, but it must notice that r is non-finite
REPORTER_ASSERT(reporter, !p.isFinite());
}
DEF_TEST(Rect_largest, reporter) {
REPORTER_ASSERT(reporter, !SkRectPriv::MakeILarge().isEmpty());
REPORTER_ASSERT(reporter, SkRectPriv::MakeILargestInverted().isEmpty());
REPORTER_ASSERT(reporter, !SkRectPriv::MakeLargest().isEmpty());
REPORTER_ASSERT(reporter, !SkRectPriv::MakeLargeS32().isEmpty());
REPORTER_ASSERT(reporter, SkRectPriv::MakeLargestInverted().isEmpty());
}
/*
* Test the setBounds always handles non-finite values correctly:
* - setBoundsCheck should return false, and set the rect to all zeros
* - setBoundsNoCheck should ensure that rect.isFinite() is false (definitely NOT all zeros)
*/
DEF_TEST(Rect_setbounds, reporter) {
const SkPoint p0[] = { { SK_ScalarInfinity, 0 }, { 1, 1 }, { 2, 2 }, { 3, 3 } };
const SkPoint p1[] = { { 0, SK_ScalarInfinity }, { 1, 1 }, { 2, 2 }, { 3, 3 } };
const SkPoint p2[] = { { SK_ScalarNaN, 0 }, { 1, 1 }, { 2, 2 }, { 3, 3 } };
const SkPoint p3[] = { { 0, SK_ScalarNaN }, { 1, 1 }, { 2, 2 }, { 3, 3 } };
SkRect r;
const SkRect zeror = { 0, 0, 0, 0 };
for (const SkPoint* pts : { p0, p1, p2, p3 }) {
for (int n = 1; n <= 4; ++n) {
bool isfinite = r.setBoundsCheck(pts, n);
REPORTER_ASSERT(reporter, !isfinite);
REPORTER_ASSERT(reporter, r == zeror);
r.setBoundsNoCheck(pts, n);
if (r.isFinite())
r.setBoundsNoCheck(pts, n);
REPORTER_ASSERT(reporter, !r.isFinite());
}
}
}
static float make_big_value(skiatest::Reporter* reporter) {
// need to make a big value, one that will cause rect.width() to overflow to inf.
// however, the windows compiler wants about this if it can see the big value inlined.
// hence, this stupid trick to try to fool their compiler.
SkASSERT(reporter);
return reporter ? SK_ScalarMax * 0.75f : 0;
}
DEF_TEST(Rect_center, reporter) {
// ensure we can compute center even when the width/height might overflow
const SkScalar big = make_big_value(reporter);
const SkRect r = { -big, -big, big, big };
REPORTER_ASSERT(reporter, r.isFinite());
REPORTER_ASSERT(reporter, SkScalarIsFinite(r.centerX()));
REPORTER_ASSERT(reporter, SkScalarIsFinite(r.centerY()));
REPORTER_ASSERT(reporter, !SkScalarIsFinite(r.width()));
REPORTER_ASSERT(reporter, !SkScalarIsFinite(r.height()));
}
DEF_TEST(Rect_subtract, reporter) {
struct Expectation {
SkIRect fA;
SkIRect fB;
SkIRect fExpected;
bool fExact;
};
SkIRect a = SkIRect::MakeLTRB(2, 3, 12, 15);
Expectation tests[] = {
// B contains A == empty rect
{a, a.makeOutset(2, 2), SkIRect::MakeEmpty(), true},
// A contains B, producing 4x12 (left), 2x12 (right), 4x10(top), and 5x10(bottom)
{a, {6, 6, 10, 10}, {2, 10, 12, 15}, false},
// A is empty, B is not == empty rect
{SkIRect::MakeEmpty(), a, SkIRect::MakeEmpty(), true},
// A is not empty, B is empty == a
{a, SkIRect::MakeEmpty(), a, true},
// A and B are empty == empty
{SkIRect::MakeEmpty(), SkIRect::MakeEmpty(), SkIRect::MakeEmpty(), true},
// A and B do not intersect == a
{a, {15, 17, 20, 40}, a, true},
// B cuts off left side of A, producing 6x12 (right)
{a, {0, 0, 6, 20}, {6, 3, 12, 15}, true},
// B cuts off right side of A, producing 4x12 (left)
{a, {6, 0, 20, 20}, {2, 3, 6, 15}, true},
// B cuts off top side of A, producing 10x9 (bottom)
{a, {0, 0, 20, 6}, {2, 6, 12, 15}, true},
// B cuts off bottom side of A, producing 10x7 (top)
{a, {0, 10, 20, 20}, {2, 3, 12, 10}, true},
// B splits A horizontally, producing 10x3 (top) or 10x5 (bottom)
{a, {0, 6, 20, 10}, {2, 10, 12, 15}, false},
// B splits A vertically, producing 4x12 (left) or 2x12 (right)
{a, {6, 0, 10, 20}, {2, 3, 6, 15}, false},
// B cuts top-left of A, producing 8x12 (right) or 10x11 (bottom)
{a, {0, 0, 4, 4}, {2, 4, 12, 15}, false},
// B cuts top-right of A, producing 8x12 (left) or 10x8 (bottom)
{a, {10, 0, 14, 7}, {2, 3, 10, 15}, false},
// B cuts bottom-left of A, producing 7x12 (right) or 10x9 (top)
{a, {0, 12, 5, 20}, {2, 3, 12, 12}, false},
// B cuts bottom-right of A, producing 8x12 (left) or 10x9 (top)
{a, {10, 12, 20, 20}, {2, 3, 10, 15}, false},
// B crosses the left of A, producing 4x12 (right) or 10x3 (top) or 10x5 (bottom)
{a, {0, 6, 8, 10}, {2, 10, 12, 15}, false},
// B crosses the right side of A, producing 6x12 (left) or 10x3 (top) or 10x5 (bottom)
{a, {8, 6, 20, 10}, {2, 3, 8, 15}, false},
// B crosses the top side of A, producing 4x12 (left) or 2x12 (right) or 10x8 (bottom)
{a, {6, 0, 10, 7}, {2, 7, 12, 15}, false},
// B crosses the bottom side of A, producing 1x12 (left) or 4x12 (right) or 10x3 (top)
{a, {4, 6, 8, 20}, {8, 3, 12, 15}, false}
};
for (const Expectation& e : tests) {
SkIRect difference;
bool exact = SkRectPriv::Subtract(e.fA, e.fB, &difference);
REPORTER_ASSERT(reporter, exact == e.fExact);
REPORTER_ASSERT(reporter, difference == e.fExpected);
// Generate equivalent tests for the SkRect case by moving the input rects by 0.5px
SkRect af = SkRect::Make(e.fA);
SkRect bf = SkRect::Make(e.fB);
SkRect ef = SkRect::Make(e.fExpected);
af.offset(0.5f, 0.5f);
bf.offset(0.5f, 0.5f);
ef.offset(0.5f, 0.5f);
SkRect df;
exact = SkRectPriv::Subtract(af, bf, &df);
REPORTER_ASSERT(reporter, exact == e.fExact);
REPORTER_ASSERT(reporter, (df.isEmpty() && ef.isEmpty()) || (df == ef));
}
}
#include "include/core/SkSurface.h"
// Before the fix, this sequence would trigger a release_assert in the Tiler
// in SkBitmapDevice.cpp
DEF_TEST(big_tiled_rect_crbug_927075, reporter) {
// since part of the regression test allocates a huge buffer, don't bother trying on
// 32-bit devices (e.g. chromecast) so we avoid them failing to allocated.
if (sizeof(void*) == 8) {
const int w = 67108863;
const int h = 1;
const auto info = SkImageInfo::MakeN32Premul(w, h);
auto surf = SkSurface::MakeRaster(info);
auto canvas = surf->getCanvas();
const SkRect r = { 257, 213, 67109120, 214 };
SkPaint paint;
paint.setAntiAlias(true);
canvas->translate(-r.fLeft, -r.fTop);
canvas->drawRect(r, paint);
}
}