v1.4.4

source/core/StarFont.cpp

@@ -0,0 +1,123 @@
+#include "StarFont.hpp"
+#include "StarFile.hpp"
+#include "StarFormat.hpp"
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+namespace Star {
+
+struct FTContext {
+  FT_Library library;
+
+  FTContext() {
+    library = nullptr;
+    if (FT_Init_FreeType(&library))
+      throw FontException("Could not initialize freetype library.");
+  }
+
+  ~FTContext() {
+    if (library) {
+      FT_Done_FreeType(library);
+      library = nullptr;
+    }
+  }
+};
+
+FTContext ftContext;
+
+struct FontImpl {
+  FT_Face face;
+};
+
+FontPtr Font::loadTrueTypeFont(String const& fileName, unsigned pixelSize) {
+  return loadTrueTypeFont(make_shared<ByteArray>(File::readFile(fileName)), pixelSize);
+}
+
+FontPtr Font::loadTrueTypeFont(ByteArrayConstPtr const& bytes, unsigned pixelSize) {
+  FontPtr font = make_shared<Font>();
+  font->m_fontBuffer = bytes;
+
+  shared_ptr<FontImpl> fontImpl = make_shared<FontImpl>();
+  if (FT_New_Memory_Face(
+          ftContext.library, (FT_Byte const*)font->m_fontBuffer->ptr(), font->m_fontBuffer->size(), 0, &fontImpl->face))
+    throw FontException("Could not load font from buffer");
+
+  font->m_fontImpl = fontImpl;
+  font->setPixelSize(pixelSize);
+
+  return font;
+}
+
+Font::Font() {
+  m_pixelSize = 0;
+}
+
+FontPtr Font::clone() const {
+  return Font::loadTrueTypeFont(m_fontBuffer, m_pixelSize);
+}
+
+void Font::setPixelSize(unsigned pixelSize) {
+  if (pixelSize == 0) {
+    pixelSize = 1;
+  }
+
+  if (m_pixelSize == pixelSize)
+    return;
+
+  if (FT_Set_Pixel_Sizes(m_fontImpl->face, pixelSize, 0))
+    throw FontException(strf("Cannot set font pixel size to: %s", pixelSize));
+  m_pixelSize = pixelSize;
+}
+
+unsigned Font::height() const {
+  return m_pixelSize;
+}
+
+unsigned Font::width(String::Char c) {
+  if (auto width = m_widthCache.maybe({c, m_pixelSize})) {
+    return *width;
+  } else {
+    FT_Load_Char(m_fontImpl->face, c, FT_LOAD_DEFAULT);
+    unsigned newWidth = (m_fontImpl->face->glyph->advance.x + 32) / 64;
+    m_widthCache.insert({c, m_pixelSize}, newWidth);
+    return newWidth;
+  }
+}
+
+Image Font::render(String::Char c) {
+  if (!m_fontImpl)
+    throw FontException("Font::render called on uninitialzed font.");
+
+  FT_UInt glyph_index = FT_Get_Char_Index(m_fontImpl->face, c);
+  if (FT_Load_Glyph(m_fontImpl->face, glyph_index, FT_LOAD_DEFAULT) != 0)
+    return {};
+
+  /* convert to an anti-aliased bitmap */
+  if (FT_Render_Glyph(m_fontImpl->face->glyph, FT_RENDER_MODE_NORMAL) != 0)
+    return {};
+
+  FT_GlyphSlot slot = m_fontImpl->face->glyph;
+
+  int width = (slot->advance.x + 32) / 64;
+  int height = m_pixelSize;
+
+  Image image(width, height, PixelFormat::RGBA32);
+  for (int y = 0; y < height; ++y) {
+    for (int x = 0; x < width; ++x) {
+      int bx = x;
+      int by = y + slot->bitmap_top - m_fontImpl->face->size->metrics.ascender / 64;
+      if (bx >= 0 && by >= 0 && bx < (int)slot->bitmap.width && by < (int)slot->bitmap.rows) {
+        unsigned char* p = slot->bitmap.buffer + by * slot->bitmap.pitch;
+        unsigned char val = *(p + bx);
+        image.set(x, height - y - 1, Vec4B(255, 255, 255, val));
+      } else {
+        image.set(x, height - y - 1, Vec4B(255, 255, 255, 0));
+      }
+    }
+  }
+
+  return image;
+}
+
+}