Implement support for expanding crop rects in image filters

gm/imagefilterscropexpand.cpp

+/*
+ * Copyright 2014 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 "SkCanvas.h"
+#include "SkColorFilter.h"
+#include "SkColorPriv.h"
+#include "SkShader.h"
+
+#include "SkBitmapSource.h"
+#include "SkBlurImageFilter.h"
+#include "SkColorMatrixFilter.h"
+#include "SkDisplacementMapEffect.h"
+#include "SkDropShadowImageFilter.h"
+#include "SkGradientShader.h"
+#include "SkMorphologyImageFilter.h"
+#include "SkColorFilterImageFilter.h"
+#include "SkMergeImageFilter.h"
+#include "SkOffsetImageFilter.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+class ImageFiltersCropExpandGM : public skiagm::GM {
+public:
+    ImageFiltersCropExpandGM () {}
+
+protected:
+
+    virtual SkString onShortName() {
+        return SkString("imagefilterscropexpand");
+    }
+
+    virtual SkISize onISize() { return SkISize::Make(570, 650); }
+
+    void make_checkerboard(SkBitmap* bitmap) {
+        bitmap->allocN32Pixels(64, 64);
+        SkCanvas canvas(*bitmap);
+        canvas.clear(0xFFFF0000);
+        SkPaint darkPaint;
+        darkPaint.setColor(0xFF404040);
+        SkPaint lightPaint;
+        lightPaint.setColor(0xFFA0A0A0);
+        for (int y = 8; y < 48; y += 16) {
+            for (int x = 8; x < 48; x += 16) {
+                canvas.save();
+                canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
+                canvas.drawRect(SkRect::MakeXYWH(0, 0, 8, 8), darkPaint);
+                canvas.drawRect(SkRect::MakeXYWH(8, 0, 8, 8), lightPaint);
+                canvas.drawRect(SkRect::MakeXYWH(0, 8, 8, 8), lightPaint);
+                canvas.drawRect(SkRect::MakeXYWH(8, 8, 8, 8), darkPaint);
+                canvas.restore();
+            }
+        }
+    }
+
+    void make_gradient_circle(int width, int height, SkBitmap* bitmap) {
+        SkScalar x = SkIntToScalar(width / 2);
+        SkScalar y = SkIntToScalar(height / 2);
+        SkScalar radius = SkMinScalar(x, y) * 0.8f;
+        bitmap->allocN32Pixels(width, height);
+        SkCanvas canvas(*bitmap);
+        canvas.clear(0x00000000);
+        SkColor colors[2];
+        colors[0] = SK_ColorWHITE;
+        colors[1] = SK_ColorBLACK;
+        SkAutoTUnref<SkShader> shader(
+            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, NULL, 2,
+                                           SkShader::kClamp_TileMode)
+        );
+        SkPaint paint;
+        paint.setShader(shader);
+        canvas.drawCircle(x, y, radius, paint);
+    }
+
+    static void draw(SkCanvas* canvas, const SkBitmap& bitmap, const SkRect& rect, SkImageFilter* filter) {
+        SkPaint paint;
+        paint.setImageFilter(filter)->unref();
+        canvas->saveLayer(&rect, &paint);
+        canvas->drawBitmap(bitmap, 0, 0);
+        canvas->restore();
+        
+        SkPaint strokePaint;
+        strokePaint.setColor(0xFFFF0000);
+        strokePaint.setStyle(SkPaint::kStroke_Style);
+        canvas->drawRect(rect, strokePaint);
+
+        canvas->translate(SkIntToScalar(80), 0);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        SkAutoTUnref<SkColorFilter> cf(
+            SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrcIn_Mode));
+        SkImageFilter::CropRect crop_rect(
+            SkRect::Make(SkIRect::MakeXYWH(10, 10, 44, 44)),
+            SkImageFilter::CropRect::kHasAll_CropEdge);
+
+        SkBitmap gradient_circle, checkerboard;
+        make_gradient_circle(64, 64, &gradient_circle);
+        make_checkerboard(&checkerboard);
+
+        SkAutoTUnref<SkImageFilter> gradient_circle_source(
+            SkBitmapSource::Create(gradient_circle));
+        SkAutoTUnref<SkImageFilter> noop_cropped(
+            SkOffsetImageFilter::Create(0, 0, NULL, &crop_rect));
+        SkScalar sk255 = SkIntToScalar(255);
+        SkScalar matrix[20] = { 1, 0, 0, 0, 0,
+                                0, 1, 0, 0, sk255,
+                                0, 0, 1, 0, 0,
+                                0, 0, 0, 0, sk255 };
+        SkAutoTUnref<SkColorFilter> cf_alpha_trans(SkColorMatrixFilter::Create(matrix));
+
+        SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));
+        SkScalar MARGIN = SkIntToScalar(12);
+
+        SkIRect bounds;
+        r.roundOut(&bounds);
+
+        SkPaint paint;
+        canvas->translate(MARGIN, MARGIN);
+        for (int outset = -15; outset <= 20; outset += 5) {
+            canvas->save();
+            SkRect rect = crop_rect.rect();
+            rect.outset(SkIntToScalar(outset),
+                        SkIntToScalar(outset));
+            SkImageFilter::CropRect big_rect(rect, SkImageFilter::CropRect::kHasAll_CropEdge);
+            
+            draw(canvas, checkerboard, rect, SkColorFilterImageFilter::Create(
+                cf_alpha_trans, noop_cropped.get(), &big_rect));
+
+            draw(canvas, checkerboard, rect, SkBlurImageFilter::Create(
+                8.0f, 8.0f, noop_cropped.get(), &big_rect));
+
+            draw(canvas, checkerboard, rect, SkDilateImageFilter::Create(
+                2, 2, noop_cropped.get(), &big_rect));
+
+            draw(canvas, checkerboard, rect, SkErodeImageFilter::Create(
+                2, 2, noop_cropped.get(), &big_rect));
+
+            draw(canvas, checkerboard, rect, SkDropShadowImageFilter::Create(
+                SkIntToScalar(10), SkIntToScalar(10), SkIntToScalar(3), SkIntToScalar(3),
+                SK_ColorBLUE, noop_cropped.get(), &big_rect));
+
+            draw(canvas, checkerboard, rect, SkDisplacementMapEffect::Create(
+                SkDisplacementMapEffect::kR_ChannelSelectorType,
+                SkDisplacementMapEffect::kR_ChannelSelectorType,
+                SkIntToScalar(12),
+                gradient_circle_source.get(),
+                noop_cropped.get(),
+                &big_rect));
+
+            draw(canvas, checkerboard, rect, SkOffsetImageFilter::Create(
+                SkIntToScalar(-8), SkIntToScalar(16), noop_cropped.get(), &big_rect));
+
+            canvas->restore();
+            canvas->translate(0, SkIntToScalar(80));
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+static skiagm::GM* MyFactory(void*) { return new ImageFiltersCropExpandGM; }
+static skiagm::GMRegistry reg(MyFactory);