bool GetFace(uint codepoint, out uint index, out IntPtr face)
{
//use our font!
index = FT.FT_Get_Char_Index(facePtr, codepoint);
if (index != 0)
{
face = facePtr;
return(true);
}
//try fallback font
if (context.Fallback == IntPtr.Zero)
{
face = IntPtr.Zero;
return(false);
}
FT.FT_Set_Char_Size(context.Fallback,
FTMath.To26Dot6(0),
size26d6,
0,
96
);
index = FT.FT_Get_Char_Index(context.Fallback, codepoint);
if (index != 0)
{
face = context.Fallback;
return(true);
}
//none of the fonts have this mysterious character
face = IntPtr.Zero;
return(false);
}
public void DrawString(SpriteBatch spriteBatch, string text, int x, int y, Color4 color)
{
if (text == "") //Skip empty strings
{
return;
}
var iter = new CodepointIterator(text);
float penX = x, penY = y;
while (iter.Iterate())
{
uint c = iter.Codepoint;
if (c == (uint)'\n')
{
penY += lineHeight;
penX = x;
continue;
}
var glyph = GetGlyph(c);
if (glyph.Render)
{
spriteBatch.Draw(
glyph.Texture,
glyph.Rectangle,
new Rectangle(
(int)penX + glyph.XOffset,
(int)penY + (LineHeight - glyph.YOffset),
glyph.Rectangle.Width,
glyph.Rectangle.Height
),
color
);
penX += glyph.HorizontalAdvance;
penY += glyph.AdvanceY;
}
else
{
penX += glyph.AdvanceX;
penY += glyph.AdvanceY;
}
if (glyph.Kerning && iter.Index < iter.Count - 1)
{
var g2 = GetGlyph(iter.PeekNext());
if (g2.Face == glyph.Face)
{
FT.FT_Vector vec;
FT.FT_Get_Kerning(glyph.Face, glyph.CharIndex, g2.CharIndex, 2, out vec);
var krn = FTMath.From26Dot6(vec.x);
penX += krn;
}
}
}
}
public Point MeasureString(string text)
{
if (text == "") //Skip empty strings
{
return(new Point(0, 0));
}
var iter = new CodepointIterator(text);
float penX = 0, penY = 0;
while (iter.Iterate())
{
uint c = iter.Codepoint;
if (c == (uint)'\n')
{
penY += lineHeight;
penX = 0;
continue;
}
var glyph = GetGlyph(c);
if (glyph.Render)
{
penX += glyph.HorizontalAdvance;
penY += glyph.AdvanceY;
}
else
{
penX += glyph.AdvanceX;
penY += glyph.AdvanceY;
}
if (glyph.Kerning && iter.Index < iter.Count - 1)
{
var g2 = GetGlyph(iter.PeekNext());
if (g2.Face == glyph.Face)
{
FT.FT_Vector vec;
FT.FT_Get_Kerning(glyph.Face, glyph.CharIndex, g2.CharIndex, 2, out vec);
var krn = FTMath.From26Dot6(vec.x);
penX += krn;
}
}
}
return(new Point((int)penX, (int)penY));
}
public Font(FontContext ctx, string filename, float size)
{
context = ctx;
size26d6 = FTMath.To26Dot6(size);
if (!File.Exists(filename))
{
throw new FileNotFoundException("Font not found " + filename, filename);
}
var err = FT.FT_New_Face(context.Library, filename, 0, out facePtr);
if (err != 0)
{
throw new Exception("Freetype Error");
}
FT.FT_Set_Char_Size(facePtr,
FTMath.To26Dot6(0),
size26d6,
0,
96
);
//get metrics
var faceRec = Marshal.PtrToStructure <FT.FaceRec> (facePtr);
var szRec = Marshal.PtrToStructure <FT.SizeRec> (faceRec.size);
lineHeight = (int)FTMath.From26Dot6(szRec.metrics.height);
pages.Add(new Texture(
PAGE_SIZE, PAGE_SIZE
));
//Rasterize standard ASCII
for (int i = 32; i < 127; i++)
{
AddCharacter((uint)i);
}
}
unsafe void AddCharacter(uint codepoint)
{
if (codepoint == (uint)'\t')
{
var spaceGlyph = GetGlyph((uint)' ');
glyphs.Add(codepoint, new GlyphInfo(spaceGlyph.AdvanceX * 4, spaceGlyph.AdvanceY, spaceGlyph.CharIndex, spaceGlyph.Face, spaceGlyph.Kerning));
return;
}
IntPtr face;
uint index;
if (!GetFace(codepoint, out index, out face))
{
if (codepoint == (uint)'?')
{
throw new Exception("Font does not have required ASCII characters");
}
var qmGlyph = GetGlyph((uint)'?');
glyphs.Add(codepoint, qmGlyph);
return;
}
FT.FT_Load_Glyph(face, index, FT.FT_LOAD_DEFAULT | FT.FT_LOAD_TARGET_NORMAL);
var faceRec = Marshal.PtrToStructure <FT.FaceRec> (face);
//not exactly the right spot, but this is the only place we access the members of the face
bool kerning = (((long)faceRec.face_flags) & FT.FT_FACE_FLAG_KERNING) == FT.FT_FACE_FLAG_KERNING;
FT.FT_Render_Glyph(faceRec.glyph, FT.FT_RENDER_MODE_NORMAL);
var glyphRec = Marshal.PtrToStructure <FT.GlyphSlotRec> (faceRec.glyph);
if (glyphRec.bitmap.width == 0 || glyphRec.bitmap.rows == 0)
{
glyphs.Add(codepoint,
new GlyphInfo(
(int)Math.Ceiling(FTMath.From26Dot6(glyphRec.advance.x)),
(int)Math.Ceiling(FTMath.From26Dot6(glyphRec.advance.y)),
index,
face,
kerning
)
);
}
else
{
var colors = new ByteColor[glyphRec.bitmap.width * glyphRec.bitmap.rows];
if (glyphRec.bitmap.pixel_mode == 2)
{
byte *data = (byte *)glyphRec.bitmap.buffer;
for (int i = 0; i < glyphRec.bitmap.width * glyphRec.bitmap.rows; i++)
{
//TODO: 4 bytes used for 1 byte of alpha data? investigate compression with GL_RED and shader.
colors [i] = new ByteColor(255, 255, 255, data [i]);
}
}
else
{
throw new NotImplementedException();
}
if (currentX + glyphRec.bitmap.width > PAGE_SIZE)
{
currentX = 0;
currentY += lineMax;
lineMax = 0;
}
if (currentY + glyphRec.bitmap.rows > PAGE_SIZE)
{
currentX = 0;
currentY = 0;
lineMax = 0;
pages.Add(new Texture(PAGE_SIZE, PAGE_SIZE));
//TODO: new font page! should probably log this
}
lineMax = (int)Math.Max(lineMax, glyphRec.bitmap.rows);
var rect = new Rectangle(currentX, currentY, glyphRec.bitmap.width, glyphRec.bitmap.rows);
var tex = pages [pages.Count - 1];
tex.SetData(colors, rect);
currentX += glyphRec.bitmap.width;
glyphs.Add(codepoint,
new GlyphInfo(
tex,
rect,
(int)Math.Ceiling(FTMath.From26Dot6(glyphRec.advance.x)),
(int)Math.Ceiling(FTMath.From26Dot6(glyphRec.advance.y)),
(int)Math.Ceiling(FTMath.From26Dot6(glyphRec.metrics.horiAdvance)),
glyphRec.bitmap_left,
glyphRec.bitmap_top,
index,
face,
kerning
)
);
}
}