New SVG turbulence in Skia

This cl contains the code for both CPU and GPU generation of noise. Both
codepaths yield equivalent results.

TEST:Added 'perlinnoise' gm
Review URL: https://codereview.chromium.org/13047005

git-svn-id: http://skia.googlecode.com/svn/trunk@8371 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 113 insertions, 0 deletions

diff --git a/gm/perlinnoise.cpp b/gm/perlinnoise.cpp
new file mode 100644
index 0000000000..0afdd4773a
--- /dev/null
+++ b/gm/perlinnoise.cpp
@@ -0,0 +1,113 @@
+/*
+ * 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 "SkPerlinNoiseShader.h"
+
+namespace skiagm {
+
+class PerlinNoiseGM : public GM {
+public:
+    PerlinNoiseGM() {
+        this->setBGColor(0xFF000000);
+        fSize = SkISize::Make(80, 80);
+    }
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("perlinnoise");
+    }
+
+    virtual SkISize onISize() {
+        return make_isize(500, 400);
+    }
+
+    void drawClippedRect(SkCanvas* canvas, int x, int y, const SkPaint& paint) {
+        canvas->save();
+        canvas->clipRect(SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y),
+                         SkIntToScalar(fSize.width()), SkIntToScalar(fSize.height())));
+        SkRect r = SkRect::MakeXYWH(x, y, SkIntToScalar(fSize.width()),
+                                          SkIntToScalar(fSize.height()));
+        canvas->drawRect(r, paint);
+        canvas->restore();
+    }
+
+    void test(SkCanvas* canvas, int x, int y, SkPerlinNoiseShader::Type type,
+              float baseFrequencyX, float baseFrequencyY, int numOctaves, float seed,
+              bool stitchTiles)
+    {
+        SkShader* shader = (type == SkPerlinNoiseShader::kFractalNoise_Type) ?
+            SkPerlinNoiseShader::CreateFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves,
+                                                   seed, stitchTiles ? &fSize : NULL) :
+            SkPerlinNoiseShader::CreateTubulence(baseFrequencyX, baseFrequencyY, numOctaves,
+                                                seed, stitchTiles ? &fSize : NULL);
+        SkPaint paint;
+        paint.setShader(shader)->unref();
+        drawClippedRect(canvas, x, y, paint);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        canvas->clear(0x00000000);
+        
+        test(canvas,   0, 0, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 2, 0, false);
+        test(canvas, 100, 0, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.4f, 0.2f, 3, 0, true);
+        test(canvas, 200, 0, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.3f, 0.6f, 4, 0, false);
+        test(canvas, 300, 0, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.2f, 0.4f, 5, 0, true);
+        test(canvas, 400, 0, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.5f, 0.8f, 6, 0, false);
+
+        test(canvas,   0, 100, SkPerlinNoiseShader::kTurbulence_Type,
+             0.1f, 0.1f, 2, 0, true);
+        test(canvas, 100, 100, SkPerlinNoiseShader::kTurbulence_Type,
+             0.4f, 0.2f, 3, 0, false);
+        test(canvas, 200, 100, SkPerlinNoiseShader::kTurbulence_Type,
+             0.3f, 0.6f, 4, 0, true);
+        test(canvas, 300, 100, SkPerlinNoiseShader::kTurbulence_Type,
+             0.2f, 0.4f, 5, 0, false);
+        test(canvas, 400, 100, SkPerlinNoiseShader::kTurbulence_Type,
+             0.5f, 0.8f, 6, 0, true);
+
+        test(canvas,   0, 200, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 3, 1, false);
+        test(canvas, 100, 200, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 3, 2, false);
+        test(canvas, 200, 200, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 3, 3, false);
+        test(canvas, 300, 200, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 3, 4, false);
+        test(canvas, 400, 200, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 3, 5, false);
+
+        canvas->scale(SkFloatToScalar(0.75f), SkFloatToScalar(1.0f));
+
+        test(canvas,   0, 300, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.1f, 0.1f, 2, 0, false);
+        test(canvas, 100, 300, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.4f, 0.2f, 3, 0, true);
+        test(canvas, 200, 300, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.3f, 0.6f, 4, 0, false);
+        test(canvas, 300, 300, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.2f, 0.4f, 5, 0, true);
+        test(canvas, 400, 300, SkPerlinNoiseShader::kFractalNoise_Type,
+             0.5f, 0.8f, 6, 0, false);
+    }
+
+private:
+    typedef GM INHERITED;
+    SkISize fSize;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new PerlinNoiseGM; }
+static GMRegistry reg(MyFactory);
+
+}