tests/TileGridTest.cpp

/*
 * 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 "Test.h"
#include "SkBitmapDevice.h"
#include "SkCanvas.h"
#include "SkTileGrid.h"
#include "SkTileGridPicture.h"

enum Tile {
    kTopLeft_Tile = 0x1,
    kTopRight_Tile = 0x2,
    kBottomLeft_Tile = 0x4,
    kBottomRight_Tile = 0x8,

    kAll_Tile = kTopLeft_Tile | kTopRight_Tile | kBottomLeft_Tile | kBottomRight_Tile,
};

class MockCanvas : public SkCanvas {
public:
    MockCanvas(SkBaseDevice* device) : SkCanvas(device)
    {}

    virtual void drawRect(const SkRect& rect, const SkPaint&)
    {
        // This capture occurs before quick reject.
        fRects.push(rect);
    }

    SkTDArray<SkRect> fRects;
};

class TileGridTest {
public:
    static void verifyTileHits(skiatest::Reporter* reporter, SkIRect rect, uint32_t tileMask,
                               int borderPixels = 0) {
        SkTileGridPicture::TileGridInfo info;
        info.fMargin.set(borderPixels, borderPixels);
        info.fOffset.setZero();
        info.fTileInterval.set(10 - 2 * borderPixels, 10 - 2 * borderPixels);
        SkTileGrid grid(2, 2, info, NULL);
        grid.insert(NULL, rect, false);
        REPORTER_ASSERT(reporter, grid.tile(0,0).count() ==
            ((tileMask & kTopLeft_Tile)? 1 : 0));
        REPORTER_ASSERT(reporter, grid.tile(1,0).count() ==
            ((tileMask & kTopRight_Tile)? 1 : 0));
        REPORTER_ASSERT(reporter, grid.tile(0,1).count() ==
            ((tileMask & kBottomLeft_Tile)? 1 : 0));
        REPORTER_ASSERT(reporter, grid.tile(1,1).count() ==
            ((tileMask & kBottomRight_Tile)? 1 : 0));
    }

    static void TestUnalignedQuery(skiatest::Reporter* reporter) {
        // Use SkTileGridPicture to generate a SkTileGrid with a helper
        SkTileGridPicture::TileGridInfo info;
        info.fMargin.setEmpty();
        info.fOffset.setZero();
        info.fTileInterval.set(10, 10);
        SkTileGridPicture picture(20, 20, info);
        SkRect rect1 = SkRect::MakeXYWH(SkIntToScalar(0), SkIntToScalar(0),
            SkIntToScalar(8), SkIntToScalar(8));
        SkRect rect2 = SkRect::MakeXYWH(SkIntToScalar(11), SkIntToScalar(11),
            SkIntToScalar(1), SkIntToScalar(1));
        SkCanvas* canvas = picture.beginRecording(20, 20, SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
        SkPaint paint;
        canvas->drawRect(rect1, paint);
        canvas->drawRect(rect2, paint);
        picture.endRecording();

        SkBitmap store;
        store.setConfig(SkBitmap::kARGB_8888_Config, 1, 1);
        store.allocPixels();

        // Test parts of top-left tile
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
        }
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-7.99f, -7.99f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
        }
        // Corner overlap
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-9.5f, -9.5f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 2 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[1]);
        }
        // Intersect bottom right tile, but does not overlap rect 2
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-16.0f, -16.0f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[0]);
        }
        // Out of bounds queries, snap to border tiles
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(2.0f, 0.0f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
        }
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(0.0f, 2.0f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
        }
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-22.0f, -16.0f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[0]);
        }
        {
            SkBitmapDevice device(store);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-16.0f, -22.0f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[0]);
        }
    }

    static void TestOverlapOffsetQueryAlignment(skiatest::Reporter* reporter) {
        // Use SkTileGridPicture to generate a SkTileGrid with a helper
        SkTileGridPicture::TileGridInfo info;
        info.fMargin.set(1, 1);
        info.fOffset.set(-1, -1);
        info.fTileInterval.set(8, 8);
        SkTileGridPicture picture(20, 20, info);

        // rect landing entirely in top left tile
        SkRect rect1 = SkRect::MakeXYWH(SkIntToScalar(0), SkIntToScalar(0),
            SkIntToScalar(1), SkIntToScalar(1));
        // rect landing entirely in center tile
        SkRect rect2 = SkRect::MakeXYWH(SkIntToScalar(12), SkIntToScalar(12),
            SkIntToScalar(1), SkIntToScalar(1));
                // rect landing entirely in bottomright tile
        SkRect rect3 = SkRect::MakeXYWH(SkIntToScalar(19), SkIntToScalar(19),
            SkIntToScalar(1), SkIntToScalar(1));
        SkCanvas* canvas = picture.beginRecording(20, 20, SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
        SkPaint paint;
        canvas->drawRect(rect1, paint);
        canvas->drawRect(rect2, paint);
        canvas->drawRect(rect3, paint);
        picture.endRecording();

        SkBitmap tileBitmap;
        tileBitmap.setConfig(SkBitmap::kARGB_8888_Config, 10, 10);
        tileBitmap.allocPixels();
        SkBitmap moreThanATileBitmap;
        moreThanATileBitmap.setConfig(SkBitmap::kARGB_8888_Config, 11, 11);
        moreThanATileBitmap.allocPixels();
        SkBitmap tinyBitmap;
        tinyBitmap.setConfig(SkBitmap::kARGB_8888_Config, 2, 2);
        tinyBitmap.allocPixels();
        // Test parts of top-left tile
        {
            // The offset should cancel the top and left borders of the top left tile
            // So a look-up at interval 0-10 should be grid aligned,
            SkBitmapDevice device(tileBitmap);
            MockCanvas mockCanvas(&device);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
        }
        {
            // Encroaching border by one pixel
            SkBitmapDevice device(moreThanATileBitmap);
            MockCanvas mockCanvas(&device);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 2 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[1]);
        }
        {
            // Tile stride is 8 (tileWidth - 2 * border pixels
            // so translating by 8, should make query grid-aligned
            // with middle tile.
            SkBitmapDevice device(tileBitmap);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(SkIntToScalar(-8), SkIntToScalar(-8));
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 1 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[0]);
        }
        {
            SkBitmapDevice device(tileBitmap);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-7.9f, -7.9f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 2 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect1 == mockCanvas.fRects[0]);
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[1]);
        }
        {
            SkBitmapDevice device(tileBitmap);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-8.1f, -8.1f);
            picture.draw(&mockCanvas);
            REPORTER_ASSERT(reporter, 2 == mockCanvas.fRects.count());
            REPORTER_ASSERT(reporter, rect2 == mockCanvas.fRects[0]);
            REPORTER_ASSERT(reporter, rect3 == mockCanvas.fRects[1]);
        }
        {
            // Regression test for crbug.com/234688
            // Once the 2x2 device region is inset by margin, it yields an empty
            // adjusted region, sitting right on top of the tile boundary.
            SkBitmapDevice device(tinyBitmap);
            MockCanvas mockCanvas(&device);
            mockCanvas.translate(-8.0f, -8.0f);
            picture.draw(&mockCanvas);
            // This test passes by not asserting. We do not validate the rects recorded
            // because the result is numerically unstable (floating point equality).
            // The content of any one of the four tiles of the tilegrid would be a valid
            // result since any bbox that covers the center point of the canvas will be
            // recorded in all four tiles.
        }
    }

    static void Test(skiatest::Reporter* reporter) {
        // Out of bounds
        verifyTileHits(reporter, SkIRect::MakeXYWH(30, 0, 1, 1),  0);
        verifyTileHits(reporter, SkIRect::MakeXYWH(0, 30, 1, 1),  0);
        verifyTileHits(reporter, SkIRect::MakeXYWH(-10, 0, 1, 1),  0);
        verifyTileHits(reporter, SkIRect::MakeXYWH(0, -10, 1, 1),  0);

        // Dilation for AA consideration
        verifyTileHits(reporter, SkIRect::MakeXYWH(0, 0, 9, 9),  kTopLeft_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(0, 0, 10, 10),  kAll_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(9, 9, 1, 1),  kAll_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(10, 10, 1, 1),  kAll_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(11, 11, 1, 1),  kBottomRight_Tile);

        // BorderPixels
        verifyTileHits(reporter, SkIRect::MakeXYWH(0, 0, 6, 6),  kTopLeft_Tile, 1);
        verifyTileHits(reporter, SkIRect::MakeXYWH(0, 0, 7, 7),  kAll_Tile, 1);
        verifyTileHits(reporter, SkIRect::MakeXYWH(9, 9, 1, 1),  kAll_Tile, 1);
        verifyTileHits(reporter, SkIRect::MakeXYWH(10, 10, 1, 1),  kBottomRight_Tile, 1);
        verifyTileHits(reporter, SkIRect::MakeXYWH(17, 17, 1, 1),  kBottomRight_Tile, 1);

        // BBoxes that overlap tiles
        verifyTileHits(reporter, SkIRect::MakeXYWH(5, 5, 10, 1),  kTopLeft_Tile | kTopRight_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(5, 5, 1, 10),  kTopLeft_Tile |
                       kBottomLeft_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(5, 5, 10, 10),  kAll_Tile);
        verifyTileHits(reporter, SkIRect::MakeXYWH(-10, -10, 40, 40),  kAll_Tile);

        TestUnalignedQuery(reporter);
        TestOverlapOffsetQueryAlignment(reporter);
    }
};

#include "TestClassDef.h"
DEFINE_TESTCLASS("TileGrid", TileGridTestClass, TileGridTest::Test)