tests/ImageFilterTest.cpp

/*
 * 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 "SkBicubicImageFilter.h"
#include "SkBitmap.h"
#include "SkBitmapDevice.h"
#include "SkBitmapSource.h"
#include "SkCanvas.h"
#include "SkColorMatrixFilter.h"
#include "SkColorFilterImageFilter.h"
#include "SkDeviceImageFilterProxy.h"
#include "SkLightingImageFilter.h"
#include "SkRect.h"

class ImageFilterTest {
public:
    static const int kBitmapSize = 4;

    static void make_small_bitmap(SkBitmap& bitmap) {
        bitmap.setConfig(SkBitmap::kARGB_8888_Config, kBitmapSize, kBitmapSize);
        bitmap.allocPixels();
        SkBitmapDevice device(bitmap);
        SkCanvas canvas(&device);
        canvas.clear(0x00000000);
        SkPaint darkPaint;
        darkPaint.setColor(0xFF804020);
        SkPaint lightPaint;
        lightPaint.setColor(0xFF244484);
        const int i = kBitmapSize / 4;
        for (int y = 0; y < kBitmapSize; y += i) {
            for (int x = 0; x < kBitmapSize; x += i) {
                canvas.save();
                canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
                canvas.drawRect(SkRect::MakeXYWH(0, 0, i, i), darkPaint);
                canvas.drawRect(SkRect::MakeXYWH(i, 0, i, i), lightPaint);
                canvas.drawRect(SkRect::MakeXYWH(0, i, i, i), lightPaint);
                canvas.drawRect(SkRect::MakeXYWH(i, i, i, i), darkPaint);
                canvas.restore();
            }
        }
    }

    static SkImageFilter* make_scale(float amount, SkImageFilter* input = NULL) {
        SkScalar s = SkFloatToScalar(amount);
        SkScalar matrix[20] = { s, 0, 0, 0, 0,
                                0, s, 0, 0, 0,
                                0, 0, s, 0, 0,
                                0, 0, 0, s, 0 };
        SkAutoTUnref<SkColorFilter> filter(new SkColorMatrixFilter(matrix));
        return SkColorFilterImageFilter::Create(filter, input);
    }

    static SkImageFilter* make_grayscale(SkImageFilter* input = NULL, const SkIRect* cropRect = 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 SkColorFilterImageFilter::Create(filter, input, cropRect);
    }

    static SkImageFilter* make_mode_blue(SkImageFilter* input = NULL) {
        SkAutoTUnref<SkColorFilter> filter(
            SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrcIn_Mode));
        return SkColorFilterImageFilter::Create(filter, input);
    }

    static void Test(skiatest::Reporter* reporter) {
        {
            // Check that two non-clipping color matrices concatenate into a single filter.
            SkAutoTUnref<SkImageFilter> halfBrightness(make_scale(0.5f));
            SkAutoTUnref<SkImageFilter> quarterBrightness(make_scale(0.5f, halfBrightness));
            REPORTER_ASSERT(reporter, NULL == quarterBrightness->getInput(0));
        }

        {
            // Check that a clipping color matrix followed by a grayscale does not concatenate into a single filter.
            SkAutoTUnref<SkImageFilter> doubleBrightness(make_scale(2.0f));
            SkAutoTUnref<SkImageFilter> halfBrightness(make_scale(0.5f, doubleBrightness));
            REPORTER_ASSERT(reporter, NULL != halfBrightness->getInput(0));
        }

        {
            // Check that a color filter image filter without a crop rect can be
            // expressed as a color filter.
            SkAutoTUnref<SkImageFilter> gray(make_grayscale());
            REPORTER_ASSERT(reporter, true == gray->asColorFilter(NULL));
        }

        {
            // Check that a color filter image filter with a crop rect cannot
            // be expressed as a color filter.
            SkIRect cropRect = SkIRect::MakeXYWH(0, 0, 100, 100);
            SkAutoTUnref<SkImageFilter> grayWithCrop(make_grayscale(NULL, &cropRect));
            REPORTER_ASSERT(reporter, false == grayWithCrop->asColorFilter(NULL));
        }

        {
            // Tests pass by not asserting
            SkBitmap bitmap, result;
            make_small_bitmap(bitmap);
            result.setConfig(SkBitmap::kARGB_8888_Config, kBitmapSize, kBitmapSize);
            result.allocPixels();

            {
                // This tests for :
                // 1 ) location at (0,0,1)
                SkPoint3 location(0, 0, SK_Scalar1);
                // 2 ) location and target at same value
                SkPoint3 target(location.fX, location.fY, location.fZ);
                // 3 ) large negative specular exponent value
                SkScalar specularExponent = SkFloatToScalar(-1000);
        
                SkPaint paint;
                paint.setImageFilter(SkLightingImageFilter::CreateSpotLitSpecular(
                        location, target, specularExponent, SkFloatToScalar(180),
                        0xFFFFFFFF, SK_Scalar1, SK_Scalar1, SK_Scalar1,
                        new SkBitmapSource(bitmap)))->unref();
                SkCanvas canvas(result);
                SkRect r = SkRect::MakeWH(kBitmapSize, kBitmapSize);
                canvas.drawRect(r, paint);
            }

            {
                // This tests for scale bringing width to 0
                SkSize scale = SkSize::Make(SkFloatToScalar(-0.001), SK_Scalar1);
                SkAutoTUnref<SkBicubicImageFilter> bicubic(
                    SkBicubicImageFilter::CreateMitchell(
                        scale, new SkBitmapSource(bitmap)));
                SkBitmapDevice device(bitmap);
                SkDeviceImageFilterProxy proxy(&device);
                SkIPoint loc = SkIPoint::Make(0, 0);
                // An empty input should early return and return false
                REPORTER_ASSERT(reporter,
                    !bicubic->filterImage(&proxy, bitmap, SkMatrix::I(), &result, &loc));
            }
        }
    }
};


#include "TestClassDef.h"
DEFINE_TESTCLASS("ImageFilterTest", ImageFilterTestClass, ImageFilterTest::Test)