Method InternalGetGlyph

src/fontcache/freetypefontcache.cpp:136–194

const Sprite *FreeTypeFontCache::InternalGetGlyph(GlyphID key, bool aa)
{
	FT_GlyphSlot slot = this->face->glyph;

	FT_Load_Glyph(this->face, key, aa ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO);
	FT_Render_Glyph(this->face->glyph, aa ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO);

	/* Despite requesting a normal glyph, FreeType may have returned a bitmap */
	aa = (slot->bitmap.pixel_mode == FT_PIXEL_MODE_GRAY);

	/* Add 1 scaled pixel for the shadow on the medium font. Our sprite must be at least 1x1 pixel */
	uint shadow = (this->fs == FS_NORMAL) ? ScaleGUITrad(1) : 0;
	uint width  = std::max(1U, (uint)slot->bitmap.width + shadow);
	uint height = std::max(1U, (uint)slot->bitmap.rows  + shadow);

	/* Limit glyph size to prevent overflows later on. */
	if (width > MAX_GLYPH_DIM || height > MAX_GLYPH_DIM) UserError("Font glyph is too large");

	/* FreeType has rendered the glyph, now we allocate a sprite and copy the image into it */
	SpriteLoader::SpriteCollection spritecollection;
	SpriteLoader::Sprite &sprite = spritecollection[ZoomLevel::Min];
	sprite.AllocateData(ZoomLevel::Min, static_cast<size_t>(width) * height);
	sprite.colours = SpriteComponent::Palette;
	if (aa) sprite.colours.Set(SpriteComponent::Alpha);
	sprite.width = width;
	sprite.height = height;
	sprite.x_offs = slot->bitmap_left;
	sprite.y_offs = this->ascender - slot->bitmap_top;

	/* Draw shadow for medium size */
	if (this->fs == FS_NORMAL && !aa) {
		for (uint y = 0; y < (uint)slot->bitmap.rows; y++) {
			for (uint x = 0; x < (uint)slot->bitmap.width; x++) {
				if (HasBit(slot->bitmap.buffer[(x / 8) + y * slot->bitmap.pitch], 7 - (x % 8))) {
					sprite.data[shadow + x + (shadow + y) * sprite.width].m = SHADOW_COLOUR;
					sprite.data[shadow + x + (shadow + y) * sprite.width].a = 0xFF;
				}
			}
		}
	}

	for (uint y = 0; y < (uint)slot->bitmap.rows; y++) {
		for (uint x = 0; x < (uint)slot->bitmap.width; x++) {
			if (aa ? (slot->bitmap.buffer[x + y * slot->bitmap.pitch] > 0) : HasBit(slot->bitmap.buffer[(x / 8) + y * slot->bitmap.pitch], 7 - (x % 8))) {
				sprite.data[x + y * sprite.width].m = FACE_COLOUR;
				sprite.data[x + y * sprite.width].a = aa ? slot->bitmap.buffer[x + y * slot->bitmap.pitch] : 0xFF;
			}
		}
	}

	UniquePtrSpriteAllocator allocator;
	BlitterFactory::GetCurrentBlitter()->Encode(SpriteType::Font, spritecollection, allocator);

	GlyphEntry new_glyph;
	new_glyph.data = std::move(allocator.data);
	new_glyph.width = slot->advance.x >> 6;

	return this->SetGlyphPtr(key, std::move(new_glyph)).GetSprite();