class GLFont
{
public:
GLFont(){}
~GLFont()
{
glDeleteLists(base,256);
}
void Build(HDC hdc,const char* typeface,int height,int weight,bool italic = false,bool underline = false,bool strikethrough = false)
{
int charset;
m_hdc = hdc;
glDeleteLists(base,256);
base = glGenLists(256);
if (stricmp(typeface,"symbol") == 0)
charset = SYMBOL_CHARSET;
else
charset = ANSI_CHARSET;
fontid = CreateFont(height,0,0,0,weight,italic,underline,strikethrough,charset,OUT_TT_PRECIS,CLIP_DEFAULT_PRECIS,DRAFT_QUALITY,DEFAULT_PITCH,typeface);
SelectObject(hdc,fontid);
wglUseFontBitmaps(hdc,0,256,base);
GetCharWidth(hdc,0,255,widths);
this->height = height;
}
int Measure(aString str)
{
uint len = 0;
for (uint i = 0;i < strlen(str);i++)
{
len += widths[str[i]];
}
}
void Draw(aString str)
{
glPushAttrib(GL_LIST_BIT);
glListBase(base);
glCallLists((GLsizei)strlen(str),GL_UNSIGNED_BYTE,str);
glPopAttrib();
}
private:
HDC m_hdc;
HFONT fontid;
GLuint base;
int widths[256];
int height;
};
Multi-font use.
I am attempting to use multiple fonts in a program, but from what I can tell, it will only use the last font that I tried building. Here''s my font class.
From what I can tell, I am guessing that when a font is ''selected'' as per within the Build() function, it will only use that font. I ask because I am working on a project where having a clean thin font and a bold ''status'' font would be advantageous.
Thanks in advance.
Oh, and feel free to rip off this class. It seems to work well. Replace aString with your favorite string class.
I had the same problem.
The problem has to do with the hdc you are using when creating the fonts. Try changing the following lines from hdc to m_hdc like so:
SelectObject(m_hdc,fontid);
wglUseFontBitmaps(m_hdc,0,256,base);
GetCharWidth(m_hdc,0,255,widths);
By using a global hdc you are only allowed to create one font at a time.
hope that helps
The problem has to do with the hdc you are using when creating the fonts. Try changing the following lines from hdc to m_hdc like so:
SelectObject(m_hdc,fontid);
wglUseFontBitmaps(m_hdc,0,256,base);
GetCharWidth(m_hdc,0,255,widths);
By using a global hdc you are only allowed to create one font at a time.
hope that helps
quote:
Original post by adamxiii
The problem has to do with the hdc you are using when creating the fonts.
since you only have one dc for the entire program, i don''t see how using a global variable to reference it instead of a local one if going to affect anything.
quote:
By using a global hdc you are only allowed to create one font at a time.
you are always restricted to selecting one font in any dc at any time, but you don''t need a dc to create a font at all.
quote:
Original post by Lomilar
Here''s my font class.
you, however, didn''t provide any code to show how you managed multiple fonts in your application. copying nehe''s font creation code here tell us nothing why multiple fonts aren''t working for you.
quote:
From what I can tell, I am guessing that when a font is ''selected'' as per within the Build() function, it will only use that font.
this is correct. wglusefontbitmaps will use the currently selected font for its operation.
quote:
I ask because I am working on a project where having a clean thin font and a bold ''status'' font would be advantageous.
so select another font into the dc, and call wglusefontbitmaps again.
quote:
Oh, and feel free to rip off this class. It seems to work well.
why thanks, but no thanks.
quote:
fontid = CreateFont(height,0,0,0,weight,italic,underline,strikethrough,charset,OUT_TT_PRECIS,CLIP_DEFAULT_PRECIS,DRAFT_QUALITY,DEFAULT_PITCH,typeface);
SelectObject(hdc,fontid);
wglUseFontBitmaps(hdc,0,256,base);
have you thought about relesing resources occupied by the font? take another look at how nehe creates his fonts.
since you didn''t give any information that will help us tell you where you went wrong, i hacked together some code that draws text in two alternating fonts. the code is ugly because nehe uses a whole bunch of globals and a bit because he doesn''t have a timer class. so don''t copypaste it, understand what i''ve done and make a cleaner version.
code dump [modified lesson 13]:
/* * This Code Was Created By Jeff Molofee 2000 * Modified by Shawn T. to handle (%3.2f, num) parameters. * A HUGE Thanks To Fredric Echols For Cleaning Up * And Optimizing The Base Code, Making It More Flexible! * If You''ve Found This Code Useful, Please Let Me Know. * Visit My Site At nehe.gamedev.net */#include <windows.h> // Header File For Windows#include <math.h> // Header File For Windows Math Library#include <stdio.h> // Header File For Standard Input/Output#include <stdarg.h> // Header File For Variable Argument Routines#include <gl\gl.h> // Header File For The OpenGL32 Library#include <gl\glu.h> // Header File For The GLu32 Library#include <gl\glaux.h> // Header File For The Glaux LibraryHDC hDC=NULL; // Private GDI Device ContextHGLRC hRC=NULL; // Permanent Rendering ContextHWND hWnd=NULL; // Holds Our Window HandleHINSTANCE hInstance; // Holds The Instance Of The ApplicationGLuint base, base2; // Base Display List For The Font SetGLfloat cnt1; // 1st Counter Used To Move Text & For ColoringGLfloat cnt2; // 2nd Counter Used To Move Text & For Coloringbool keys[256]; // Array Used For The Keyboard Routinebool active=TRUE; // Window Active Flag Set To TRUE By Defaultbool fullscreen=TRUE; // Fullscreen Flag Set To Fullscreen Mode By DefaultLRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); // Declaration For WndProcunsigned BuildFont(const char *name) // Build Our Bitmap Font{ HFONT font; // Windows Font ID HFONT oldfont; // Used For Good House Keeping unsigned base = glGenLists(96); // Storage For 96 Characters font = CreateFont( -24, // Height Of Font 0, // Width Of Font 0, // Angle Of Escapement 0, // Orientation Angle FW_BOLD, // Font Weight FALSE, // Italic FALSE, // Underline FALSE, // Strikeout ANSI_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 name); // Font Name oldfont = (HFONT)SelectObject(hDC, font); // Selects The Font We Want wglUseFontBitmaps(hDC, 32, 96, base); // Builds 96 Characters Starting At Character 32 SelectObject(hDC, oldfont); // Selects The Font We Want DeleteObject(font); // Delete The Font return base;}GLvoid KillFont(GLvoid) // Delete The Font List{ glDeleteLists(base, 96); // Delete All 96 Characters}GLvoid glPrint(unsigned base, const char *fmt, ...) // Custom GL "Print" Routine{ 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 glPushAttrib(GL_LIST_BIT); // Pushes The Display List Bits glListBase(base - 32); // Sets The Base Character to 32 glCallLists(strlen(text), GL_UNSIGNED_BYTE, text); // Draws The Display List Text glPopAttrib(); // Pops The Display List Bits}GLvoid ReSizeGLScene(GLsizei width, GLsizei height) // Resize And Initialize The GL Window{ if (height==0) // Prevent A Divide By Zero By { height=1; // Making Height Equal One } glViewport(0,0,width,height); // Reset The Current Viewport glMatrixMode(GL_PROJECTION); // Select The Projection Matrix glLoadIdentity(); // Reset The Projection Matrix // Calculate The Aspect Ratio Of The Window gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f); glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix glLoadIdentity(); // Reset The Modelview Matrix}int InitGL(GLvoid) // All Setup For OpenGL Goes Here{ glShadeModel(GL_SMOOTH); // Enable Smooth Shading glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background glClearDepth(1.0f); // Depth Buffer Setup glEnable(GL_DEPTH_TEST); // Enables Depth Testing glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations base = BuildFont("courier new"); // Build The Font base2 = BuildFont("times new roman"); // Build The Font return TRUE; // Initialization Went OK}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 // Pulsing Colors Based On Text Position glColor3f(1.0f*float(cos(cnt1)),1.0f*float(sin(cnt2)),1.0f-0.5f*float(cos(cnt1+cnt2))); // Position The Text On The Screen glRasterPos2f(-0.45f+0.05f*float(cos(cnt1)), 0.32f*float(sin(cnt2))); unsigned base = ::base; static count = 0; if (((++count)/100)&1) base = ::base2; glPrint(base, "Active OpenGL Text With NeHe - %7.2f", cnt1); // Print GL Text To The Screen cnt1+=0.051f; // Increase The First Counter cnt2+=0.005f; // Increase The First Counter return TRUE; // Everything Went OK}GLvoid KillGLWindow(GLvoid) // Properly Kill The Window{ if (fullscreen) // Are We In Fullscreen Mode? { ChangeDisplaySettings(NULL,0); // If So Switch Back To The Desktop ShowCursor(TRUE); // Show Mouse Pointer } if (hRC) // Do We Have A Rendering Context? { if (!wglMakeCurrent(NULL,NULL)) // Are We Able To Release The DC And RC Contexts? { MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); } if (!wglDeleteContext(hRC)) // Are We Able To Delete The RC? { MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); } hRC=NULL; // Set RC To NULL } if (hDC && !ReleaseDC(hWnd,hDC)) // Are We Able To Release The DC { MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); hDC=NULL; // Set DC To NULL } if (hWnd && !DestroyWindow(hWnd)) // Are We Able To Destroy The Window? { MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); hWnd=NULL; // Set hWnd To NULL } if (!UnregisterClass("OpenGL",hInstance)) // Are We Able To Unregister Class { MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); hInstance=NULL; // Set hInstance To NULL } KillFont();}/* This Code Creates Our OpenGL Window. Parameters Are: * * title - Title To Appear At The Top Of The Window * * width - Width Of The GL Window Or Fullscreen Mode * * height - Height Of The GL Window Or Fullscreen Mode * * bits - Number Of Bits To Use For Color (8/16/24/32) * * fullscreenflag - Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE) */ BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag){ GLuint PixelFormat; // Holds The Results After Searching For A Match WNDCLASS wc; // Windows Class Structure DWORD dwExStyle; // Window Extended Style DWORD dwStyle; // Window Style RECT WindowRect; // Grabs Rectangle Upper Left / Lower Right Values WindowRect.left=(long)0; // Set Left Value To 0 WindowRect.right=(long)width; // Set Right Value To Requested Width WindowRect.top=(long)0; // Set Top Value To 0 WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height fullscreen=fullscreenflag; // Set The Global Fullscreen Flag hInstance = GetModuleHandle(NULL); // Grab An Instance For Our Window wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // Redraw On Size, And Own DC For Window. wc.lpfnWndProc = (WNDPROC) WndProc; // WndProc Handles Messages wc.cbClsExtra = 0; // No Extra Window Data wc.cbWndExtra = 0; // No Extra Window Data wc.hInstance = hInstance; // Set The Instance wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); // Load The Default Icon wc.hCursor = LoadCursor(NULL, IDC_ARROW); // Load The Arrow Pointer wc.hbrBackground = NULL; // No Background Required For GL wc.lpszMenuName = NULL; // We Don''t Want A Menu wc.lpszClassName = "OpenGL"; // Set The Class Name if (!RegisterClass(&wc)) // Attempt To Register The Window Class { MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } if (fullscreen) // Attempt Fullscreen Mode? { DEVMODE dmScreenSettings; // Device Mode memset(&dmScreenSettings,0,sizeof(dmScreenSettings)); // Makes Sure Memory''s Cleared dmScreenSettings.dmSize=sizeof(dmScreenSettings); // Size Of The Devmode Structure dmScreenSettings.dmPelsWidth = width; // Selected Screen Width dmScreenSettings.dmPelsHeight = height; // Selected Screen Height dmScreenSettings.dmBitsPerPel = bits; // Selected Bits Per Pixel dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT; // Try To Set Selected Mode And Get Results. NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar. if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL) { // If The Mode Fails, Offer Two Options. Quit Or Use Windowed Mode. if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES) { fullscreen=FALSE; // Windowed Mode Selected. Fullscreen = FALSE } else { // Pop Up A Message Box Letting User Know The Program Is Closing. MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP); return FALSE; // Return FALSE } } } if (fullscreen) // Are We Still In Fullscreen Mode? { dwExStyle=WS_EX_APPWINDOW; // Window Extended Style dwStyle=WS_POPUP; // Windows Style ShowCursor(FALSE); // Hide Mouse Pointer } else { dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window Extended Style dwStyle=WS_OVERLAPPEDWINDOW; // Windows Style } AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle); // Adjust Window To True Requested Size // Create The Window if (!(hWnd=CreateWindowEx( dwExStyle, // Extended Style For The Window "OpenGL", // Class Name title, // Window Title dwStyle | // Defined Window Style WS_CLIPSIBLINGS | // Required Window Style WS_CLIPCHILDREN, // Required Window Style 0, 0, // Window Position WindowRect.right-WindowRect.left, // Calculate Window Width WindowRect.bottom-WindowRect.top, // Calculate Window Height NULL, // No Parent Window NULL, // No Menu hInstance, // Instance NULL))) // Dont Pass Anything To WM_CREATE { KillGLWindow(); // Reset The Display MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } static PIXELFORMATDESCRIPTOR pfd= // pfd Tells Windows How We Want Things To Be { sizeof(PIXELFORMATDESCRIPTOR), // Size Of This Pixel Format Descriptor 1, // Version Number PFD_DRAW_TO_WINDOW | // Format Must Support Window PFD_SUPPORT_OPENGL | // Format Must Support OpenGL PFD_DOUBLEBUFFER, // Must Support Double Buffering PFD_TYPE_RGBA, // Request An RGBA Format bits, // Select Our Color Depth 0, 0, 0, 0, 0, 0, // Color Bits Ignored 0, // No Alpha Buffer 0, // Shift Bit Ignored 0, // No Accumulation Buffer 0, 0, 0, 0, // Accumulation Bits Ignored 16, // 16Bit Z-Buffer (Depth Buffer) 0, // No Stencil Buffer 0, // No Auxiliary Buffer PFD_MAIN_PLANE, // Main Drawing Layer 0, // Reserved 0, 0, 0 // Layer Masks Ignored }; if (!(hDC=GetDC(hWnd))) // Did We Get A Device Context? { KillGLWindow(); // Reset The Display MessageBox(NULL,"Can''t Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd))) // Did Windows Find A Matching Pixel Format? { KillGLWindow(); // Reset The Display MessageBox(NULL,"Can''t Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } if(!SetPixelFormat(hDC,PixelFormat,&pfd)) // Are We Able To Set The Pixel Format? { KillGLWindow(); // Reset The Display MessageBox(NULL,"Can''t Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } if (!(hRC=wglCreateContext(hDC))) // Are We Able To Get A Rendering Context? { KillGLWindow(); // Reset The Display MessageBox(NULL,"Can''t Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } if(!wglMakeCurrent(hDC,hRC)) // Try To Activate The Rendering Context { KillGLWindow(); // Reset The Display MessageBox(NULL,"Can''t Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } ShowWindow(hWnd,SW_SHOW); // Show The Window SetForegroundWindow(hWnd); // Slightly Higher Priority SetFocus(hWnd); // Sets Keyboard Focus To The Window ReSizeGLScene(width, height); // Set Up Our Perspective GL Screen if (!InitGL()) // Initialize Our Newly Created GL Window { KillGLWindow(); // Reset The Display MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Return FALSE } return TRUE; // Success}LRESULT CALLBACK WndProc( HWND hWnd, // Handle For This Window UINT uMsg, // Message For This Window WPARAM wParam, // Additional Message Information LPARAM lParam) // Additional Message Information{ switch (uMsg) // Check For Windows Messages { case WM_ACTIVATE: // Watch For Window Activate Message { if (!HIWORD(wParam)) // Check Minimization State { active=TRUE; // Program Is Active } else { active=FALSE; // Program Is No Longer Active } return 0; // Return To The Message Loop } case WM_SYSCOMMAND: // Intercept System Commands { switch (wParam) // Check System Calls { case SC_SCREENSAVE: // Screensaver Trying To Start? case SC_MONITORPOWER: // Monitor Trying To Enter Powersave? return 0; // Prevent From Happening } break; // Exit } case WM_CLOSE: // Did We Receive A Close Message? { PostQuitMessage(0); // Send A Quit Message return 0; // Jump Back } case WM_KEYDOWN: // Is A Key Being Held Down? { keys[wParam] = TRUE; // If So, Mark It As TRUE return 0; // Jump Back } case WM_KEYUP: // Has A Key Been Released? { keys[wParam] = FALSE; // If So, Mark It As FALSE return 0; // Jump Back } case WM_SIZE: // Resize The OpenGL Window { ReSizeGLScene(LOWORD(lParam),HIWORD(lParam)); // LoWord=Width, HiWord=Height return 0; // Jump Back } } // Pass All Unhandled Messages To DefWindowProc return DefWindowProc(hWnd,uMsg,wParam,lParam);}int WINAPI WinMain( HINSTANCE hInstance, // Instance HINSTANCE hPrevInstance, // Previous Instance LPSTR lpCmdLine, // Command Line Parameters int nCmdShow) // Window Show State{ MSG msg; // Windows Message Structure BOOL done=FALSE; // Bool Variable To Exit Loop // Ask The User Which Screen Mode They Prefer// if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO) { fullscreen=FALSE; // Windowed Mode } // Create Our OpenGL Window if (!CreateGLWindow("NeHe''s Bitmap Font Tutorial",640,480,16,fullscreen)) { return 0; // Quit If Window Was Not Created } while(!done) // Loop That Runs While done=FALSE { if (PeekMessage(&msg,NULL,0,0,PM_REMOVE)) // Is There A Message Waiting? { if (msg.message==WM_QUIT) // Have We Received A Quit Message? { done=TRUE; // If So done=TRUE } else // If Not, Deal With Window Messages { TranslateMessage(&msg); // Translate The Message DispatchMessage(&msg); // Dispatch The Message } } else // If There Are No Messages { // Draw The Scene. Watch For ESC Key And Quit Messages From DrawGLScene() if ((active && !DrawGLScene()) || keys[VK_ESCAPE]) // Active? Was There A Quit Received? { done=TRUE; // ESC or DrawGLScene Signalled A Quit } else // Not Time To Quit, Update Screen { SwapBuffers(hDC); // Swap Buffers (Double Buffering) } if (keys[VK_F1]) // Is F1 Being Pressed? { keys[VK_F1]=FALSE; // If So Make Key FALSE KillGLWindow(); // Kill Our Current Window fullscreen=!fullscreen; // Toggle Fullscreen / Windowed Mode // Recreate Our OpenGL Window if (!CreateGLWindow("NeHe''s Bitmap Font Tutorial",640,480,16,fullscreen)) { return 0; // Quit If Window Was Not Created } } } } // Shutdown KillGLWindow(); // Kill The Window return (msg.wParam); // Exit The Program}
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