Add methods to SkLayerDrawLooper to allow adding layers on top
as well as on the bottom.
This is more convenient for some callers who generate layers
from a data structure in bottom-to-top, rather than top-to-bottom,
order.
BUG=242529
R=tomhudson@chromium.org
Author: jbroman@chromium.org
Review URL: https://chromiumcodereview.appspot.com/15314003
git-svn-id: http://skia.googlecode.com/svn/trunk@9233 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/tests.gyp b/gyp/tests.gyp
index 8e82d1b..a15671d 100644
--- a/gyp/tests.gyp
+++ b/gyp/tests.gyp
@@ -68,6 +68,7 @@
'../tests/HashCacheTest.cpp',
'../tests/InfRectTest.cpp',
'../tests/LListTest.cpp',
+ '../tests/LayerDrawLooperTest.cpp',
'../tests/MD5Test.cpp',
'../tests/MathTest.cpp',
'../tests/MatrixTest.cpp',
diff --git a/include/effects/SkLayerDrawLooper.h b/include/effects/SkLayerDrawLooper.h
index bc1db1a..adf07a9 100644
--- a/include/effects/SkLayerDrawLooper.h
+++ b/include/effects/SkLayerDrawLooper.h
@@ -99,6 +99,9 @@
*/
void addLayer() { this->addLayer(0, 0); }
+ /// Similar to addLayer, but adds a layer to the top.
+ SkPaint* addLayerOnTop(const LayerInfo&);
+
// overrides from SkDrawLooper
virtual void init(SkCanvas*);
virtual bool next(SkCanvas*, SkPaint* paint);
@@ -115,10 +118,9 @@
Rec* fNext;
SkPaint fPaint;
LayerInfo fInfo;
-
- static Rec* Reverse(Rec*);
};
Rec* fRecs;
+ Rec* fTopRec;
int fCount;
// state-machine during the init/next cycle
diff --git a/src/effects/SkLayerDrawLooper.cpp b/src/effects/SkLayerDrawLooper.cpp
index 34aaad8..401bea4 100644
--- a/src/effects/SkLayerDrawLooper.cpp
+++ b/src/effects/SkLayerDrawLooper.cpp
@@ -25,6 +25,7 @@
SkLayerDrawLooper::SkLayerDrawLooper()
: fRecs(NULL),
+ fTopRec(NULL),
fCount(0),
fCurrRec(NULL) {
}
@@ -45,6 +46,9 @@
rec->fNext = fRecs;
rec->fInfo = info;
fRecs = rec;
+ if (NULL == fTopRec) {
+ fTopRec = rec;
+ }
return &rec->fPaint;
}
@@ -56,6 +60,23 @@
(void)this->addLayer(info);
}
+SkPaint* SkLayerDrawLooper::addLayerOnTop(const LayerInfo& info) {
+ fCount += 1;
+
+ Rec* rec = SkNEW(Rec);
+ rec->fNext = NULL;
+ rec->fInfo = info;
+ if (NULL == fRecs) {
+ fRecs = rec;
+ } else {
+ SkASSERT(NULL != fTopRec);
+ fTopRec->fNext = rec;
+ }
+ fTopRec = rec;
+
+ return &rec->fPaint;
+}
+
void SkLayerDrawLooper::init(SkCanvas* canvas) {
fCurrRec = fRecs;
canvas->save(SkCanvas::kMatrix_SaveFlag);
@@ -170,18 +191,6 @@
return true;
}
-SkLayerDrawLooper::Rec* SkLayerDrawLooper::Rec::Reverse(Rec* head) {
- Rec* rec = head;
- Rec* prev = NULL;
- while (rec) {
- Rec* next = rec->fNext;
- rec->fNext = prev;
- prev = rec;
- rec = next;
- }
- return prev;
-}
-
///////////////////////////////////////////////////////////////////////////////
void SkLayerDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) const {
@@ -216,6 +225,7 @@
SkLayerDrawLooper::SkLayerDrawLooper(SkFlattenableReadBuffer& buffer)
: INHERITED(buffer),
fRecs(NULL),
+ fTopRec(NULL),
fCount(0),
fCurrRec(NULL) {
int count = buffer.readInt();
@@ -227,13 +237,10 @@
info.fColorMode = (SkXfermode::Mode)buffer.readInt();
buffer.readPoint(&info.fOffset);
info.fPostTranslate = buffer.readBool();
- buffer.readPaint(this->addLayer(info));
+ buffer.readPaint(this->addLayerOnTop(info));
}
SkASSERT(count == fCount);
- // we're in reverse order, so fix it now
- fRecs = Rec::Reverse(fRecs);
-
#ifdef SK_DEBUG
{
Rec* rec = fRecs;
diff --git a/tests/LayerDrawLooperTest.cpp b/tests/LayerDrawLooperTest.cpp
new file mode 100644
index 0000000..7b85fc8
--- /dev/null
+++ b/tests/LayerDrawLooperTest.cpp
@@ -0,0 +1,154 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "Test.h"
+#include "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkDraw.h"
+#include "SkDevice.h"
+#include "SkLayerDrawLooper.h"
+#include "SkMatrix.h"
+#include "SkPaint.h"
+#include "SkRect.h"
+#include "SkRefCnt.h"
+#include "SkScalar.h"
+#include "SkXfermode.h"
+
+namespace {
+
+class FakeDevice : public SkDevice {
+public:
+ FakeDevice() : SkDevice(SkBitmap::kARGB_8888_Config, 100, 100) { }
+
+ virtual void drawRect(const SkDraw& draw, const SkRect& r, const SkPaint& paint) {
+ fLastMatrix = *draw.fMatrix;
+ SkDevice::drawRect(draw, r, paint);
+ }
+
+ SkMatrix fLastMatrix;
+};
+
+} // namespace
+
+static void test_frontToBack(skiatest::Reporter* reporter) {
+ SkAutoTUnref<SkLayerDrawLooper> looper(SkNEW(SkLayerDrawLooper));
+ SkLayerDrawLooper::LayerInfo layerInfo;
+
+ // Add the front layer, with the defaults.
+ (void)looper->addLayer(layerInfo);
+
+ // Add the back layer, with some layer info set.
+ layerInfo.fOffset.set(SkFloatToScalar(10.0f), SkFloatToScalar(20.0f));
+ layerInfo.fPaintBits |= SkLayerDrawLooper::kXfermode_Bit;
+ SkPaint* layerPaint = looper->addLayer(layerInfo);
+ layerPaint->setXfermodeMode(SkXfermode::kSrc_Mode);
+
+ FakeDevice device;
+ SkCanvas canvas(&device);
+ SkPaint paint;
+ looper->init(&canvas);
+
+ // The back layer should come first.
+ REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+ REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrc_Mode));
+ canvas.drawRect(SkRect::MakeWH(SkFloatToScalar(50.0f), SkFloatToScalar(50.0f)), paint);
+ REPORTER_ASSERT(reporter, SkFloatToScalar(10.0f) == device.fLastMatrix.getTranslateX());
+ REPORTER_ASSERT(reporter, SkFloatToScalar(20.0f) == device.fLastMatrix.getTranslateY());
+ paint.reset();
+
+ // Then the front layer.
+ REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+ REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode));
+ canvas.drawRect(SkRect::MakeWH(SkFloatToScalar(50.0f), SkFloatToScalar(50.0f)), paint);
+ REPORTER_ASSERT(reporter, SkFloatToScalar(0.0f) == device.fLastMatrix.getTranslateX());
+ REPORTER_ASSERT(reporter, SkFloatToScalar(0.0f) == device.fLastMatrix.getTranslateY());
+
+ // Only two layers were added, so that should be the end.
+ REPORTER_ASSERT(reporter, !looper->next(&canvas, &paint));
+}
+
+static void test_backToFront(skiatest::Reporter* reporter) {
+ SkAutoTUnref<SkLayerDrawLooper> looper(SkNEW(SkLayerDrawLooper));
+ SkLayerDrawLooper::LayerInfo layerInfo;
+
+ // Add the back layer, with the defaults.
+ (void)looper->addLayerOnTop(layerInfo);
+
+ // Add the front layer, with some layer info set.
+ layerInfo.fOffset.set(SkFloatToScalar(10.0f), SkFloatToScalar(20.0f));
+ layerInfo.fPaintBits |= SkLayerDrawLooper::kXfermode_Bit;
+ SkPaint* layerPaint = looper->addLayerOnTop(layerInfo);
+ layerPaint->setXfermodeMode(SkXfermode::kSrc_Mode);
+
+ FakeDevice device;
+ SkCanvas canvas(&device);
+ SkPaint paint;
+ looper->init(&canvas);
+
+ // The back layer should come first.
+ REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+ REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode));
+ canvas.drawRect(SkRect::MakeWH(SkFloatToScalar(50.0f), SkFloatToScalar(50.0f)), paint);
+ REPORTER_ASSERT(reporter, SkFloatToScalar(0.0f) == device.fLastMatrix.getTranslateX());
+ REPORTER_ASSERT(reporter, SkFloatToScalar(0.0f) == device.fLastMatrix.getTranslateY());
+ paint.reset();
+
+ // Then the front layer.
+ REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+ REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrc_Mode));
+ canvas.drawRect(SkRect::MakeWH(SkFloatToScalar(50.0f), SkFloatToScalar(50.0f)), paint);
+ REPORTER_ASSERT(reporter, SkFloatToScalar(10.0f) == device.fLastMatrix.getTranslateX());
+ REPORTER_ASSERT(reporter, SkFloatToScalar(20.0f) == device.fLastMatrix.getTranslateY());
+
+ // Only two layers were added, so that should be the end.
+ REPORTER_ASSERT(reporter, !looper->next(&canvas, &paint));
+}
+
+static void test_mixed(skiatest::Reporter* reporter) {
+ SkAutoTUnref<SkLayerDrawLooper> looper(SkNEW(SkLayerDrawLooper));
+ SkLayerDrawLooper::LayerInfo layerInfo;
+
+ // Add the back layer, with the defaults.
+ (void)looper->addLayer(layerInfo);
+
+ // Add the front layer, with some layer info set.
+ layerInfo.fOffset.set(SkFloatToScalar(10.0f), SkFloatToScalar(20.0f));
+ layerInfo.fPaintBits |= SkLayerDrawLooper::kXfermode_Bit;
+ SkPaint* layerPaint = looper->addLayerOnTop(layerInfo);
+ layerPaint->setXfermodeMode(SkXfermode::kSrc_Mode);
+
+ FakeDevice device;
+ SkCanvas canvas(&device);
+ SkPaint paint;
+ looper->init(&canvas);
+
+ // The back layer should come first.
+ REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+ REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode));
+ canvas.drawRect(SkRect::MakeWH(SkFloatToScalar(50.0f), SkFloatToScalar(50.0f)), paint);
+ REPORTER_ASSERT(reporter, SkFloatToScalar(0.0f) == device.fLastMatrix.getTranslateX());
+ REPORTER_ASSERT(reporter, SkFloatToScalar(0.0f) == device.fLastMatrix.getTranslateY());
+ paint.reset();
+
+ // Then the front layer.
+ REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+ REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrc_Mode));
+ canvas.drawRect(SkRect::MakeWH(SkFloatToScalar(50.0f), SkFloatToScalar(50.0f)), paint);
+ REPORTER_ASSERT(reporter, SkFloatToScalar(10.0f) == device.fLastMatrix.getTranslateX());
+ REPORTER_ASSERT(reporter, SkFloatToScalar(20.0f) == device.fLastMatrix.getTranslateY());
+
+ // Only two layers were added, so that should be the end.
+ REPORTER_ASSERT(reporter, !looper->next(&canvas, &paint));
+}
+
+static void TestLayerDrawLooper(skiatest::Reporter* reporter) {
+ test_frontToBack(reporter);
+ test_backToFront(reporter);
+ test_mixed(reporter);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("LayerDrawLooper", TestLayerDrawLooperClass, TestLayerDrawLooper)