Revert "Revert "Add Atlas Text interface for rendering SDF glyphs.""

This reverts commit 9c2202ffc22b4293b48a4edeafa1b5d2bab8bb83.

Bug: skia:
Change-Id: I482ddf74f8e40d3d0908c840ba5c6ff981ccefbd
Reviewed-on: https://skia-review.googlesource.com/73345
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

4 files changed, 357 insertions, 0 deletions

diff --git a/src/atlastext/SkAtlasTextContext.cpp b/src/atlastext/SkAtlasTextContext.cpp
new file mode 100644
index 0000000000..85e79118ee
--- /dev/null
+++ b/src/atlastext/SkAtlasTextContext.cpp
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkAtlasTextContext.h"
+#include "SkAtlasTextRenderer.h"
+#include "SkInternalAtlasTextContext.h"
+
+sk_sp<SkAtlasTextContext> SkAtlasTextContext::Make(sk_sp<SkAtlasTextRenderer> renderer) {
+    return sk_sp<SkAtlasTextContext>(new SkAtlasTextContext(std::move(renderer)));
+}
+
+SkAtlasTextContext::SkAtlasTextContext(sk_sp<SkAtlasTextRenderer> renderer)
+        : fInternalContext(SkInternalAtlasTextContext::Make(std::move(renderer))) {}
diff --git a/src/atlastext/SkAtlasTextTarget.cpp b/src/atlastext/SkAtlasTextTarget.cpp
new file mode 100644
index 0000000000..57ece37b4f
--- /dev/null
+++ b/src/atlastext/SkAtlasTextTarget.cpp
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkAtlasTextTarget.h"
+#include "GrClip.h"
+#include "SkAtlasTextContext.h"
+#include "SkAtlasTextFont.h"
+#include "SkAtlasTextRenderer.h"
+#include "SkGr.h"
+#include "SkInternalAtlasTextContext.h"
+#include "ops/GrAtlasTextOp.h"
+#include "text/GrAtlasTextContext.h"
+
+SkAtlasTextTarget::SkAtlasTextTarget(sk_sp<SkAtlasTextContext> context, int width, int height,
+                                     void* handle)
+        : fHandle(handle), fContext(std::move(context)), fWidth(width), fHeight(height) {}
+
+SkAtlasTextTarget::~SkAtlasTextTarget() { fContext->renderer()->targetDeleted(fHandle); }
+
+//////////////////////////////////////////////////////////////////////////////
+
+static const GrColorSpaceInfo kColorSpaceInfo(nullptr, kRGBA_8888_GrPixelConfig);
+
+//////////////////////////////////////////////////////////////////////////////
+
+class SkInternalAtlasTextTarget : public GrTextUtils::Target, public SkAtlasTextTarget {
+public:
+    SkInternalAtlasTextTarget(sk_sp<SkAtlasTextContext> context, int width, int height,
+                              void* handle)
+            : GrTextUtils::Target(width, height, kColorSpaceInfo)
+            , SkAtlasTextTarget(std::move(context), width, height, handle) {}
+
+    /** GrTextUtils::Target overrides */
+
+    void addDrawOp(const GrClip&, std::unique_ptr<GrAtlasTextOp> op) override;
+
+    void drawPath(const GrClip&, const SkPath&, const SkPaint&, const SkMatrix& viewMatrix,
+                  const SkMatrix* pathMatrix, const SkIRect& clipBounds) override {
+        SkDebugf("Path glyph??");
+    }
+
+    void makeGrPaint(GrMaskFormat, const SkPaint& skPaint, const SkMatrix&,
+                     GrPaint* grPaint) override {
+        grPaint->setColor4f(SkColorToPremulGrColor4fLegacy(skPaint.getColor()));
+    }
+
+    /** SkAtlasTextTarget overrides */
+
+    void drawText(const void* text, size_t byteLength, SkScalar x, SkScalar y, uint32_t color,
+                  const SkAtlasTextFont&) override;
+    void flush() override;
+
+private:
+    uint32_t fColor;
+    using SkAtlasTextTarget::fWidth;
+    using SkAtlasTextTarget::fHeight;
+    struct RecordedOp {
+        std::unique_ptr<GrAtlasTextOp> fOp;
+        uint32_t fColor;
+    };
+    SkTArray<RecordedOp, true> fOps;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+std::unique_ptr<SkAtlasTextTarget> SkAtlasTextTarget::Make(sk_sp<SkAtlasTextContext> context,
+                                                           int width, int height, void* handle) {
+    return std::unique_ptr<SkAtlasTextTarget>(
+            new SkInternalAtlasTextTarget(std::move(context), width, height, handle));
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#include "GrContextPriv.h"
+#include "GrDrawingManager.h"
+
+void SkInternalAtlasTextTarget::drawText(const void* text, size_t byteLength, SkScalar x,
+                                         SkScalar y, uint32_t color, const SkAtlasTextFont& font) {
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    paint.setTypeface(font.refTypeface());
+    paint.setTextSize(font.size());
+    paint.setStyle(SkPaint::kFill_Style);
+
+    // TODO: Figure out what if anything to do with these:
+    // Paint setTextEncoding? Font isEnableByteCodeHints()? Font isUseNonLinearMetrics()?
+
+    // The atlas text context does munging of the paint color. We store the client's color here
+    // and the context will write it into the final vertices given to the client's renderer.
+    fColor = color;
+
+    // The pixel geometry here is arbitrary. We don't draw LCD text.
+    SkSurfaceProps props(SkSurfaceProps::kUseDistanceFieldFonts_Flag, kUnknown_SkPixelGeometry);
+    auto* grContext = this->context()->internal().grContext();
+    auto bounds = SkIRect::MakeWH(fWidth, fHeight);
+    auto atlasTextContext = grContext->contextPriv().drawingManager()->getAtlasTextContext();
+    atlasTextContext->drawText(grContext, this, GrNoClip(), paint, SkMatrix::I(), props,
+                               (const char*)text, byteLength, x, y, bounds);
+}
+
+void SkInternalAtlasTextTarget::addDrawOp(const GrClip& clip, std::unique_ptr<GrAtlasTextOp> op) {
+    SkASSERT(clip.quickContains(SkRect::MakeIWH(fWidth, fHeight)));
+    // The SkAtlasTextRenderer currently only handles grayscale SDF glyphs.
+    if (op->maskType() != GrAtlasTextOp::kGrayscaleDistanceField_MaskType) {
+        return;
+    }
+    // TODO: batch ops here.
+    op->visitProxies([](GrSurfaceProxy*) {});
+    fOps.emplace_back(RecordedOp{std::move(op), fColor});
+}
+
+void SkInternalAtlasTextTarget::flush() {
+    for (int i = 0; i < fOps.count(); ++i) {
+        fOps[i].fOp->executeForTextTarget(this, fOps[i].fColor);
+    }
+    this->context()->internal().flush();
+    fOps.reset();
+}
+
+void GrAtlasTextOp::executeForTextTarget(SkAtlasTextTarget* target, uint32_t color) {
+    FlushInfo flushInfo;
+    SkAutoGlyphCache glyphCache;
+    auto& context = target->context()->internal();
+    auto* atlasGlyphCache = context.grContext()->getAtlasGlyphCache();
+    for (int i = 0; i < fGeoCount; ++i) {
+        GrAtlasTextBlob::VertexRegenerator regenerator(
+                fGeoData[i].fBlob, fGeoData[i].fRun, fGeoData[i].fSubRun, fGeoData[i].fViewMatrix,
+                fGeoData[i].fX, fGeoData[i].fY, color, &context, atlasGlyphCache, &glyphCache);
+        GrAtlasTextBlob::VertexRegenerator::Result result;
+        do {
+            result = regenerator.regenerate();
+            context.recordDraw(result.fFirstVertex, result.fGlyphsRegenerated, target->handle());
+            if (!result.fFinished) {
+                // Make space in the atlas so we can continue generating vertices.
+                context.flush();
+            }
+        } while (!result.fFinished);
+    }
+}
diff --git a/src/atlastext/SkInternalAtlasTextContext.cpp b/src/atlastext/SkInternalAtlasTextContext.cpp
new file mode 100644
index 0000000000..8be7e1fb67
--- /dev/null
+++ b/src/atlastext/SkInternalAtlasTextContext.cpp
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkInternalAtlasTextContext.h"
+#include "GrContext.h"
+#include "SkAtlasTextContext.h"
+#include "SkAtlasTextRenderer.h"
+#include "text/GrAtlasGlyphCache.h"
+
+SkAtlasTextRenderer* SkGetAtlasTextRendererFromInternalContext(
+        class SkInternalAtlasTextContext& internal) {
+    return internal.renderer();
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+std::unique_ptr<SkInternalAtlasTextContext> SkInternalAtlasTextContext::Make(
+        sk_sp<SkAtlasTextRenderer> renderer) {
+    return std::unique_ptr<SkInternalAtlasTextContext>(
+            new SkInternalAtlasTextContext(std::move(renderer)));
+}
+
+SkInternalAtlasTextContext::SkInternalAtlasTextContext(sk_sp<SkAtlasTextRenderer> renderer)
+        : fRenderer(std::move(renderer)) {
+    GrContextOptions options;
+    options.fAllowMultipleGlyphCacheTextures = GrContextOptions::Enable::kNo;
+    options.fMinDistanceFieldFontSize = 0.f;
+    options.fGlyphsAsPathsFontSize = SK_ScalarInfinity;
+    fGrContext = GrContext::MakeMock(nullptr, options);
+}
+
+SkInternalAtlasTextContext::~SkInternalAtlasTextContext() {
+    if (fDistanceFieldAtlas.fProxy) {
+        SkASSERT(1 == fGrContext->getAtlasGlyphCache()->getAtlasPageCount(kA8_GrMaskFormat));
+        fRenderer->deleteTexture(fDistanceFieldAtlas.fTextureHandle);
+    }
+}
+
+GrAtlasGlyphCache* SkInternalAtlasTextContext::atlasGlyphCache() {
+    return fGrContext->getAtlasGlyphCache();
+}
+
+GrTextBlobCache* SkInternalAtlasTextContext::textBlobCache() {
+    return fGrContext->getTextBlobCache();
+}
+
+GrDeferredUploadToken SkInternalAtlasTextContext::addInlineUpload(
+        GrDeferredTextureUploadFn&& upload) {
+    auto token = this->nextDrawToken();
+    fInlineUploads.append(&fArena, InlineUpload{std::move(upload), token});
+    return token;
+}
+
+GrDeferredUploadToken SkInternalAtlasTextContext::addASAPUpload(
+        GrDeferredTextureUploadFn&& upload) {
+    fASAPUploads.append(&fArena, std::move(upload));
+    return this->nextTokenToFlush();
+}
+
+void SkInternalAtlasTextContext::recordDraw(const void* srcVertexData, int glyphCnt,
+                                            void* targetHandle) {
+    auto vertexDataSize = sizeof(SkAtlasTextRenderer::SDFVertex) * 4 * glyphCnt;
+    auto vertexData = fArena.makeArrayDefault<char>(vertexDataSize);
+    memcpy(vertexData, srcVertexData, vertexDataSize);
+    for (int i = 0; i < 4 * glyphCnt; ++i) {
+        auto* vertex = reinterpret_cast<SkAtlasTextRenderer::SDFVertex*>(vertexData) + i;
+        // GrAtlasTextContext encodes a texture index into the lower bit of each texture coord.
+        // This isn't expected by SkAtlasTextRenderer subclasses.
+        vertex->fTextureCoord.fX /= 2;
+        vertex->fTextureCoord.fY /= 2;
+    }
+    fDraws.append(&fArena, Draw{glyphCnt, this->issueDrawToken(), targetHandle, vertexData});
+}
+
+void SkInternalAtlasTextContext::flush() {
+    auto* atlasGlyphCache = fGrContext->getAtlasGlyphCache();
+    if (!fDistanceFieldAtlas.fProxy) {
+        SkASSERT(1 == atlasGlyphCache->getAtlasPageCount(kA8_GrMaskFormat));
+        fDistanceFieldAtlas.fProxy = atlasGlyphCache->getProxies(kA8_GrMaskFormat)->get();
+        fDistanceFieldAtlas.fTextureHandle =
+                fRenderer->createTexture(SkAtlasTextRenderer::AtlasFormat::kA8,
+                                         fDistanceFieldAtlas.fProxy->width(),
+                                         fDistanceFieldAtlas.fProxy->height());
+    }
+    GrDeferredTextureUploadWritePixelsFn writePixelsFn =
+            [this](GrTextureProxy* proxy, int left, int top, int width, int height,
+                   GrPixelConfig config, const void* data, size_t rowBytes) -> bool {
+        SkASSERT(kAlpha_8_GrPixelConfig == config);
+        SkASSERT(proxy == this->fDistanceFieldAtlas.fProxy);
+        void* handle = fDistanceFieldAtlas.fTextureHandle;
+        this->fRenderer->setTextureData(handle, data, left, top, width, height, rowBytes);
+        return true;
+    };
+    for (const auto& upload : fASAPUploads) {
+        upload(writePixelsFn);
+    }
+    auto draw = fDraws.begin();
+    auto inlineUpload = fInlineUploads.begin();
+    while (draw != fDraws.end()) {
+        while (inlineUpload != fInlineUploads.end() && inlineUpload->fToken == draw->fToken) {
+            inlineUpload->fUpload(writePixelsFn);
+            ++inlineUpload;
+        }
+        auto vertices = reinterpret_cast<const SkAtlasTextRenderer::SDFVertex*>(draw->fVertexData);
+        fRenderer->drawSDFGlyphs(draw->fTargetHandle, fDistanceFieldAtlas.fTextureHandle, vertices,
+                                 draw->fGlyphCnt);
+        ++draw;
+    }
+    fASAPUploads.reset();
+    fInlineUploads.reset();
+    fDraws.reset();
+    fArena.reset();
+}
diff --git a/src/atlastext/SkInternalAtlasTextContext.h b/src/atlastext/SkInternalAtlasTextContext.h
new file mode 100644
index 0000000000..1bb12cee5a
--- /dev/null
+++ b/src/atlastext/SkInternalAtlasTextContext.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkInternalAtlasTextContext_DEFINED
+#define SkInternalAtlasTextContext_DEFINED
+
+#include "GrDeferredUpload.h"
+#include "SkArenaAlloc.h"
+#include "SkArenaAllocList.h"
+#include "SkRefCnt.h"
+
+class SkAtlasTextRenderer;
+class GrContext;
+class GrAtlasGlyphCache;
+class GrTextBlobCache;
+
+/**
+ * The implementation of SkAtlasTextContext. This exists to hide the details from the public class.
+ * and to be able to use other private types.
+ */
+class SkInternalAtlasTextContext : public GrDeferredUploadTarget {
+public:
+    static std::unique_ptr<SkInternalAtlasTextContext> Make(sk_sp<SkAtlasTextRenderer>);
+
+    ~SkInternalAtlasTextContext() override;
+
+    SkAtlasTextRenderer* renderer() const { return fRenderer.get(); }
+
+    GrContext* grContext() const { return fGrContext.get(); }
+    GrAtlasGlyphCache* atlasGlyphCache();
+    GrTextBlobCache* textBlobCache();
+
+    GrDeferredUploadToken addInlineUpload(GrDeferredTextureUploadFn&&) override;
+
+    GrDeferredUploadToken addASAPUpload(GrDeferredTextureUploadFn&&) override;
+
+    void recordDraw(const void* vertexData, int glyphCnt, void* targetHandle);
+
+    void flush();
+
+private:
+    class DeferredUploader;
+    SkInternalAtlasTextContext() = delete;
+    SkInternalAtlasTextContext(const SkInternalAtlasTextContext&) = delete;
+    SkInternalAtlasTextContext& operator=(const SkInternalAtlasTextContext&) = delete;
+
+    SkInternalAtlasTextContext(sk_sp<SkAtlasTextRenderer>);
+
+    sk_sp<SkAtlasTextRenderer> fRenderer;
+
+    struct AtlasTexture {
+        void* fTextureHandle = nullptr;
+        GrTextureProxy* fProxy = nullptr;
+    };
+
+    struct Draw {
+        int fGlyphCnt;
+        GrDeferredUploadToken fToken;
+        void* fTargetHandle;
+        const void* fVertexData;
+    };
+
+    struct InlineUpload {
+        GrDeferredTextureUploadFn fUpload;
+        GrDeferredUploadToken fToken;
+    };
+
+    SkArenaAllocList<InlineUpload> fInlineUploads;
+    SkArenaAllocList<Draw> fDraws;
+    SkArenaAllocList<GrDeferredTextureUploadFn> fASAPUploads;
+    SkArenaAlloc fArena{1024 * 40};
+    sk_sp<GrContext> fGrContext;
+    AtlasTexture fDistanceFieldAtlas;
+};
+
+#endif