Glyph Font::loadGlyph(Uint32 codePoint, unsigned int characterSize, bool bold) const
{
// The glyph to return
Glyph glyph;
// First, transform our ugly void* to a FT_Face
FT_Face face = static_cast<FT_Face>(m_face);
if (!face)
return glyph;
// Set the character size
if (!setCurrentSize(characterSize))
return glyph;
// Load the glyph corresponding to the code point
if (FT_Load_Char(face, codePoint, FT_LOAD_TARGET_NORMAL | FT_LOAD_FORCE_AUTOHINT) != 0)
return glyph;
// Retrieve the glyph
FT_Glyph glyphDesc;
if (FT_Get_Glyph(face->glyph, &glyphDesc) != 0)
return glyph;
// Apply bold if necessary -- first technique using outline (highest quality)
FT_Pos weight = 1 << 6;
bool outline = (glyphDesc->format == FT_GLYPH_FORMAT_OUTLINE);
if (bold && outline)
{
FT_OutlineGlyph outlineGlyph = (FT_OutlineGlyph)glyphDesc;
FT_Outline_Embolden(&outlineGlyph->outline, weight);
}
// Convert the glyph to a bitmap (i.e. rasterize it)
FT_Glyph_To_Bitmap(&glyphDesc, FT_RENDER_MODE_NORMAL, 0, 1);
FT_Bitmap& bitmap = reinterpret_cast<FT_BitmapGlyph>(glyphDesc)->bitmap;
// Apply bold if necessary -- fallback technique using bitmap (lower quality)
if (bold && !outline)
{
FT_Bitmap_Embolden(static_cast<FT_Library>(m_library), &bitmap, weight, weight);
}
// Compute the glyph's advance offset
glyph.advance = static_cast<float>(face->glyph->metrics.horiAdvance) / static_cast<float>(1 << 6);
if (bold)
glyph.advance += static_cast<float>(weight) / static_cast<float>(1 << 6);
int width = bitmap.width;
int height = bitmap.rows;
if ((width > 0) && (height > 0))
{
// Leave a small padding around characters, so that filtering doesn't
// pollute them with pixels from neighbors
const unsigned int padding = 1;
// Get the glyphs page corresponding to the character size
Page& page = m_pages[characterSize];
// Find a good position for the new glyph into the texture
glyph.textureRect = findGlyphRect(page, width + 2 * padding, height + 2 * padding);
// Make sure the texture data is positioned in the center
// of the allocated texture rectangle
glyph.textureRect.left += padding;
glyph.textureRect.top += padding;
glyph.textureRect.width -= 2 * padding;
glyph.textureRect.height -= 2 * padding;
// Compute the glyph's bounding box
glyph.bounds.left = static_cast<float>(face->glyph->metrics.horiBearingX) / static_cast<float>(1 << 6);
glyph.bounds.top = -static_cast<float>(face->glyph->metrics.horiBearingY) / static_cast<float>(1 << 6);
glyph.bounds.width = static_cast<float>(face->glyph->metrics.width) / static_cast<float>(1 << 6);
glyph.bounds.height = static_cast<float>(face->glyph->metrics.height) / static_cast<float>(1 << 6);
// Extract the glyph's pixels from the bitmap
m_pixelBuffer.resize(width * height * 4, 255);
const Uint8* pixels = bitmap.buffer;
if (bitmap.pixel_mode == FT_PIXEL_MODE_MONO)
{
// Pixels are 1 bit monochrome values
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
// The color channels remain white, just fill the alpha channel
std::size_t index = (x + y * width) * 4 + 3;
m_pixelBuffer[index] = ((pixels[x / 8]) & (1 << (7 - (x % 8)))) ? 255 : 0;
}
pixels += bitmap.pitch;
}
}
else
{
// Pixels are 8 bits gray levels
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
// The color channels remain white, just fill the alpha channel
std::size_t index = (x + y * width) * 4 + 3;
m_pixelBuffer[index] = pixels[x];
}
pixels += bitmap.pitch;
}
}
// Write the pixels to the texture
unsigned int x = glyph.textureRect.left;
unsigned int y = glyph.textureRect.top;
unsigned int w = glyph.textureRect.width;
unsigned int h = glyph.textureRect.height;
page.texture.update(&m_pixelBuffer[0], w, h, x, y);
}
// Delete the FT glyph
FT_Done_Glyph(glyphDesc);
// Force an OpenGL flush, so that the font's texture will appear updated
// in all contexts immediately (solves problems in multi-threaded apps)
glCheck(glFlush());
// Done :)
return glyph;
}
Glyph Font::loadGlyph(Uint32 codePoint, unsigned int characterSize, bool bold, float outlineThickness) const
{
// The glyph to return
Glyph glyph;
// First, transform our ugly void* to a FT_Face
FT_Face face = static_cast<FT_Face>(m_face);
if (!face)
return glyph;
// Set the character size
if (!setCurrentSize(characterSize))
return glyph;
// Load the glyph corresponding to the code point
FT_Int32 flags = FT_LOAD_TARGET_NORMAL | FT_LOAD_FORCE_AUTOHINT;
if (outlineThickness != 0)
flags |= FT_LOAD_NO_BITMAP;
if (FT_Load_Char(face, codePoint, flags) != 0)
return glyph;
// Retrieve the glyph
FT_Glyph glyphDesc;
if (FT_Get_Glyph(face->glyph, &glyphDesc) != 0)
return glyph;
// Apply bold and outline (there is no fallback for outline) if necessary -- first technique using outline (highest quality)
FT_Pos weight = 1 << 6;
bool outline = (glyphDesc->format == FT_GLYPH_FORMAT_OUTLINE);
if (outline)
{
if (bold)
{
FT_OutlineGlyph outlineGlyph = (FT_OutlineGlyph)glyphDesc;
FT_Outline_Embolden(&outlineGlyph->outline, weight);
}
if (outlineThickness != 0)
{
FT_Stroker stroker = static_cast<FT_Stroker>(m_stroker);
FT_Stroker_Set(stroker, static_cast<FT_Fixed>(outlineThickness * static_cast<float>(1 << 6)), FT_STROKER_LINECAP_ROUND, FT_STROKER_LINEJOIN_ROUND, 0);
FT_Glyph_Stroke(&glyphDesc, stroker, true);
}
}
// Convert the glyph to a bitmap (i.e. rasterize it)
FT_Glyph_To_Bitmap(&glyphDesc, FT_RENDER_MODE_NORMAL, 0, 1);
FT_Bitmap& bitmap = reinterpret_cast<FT_BitmapGlyph>(glyphDesc)->bitmap;
// Apply bold if necessary -- fallback technique using bitmap (lower quality)
if (!outline)
{
if (bold)
FT_Bitmap_Embolden(static_cast<FT_Library>(m_library), &bitmap, weight, weight);
if (outlineThickness != 0)
err() << "Failed to outline glyph (no fallback available)" << std::endl;
}
// Compute the glyph's advance offset
glyph.advance = static_cast<float>(face->glyph->metrics.horiAdvance) / static_cast<float>(1 << 6);
if (bold)
glyph.advance += static_cast<float>(weight) / static_cast<float>(1 << 6);
int width = bitmap.width;
int height = bitmap.rows;
if ((width > 0) && (height > 0))
{
// Leave a small padding around characters, so that filtering doesn't
// pollute them with pixels from neighbors
const unsigned int padding = 1;
width += 2 * padding;
height += 2 * padding;
// Get the glyphs page corresponding to the character size
Page& page = m_pages[characterSize];
// Find a good position for the new glyph into the texture
glyph.textureRect = findGlyphRect(page, width, height);
// Make sure the texture data is positioned in the center
// of the allocated texture rectangle
glyph.textureRect.left += padding;
glyph.textureRect.top += padding;
glyph.textureRect.width -= 2 * padding;
glyph.textureRect.height -= 2 * padding;
// Compute the glyph's bounding box
glyph.bounds.left = static_cast<float>(face->glyph->metrics.horiBearingX) / static_cast<float>(1 << 6);
glyph.bounds.top = -static_cast<float>(face->glyph->metrics.horiBearingY) / static_cast<float>(1 << 6);
glyph.bounds.width = static_cast<float>(face->glyph->metrics.width) / static_cast<float>(1 << 6) + outlineThickness * 2;
glyph.bounds.height = static_cast<float>(face->glyph->metrics.height) / static_cast<float>(1 << 6) + outlineThickness * 2;
// Resize the pixel buffer to the new size and fill it with transparent white pixels
m_pixelBuffer.resize(width * height * 4);
Uint8* current = &m_pixelBuffer[0];
Uint8* end = current + width * height * 4;
while (current != end)
{
(*current++) = 255;
(*current++) = 255;
(*current++) = 255;
(*current++) = 0;
}
// Extract the glyph's pixels from the bitmap
const Uint8* pixels = bitmap.buffer;
if (bitmap.pixel_mode == FT_PIXEL_MODE_MONO)
{
// Pixels are 1 bit monochrome values
for (unsigned int y = padding; y < height - padding; ++y)
{
for (unsigned int x = padding; x < width - padding; ++x)
{
// The color channels remain white, just fill the alpha channel
std::size_t index = x + y * width;
m_pixelBuffer[index * 4 + 3] = ((pixels[(x - padding) / 8]) & (1 << (7 - ((x - padding) % 8)))) ? 255 : 0;
}
pixels += bitmap.pitch;
}
}
else
{
// Pixels are 8 bits gray levels
for (unsigned int y = padding; y < height - padding; ++y)
{
for (unsigned int x = padding; x < width - padding; ++x)
{
// The color channels remain white, just fill the alpha channel
std::size_t index = x + y * width;
m_pixelBuffer[index * 4 + 3] = pixels[x - padding];
}
pixels += bitmap.pitch;
}
}
// Write the pixels to the texture
unsigned int x = glyph.textureRect.left - padding;
unsigned int y = glyph.textureRect.top - padding;
unsigned int w = glyph.textureRect.width + 2 * padding;
unsigned int h = glyph.textureRect.height + 2 * padding;
page.texture.update(&m_pixelBuffer[0], w, h, x, y);
}
// Delete the FT glyph
FT_Done_Glyph(glyphDesc);
// Done :)
return glyph;
}
