tools/PictureRenderer.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 "PictureRenderer.h"
#include "picture_utils.h"
#include "SamplePipeControllers.h"
#include "SkCanvas.h"
#include "SkDevice.h"
#include "SkGPipe.h"
#if SK_SUPPORT_GPU
#include "SkGpuDevice.h"
#endif
#include "SkGraphics.h"
#include "SkImageEncoder.h"
#include "SkMatrix.h"
#include "SkPicture.h"
#include "SkScalar.h"
#include "SkString.h"
#include "SkTemplates.h"
#include "SkTDArray.h"
#include "SkThreadUtils.h"
#include "SkTypes.h"

namespace sk_tools {

enum {
    kDefaultTileWidth = 256,
    kDefaultTileHeight = 256
};

void PictureRenderer::init(SkPicture* pict) {
    SkASSERT(NULL == fPicture);
    SkASSERT(NULL == fCanvas.get());
    if (fPicture != NULL || NULL != fCanvas.get()) {
        return;
    }

    SkASSERT(pict != NULL);
    if (NULL == pict) {
        return;
    }

    fPicture = pict;
    fCanvas.reset(this->setupCanvas());
}

SkCanvas* PictureRenderer::setupCanvas() {
    return this->setupCanvas(fPicture->width(), fPicture->height());
}

SkCanvas* PictureRenderer::setupCanvas(int width, int height) {
    switch(fDeviceType) {
        case kBitmap_DeviceType: {
            SkBitmap bitmap;
            sk_tools::setup_bitmap(&bitmap, width, height);
            return SkNEW_ARGS(SkCanvas, (bitmap));
            break;
        }
#if SK_SUPPORT_GPU
        case kGPU_DeviceType: {
            SkAutoTUnref<SkGpuDevice> device(SkNEW_ARGS(SkGpuDevice,
                                                    (fGrContext, SkBitmap::kARGB_8888_Config,
                                                    width, height)));
            return SkNEW_ARGS(SkCanvas, (device.get()));
            break;
        }
#endif
        default:
            SkASSERT(0);
    }

    return NULL;
}

void PictureRenderer::end() {
    this->resetState();
    fPicture = NULL;
    fCanvas.reset(NULL);
}

void PictureRenderer::resetState() {
#if SK_SUPPORT_GPU
    if (this->isUsingGpuDevice()) {
        SkGLContext* glContext = fGrContextFactory.getGLContext(
            GrContextFactory::kNative_GLContextType);

        SkASSERT(glContext != NULL);
        if (NULL == glContext) {
            return;
        }

        fGrContext->flush();
        SK_GL(*glContext, Finish());
    }
#endif
}

bool PictureRenderer::write(const SkString& path) const {
    SkASSERT(fCanvas.get() != NULL);
    SkASSERT(fPicture != NULL);
    if (NULL == fCanvas.get() || NULL == fPicture) {
        return false;
    }

    SkBitmap bitmap;
    sk_tools::setup_bitmap(&bitmap, fPicture->width(), fPicture->height());

    fCanvas->readPixels(&bitmap, 0, 0);
    sk_tools::force_all_opaque(bitmap);

    return SkImageEncoder::EncodeFile(path.c_str(), bitmap, SkImageEncoder::kPNG_Type, 100);
}

///////////////////////////////////////////////////////////////////////////////////////////////

void RecordPictureRenderer::render(bool doExtraWorkToDrawToBaseCanvas) {
    SkPicture replayer;
    SkCanvas* recorder = replayer.beginRecording(fPicture->width(), fPicture->height());
    fPicture->draw(recorder);
    replayer.endRecording();
}

///////////////////////////////////////////////////////////////////////////////////////////////

void PipePictureRenderer::render(bool doExtraWorkToDrawToBaseCanvas) {
    SkASSERT(fCanvas.get() != NULL);
    SkASSERT(fPicture != NULL);
    if (NULL == fCanvas.get() || NULL == fPicture) {
        return;
    }

    PipeController pipeController(fCanvas.get());
    SkGPipeWriter writer;
    SkCanvas* pipeCanvas = writer.startRecording(&pipeController);
    pipeCanvas->drawPicture(*fPicture);
    writer.endRecording();
    fCanvas->flush();
}

///////////////////////////////////////////////////////////////////////////////////////////////

void SimplePictureRenderer::render(bool doExtraWorkToDrawToBaseCanvas) {
    SkASSERT(fCanvas.get() != NULL);
    SkASSERT(fPicture != NULL);
    if (NULL == fCanvas.get() || NULL == fPicture) {
        return;
    }

    fCanvas->drawPicture(*fPicture);
    fCanvas->flush();
}

///////////////////////////////////////////////////////////////////////////////////////////////

TiledPictureRenderer::TiledPictureRenderer()
    : fMultiThreaded(false)
    , fUsePipe(false)
    , fTileWidth(kDefaultTileWidth)
    , fTileHeight(kDefaultTileHeight)
    , fTileWidthPercentage(0.0)
    , fTileHeightPercentage(0.0)
    , fTileMinPowerOf2Width(0) { }

void TiledPictureRenderer::init(SkPicture* pict) {
    SkASSERT(pict != NULL);
    SkASSERT(0 == fTileRects.count());
    if (NULL == pict || fTileRects.count() != 0) {
        return;
    }

    // Do not call INHERITED::init(), which would create a (potentially large) canvas which is not
    // used by bench_pictures.
    fPicture = pict;

    if (fTileWidthPercentage > 0) {
        fTileWidth = sk_float_ceil2int(float(fTileWidthPercentage * fPicture->width() / 100));
    }
    if (fTileHeightPercentage > 0) {
        fTileHeight = sk_float_ceil2int(float(fTileHeightPercentage * fPicture->height() / 100));
    }

    if (fTileMinPowerOf2Width > 0) {
        this->setupPowerOf2Tiles();
    } else {
        this->setupTiles();
    }
}

void TiledPictureRenderer::end() {
    this->deleteTiles();
    this->INHERITED::end();
}

TiledPictureRenderer::~TiledPictureRenderer() {
    this->deleteTiles();
}

void TiledPictureRenderer::setupTiles() {
    for (int tile_y_start = 0; tile_y_start < fPicture->height(); tile_y_start += fTileHeight) {
        for (int tile_x_start = 0; tile_x_start < fPicture->width(); tile_x_start += fTileWidth) {
            *fTileRects.append() = SkRect::MakeXYWH(SkIntToScalar(tile_x_start),
                                                    SkIntToScalar(tile_y_start),
                                                    SkIntToScalar(fTileWidth),
                                                    SkIntToScalar(fTileHeight));
        }
    }
}

// The goal of the powers of two tiles is to minimize the amount of wasted tile
// space in the width-wise direction and then minimize the number of tiles. The
// constraints are that every tile must have a pixel width that is a power of
// two and also be of some minimal width (that is also a power of two).
//
// This is solved by first taking our picture size and rounding it up to the
// multiple of the minimal width. The binary representation of this rounded
// value gives us the tiles we need: a bit of value one means we need a tile of
// that size.
void TiledPictureRenderer::setupPowerOf2Tiles() {
    int rounded_value = fPicture->width();
    if (fPicture->width() % fTileMinPowerOf2Width != 0) {
        rounded_value = fPicture->width() - (fPicture->width() % fTileMinPowerOf2Width)
            + fTileMinPowerOf2Width;
    }

    int num_bits = SkScalarCeilToInt(SkScalarLog2(SkIntToScalar(fPicture->width())));
    int largest_possible_tile_size = 1 << num_bits;

    // The tile height is constant for a particular picture.
    for (int tile_y_start = 0; tile_y_start < fPicture->height(); tile_y_start += fTileHeight) {
        int tile_x_start = 0;
        int current_width = largest_possible_tile_size;
        // Set fTileWidth to be the width of the widest tile, so that each canvas is large enough
        // to draw each tile.
        fTileWidth = current_width;

        while (current_width >= fTileMinPowerOf2Width) {
            // It is very important this is a bitwise AND.
            if (current_width & rounded_value) {
                *fTileRects.append() = SkRect::MakeXYWH(SkIntToScalar(tile_x_start),
                                                        SkIntToScalar(tile_y_start),
                                                        SkIntToScalar(current_width),
                                                        SkIntToScalar(fTileHeight));
                tile_x_start += current_width;
            }

            current_width >>= 1;
        }
    }
}

void TiledPictureRenderer::deleteTiles() {
    fTileRects.reset();
}

///////////////////////////////////////////////////////////////////////////////////////////////
// Draw using Pipe

struct TileData {
    TileData(SkCanvas* canvas, ThreadSafePipeController* controller);
    SkCanvas* fCanvas;
    ThreadSafePipeController* fController;
    SkThread fThread;
};

static void DrawTile(void* data) {
    SkGraphics::SetTLSFontCacheLimit(1 * 1024 * 1024);
    TileData* tileData = static_cast<TileData*>(data);
    tileData->fController->playback(tileData->fCanvas);
    tileData->fCanvas->flush();
}

TileData::TileData(SkCanvas* canvas, ThreadSafePipeController* controller)
: fCanvas(canvas)
, fController(controller)
, fThread(&DrawTile, static_cast<void*>(this)) {}

///////////////////////////////////////////////////////////////////////////////////////////////
// Draw using Picture

struct CloneData {
    CloneData(SkCanvas* target, SkPicture* original);
    SkCanvas* fCanvas;
    SkPicture* fClone;
    SkThread fThread;
};

static void DrawClonedTile(void* data) {
    SkGraphics::SetTLSFontCacheLimit(1 * 1024 * 1024);
    CloneData* cloneData = static_cast<CloneData*>(data);
    cloneData->fCanvas->drawPicture(*cloneData->fClone);
    cloneData->fCanvas->flush();
}

CloneData::CloneData(SkCanvas* target, SkPicture* clone)
: fCanvas(target)
, fClone(clone)
, fThread(&DrawClonedTile, static_cast<void*>(this)) {}

///////////////////////////////////////////////////////////////////////////////////////////////

void TiledPictureRenderer::render(bool doExtraWorkToDrawToBaseCanvas) {
    SkASSERT(fPicture != NULL);
    if (NULL == fPicture) {
        return;
    }

    if (doExtraWorkToDrawToBaseCanvas) {
        if (NULL == fCanvas.get()) {
            fCanvas.reset(this->setupCanvas());
        }
    }

    if (fMultiThreaded) {
        // FIXME: Turning off multi threading while we transition to using a pool of tiles
/*
        if (fUsePipe) {
            // First, draw into a pipe controller
            SkGPipeWriter writer;
            ThreadSafePipeController controller(fTiles.count());
            SkCanvas* pipeCanvas = writer.startRecording(&controller,
                                                         SkGPipeWriter::kSimultaneousReaders_Flag);
            pipeCanvas->drawPicture(*(fPicture));
            writer.endRecording();

            // Create and start the threads.
            TileData** tileData = SkNEW_ARRAY(TileData*, fTiles.count());
            SkAutoTDeleteArray<TileData*> deleteTileData(tileData);
            for (int i = 0; i < fTiles.count(); i++) {
                tileData[i] = SkNEW_ARGS(TileData, (fTiles[i], &controller));
                if (!tileData[i]->fThread.start()) {
                    SkDebugf("could not start thread %i\n", i);
                }
            }
            for (int i = 0; i < fTiles.count(); i++) {
                tileData[i]->fThread.join();
                SkDELETE(tileData[i]);
            }
        } else {
            SkPicture* clones = SkNEW_ARRAY(SkPicture, fTiles.count());
            SkAutoTDeleteArray<SkPicture> autodelete(clones);
            fPicture->clone(clones, fTiles.count());
            CloneData** cloneData = SkNEW_ARRAY(CloneData*, fTiles.count());
            SkAutoTDeleteArray<CloneData*> deleteCloneData(cloneData);
            for (int i = 0; i < fTiles.count(); i++) {
                cloneData[i] = SkNEW_ARGS(CloneData, (fTiles[i], &clones[i]));
                if (!cloneData[i]->fThread.start()) {
                    SkDebugf("Could not start picture thread %i\n", i);
                }
            }
            for (int i = 0; i < fTiles.count(); i++) {
                cloneData[i]->fThread.join();
                SkDELETE(cloneData[i]);
            }
        }
 */
    } else {
        // For single thread, we really only need one canvas total
        SkCanvas* canvas = this->setupCanvas(fTileWidth, fTileHeight);
        SkAutoUnref aur(canvas);

        // Clip the tile to an area that is completely in what the SkPicture says is the
        // drawn-to area. This is mostly important for tiles on the right and bottom edges
        // as they may go over this area and the picture may have some commands that
        // draw outside of this area and so should not actually be written.
        SkRect clip = SkRect::MakeWH(SkIntToScalar(fPicture->width()),
                                     SkIntToScalar(fPicture->height()));
        for (int i = 0; i < fTileRects.count(); ++i) {
            canvas->resetMatrix();
            canvas->clipRect(clip);
            // Translate so that we draw the correct portion of the picture
            canvas->translate(-fTileRects[i].fLeft, -fTileRects[i].fTop);
            canvas->drawPicture(*(fPicture));
            canvas->flush();
            if (doExtraWorkToDrawToBaseCanvas) {
                SkASSERT(fCanvas.get() != NULL);
                SkBitmap source = canvas->getDevice()->accessBitmap(false);
                fCanvas->drawBitmap(source, fTileRects[i].fLeft, fTileRects[i].fTop);
                fCanvas->flush();
            }
        }
    }
}

///////////////////////////////////////////////////////////////////////////////////////////////

void PlaybackCreationRenderer::setup() {
    SkCanvas* recorder = fReplayer.beginRecording(fPicture->width(), fPicture->height());
    fPicture->draw(recorder);
}

void PlaybackCreationRenderer::render(bool doExtraWorkToDrawToBaseCanvas) {
    fReplayer.endRecording();
}

}