Sign in to follow this  
crslimin

OpenGL How to display chinese characters with wglUseFontOutlines?

Recommended Posts

crslimin    122
Is there anyone has experience in using wglUseFontOutlines or Do you have any sample code about draw chinese characters with OpenGL? I am using wglUseFontOutlines, glCallLists, but it doesn't work. Please see my program(modified from nehe program) below: GLvoid BuildFont(GLvoid) // Build Our Bitmap Font { HFONT font; // Windows Font ID base = glGenLists(256); // Storage For 256 Characters font = CreateFont( -12, // Height Of Font 0, // Width Of Font 0, // Angle Of Escapement 0, // Orientation Angle FW_BOLD, // Font Weight FALSE, // Italic FALSE, // Underline FALSE, // Strikeout CHINESEBIG5_CHARSET, // Character Set Identifier OUT_TT_PRECIS, // Output Precision CLIP_DEFAULT_PRECIS, // Clipping Precision ANTIALIASED_QUALITY, // Output Quality FF_DONTCARE|DEFAULT_PITCH, // Family And Pitch " 宋体"); // Font Name SelectObject(hDC, font); // Selects The Font We Created wglUseFontOutlines( hDC, // Select The Current DC 0, // Starting Character 255, // Number Of Display Lists To Build base, // Starting Display Lists 0.0f, // Deviation From The True Outlines 0.2f, // Font Thickness In The Z Direction WGL_FONT_POLYGONS, // Use Polygons, Not Lines gmf); } GLvoid glPrint(const char *fmt, ...) // Custom GL "Print" Routine { float length=0; // Used To Find The Length Of The Text char text[256]; // Holds Our String va_list ap; // Pointer To List Of Arguments if (fmt == NULL) // If There's No Text return; // Do Nothing va_start(ap, fmt); // Parses The String For Variables vsprintf(text, fmt, ap); // And Converts Symbols To Actual Numbers va_end(ap); // Results Are Stored In Text for (unsigned int loop=0;loop<(strlen(text));loop++) // Loop To Find Text Length { length+=gmf[text[loop]].gmfCellIncX; // Increase Length By Each Characters Width } glTranslatef(-length/2,0.0f, 0.0f); // Center Our Text On The Screen glPushAttrib(GL_LIST_BIT); // Pushes The Display List Bits glListBase(base); // Sets The Base Character to 0 glCallLists(strlen(text), GL_UNSIGNED_BYTE, text); // Draws The Display List Text glPopAttrib(); } int DrawGLScene(GLvoid) // Here's Where We Do All The Drawing { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear Screen And Depth Buffer glLoadIdentity(); // Reset The Current Modelview Matrix glTranslatef(0.0f,0.0f,-1.0f); // Move One Unit Into The Screen glScalef(0.04, 0.04, 0.04); glRotatef(-20.0f,0.0f,1.0f,0.0f); // Rotate On The Y Axis // Pulsing Colors Based On Text Position glColor3f(1.0f,0.0f,0.5f); glPrint("Active OpenGL Text With NeHe abc中文def-%7.2f", 10.0); // Print GL Text To The Screen return TRUE; // Everything Went OK } After runing the program, I can see English characters only, no chinese characters. It will be grateful if you can let me know what it is wrong in the program.

Share this post


Link to post
Share on other sites
Nathan Baum    1027
I'm rather ignorant on the subject, but surely there's more than one byte to a character in any Chinese encoding? And won't there be more than 255 glyphs? You're only making display lists for the first 255, which are probably just the normal ASCII ones.

Since you're using a char array, I'm guessing you're using UTF-8. If you are, then even if you had enough display lists, you'd still need to redo your glPrint to handle UTF-8 correctly.

Even if the WGL functions can do it, I'd see about using FreeType as Promit suggests. It's generally more featureful, and it'll be useful knowledge to have if you ever need to develop for a platform which doesn't have WGL. Google says you might like to look here and here, amongst other places.

Share this post


Link to post
Share on other sites
Nathan Baum    1027
Having examined the source on the other end of the links I posted, it looks like neither of them are exactly what you want. NeHe's still can't cope with UCS2 or UTF-8 strings, and the other will do Unicode if you want to link it with Qt. Unless another library turns up which can do Unicode text in OpenGL using FreeType, I'd go with modifying NeHe's, since it's probably the easier starting point.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Similar Content

    • By povilaslt2
      Hello. I'm Programmer who is in search of 2D game project who preferably uses OpenGL and C++. You can see my projects in GitHub. Project genre doesn't matter (except MMO's :D).
    • By ZeldaFan555
      Hello, My name is Matt. I am a programmer. I mostly use Java, but can use C++ and various other languages. I'm looking for someone to partner up with for random projects, preferably using OpenGL, though I'd be open to just about anything. If you're interested you can contact me on Skype or on here, thank you!
      Skype: Mangodoor408
    • By tyhender
      Hello, my name is Mark. I'm hobby programmer. 
      So recently,I thought that it's good idea to find people to create a full 3D engine. I'm looking for people experienced in scripting 3D shaders and implementing physics into engine(game)(we are going to use the React physics engine). 
      And,ye,no money =D I'm just looking for hobbyists that will be proud of their work. If engine(or game) will have financial succes,well,then maybe =D
      Sorry for late replies.
      I mostly give more information when people PM me,but this post is REALLY short,even for me =D
      So here's few more points:
      Engine will use openGL and SDL for graphics. It will use React3D physics library for physics simulation. Engine(most probably,atleast for the first part) won't have graphical fron-end,it will be a framework . I think final engine should be enough to set up an FPS in a couple of minutes. A bit about my self:
      I've been programming for 7 years total. I learned very slowly it as "secondary interesting thing" for like 3 years, but then began to script more seriously.  My primary language is C++,which we are going to use for the engine. Yes,I did 3D graphics with physics simulation before. No, my portfolio isn't very impressive. I'm working on that No,I wasn't employed officially. If anybody need to know more PM me. 
       
    • By Zaphyk
      I am developing my engine using the OpenGL 3.3 compatibility profile. It runs as expected on my NVIDIA card and on my Intel Card however when I tried it on an AMD setup it ran 3 times worse than on the other setups. Could this be a AMD driver thing or is this probably a problem with my OGL code? Could a different code standard create such bad performance?
    • By Kjell Andersson
      I'm trying to get some legacy OpenGL code to run with a shader pipeline,
      The legacy code uses glVertexPointer(), glColorPointer(), glNormalPointer() and glTexCoordPointer() to supply the vertex information.
      I know that it should be using setVertexAttribPointer() etc to clearly define the layout but that is not an option right now since the legacy code can't be modified to that extent.
      I've got a version 330 vertex shader to somewhat work:
      #version 330 uniform mat4 osg_ModelViewProjectionMatrix; uniform mat4 osg_ModelViewMatrix; layout(location = 0) in vec4 Vertex; layout(location = 2) in vec4 Normal; // Velocity layout(location = 3) in vec3 TexCoord; // TODO: is this the right layout location? out VertexData { vec4 color; vec3 velocity; float size; } VertexOut; void main(void) { vec4 p0 = Vertex; vec4 p1 = Vertex + vec4(Normal.x, Normal.y, Normal.z, 0.0f); vec3 velocity = (osg_ModelViewProjectionMatrix * p1 - osg_ModelViewProjectionMatrix * p0).xyz; VertexOut.velocity = velocity; VertexOut.size = TexCoord.y; gl_Position = osg_ModelViewMatrix * Vertex; } What works is the Vertex and Normal information that the legacy C++ OpenGL code seem to provide in layout location 0 and 2. This is fine.
      What I'm not getting to work is the TexCoord information that is supplied by a glTexCoordPointer() call in C++.
      Question:
      What layout location is the old standard pipeline using for glTexCoordPointer()? Or is this undefined?
       
      Side note: I'm trying to get an OpenSceneGraph 3.4.0 particle system to use custom vertex, geometry and fragment shaders for rendering the particles.
  • Popular Now