diff options
Diffstat (limited to 'src/mbgl/text/glyph_store.cpp')
| -rw-r--r-- | src/mbgl/text/glyph_store.cpp | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/src/mbgl/text/glyph_store.cpp b/src/mbgl/text/glyph_store.cpp new file mode 100644 index 0000000000..2f5db180fd --- /dev/null +++ b/src/mbgl/text/glyph_store.cpp @@ -0,0 +1,294 @@ +#include <mbgl/text/glyph_store.hpp> + +#include <mbgl/util/std.hpp> +#include <mbgl/util/string.hpp> +#include <mbgl/util/utf.hpp> +#include <mbgl/util/pbf.hpp> +#include <mbgl/util/url.hpp> +#include <mbgl/util/constants.hpp> +#include <mbgl/util/token.hpp> +#include <mbgl/util/math.hpp> +#include <mbgl/storage/file_source.hpp> +#include <mbgl/platform/platform.hpp> +#include <mbgl/util/uv_detail.hpp> +#include <algorithm> + +namespace mbgl { + + +void FontStack::insert(uint32_t id, const SDFGlyph &glyph) { + std::lock_guard<std::mutex> lock(mtx); + metrics.emplace(id, glyph.metrics); + bitmaps.emplace(id, glyph.bitmap); + sdfs.emplace(id, glyph); +} + +const std::map<uint32_t, GlyphMetrics> &FontStack::getMetrics() const { + std::lock_guard<std::mutex> lock(mtx); + return metrics; +} + +const std::map<uint32_t, SDFGlyph> &FontStack::getSDFs() const { + std::lock_guard<std::mutex> lock(mtx); + return sdfs; +} + +const Shaping FontStack::getShaping(const std::u32string &string, const float maxWidth, + const float lineHeight, const float horizontalAlign, + const float verticalAlign, const float justify, + const float spacing, const vec2<float> &translate) const { + std::lock_guard<std::mutex> lock(mtx); + + Shaping shaping; + + int32_t x = std::round(translate.x * 24); // one em + const int32_t y = std::round(translate.y * 24); // one em + + // Loop through all characters of this label and shape. + for (uint32_t chr : string) { + shaping.emplace_back(chr, x, y); + auto metric = metrics.find(chr); + if (metric != metrics.end()) { + x += metric->second.advance + spacing; + } + } + + if (!shaping.size()) + return shaping; + + lineWrap(shaping, lineHeight, maxWidth, horizontalAlign, verticalAlign, justify); + + return shaping; +} + +void align(Shaping &shaping, const float justify, const float horizontalAlign, + const float verticalAlign, const uint32_t maxLineLength, const float lineHeight, + const uint32_t line) { + const float shiftX = (justify - horizontalAlign) * maxLineLength; + const float shiftY = (-verticalAlign * (line + 1) + 0.5) * lineHeight; + + for (PositionedGlyph &glyph : shaping) { + glyph.x += shiftX; + glyph.y += shiftY; + } +} + +void justifyLine(Shaping &shaping, const std::map<uint32_t, GlyphMetrics> &metrics, uint32_t start, + uint32_t end, float justify) { + PositionedGlyph &glyph = shaping[end]; + auto metric = metrics.find(glyph.glyph); + if (metric != metrics.end()) { + const uint32_t lastAdvance = metric->second.advance; + const float lineIndent = float(glyph.x + lastAdvance) * justify; + + for (uint32_t j = start; j <= end; j++) { + shaping[j].x -= lineIndent; + } + } +} + +void FontStack::lineWrap(Shaping &shaping, const float lineHeight, const float maxWidth, + const float horizontalAlign, const float verticalAlign, + const float justify) const { + uint32_t lastSafeBreak = 0; + + uint32_t lengthBeforeCurrentLine = 0; + uint32_t lineStartIndex = 0; + uint32_t line = 0; + + uint32_t maxLineLength = 0; + + if (maxWidth) { + for (uint32_t i = 0; i < shaping.size(); i++) { + PositionedGlyph &shape = shaping[i]; + + shape.x -= lengthBeforeCurrentLine; + shape.y += lineHeight * line; + + if (shape.x > maxWidth && lastSafeBreak > 0) { + + uint32_t lineLength = shaping[lastSafeBreak + 1].x; + maxLineLength = util::max(lineLength, maxLineLength); + + for (uint32_t k = lastSafeBreak + 1; k <= i; k++) { + shaping[k].y += lineHeight; + shaping[k].x -= lineLength; + } + + if (justify) { + justifyLine(shaping, metrics, lineStartIndex, lastSafeBreak - 1, justify); + } + + lineStartIndex = lastSafeBreak + 1; + lastSafeBreak = 0; + lengthBeforeCurrentLine += lineLength; + line++; + } + + if (shape.glyph == 32) { + lastSafeBreak = i; + } + } + } + + if (!maxLineLength) maxLineLength = shaping.back().x; + + justifyLine(shaping, metrics, lineStartIndex, uint32_t(shaping.size()) - 1, justify); + align(shaping, justify, horizontalAlign, verticalAlign, maxLineLength, lineHeight, line); +} + +GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, FileSource& fileSource) + : future(promise.get_future().share()) +{ + // Load the glyph set URL + std::string url = util::replaceTokens(glyphURL, [&](const std::string &name) -> std::string { + if (name == "fontstack") return util::percentEncode(fontStack); + if (name == "range") return util::toString(glyphRange.first) + "-" + util::toString(glyphRange.second); + return ""; + }); + + // The prepare call jumps back to the main thread. + fileSource.prepare([&, url] { + auto request = fileSource.request(ResourceType::Glyphs, url); + request->onload([&, url](const Response &res) { + if (res.code != 200) { + // Something went wrong with loading the glyph pbf. Pass on the error to the future listeners. + const std::string msg = std::string { "[ERROR] failed to load glyphs (" } + util::toString(res.code) + "): " + res.message; + promise.set_exception(std::make_exception_ptr(std::runtime_error(msg))); + } else { + // Transfer the data to the GlyphSet and signal its availability. + // Once it is available, the caller will need to call parse() to actually + // parse the data we received. We are not doing this here since this callback is being + // called from another (unknown) thread. + data = res.data; + promise.set_value(*this); + } + }); + request->oncancel([&]() { + promise.set_exception(std::make_exception_ptr(std::runtime_error("Loading glyphs was canceled"))); + }); + }); +} + +std::shared_future<GlyphPBF &> GlyphPBF::getFuture() { + return future; +} + +void GlyphPBF::parse(FontStack &stack) { + std::lock_guard<std::mutex> lock(mtx); + + if (!data.size()) { + // If there is no data, this means we either haven't received any data, or + // we have already parsed the data. + return; + } + + // Parse the glyph PBF + pbf glyphs_pbf(reinterpret_cast<const uint8_t *>(data.data()), data.size()); + + while (glyphs_pbf.next()) { + if (glyphs_pbf.tag == 1) { // stacks + pbf fontstack_pbf = glyphs_pbf.message(); + while (fontstack_pbf.next()) { + if (fontstack_pbf.tag == 3) { // glyphs + pbf glyph_pbf = fontstack_pbf.message(); + + SDFGlyph glyph; + + while (glyph_pbf.next()) { + if (glyph_pbf.tag == 1) { // id + glyph.id = glyph_pbf.varint(); + } else if (glyph_pbf.tag == 2) { // bitmap + glyph.bitmap = glyph_pbf.string(); + } else if (glyph_pbf.tag == 3) { // width + glyph.metrics.width = glyph_pbf.varint(); + } else if (glyph_pbf.tag == 4) { // height + glyph.metrics.height = glyph_pbf.varint(); + } else if (glyph_pbf.tag == 5) { // left + glyph.metrics.left = glyph_pbf.svarint(); + } else if (glyph_pbf.tag == 6) { // top + glyph.metrics.top = glyph_pbf.svarint(); + } else if (glyph_pbf.tag == 7) { // advance + glyph.metrics.advance = glyph_pbf.varint(); + } else { + glyph_pbf.skip(); + } + } + + stack.insert(glyph.id, glyph); + } else { + fontstack_pbf.skip(); + } + } + } else { + glyphs_pbf.skip(); + } + } + + data.clear(); +} + +GlyphStore::GlyphStore(FileSource& fileSource_) : fileSource(fileSource_) {} + +void GlyphStore::setURL(const std::string &url) { + glyphURL = url; +} + + +void GlyphStore::waitForGlyphRanges(const std::string &fontStack, const std::set<GlyphRange> &glyphRanges) { + // We are implementing a blocking wait with futures: Every GlyphSet has a future that we are + // waiting for until it is loaded. + if (glyphRanges.empty()) { + return; + } + + FontStack *stack = nullptr; + + std::vector<std::shared_future<GlyphPBF &>> futures; + futures.reserve(glyphRanges.size()); + { + std::lock_guard<std::mutex> lock(mtx); + auto &rangeSets = ranges[fontStack]; + + stack = &createFontStack(fontStack); + + // Attempt to load the glyph range. If the GlyphSet already exists, we are getting back + // the same shared_future. + for (GlyphRange range : glyphRanges) { + futures.emplace_back(loadGlyphRange(fontStack, rangeSets, range)); + } + } + + // Now that we potentially created all GlyphSets, we are waiting for the results, one by one. + // When we get a result (or the GlyphSet is aready loaded), we are attempting to parse the + // GlyphSet. + for (std::shared_future<GlyphPBF &> &future : futures) { + future.get().parse(*stack); + } +} + +std::shared_future<GlyphPBF &> GlyphStore::loadGlyphRange(const std::string &fontStack, std::map<GlyphRange, std::unique_ptr<GlyphPBF>> &rangeSets, const GlyphRange range) { + auto range_it = rangeSets.find(range); + if (range_it == rangeSets.end()) { + // We don't have this glyph set yet for this font stack. + range_it = rangeSets.emplace(range, util::make_unique<GlyphPBF>(glyphURL, fontStack, range, fileSource)).first; + } + + return range_it->second->getFuture(); +} + +FontStack &GlyphStore::createFontStack(const std::string &fontStack) { + auto stack_it = stacks.find(fontStack); + if (stack_it == stacks.end()) { + stack_it = stacks.emplace(fontStack, util::make_unique<FontStack>()).first; + } + return *stack_it->second.get(); +} + +FontStack &GlyphStore::getFontStack(const std::string &fontStack) { + std::lock_guard<std::mutex> lock(mtx); + return createFontStack(fontStack); +} + + +} |