public int GetCharWidth(char ch, IFont font)
{
OpenGLFont f = (OpenGLFont)font;
ABC abc = f.GLYPHINFO[(int)ch];
return(abc.abcA +
(int)abc.abcB +
abc.abcC);
}
public Size MeasureString(string str, IFont f)
{
//return Size.Empty;
//empty?
if (String.IsNullOrEmpty(str))
{
return(Size.Empty);
}
//get the OpenGL font for this font.
OpenGLFont font = (OpenGLFont)f;
//calculate string height from line count
string[] lines = str.Split('\n');
int lineCount = lines.Length;
int maxWidth = 0;
//find the largest width of all the lines
for (int y = 0; y < lineCount; y++)
{
//get the line render width.
int lineWidth = 0;
fixed(char *line = lines[y].ToCharArray())
{
//empty?
if (line == (char *)0)
{
continue;
}
int lineLength = lines[y].Length;
char *ptr = line;
char *ptrEnd = ptr + lineLength;
while (ptr != ptrEnd)
{
ABC g = font.GLYPHINFO[(int)(*ptr++)];
lineWidth +=
g.abcA +
(int)g.abcB +
g.abcC;
}
}
//largest width so far?
if (lineWidth > maxWidth)
{
maxWidth = lineWidth;
}
}
return(new Size(
maxWidth,
font.METRIC.tmAscent * lineCount));
}
public void DrawString(string txt, int x, int y)
{
if (txt.Length == 0)
{
return;
}
//get the font selected.
OpenGLFont font = p_Font;
//is there any lines?
if (txt.Contains("\n"))
{
//recall DrawString per line since OpenGL
//bitmap calllists do not support multi-line
int currentY = y;
string[] lines = txt.Split('\n');
int lineLength = lines.Length;
for (int c = 0; c < lineLength; c++)
{
DrawString(
lines[c],
x,
currentY);
//move y to the start of the next line
currentY += font.METRIC.tmAscent;
}
return;
}
/*
* since OpenGL will render the bottom of the text
* along the y coord we give it, we need to offset
* it by the font height - the gap between the top
* of quad and the character.
*/
y += font.METRIC.tmAscent;
//jump to the start of the compiled GL list for
//rendering the font bitmaps.
glListBase(font.LIST);
glRasterPos2f(x, y);
//call it.
glCallLists(
txt.Length,
UNSIGNED_BYTE,
txt);
/*we assume every character is drawn as a textured quad...*/
p_CurrentVertCount += (txt.Length << 2); // (*4)
}
void InitGL()
{
gl.ShadeModel(gl.GL_SMOOTH);
gl.ClearColor(0.0f, 0.0f, 0.0f, 0.5f);
gl.ClearDepthf(1.0f);
//gl.Enable(gl.GL_DEPTH_TEST);
gl.BlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA);
gl.DepthFunc(gl.GL_LEQUAL);
gl.Hint(gl.GL_PERSPECTIVE_CORRECTION_HINT, gl.GL_NICEST);
myFont = new OpenGLFont(new Font(FontFamily.GenericSerif, 12, FontStyle.Regular));
myHugeFont = new OpenGLFont(new Font(FontFamily.GenericSerif, 32, FontStyle.Regular));
myLeftAligned = new GlyphRun(myHugeFont, "hello world", float.PositiveInfinity, float.PositiveInfinity, OpenGLTextAlignment.Left, true);
myCentered = new GlyphRun(myFont, "centered text", ClientSize.Width, ClientSize.Height, OpenGLTextAlignment.Center, true);
myJustified = new GlyphRun(myFont, "this text blob is really long and hopefully it will be justified to the edges as the lines wrap and stuff", ClientSize.Width, ClientSize.Height, OpenGLTextAlignment.Justified, true);
myTexture = Texture.LoadStream(System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("TestOpenGLES.BitmapBrush.bmp"), false);
myLeftAligned.ApplyTextureShader((glyphPos) =>
{
float left = glyphPos.TopLeft.X / myLeftAligned.Width;
float top = glyphPos.TopLeft.Y / myLeftAligned.Height;
float right = glyphPos.TopRight.X / myLeftAligned.Width;
float bottom = glyphPos.BottomLeft.Y / myLeftAligned.Height;
return(new GlyphTexCoords(left, top, right, bottom));
}
);
myLeftAligned.Texture = myTexture;
myJustified.ApplyColorShader((glyphPos) =>
{
GlyphColors colors = new GlyphColors();
colors.TopLeft = new Vector4f(1, 0, 0, 1);
colors.BottomLeft = new Vector4f(0, 1, 0, 1);
colors.TopRight = new Vector4f(1, 0, 0, 1);
colors.BottomRight = new Vector4f(0, 0, 1, 1);
return(colors);
}
);
}
public IFont AllocateFont(Font font)
{
Monitor.Enter(p_Mutex);
//create a hash code for this font.
int fontHash = createFontHash(font);
//does this font already exist?
int fontListLength = p_Fonts.Length;
for (int c = 0; c < fontListLength; c++)
{
if (fontHash == p_Fonts[c].HASH)
{
//return the font
Monitor.Exit(p_Mutex);
return(p_Fonts[c]);
}
}
/*select the font on the GDI stack*/
IntPtr hfont = font.ToHfont();
SelectObject(p_DeviceContext, hfont);
/*create the internal struct we use to handle this fonts rendering.*/
OpenGLFont buffer = new OpenGLFont {
LIST = glGenLists(256),
HFONT = hfont,
HASH = fontHash,
GLYPHINFO = new ABC[256]
};
bool success = false;
string errorString = "";
/*get the initial gl bitmap lists for the font*/
if (!wglUseFontBitmaps(p_DeviceContext, 0, 256, buffer.LIST))
{
errorString = "OpenGL: Unable to create font bitmap! (" + GetLastError() + ")";
}
/*get the width information*/
else if (!GetCharABCWidths(p_DeviceContext, 0, 255, buffer.GLYPHINFO))
{
errorString = "OpenGL: Cannot retrieve font character width information!";
}
/*get the height information*/
else if (!GetTextMetrics(p_DeviceContext, out buffer.METRIC))
{
errorString = "OpenGL: Cannot retrieve font metrics";
}
else
{
success = true;
}
//success?
if (!success)
{
Monitor.Exit(p_Mutex);
throw new Exception(errorString);
}
//add this font to the stack
Array.Resize(ref p_Fonts, p_Fonts.Length + 1);
p_Fonts[p_Fonts.Length - 1] = buffer;
Console.WriteLine("Added font: " + font);
Monitor.Exit(p_Mutex);
return(buffer);
}
public IFont SetFont(Font font)
{
p_Font = (OpenGLFont)p_Context.AllocateFont(font);
return(p_Font);
}
