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>

1 files changed, 143 insertions, 0 deletions

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);
+    }
+}