When two or more color matrix image filters are connected together, and the non-leaf matrices do not require clamping, we can concatenate their matrices and apply them together.

Review URL: https://codereview.appspot.com/6489054

git-svn-id: http://skia.googlecode.com/svn/trunk@5931 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 134 insertions, 0 deletions

diff --git a/gm/colorfilterimagefilter.cpp b/gm/colorfilterimagefilter.cpp
new file mode 100644
index 0000000000..7963c8af73
--- /dev/null
+++ b/gm/colorfilterimagefilter.cpp
@@ -0,0 +1,134 @@
+/*
+ * Copyright 2012 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 "SkColorMatrixFilter.h"
+#include "SkColorPriv.h"
+#include "SkShader.h"
+
+#include "SkBlurImageFilter.h"
+#include "SkColorFilterImageFilter.h"
+
+#define FILTER_WIDTH    SkIntToScalar(30)
+#define FILTER_HEIGHT   SkIntToScalar(30)
+#define MARGIN          SkIntToScalar(10)
+
+static SkImageFilter* make_blur(float amount, SkImageFilter* input = NULL) {
+    return new SkBlurImageFilter(amount, amount, input);
+}
+
+static SkImageFilter* make_brightness(float amount, SkImageFilter* input = NULL) {
+    SkScalar amount255 = SkScalarMul(SkFloatToScalar(amount), SkIntToScalar(255));
+    SkScalar matrix[20] = { 1, 0, 0, 0, amount255,
+                            0, 1, 0, 0, amount255,
+                            0, 0, 1, 0, amount255,
+                            0, 0, 0, 1, 0 };
+    SkAutoTUnref<SkColorFilter> filter(new SkColorMatrixFilter(matrix));
+    return new SkColorFilterImageFilter(filter, input);
+}
+
+static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
+    SkScalar matrix[20];
+    memset(matrix, 0, 20 * sizeof(SkScalar));
+    matrix[0] = matrix[5] = matrix[10] = SkFloatToScalar(0.2126f);
+    matrix[1] = matrix[6] = matrix[11] = SkFloatToScalar(0.7152f);
+    matrix[2] = matrix[7] = matrix[12] = SkFloatToScalar(0.0722f);
+    matrix[18] = SkFloatToScalar(1.0f);
+    SkAutoTUnref<SkColorFilter> filter(new SkColorMatrixFilter(matrix));
+    return new SkColorFilterImageFilter(filter, input);
+}
+
+static SkImageFilter* make_mode_blue(SkImageFilter* input = NULL) {
+    SkAutoTUnref<SkColorFilter> filter(
+        SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrcIn_Mode));
+    return new SkColorFilterImageFilter(filter, input);
+}
+
+class ColorFilterImageFilterGM : public skiagm::GM {
+public:
+    ColorFilterImageFilterGM () {}
+
+protected:
+
+    virtual SkString onShortName() {
+        return SkString("colorfilterimagefilter");
+    }
+
+    void drawClippedRect(SkCanvas* canvas, const SkRect& r, const SkPaint& paint, float outset = 0.0f) {
+        canvas->save();
+        SkRect clip(r);
+        clip.outset(SkFloatToScalar(outset), SkFloatToScalar(outset));
+        canvas->clipRect(clip);
+        canvas->drawRect(r, paint);
+        canvas->restore();
+    }
+
+    virtual SkISize onISize() { return SkISize::Make(400, 100); }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        
+        SkRect r = SkRect::MakeWH(FILTER_WIDTH, FILTER_HEIGHT);
+        SkPaint paint;
+        paint.setColor(SK_ColorRED);
+        canvas->save();
+        for (float brightness = -1.0f; brightness <= 1.0f; brightness += 0.2f) {
+            SkAutoTUnref<SkImageFilter> dim(make_brightness(-brightness));
+            SkAutoTUnref<SkImageFilter> bright(make_brightness(brightness, dim));
+            paint.setImageFilter(bright);
+            drawClippedRect(canvas, r, paint);
+            canvas->translate(FILTER_WIDTH + MARGIN, 0);
+        }
+        canvas->restore();
+        canvas->translate(0, FILTER_HEIGHT + MARGIN);
+        {
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.9f));
+            SkAutoTUnref<SkImageFilter> grayscale(make_grayscale(brightness));
+            paint.setImageFilter(grayscale);
+            drawClippedRect(canvas, r, paint);
+            canvas->translate(FILTER_WIDTH + MARGIN, 0);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> grayscale(make_grayscale());
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.9f, grayscale));
+            paint.setImageFilter(brightness);
+            drawClippedRect(canvas, r, paint);
+            canvas->translate(FILTER_WIDTH + MARGIN, 0);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> blue(make_mode_blue());
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(1.0f, blue));
+            paint.setImageFilter(brightness);
+            drawClippedRect(canvas, r, paint);
+            canvas->translate(FILTER_WIDTH + MARGIN, 0);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(1.0f));
+            SkAutoTUnref<SkImageFilter> blue(make_mode_blue(brightness));
+            paint.setImageFilter(blue);
+            drawClippedRect(canvas, r, paint);
+            canvas->translate(FILTER_WIDTH + MARGIN, 0);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f));
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.5f, blur));
+            paint.setImageFilter(brightness);
+            drawClippedRect(canvas, r, paint, 3);
+            canvas->translate(FILTER_WIDTH + MARGIN, 0);
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static skiagm::GM* MyFactory(void*) { return new ColorFilterImageFilterGM; }
+static skiagm::GMRegistry reg(MyFactory);
+
+