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#include <mbgl/text/font_stack.hpp>
#include <cassert>
#include <mbgl/util/math.hpp>
namespace mbgl {
void FontStack::insert(uint32_t id, const SDFGlyph &glyph) {
metrics.emplace(id, glyph.metrics);
bitmaps.emplace(id, glyph.bitmap);
sdfs.emplace(id, glyph);
}
const std::map<uint32_t, GlyphMetrics> &FontStack::getMetrics() const {
return metrics;
}
const std::map<uint32_t, SDFGlyph> &FontStack::getSDFs() const {
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 {
Shaping shaping(translate.x * 24, translate.y * 24, string);
// the y offset *should* be part of the font metadata
const int32_t yOffset = -17;
float x = std::round(translate.x * 24); // one em
const float y = std::round(translate.y * 24) + yOffset; // one em
// Loop through all characters of this label and shape.
for (uint32_t chr : string) {
auto metric = metrics.find(chr);
if (metric != metrics.end()) {
shaping.positionedGlyphs.emplace_back(chr, x, y);
x += metric->second.advance + spacing;
}
}
if (shaping.positionedGlyphs.empty())
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 (auto& glyph : shaping.positionedGlyphs) {
glyph.x += shiftX;
glyph.y += shiftY;
}
}
void justifyLine(std::vector<PositionedGlyph> &positionedGlyphs, const std::map<uint32_t, GlyphMetrics> &metrics, uint32_t start,
uint32_t end, float justify) {
PositionedGlyph &glyph = positionedGlyphs[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++) {
positionedGlyphs[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;
std::vector<PositionedGlyph> &positionedGlyphs = shaping.positionedGlyphs;
if (maxWidth) {
for (uint32_t i = 0; i < positionedGlyphs.size(); i++) {
PositionedGlyph &shape = positionedGlyphs[i];
shape.x -= lengthBeforeCurrentLine;
shape.y += lineHeight * line;
if (shape.x > maxWidth && lastSafeBreak > 0) {
uint32_t lineLength = positionedGlyphs[lastSafeBreak + 1].x;
maxLineLength = util::max(lineLength, maxLineLength);
for (uint32_t k = lastSafeBreak + 1; k <= i; k++) {
positionedGlyphs[k].y += lineHeight;
positionedGlyphs[k].x -= lineLength;
}
if (justify) {
justifyLine(positionedGlyphs, metrics, lineStartIndex, lastSafeBreak - 1, justify);
}
lineStartIndex = lastSafeBreak + 1;
lastSafeBreak = 0;
lengthBeforeCurrentLine += lineLength;
line++;
}
if (shape.glyph == 32) {
lastSafeBreak = i;
}
}
}
const PositionedGlyph& lastPositionedGlyph = positionedGlyphs.back();
const auto lastGlyphMetric = metrics.find(lastPositionedGlyph.glyph);
assert(lastGlyphMetric != metrics.end());
const uint32_t lastLineLength = lastPositionedGlyph.x + lastGlyphMetric->second.advance;
maxLineLength = std::max(maxLineLength, lastLineLength);
const uint32_t height = (line + 1) * lineHeight;
justifyLine(positionedGlyphs, metrics, lineStartIndex, uint32_t(positionedGlyphs.size()) - 1, justify);
align(shaping, justify, horizontalAlign, verticalAlign, maxLineLength, lineHeight, line);
// Calculate the bounding box
shaping.top += -verticalAlign * height;
shaping.bottom = shaping.top + height;
shaping.left += -horizontalAlign * maxLineLength;
shaping.right = shaping.left + maxLineLength;
}
} // end namespace mbgl
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