private void RenderAsTexture(FT_GlyphSlotRec glyphrec, int c)
{
int ret = FT.FT_Render_Glyph(ref glyphrec, FT_Render_Mode.FT_RENDER_MODE_NORMAL);
FTGlyphOffset offset = new FTGlyphOffset();
if (ret != 0)
{
Report("Render failed for character " + c.ToString());
}
string sError = "";
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.glNewList((list_base + c), Gl.GL_COMPILE);
Gl.glTranslatef(font_size >> 1, 0, 0);
extent_x[c] = font_size >> 1;
Gl.glEndList();
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[height + 2, width + 2, 2];
for (int j = 0; j < height + 2; j++)
{
for (int i = 0; i < width + 2; i++)
{
//Luminance
expanded[j, i, 0] = (byte)255;
expanded[j, i, 1] = 0;
}
}
for (int j = 0; j < height; j++)
{
for (int i = 0; i < width; i++)
{
//expanded[4 * (i + j * width) + 1] = (byte)255;
//expanded[4 * (i + j * width) + 2] = (byte)255;
// Alpha
expanded[j + 1, i + 1,1] =
(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.glBindTexture(Engine.Renderer.GlTextureMode, textures[c]);
Gl.glTexParameteri(Engine.Renderer.GlTextureMode, Gl.GL_TEXTURE_WRAP_S, Gl.GL_CLAMP_TO_EDGE);
Gl.glTexParameteri(Engine.Renderer.GlTextureMode, Gl.GL_TEXTURE_WRAP_T, Gl.GL_CLAMP_TO_EDGE);
Gl.glTexParameteri(Engine.Renderer.GlTextureMode, Gl.GL_TEXTURE_MAG_FILTER, Gl.GL_LINEAR);
Gl.glTexParameteri(Engine.Renderer.GlTextureMode, Gl.GL_TEXTURE_MIN_FILTER, Gl.GL_LINEAR);
//Create the texture
Gl.glTexImage2D(Engine.Renderer.GlTextureMode, 0, Gl.GL_RGBA, width +2, height+2,
0, Gl.GL_LUMINANCE_ALPHA, Gl.GL_UNSIGNED_BYTE, expanded);
expanded = null;
bmp = null;
//Create a display list and bind a texture to it
Gl.glNewList((list_base + c), Gl.GL_COMPILE);
Gl.glBindTexture(Engine.Renderer.GlTextureMode, textures[c]);
//Account for freetype spacing rules
Gl.glTranslatef(glyphrec.bitmap_left, 0, 0);
Gl.glPushMatrix();
Gl.glTranslatef(0, glyphrec.bitmap_top - glyphrec.bitmap.rows, 0);
double x = Engine.Renderer.TextureCoordinate(glyphrec.bitmap.width, width);
double y = Engine.Renderer.TextureCoordinate(glyphrec.bitmap.rows, height);
offset.left = glyphrec.bitmap_left;
offset.top = glyphrec.bitmap_top;
offset.height = glyphrec.bitmap.rows;
offset.width = glyphrec.bitmap.width;
offset.advance = glyphrec.advance;
offset.lsb_delta = glyphrec.lsb_delta;
offset.rsb_delta = glyphrec.rsb_delta;
offset.linearHoriAdvance = glyphrec.linearHoriAdvance;
offset.linearVertAdvance = glyphrec.linearVertAdvance;
offsets[c] = offset;
//Draw the quad
Gl.glBegin(Gl.GL_QUADS);
Gl.glTexCoord2d(0, 0); Gl.glVertex2f(-1, glyphrec.bitmap.rows+1);
Gl.glTexCoord2d(0, y); Gl.glVertex2f(-1, -1);
Gl.glTexCoord2d(x, y); Gl.glVertex2f(glyphrec.bitmap.width+1, -1);
Gl.glTexCoord2d(x, 0); Gl.glVertex2f(glyphrec.bitmap.width+1, glyphrec.bitmap.rows+1);
Gl.glEnd();
Gl.glPopMatrix();
//Advance for the next character
Gl.glTranslatef(glyphrec.advance.x >> 6, 0, 0);
extent_x[c] = glyphrec.bitmap_left + (glyphrec.advance.x >> 6);
Gl.glEndList();
sChars += "f:" + c.ToString() + "[w:" + glyphrec.bitmap.width.ToString() + "][h:" + glyphrec.bitmap.rows.ToString() + "]" + sError;
}
public static extern int FT_Render_Glyph(ref FT_GlyphSlotRec slot, FT_Render_Mode render_mode);
