Implement srcRect and dstRect functionality in SkBitmapSource. This is required for the "preserveAspectRatio" options of SVG's feImage. Covered by new GM "bitmapsource".

This also includes some changes to the xfermodeimagefilter and tileimagefilter GMs to properly handle the CTM. This worked before only because SkBitmapSource was ignoring the CTM. Now that it respects it, we need to give the correct transform. This also means the GMs now work while zoomed. It also implements CTM support for SkTileImageFilter.

NOTE: this will require rebaselining a number of imagefilter GMs on Nexus4, since they render in perspective (using the CTM). The changes to the results should all be improvements.

R=reed@google.com, robertphillips@google.com

Review URL: https://codereview.chromium.org/106933002

git-svn-id: http://skia.googlecode.com/svn/trunk@12571 2bbb7eff-a529-9590-31e7-b0007b416f81

7 files changed, 198 insertions, 56 deletions

diff --git a/gm/bitmapsource.cpp b/gm/bitmapsource.cpp
new file mode 100644
index 0000000000..d6e98a5bbd
--- /dev/null
+++ b/gm/bitmapsource.cpp
@@ -0,0 +1,91 @@
+/*
+ * 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 "gm.h"
+
+#include "SkBitmapSource.h"
+
+// This GM exercises the SkBitmapSource ImageFilter class.
+
+class BitmapSourceGM : public skiagm::GM {
+public:
+    BitmapSourceGM() {
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("bitmapsource");
+    }
+
+    void makeBitmap() {
+        fBitmap.setConfig(SkBitmap::kARGB_8888_Config, 100, 100);
+        fBitmap.allocPixels();
+        SkBitmapDevice device(fBitmap);
+        SkCanvas canvas(&device);
+        canvas.clear(0x00000000);
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setColor(0xFFFFFFFF);
+        paint.setTextSize(SkIntToScalar(96));
+        const char* str = "e";
+        canvas.drawText(str, strlen(str), SkIntToScalar(20), SkIntToScalar(70), paint);
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE { return SkISize::Make(500, 150); }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        this->makeBitmap();
+    }
+
+    static void fillRectFiltered(SkCanvas* canvas, const SkRect& clipRect, SkImageFilter* filter) {
+        SkPaint paint;
+        paint.setImageFilter(filter);
+        canvas->save();
+        canvas->clipRect(clipRect);
+        canvas->drawPaint(paint);
+        canvas->restore();
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        canvas->clear(0x00000000);
+        {
+            SkRect srcRect = SkRect::MakeXYWH(20, 20, 30, 30);
+            SkRect dstRect = SkRect::MakeXYWH(0, 10, 60, 60);
+            SkRect clipRect = SkRect::MakeXYWH(0, 0, 100, 100);
+            SkRect bounds;
+            fBitmap.getBounds(&bounds);
+            SkAutoTUnref<SkImageFilter> bitmapSource(new SkBitmapSource(fBitmap));
+            SkAutoTUnref<SkImageFilter> bitmapSourceSrcRect(new SkBitmapSource(fBitmap, srcRect, srcRect));
+            SkAutoTUnref<SkImageFilter> bitmapSourceSrcRectDstRect(new SkBitmapSource(fBitmap, srcRect, dstRect));
+            SkAutoTUnref<SkImageFilter> bitmapSourceDstRectOnly(new SkBitmapSource(fBitmap, bounds, dstRect));
+
+            // Draw an unscaled bitmap.
+            fillRectFiltered(canvas, clipRect, bitmapSource);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw an unscaled subset of the source bitmap (srcRect -> srcRect).
+            fillRectFiltered(canvas, clipRect, bitmapSourceSrcRect);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw a subset of the bitmap scaled to a destination rect (srcRect -> dstRect).
+            fillRectFiltered(canvas, clipRect, bitmapSourceSrcRectDstRect);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw the entire bitmap scaled to a destination rect (bounds -> dstRect).
+            fillRectFiltered(canvas, clipRect, bitmapSourceDstRectOnly);
+            canvas->translate(SkIntToScalar(100), 0);
+        }
+    }
+
+private:
+    SkBitmap fBitmap;
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return new BitmapSourceGM; )
diff --git a/gm/tileimagefilter.cpp b/gm/tileimagefilter.cpp
index 9a14344772..48d65ca073 100644
--- a/gm/tileimagefilter.cpp
+++ b/gm/tileimagefilter.cpp
@@ -70,9 +70,10 @@ protected:
     void drawClippedBitmap(SkCanvas* canvas, const SkBitmap& bitmap, const SkPaint& paint,
                            SkScalar x, SkScalar y) {
         canvas->save();
-        canvas->clipRect(SkRect::MakeXYWH(x, y,
+        canvas->translate(x, y);
+        canvas->clipRect(SkRect::MakeXYWH(0, 0,
             SkIntToScalar(bitmap.width()), SkIntToScalar(bitmap.height())));
-        canvas->drawBitmap(bitmap, x, y, &paint);
+        canvas->drawBitmap(bitmap, 0, 0, &paint);
         canvas->restore();
     }
 
diff --git a/gm/xfermodeimagefilter.cpp b/gm/xfermodeimagefilter.cpp
index 01bfe0ad61..936af46ec6 100644
--- a/gm/xfermodeimagefilter.cpp
+++ b/gm/xfermodeimagefilter.cpp
@@ -19,12 +19,12 @@ namespace skiagm {
 
 class XfermodeImageFilterGM : public GM {
 public:
-    XfermodeImageFilterGM() : fInitialized(false) {
+    XfermodeImageFilterGM(){
         this->setBGColor(0xFF000000);
     }
 
 protected:
-    virtual SkString onShortName() {
+    virtual SkString onShortName() SK_OVERRIDE {
         return SkString("xfermodeimagefilter");
     }
 
@@ -65,25 +65,35 @@ protected:
         }
     }
 
-    virtual SkISize onISize() {
+    virtual SkISize onISize() SK_OVERRIDE {
         return make_isize(WIDTH, HEIGHT);
     }
 
-    void drawClippedBitmap(SkCanvas* canvas, const SkBitmap& bitmap, const SkPaint& paint,
-                           SkScalar x, SkScalar y) {
+    static void drawClippedBitmap(SkCanvas* canvas, const SkBitmap& bitmap, const SkPaint& paint,
+                           int x, int y) {
         canvas->save();
-        canvas->clipRect(SkRect::MakeXYWH(x, y,
+        canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
+        canvas->clipRect(SkRect::MakeWH(
             SkIntToScalar(bitmap.width()), SkIntToScalar(bitmap.height())));
-        canvas->drawBitmap(bitmap, x, y, &paint);
+        canvas->drawBitmap(bitmap, 0, 0, &paint);
         canvas->restore();
     }
 
-    virtual void onDraw(SkCanvas* canvas) {
-        if (!fInitialized) {
-            make_bitmap();
-            make_checkerboard();
-            fInitialized = true;
-        }
+    static void drawClippedPaint(SkCanvas* canvas, const SkRect& rect, const SkPaint& paint,
+                          int x, int y) {
+        canvas->save();
+        canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
+        canvas->clipRect(rect);
+        canvas->drawPaint(paint);
+        canvas->restore();
+    }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        make_bitmap();
+        make_checkerboard();
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         canvas->clear(0x00000000);
         SkPaint paint;
 
@@ -130,7 +140,7 @@ protected:
             SkAutoTUnref<SkImageFilter> filter(SkNEW_ARGS(
                 SkXfermodeImageFilter, (mode, background)));
             paint.setImageFilter(filter);
-            drawClippedBitmap(canvas, fBitmap, paint, SkIntToScalar(x), SkIntToScalar(y));
+            drawClippedBitmap(canvas, fBitmap, paint, x, y);
             x += fBitmap.width() + MARGIN;
             if (x + fBitmap.width() > WIDTH) {
                 x = 0;
@@ -141,7 +151,7 @@ protected:
         SkAutoTUnref<SkXfermode> mode(SkArithmeticMode::Create(0, SK_Scalar1, SK_Scalar1, 0));
         SkAutoTUnref<SkImageFilter> filter(SkNEW_ARGS(SkXfermodeImageFilter, (mode, background)));
         paint.setImageFilter(filter);
-        drawClippedBitmap(canvas, fBitmap, paint, SkIntToScalar(x), SkIntToScalar(y));
+        drawClippedBitmap(canvas, fBitmap, paint, x, y);
         x += fBitmap.width() + MARGIN;
         if (x + fBitmap.width() > WIDTH) {
             x = 0;
@@ -150,12 +160,14 @@ protected:
         // Test NULL mode
         filter.reset(SkNEW_ARGS(SkXfermodeImageFilter, (NULL, background)));
         paint.setImageFilter(filter);
-        drawClippedBitmap(canvas, fBitmap, paint, SkIntToScalar(x), SkIntToScalar(y));
+        drawClippedBitmap(canvas, fBitmap, paint, x, y);
         x += fBitmap.width() + MARGIN;
         if (x + fBitmap.width() > WIDTH) {
             x = 0;
             y += fBitmap.height() + MARGIN;
         }
+        SkRect clipRect = SkRect::MakeWH(SkIntToScalar(fBitmap.width() + 4),
+                                         SkIntToScalar(fBitmap.height() + 4));
         // Test offsets on SrcMode (uses fixed-function blend)
         SkAutoTUnref<SkImageFilter> foreground(SkNEW_ARGS(SkBitmapSource, (fBitmap)));
         SkAutoTUnref<SkImageFilter> offsetForeground(SkNEW_ARGS(SkOffsetImageFilter,
@@ -166,13 +178,7 @@ protected:
         filter.reset(SkNEW_ARGS(SkXfermodeImageFilter,
             (mode, offsetBackground, offsetForeground)));
         paint.setImageFilter(filter);
-        canvas->save();
-        canvas->clipRect(SkRect::MakeXYWH(SkIntToScalar(x),
-                                          SkIntToScalar(y),
-                                          SkIntToScalar(fBitmap.width() + 4),
-                                          SkIntToScalar(fBitmap.height() + 4)));
-        canvas->drawPaint(paint);
-        canvas->restore();
+        drawClippedPaint(canvas, clipRect, paint, x, y);
         x += fBitmap.width() + MARGIN;
         if (x + fBitmap.width() > WIDTH) {
             x = 0;
@@ -182,13 +188,7 @@ protected:
         mode.reset(SkXfermode::Create(SkXfermode::kDarken_Mode));
         filter.reset(SkNEW_ARGS(SkXfermodeImageFilter, (mode, offsetBackground, offsetForeground)));
         paint.setImageFilter(filter);
-        canvas->save();
-        canvas->clipRect(SkRect::MakeXYWH(SkIntToScalar(x),
-                                          SkIntToScalar(y),
-                                          SkIntToScalar(fBitmap.width() + 4),
-                                          SkIntToScalar(fBitmap.height() + 4)));
-        canvas->drawPaint(paint);
-        canvas->restore();
+        drawClippedPaint(canvas, clipRect, paint, x, y);
         x += fBitmap.width() + MARGIN;
         if (x + fBitmap.width() > WIDTH) {
             x = 0;
@@ -203,8 +203,8 @@ protected:
                                      { 10,  10,  10,  10},
                                      {-10, -10,  -6,  -6}};
         for (size_t i = 0; i < nbSamples; ++i) {
-            SkIRect cropRect = SkIRect::MakeXYWH(x + offsets[i][0],
-                                                 y + offsets[i][1],
+            SkIRect cropRect = SkIRect::MakeXYWH(offsets[i][0],
+                                                 offsets[i][1],
                                                  fBitmap.width()  + offsets[i][2],
                                                  fBitmap.height() + offsets[i][3]);
             SkImageFilter::CropRect rect(SkRect::Make(cropRect));
@@ -212,13 +212,7 @@ protected:
             filter.reset(SkNEW_ARGS(SkXfermodeImageFilter,
                                     (mode, offsetBackground, offsetForeground, &rect)));
             paint.setImageFilter(filter);
-            canvas->save();
-            canvas->clipRect(SkRect::MakeXYWH(SkIntToScalar(x),
-                                              SkIntToScalar(y),
-                                              SkIntToScalar(fBitmap.width() + 4),
-                                              SkIntToScalar(fBitmap.height() + 4)));
-            canvas->drawPaint(paint);
-            canvas->restore();
+            drawClippedPaint(canvas, clipRect, paint, x, y);
             x += fBitmap.width() + MARGIN;
             if (x + fBitmap.width() > WIDTH) {
                 x = 0;
@@ -227,14 +221,12 @@ protected:
         }
     }
 private:
-    typedef GM INHERITED;
     SkBitmap fBitmap, fCheckerboard;
-    bool fInitialized;
+    typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
-static GM* MyFactory(void*) { return new XfermodeImageFilterGM; }
-static GMRegistry reg(MyFactory);
+DEF_GM( return new XfermodeImageFilterGM; );
 
 }
diff --git a/gyp/gmslides.gypi b/gyp/gmslides.gypi
index 149d037b59..e29a702cfb 100644
--- a/gyp/gmslides.gypi
+++ b/gyp/gmslides.gypi
@@ -21,6 +21,7 @@
     '../gm/bitmaprecttest.cpp',
     '../gm/bitmapscroll.cpp',
     '../gm/bitmapshader.cpp',
+    '../gm/bitmapsource.cpp',
     '../gm/bleed.cpp',
     '../gm/blurs.cpp',
     '../gm/blurquickreject.cpp',
diff --git a/include/effects/SkBitmapSource.h b/include/effects/SkBitmapSource.h
index 138987e701..699186e9f1 100644
--- a/include/effects/SkBitmapSource.h
+++ b/include/effects/SkBitmapSource.h
@@ -14,6 +14,7 @@
 class SK_API SkBitmapSource : public SkImageFilter {
 public:
     explicit SkBitmapSource(const SkBitmap& bitmap);
+    SkBitmapSource(const SkBitmap& bitmap, const SkRect& srcRect, const SkRect& dstRect);
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBitmapSource)
 
@@ -25,6 +26,7 @@ protected:
 
 private:
     SkBitmap fBitmap;
+    SkRect   fSrcRect, fDstRect;
     typedef SkImageFilter INHERITED;
 };
 
diff --git a/src/effects/SkBitmapSource.cpp b/src/effects/SkBitmapSource.cpp
index 72f51f8423..ef5ea86925 100644
--- a/src/effects/SkBitmapSource.cpp
+++ b/src/effects/SkBitmapSource.cpp
@@ -6,24 +6,74 @@
  */
 
 #include "SkBitmapSource.h"
+#include "SkDevice.h"
+#include "SkCanvas.h"
+#include "SkFlattenableBuffers.h"
+#include "SkValidationUtils.h"
 
 SkBitmapSource::SkBitmapSource(const SkBitmap& bitmap)
   : INHERITED(0, 0),
-    fBitmap(bitmap) {
+    fBitmap(bitmap),
+    fSrcRect(SkRect::MakeWH(SkIntToScalar(bitmap.width()),
+                            SkIntToScalar(bitmap.height()))),
+    fDstRect(fSrcRect) {
+}
+
+SkBitmapSource::SkBitmapSource(const SkBitmap& bitmap, const SkRect& srcRect, const SkRect& dstRect)
+  : INHERITED(0, 0),
+    fBitmap(bitmap),
+    fSrcRect(srcRect),
+    fDstRect(dstRect) {
 }
 
 SkBitmapSource::SkBitmapSource(SkFlattenableReadBuffer& buffer)
   : INHERITED(0, buffer) {
     fBitmap.unflatten(buffer);
+    buffer.readRect(&fSrcRect);
+    buffer.readRect(&fDstRect);
+    buffer.validate(SkIsValidRect(fSrcRect) && SkIsValidRect(fDstRect));
 }
 
 void SkBitmapSource::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     fBitmap.flatten(buffer);
+    buffer.writeRect(fSrcRect);
+    buffer.writeRect(fDstRect);
 }
 
-bool SkBitmapSource::onFilterImage(Proxy*, const SkBitmap&, const SkMatrix&,
+bool SkBitmapSource::onFilterImage(Proxy* proxy, const SkBitmap&, const SkMatrix& matrix,
                                    SkBitmap* result, SkIPoint* offset) {
-    *result = fBitmap;
+    SkRect bounds, dstRect;
+    fBitmap.getBounds(&bounds);
+    matrix.mapRect(&dstRect, fDstRect);
+    if (fSrcRect == bounds && dstRect == bounds) {
+        // No regions cropped out or resized; return entire bitmap.
+        *result = fBitmap;
+        return true;
+    }
+    SkIRect dstIRect;
+    dstRect.roundOut(&dstIRect);
+
+    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(dstIRect.width(), dstIRect.height()));
+    if (NULL == device.get()) {
+        return false;
+    }
+
+    SkCanvas canvas(device.get());
+    SkPaint paint;
+
+    // Subtract off the integer component of the translation (will be applied in loc, below).
+    dstRect.offset(-SkIntToScalar(dstIRect.fLeft), -SkIntToScalar(dstIRect.fTop));
+    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+    // FIXME: this probably shouldn't be necessary, but drawBitmapRectToRect asserts
+    // None filtering when it's translate-only
+    paint.setFilterLevel(
+        fSrcRect.width() == dstRect.width() && fSrcRect.height() == dstRect.height() ?
+        SkPaint::kNone_FilterLevel : SkPaint::kMedium_FilterLevel);
+    canvas.drawBitmapRectToRect(fBitmap, &fSrcRect, dstRect, &paint);
+
+    *result = device.get()->accessBitmap(false);
+    offset->fX += dstIRect.fLeft;
+    offset->fY += dstIRect.fTop;
     return true;
 }
diff --git a/src/effects/SkTileImageFilter.cpp b/src/effects/SkTileImageFilter.cpp
index c5eace0b74..73e5304adb 100644
--- a/src/effects/SkTileImageFilter.cpp
+++ b/src/effects/SkTileImageFilter.cpp
@@ -24,16 +24,24 @@ bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src, const S
         return false;
     }
 
-    int w = SkScalarTruncToInt(fDstRect.width());
-    int h = SkScalarTruncToInt(fDstRect.height());
+    SkRect dstRect;
+    ctm.mapRect(&dstRect, fDstRect);
+    int w = SkScalarCeilToInt(dstRect.width());
+    int h = SkScalarCeilToInt(dstRect.height());
     if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
         return false;
     }
 
-    SkIRect srcRect;
-    fSrcRect.roundOut(&srcRect);
+    SkRect srcRect;
+    ctm.mapRect(&srcRect, fSrcRect);
+    SkIRect srcIRect;
+    srcRect.roundOut(&srcIRect);
     SkBitmap subset;
-    if (!source.extractSubset(&subset, srcRect)) {
+    SkIRect bounds;
+    source.getBounds(&bounds);
+    if (!srcIRect.intersect(bounds)) {
+        return true;
+    } else if (!source.extractSubset(&subset, srcIRect)) {
         return false;
     }
 
@@ -41,8 +49,6 @@ bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src, const S
     if (NULL == device.get()) {
         return false;
     }
-    SkIRect bounds;
-    source.getBounds(&bounds);
     SkCanvas canvas(device);
     SkPaint paint;
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
@@ -50,7 +56,6 @@ bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src, const S
     SkAutoTUnref<SkShader> shader(SkShader::CreateBitmapShader(subset,
                                   SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode));
     paint.setShader(shader);
-    SkRect dstRect = fDstRect;
     dstRect.offset(SkIntToScalar(localOffset.fX), SkIntToScalar(localOffset.fY));
     canvas.drawRect(dstRect, paint);
     *dst = device->accessBitmap(false);