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, 117 insertions, 0 deletions

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();
+}