public static GlyphService FromGlyph(char character, GlyphSlot glyph, Renderer render_context)
{
glyph.RenderGlyph(RenderMode.Normal);
Bitmap m = null;
using (var g = glyph.GetGlyph())
{
g.ToBitmap(RenderMode.Normal, new FTVector26Dot6(0, 0), false);
var bt = g.ToBitmapGlyph();
if (bt.Bitmap.Width > 0)
{
m = bt.Bitmap.ToGdipBitmap();
}
}
// Later on write a Sprite.FromBitmap for Glyph Bitmaps..
var sprite = m == null ? null : Sprite.FromBitmap(m, render_context.ShaderProgram, 0, 0, 0, true);
sprite?.AcquireUse();
return(new GlyphService(character, CalcNext(glyph), CalcOffset(glyph), sprite));
}
public static Matrix4 CalcOffset(GlyphSlot glyph)
=> Matrix4.CreateTranslation(glyph.Metrics.HorizontalBearingX.ToSingle() / Sprite.TileSize,
(glyph.Metrics.HorizontalBearingY - glyph.Metrics.Height).ToSingle() / Sprite.TileSize,
0) * Matrix4.CreateScale(0.68f);
private void CompileCharacterToTexture(Face face, int c)
{
FTGlyphOffset offset = new FTGlyphOffset();
//We first convert the number index to a character index
//uint index = FT.FT_Get_Char_Index(faceptr, (uint)c);
uint index = sharpFace.GetCharIndex((uint)c);
string sError = "";
if (index == 0)
{
sError = "No Glyph";
}
//Here we load the actual glyph for the character
//int ret = FT.FT_Load_Glyph(faceptr, index, FT.FT_LOAD_DEFAULT);
//if (ret != 0)
//{
// Console.Write("Load_Glyph failed for character " + c.ToString());
//}
try
{
sharpFace.LoadGlyph(index, LoadFlags.Default, LoadTarget.Normal);
}
catch
{
Console.Write("Load_Glyph failed for character " + c.ToString());
}
// FT_GlyphSlotRec glyphrec = (FT_GlyphSlotRec)Marshal.PtrToStructure(face.glyph, typeof(FT_GlyphSlotRec));
//ret = FT.FT_Render_Glyph(ref glyphrec, FT_Render_Mode.FT_RENDER_MODE_NORMAL);
// if (ret != 0)
//{
// Console.Write("Render failed for character " + c.ToString());
//}
GlyphSlot glyphrec = sharpFace.Glyph;
int size = (glyphrec.Bitmap.Width * glyphrec.Bitmap.Rows);
if (size <= 0)
{
//Console.Write("Blank Character: " + c.ToString());
//space is a special `blank` character
extent_x[c] = 0;
if (c == 32)
{
GL.NewList((list_base + c), ListMode.Compile);
GL.Translate(font_size >> 1, 0, 0);
extent_x[c] = font_size >> 1;
GL.EndList();
offset.left = 0;
offset.top = 0;
offset.height = 0;
offset.width = extent_x[c];
offsets[c] = offset;
}
return;
}
byte[] bmp = new byte[size];
Marshal.Copy(glyphrec.Bitmap.Buffer, bmp, 0, bmp.Length);
//Next we expand the bitmap into an opengl texture
int width = next_po2(glyphrec.Bitmap.Width);
int height = next_po2(glyphrec.Bitmap.Rows);
byte[] expanded = new byte[2 * width * height];
for (int j = 0; j < height; j++)
{
for (int i = 0; i < width; i++)
{
//Luminance
expanded[2 * (i + j * width)] = (byte)255;
//expanded[4 * (i + j * width) + 1] = (byte)255;
//expanded[4 * (i + j * width) + 2] = (byte)255;
// Alpha
expanded[2 * (i + j * width) + 1] =
(i >= glyphrec.Bitmap.Width || j >= glyphrec.Bitmap.Rows) ?
(byte)0 : (byte)(bmp[i + glyphrec.Bitmap.Width * j]);
}
}
//Set up some texture parameters for opengl
GL.BindTexture(TextureTarget.Texture2D, textures[c]);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, 0x812F); //const Int32 GL_CLAMP_TO_EDGE = 0x812F;
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, 0x812F); //const Int32 GL_CLAMP_TO_EDGE = 0x812F;
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, 0x2601); //const Int32 GL_LINEAR = 0x2601;
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, 0x2601); //const Int32 GL_LINEAR = 0x2601;
//Create the texture
GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, width, height,
0, PixelFormat.LuminanceAlpha, PixelType.UnsignedByte, expanded);
expanded = null;
bmp = null;
//Create a display list and bind a texture to it
GL.NewList((list_base + c), ListMode.Compile);
GL.BindTexture(TextureTarget.Texture2D, textures[c]);
//Account for freetype spacing rules
GL.Translate(glyphrec.BitmapLeft, 0, 0);
GL.PushMatrix();
GL.Translate(0, glyphrec.BitmapTop - glyphrec.Bitmap.Rows, 0);
float x = (float)glyphrec.Bitmap.Width / (float)width;
float y = (float)glyphrec.Bitmap.Rows / (float)height;
offset.left = glyphrec.BitmapLeft;
offset.top = glyphrec.BitmapTop;
offset.height = glyphrec.Bitmap.Rows;
offset.width = glyphrec.Bitmap.Width;
offset.advance = glyphrec.Advance;
offset.lsb_delta = glyphrec.DeltaLsb;
offset.rsb_delta = glyphrec.DeltaRsb;
offset.linearHoriAdvance = glyphrec.LinearHorizontalAdvance;
offset.linearVertAdvance = glyphrec.LinearVerticalAdvance;
offsets[c] = offset;
//Draw the quad
GL.Begin(BeginMode.Quads);
GL.TexCoord2(0, 0); GL.Vertex2(0, glyphrec.Bitmap.Rows);
GL.TexCoord2(0, y); GL.Vertex2(0, 0);
GL.TexCoord2(x, y); GL.Vertex2(glyphrec.Bitmap.Width, 0);
GL.TexCoord2(x, 0); GL.Vertex2(glyphrec.Bitmap.Width, glyphrec.Bitmap.Rows);
GL.End();
GL.PopMatrix();
//Advance for the next character
GL.Translate(glyphrec.Bitmap.Width, 0, 0);
extent_x[c] = glyphrec.BitmapLeft + glyphrec.Bitmap.Width;
GL.EndList();
sChars += "f:" + c.ToString() + "[w:" + glyphrec.Bitmap.Width.ToString() + "][h:" + glyphrec.Bitmap.Rows.ToString() + "]" + sError;
}
public static Matrix4 CalcNext(GlyphSlot glyph)
=> Matrix4.CreateTranslation((glyph.Advance.X.ToSingle() / Sprite.TileSize) * 0.68f,
glyph.Advance.Y.ToSingle() / Sprite.TileSize,
0);
public FreeTypeFont(uint pixelheight)
{
// initialize library
Library lib = new Library();
//Face face = new Face(lib, "FreeSans.ottf");
Assembly assembly = Assembly.GetExecutingAssembly();
//string[] names = assembly.GetManifestResourceNames();
Stream resource_stream = assembly.GetManifestResourceStream("OpenTK_example_5.Resource.FreeSans.ttf");
MemoryStream ms = new MemoryStream();
resource_stream.CopyTo(ms);
Face face = new Face(lib, ms.ToArray(), 0);
face.SetPixelSizes(0, pixelheight);
// set 1 byte pixel alignment
GL.PixelStore(PixelStoreParameter.UnpackAlignment, 1);
// set texture unit
GL.ActiveTexture(TextureUnit.Texture0);
// Load first 128 characters of ASCII set
for (uint c = 0; c < 128; c++)
{
try
{
// load glyph
//face.LoadGlyph(c, LoadFlags.Render, LoadTarget.Normal);
face.LoadChar(c, LoadFlags.Render, LoadTarget.Normal);
GlyphSlot glyph = face.Glyph;
FTBitmap bitmap = glyph.Bitmap;
// create glyph texture
int texObj = GL.GenTexture();
GL.BindTexture(TextureTarget.Texture2D, texObj);
GL.TexImage2D(TextureTarget.Texture2D, 0,
PixelInternalFormat.R8, bitmap.Width, bitmap.Rows, 0,
PixelFormat.Red, PixelType.UnsignedByte, bitmap.Buffer);
// set texture parameters
GL.TextureParameter(texObj, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
GL.TextureParameter(texObj, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
GL.TextureParameter(texObj, TextureParameterName.TextureWrapS, (int)TextureWrapMode.ClampToEdge);
GL.TextureParameter(texObj, TextureParameterName.TextureWrapT, (int)TextureWrapMode.ClampToEdge);
// add character
Character ch = new Character();
ch.TextureID = texObj;
ch.Size = new Vector2(bitmap.Width, bitmap.Rows);
ch.Bearing = new Vector2(glyph.BitmapLeft, glyph.BitmapTop);
ch.Advance = (int)glyph.Advance.X.Value;
_characters.Add(c, ch);
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
}
// bind default texture
GL.BindTexture(TextureTarget.Texture2D, 0);
// set default (4 byte) pixel alignment
GL.PixelStore(PixelStoreParameter.UnpackAlignment, 4);
float[] vquad =
{
// x y u v
0.0f, -1.0f, 0.0f, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f,
1.0f, 0.0f, 1.0f, 1.0f,
0.0f, -1.0f, 0.0f, 0.0f,
1.0f, 0.0f, 1.0f, 1.0f,
1.0f, -1.0f, 1.0f, 0.0f
};
// Create [Vertex Buffer Object](https://www.khronos.org/opengl/wiki/Vertex_Specification#Vertex_Buffer_Object)
_vbo = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ArrayBuffer, _vbo);
GL.BufferData(BufferTarget.ArrayBuffer, 4 * 6 * 4, vquad, BufferUsageHint.StaticDraw);
// [Vertex Array Object](https://www.khronos.org/opengl/wiki/Vertex_Specification#Vertex_Array_Object)
_vao = GL.GenVertexArray();
GL.BindVertexArray(_vao);
GL.EnableVertexAttribArray(0);
GL.VertexAttribPointer(0, 2, VertexAttribPointerType.Float, false, 4 * 4, 0);
GL.EnableVertexAttribArray(1);
GL.VertexAttribPointer(1, 2, VertexAttribPointerType.Float, false, 4 * 4, 2 * 4);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
GL.BindVertexArray(0);
}
