Refugee from Dead Machine 4: MDB Monster

src/gpu/GrAtlas.cpp

+
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrAtlas.h"
+#include "GrContext.h"
+#include "GrGpu.h"
+#include "GrRectanizer.h"
+#include "GrTracing.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+// for testing
+#define FONT_CACHE_STATS 0
+#if FONT_CACHE_STATS
+static int g_UploadCount = 0;
+#endif
+
+GrPlot::GrPlot() 
+    : fID(-1)
+    , fTexture(nullptr)
+    , fRects(nullptr)
+    , fAtlas(nullptr)
+    , fBytesPerPixel(1)
+    , fDirty(false)
+    , fBatchUploads(false)
+{
+    fOffset.set(0, 0);
+}
+
+GrPlot::~GrPlot() {
+    delete[] fPlotData;
+    fPlotData = nullptr;
+    delete fRects;
+}
+
+void GrPlot::init(GrAtlas* atlas, int id, int offX, int offY, int width, int height, size_t bpp,
+                  bool batchUploads) {
+    fID = id;
+    fRects = GrRectanizer::Factory(width, height);
+    fAtlas = atlas;
+    fOffset.set(offX * width, offY * height);
+    fBytesPerPixel = bpp;
+    fPlotData = nullptr;
+    fDirtyRect.setEmpty();
+    fDirty = false;
+    fBatchUploads = batchUploads;
+}
+
+static inline void adjust_for_offset(SkIPoint16* loc, const SkIPoint16& offset) {
+    loc->fX += offset.fX;
+    loc->fY += offset.fY;
+}
+
+bool GrPlot::addSubImage(int width, int height, const void* image, SkIPoint16* loc) {
+    float percentFull = fRects->percentFull();
+    if (!fRects->addRect(width, height, loc)) {
+        return false;
+    }
+
+    // if batching uploads, create backing memory on first use
+    // once the plot is nearly full we will revert to uploading each subimage individually
+    int plotWidth = fRects->width();
+    int plotHeight = fRects->height();
+    if (fBatchUploads && nullptr == fPlotData && 0.0f == percentFull) {
+        fPlotData = new unsigned char[fBytesPerPixel * plotWidth * plotHeight];
+        memset(fPlotData, 0, fBytesPerPixel*plotWidth*plotHeight);
+    }
+
+    // if we have backing memory, copy to the memory and set for future upload
+    if (fPlotData) {
+        const unsigned char* imagePtr = (const unsigned char*) image;
+        // point ourselves at the right starting spot
+        unsigned char* dataPtr = fPlotData;
+        dataPtr += fBytesPerPixel*plotWidth*loc->fY;
+        dataPtr += fBytesPerPixel*loc->fX;
+        // copy into the data buffer
+        for (int i = 0; i < height; ++i) {
+            memcpy(dataPtr, imagePtr, fBytesPerPixel*width);
+            dataPtr += fBytesPerPixel*plotWidth;
+            imagePtr += fBytesPerPixel*width;
+        }
+
+        fDirtyRect.join(loc->fX, loc->fY, loc->fX + width, loc->fY + height);
+        adjust_for_offset(loc, fOffset);
+        fDirty = true;
+    // otherwise, just upload the image directly
+    } else if (image) {
+        adjust_for_offset(loc, fOffset);
+        TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("skia.gpu"), "GrPlot::uploadToTexture");
+        fTexture->writePixels(NULL, loc->fX, loc->fY, width, height, fTexture->config(), image, 0,
+                              GrContext::kDontFlush_PixelOpsFlag);
+    } else {
+        adjust_for_offset(loc, fOffset);
+    }
+
+#if FONT_CACHE_STATS
+    ++g_UploadCount;
+#endif
+
+    return true;
+}
+
+void GrPlot::resetRects() {
+    SkASSERT(fRects);
+    fRects->reset();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrAtlas::GrAtlas(GrGpu* gpu, GrPixelConfig config, GrSurfaceFlags flags,
+                 const SkISize& backingTextureSize,
+                 int numPlotsX, int numPlotsY, bool batchUploads) {
+    fGpu = SkRef(gpu);
+    fPixelConfig = config;
+    fFlags = flags;
+    fBackingTextureSize = backingTextureSize;
+    fNumPlotsX = numPlotsX;
+    fNumPlotsY = numPlotsY;
+    fBatchUploads = batchUploads;
+    fTexture = nullptr;
+
+    int textureWidth = fBackingTextureSize.width();
+    int textureHeight = fBackingTextureSize.height();
+
+    int plotWidth = textureWidth / fNumPlotsX;
+    int plotHeight = textureHeight / fNumPlotsY;
+
+    SkASSERT(plotWidth * fNumPlotsX == textureWidth);
+    SkASSERT(plotHeight * fNumPlotsY == textureHeight);
+
+    // We currently do not support compressed atlases...
+    SkASSERT(!GrPixelConfigIsCompressed(config));
+
+    // set up allocated plots
+    size_t bpp = GrBytesPerPixel(fPixelConfig);
+    fPlotArray = new GrPlot[(fNumPlotsX * fNumPlotsY)];
+
+    GrPlot* currPlot = fPlotArray;
+    for (int y = numPlotsY-1; y >= 0; --y) {
+        for (int x = numPlotsX-1; x >= 0; --x) {
+            currPlot->init(this, y*numPlotsX+x, x, y, plotWidth, plotHeight, bpp, batchUploads);
+
+            // build LRU list
+            fPlotList.addToHead(currPlot);
+            ++currPlot;
+        }
+    }
+}
+
+GrAtlas::~GrAtlas() {
+    SkSafeUnref(fTexture);
+    delete[] fPlotArray;
+
+    fGpu->unref();
+#if FONT_CACHE_STATS
+      SkDebugf("Num uploads: %d\n", g_UploadCount);
+#endif
+}
+
+void GrAtlas::makeMRU(GrPlot* plot) {
+    if (fPlotList.head() == plot) {
+        return;
+    }
+
+    fPlotList.remove(plot);
+    fPlotList.addToHead(plot);
+};
+
+GrPlot* GrAtlas::addToAtlas(ClientPlotUsage* usage,
+                            int width, int height, const void* image,
+                            SkIPoint16* loc) {
+    // iterate through entire plot list for this atlas, see if we can find a hole
+    // last one was most recently added and probably most empty
+    for (int i = usage->fPlots.count()-1; i >= 0; --i) {
+        GrPlot* plot = usage->fPlots[i];
+        // client may have plots from more than one atlas, must check for ours before adding
+        if (this == plot->fAtlas && plot->addSubImage(width, height, image, loc)) {
+            this->makeMRU(plot);
+            return plot;
+        }
+    }
+
+    // before we get a new plot, make sure we have a backing texture
+    if (nullptr == fTexture) {
+        // TODO: Update this to use the cache rather than directly creating a texture.
+        GrSurfaceDesc desc;
+        desc.fFlags = fFlags;
+        desc.fWidth = fBackingTextureSize.width();
+        desc.fHeight = fBackingTextureSize.height();
+        desc.fConfig = fPixelConfig;
+
+        fTexture = fGpu->createTexture(desc, true, nullptr, 0);
+        if (nullptr == fTexture) {
+            return nullptr;
+        }
+    }
+
+    // now look through all allocated plots for one we can share, in MRU order
+    GrPlotList::Iter plotIter;
+    plotIter.init(fPlotList, GrPlotList::Iter::kHead_IterStart);
+    GrPlot* plot;
+    while ((plot = plotIter.get())) {
+        // make sure texture is set for quick lookup
+        plot->fTexture = fTexture;
+        if (plot->addSubImage(width, height, image, loc)) {
+            this->makeMRU(plot);
+            // new plot for atlas, put at end of array
+            SkASSERT(!usage->fPlots.contains(plot));
+            *(usage->fPlots.append()) = plot;
+            return plot;
+        }
+        plotIter.next();
+    }
+
+    // If the above fails, then the current plot list has no room
+    return nullptr;
+}
+
+void GrAtlas::RemovePlot(ClientPlotUsage* usage, const GrPlot* plot) {
+    int index = usage->fPlots.find(const_cast<GrPlot*>(plot));
+    if (index >= 0) {
+        usage->fPlots.remove(index);
+    }
+}