Nicolas
14-07-2003, 20:18
Hallo!
Ich habe große Probleme mit OpenGL unter Debian Linux. Ich versuche die ganze Zeit ein OpenGL zu bauen. Dazu hab ich als Vorlage das Tutorial 02 genommen. Das sieht so aus:
/*
* This code was created by Jeff Molofee '99
* (ported to Linux/SDL by Ti Leggett '01)
*
* If you've found this code useful, please let me know.
*
* Visit Jeff at http://nehe.gamedev.net/
*
* or for port-specific comments, questions, bugreports etc.
* email to leggett@eecs.tulane.edu
*/
#include <stdio.h>
#include <stdlib.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include "SDL.h"
/* screen width, height, and bit depth */
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define SCREEN_BPP 16
/* Define our booleans */
#define TRUE 1
#define FALSE 0
/* This is our SDL surface */
SDL_Surface *surface;
/* function to release/destroy our resources and restoring the old desktop */
void Quit( int returnCode )
{
/* clean up the window */
SDL_Quit( );
/* and exit appropriately */
exit( returnCode );
}
/* function to reset our viewport after a window resize */
int resizeWindow( int width, int height )
{
/* Height / width ration */
GLfloat ratio;
/* Protect against a divide by zero */
if ( height == 0 )
height = 1;
ratio = ( GLfloat )width / ( GLfloat )height;
/* Setup our viewport. */
glViewport( 0, 0, ( GLsizei )width, ( GLsizei )height );
/* change to the projection matrix and set our viewing volume. */
glMatrixMode( GL_PROJECTION );
glLoadIdentity( );
/* Set our perspective */
gluPerspective( 45.0f, ratio, 0.1f, 100.0f );
/* Make sure we're chaning the model view and not the projection */
glMatrixMode( GL_MODELVIEW );
/* Reset The View */
glLoadIdentity( );
return( TRUE );
}
/* function to handle key press events */
void handleKeyPress( SDL_keysym *keysym )
{
switch ( keysym->sym )
{
case SDLK_ESCAPE:
/* ESC key was pressed */
Quit( 0 );
break;
case SDLK_F1:
/* F1 key was pressed
* this toggles fullscreen mode
*/
SDL_WM_ToggleFullScreen( surface );
break;
default:
break;
}
return;
}
/* general OpenGL initialization function */
int initGL( GLvoid )
{
/* Enable smooth shading */
glShadeModel( GL_SMOOTH );
/* Set the background black */
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
/* Depth buffer setup */
glClearDepth( 1.0f );
/* Enables Depth Testing */
glEnable( GL_DEPTH_TEST );
/* The Type Of Depth Test To Do */
glDepthFunc( GL_LEQUAL );
/* Really Nice Perspective Calculations */
glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
return( TRUE );
}
/* Here goes our drawing code */
int drawGLScene( GLvoid )
{
/* These are to calculate our fps */
static GLint T0 = 0;
static GLint Frames = 0;
/* Clear The Screen And The Depth Buffer */
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
/* Move Left 1.5 Units And Into The Screen 6.0 */
glLoadIdentity();
glTranslatef( -1.5f, 0.0f, -6.0f );
glBegin( GL_TRIANGLES ); /* Drawing Using Triangles */
glVertex3f( 0.0f, 1.0f, 0.0f ); /* Top */
glVertex3f( -1.0f, -1.0f, 0.0f ); /* Bottom Left */
glVertex3f( 1.0f, -1.0f, 0.0f ); /* Bottom Right */
glEnd( ); /* Finished Drawing The Triangle */
/* Move Right 3 Units */
glTranslatef( 3.0f, 0.0f, 0.0f );
glBegin( GL_QUADS ); /* Draw A Quad */
glVertex3f( -1.0f, 1.0f, 0.0f ); /* Top Left */
glVertex3f( 1.0f, 1.0f, 0.0f ); /* Top Right */
glVertex3f( 1.0f, -1.0f, 0.0f ); /* Bottom Right */
glVertex3f( -1.0f, -1.0f, 0.0f ); /* Bottom Left */
glEnd( ); /* Done Drawing The Quad */
/* Draw it to the screen */
SDL_GL_SwapBuffers( );
/* Gather our frames per second */
Frames++;
{
GLint t = SDL_GetTicks();
if (t - T0 >= 5000) {
GLfloat seconds = (t - T0) / 1000.0;
GLfloat fps = Frames / seconds;
printf("%d frames in %g seconds = %g FPS\n", Frames, seconds, fps);
T0 = t;
Frames = 0;
}
}
return( TRUE );
}
int main( int argc, char **argv )
{
/* Flags to pass to SDL_SetVideoMode */
int videoFlags;
/* main loop variable */
int done = FALSE;
/* used to collect events */
SDL_Event event;
/* this holds some info about our display */
const SDL_VideoInfo *videoInfo;
/* whether or not the window is active */
int isActive = TRUE;
/* initialize SDL */
if ( SDL_Init( SDL_INIT_VIDEO ) < 0 )
{
fprintf( stderr, "Video initialization failed: %s\n",
SDL_GetError( ) );
Quit( 1 );
}
/* Fetch the video info */
videoInfo = SDL_GetVideoInfo( );
if ( !videoInfo )
{
fprintf( stderr, "Video query failed: %s\n",
SDL_GetError( ) );
Quit( 1 );
}
/* the flags to pass to SDL_SetVideoMode */
videoFlags = SDL_OPENGL; /* Enable OpenGL in SDL */
videoFlags |= SDL_GL_DOUBLEBUFFER; /* Enable double buffering */
videoFlags |= SDL_HWPALETTE; /* Store the palette in hardware */
videoFlags |= SDL_RESIZABLE; /* Enable window resizing */
/* This checks to see if surfaces can be stored in memory */
if ( videoInfo->hw_available )
videoFlags |= SDL_HWSURFACE;
else
videoFlags |= SDL_SWSURFACE;
/* This checks if hardware blits can be done */
if ( videoInfo->blit_hw )
videoFlags |= SDL_HWACCEL;
/* Sets up OpenGL double buffering */
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
/* get a SDL surface */
surface = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP,
videoFlags );
/* Verify there is a surface */
if ( !surface )
{
fprintf( stderr, "Video mode set failed: %s\n", SDL_GetError( ) );
Quit( 1 );
}
/* initialize OpenGL */
initGL( );
/* resize the initial window */
resizeWindow( SCREEN_WIDTH, SCREEN_HEIGHT );
/* wait for events */
while ( !done )
{
/* handle the events in the queue */
while ( SDL_PollEvent( &event ) )
{
switch( event.type )
{
case SDL_ACTIVEEVENT:
/* Something's happend with our focus
* If we lost focus or we are iconified, we
* shouldn't draw the screen
*/
if ( event.active.gain == 0 )
isActive = FALSE;
else
isActive = TRUE;
break;
case SDL_VIDEORESIZE:
/* handle resize event */
surface = SDL_SetVideoMode( event.resize.w,
event.resize.h,
16, videoFlags );
if ( !surface )
{
fprintf( stderr, "Could not get a surface after resize: %s\n", SDL_GetError( ) );
Quit( 1 );
}
resizeWindow( event.resize.w, event.resize.h );
break;
case SDL_KEYDOWN:
/* handle key presses */
handleKeyPress( &event.key.keysym );
break;
case SDL_QUIT:
/* handle quit requests */
done = TRUE;
break;
default:
break;
}
}
/* draw the scene */
if ( isActive )
drawGLScene( );
}
/* clean ourselves up and exit */
Quit( 0 );
/* Should never get here */
return( 0 );
}
Nun habe ich diese Zeilen auskommentiert:
glBegin( GL_TRIANGLES ); /* Drawing Using Triangles */
glVertex3f( 0.0f, 1.0f, 0.0f ); /* Top */
glVertex3f( -1.0f, -1.0f, 0.0f ); /* Bottom Left */
glVertex3f( 1.0f, -1.0f, 0.0f ); /* Bottom Right */
glEnd( ); /* Finished Drawing The Triangle */
Dann hab ich erwartet, dass das Dreieck verschwindet. Aber es ist immer noch ein Dreieck und ein Viereck zu sehen. Zwischendurch hab ich mal glxgears ausprobiert, bei dem die Zahnräder etwas unrund liefen, und dann hat mein Programm plötzlich Spuren von glxgears enthalten.
Kann mir jemand weiterhelfen?
Für eine Hilfe wäre ich sehr dankbar!
Nicolas
Ich habe große Probleme mit OpenGL unter Debian Linux. Ich versuche die ganze Zeit ein OpenGL zu bauen. Dazu hab ich als Vorlage das Tutorial 02 genommen. Das sieht so aus:
/*
* This code was created by Jeff Molofee '99
* (ported to Linux/SDL by Ti Leggett '01)
*
* If you've found this code useful, please let me know.
*
* Visit Jeff at http://nehe.gamedev.net/
*
* or for port-specific comments, questions, bugreports etc.
* email to leggett@eecs.tulane.edu
*/
#include <stdio.h>
#include <stdlib.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include "SDL.h"
/* screen width, height, and bit depth */
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define SCREEN_BPP 16
/* Define our booleans */
#define TRUE 1
#define FALSE 0
/* This is our SDL surface */
SDL_Surface *surface;
/* function to release/destroy our resources and restoring the old desktop */
void Quit( int returnCode )
{
/* clean up the window */
SDL_Quit( );
/* and exit appropriately */
exit( returnCode );
}
/* function to reset our viewport after a window resize */
int resizeWindow( int width, int height )
{
/* Height / width ration */
GLfloat ratio;
/* Protect against a divide by zero */
if ( height == 0 )
height = 1;
ratio = ( GLfloat )width / ( GLfloat )height;
/* Setup our viewport. */
glViewport( 0, 0, ( GLsizei )width, ( GLsizei )height );
/* change to the projection matrix and set our viewing volume. */
glMatrixMode( GL_PROJECTION );
glLoadIdentity( );
/* Set our perspective */
gluPerspective( 45.0f, ratio, 0.1f, 100.0f );
/* Make sure we're chaning the model view and not the projection */
glMatrixMode( GL_MODELVIEW );
/* Reset The View */
glLoadIdentity( );
return( TRUE );
}
/* function to handle key press events */
void handleKeyPress( SDL_keysym *keysym )
{
switch ( keysym->sym )
{
case SDLK_ESCAPE:
/* ESC key was pressed */
Quit( 0 );
break;
case SDLK_F1:
/* F1 key was pressed
* this toggles fullscreen mode
*/
SDL_WM_ToggleFullScreen( surface );
break;
default:
break;
}
return;
}
/* general OpenGL initialization function */
int initGL( GLvoid )
{
/* Enable smooth shading */
glShadeModel( GL_SMOOTH );
/* Set the background black */
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
/* Depth buffer setup */
glClearDepth( 1.0f );
/* Enables Depth Testing */
glEnable( GL_DEPTH_TEST );
/* The Type Of Depth Test To Do */
glDepthFunc( GL_LEQUAL );
/* Really Nice Perspective Calculations */
glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
return( TRUE );
}
/* Here goes our drawing code */
int drawGLScene( GLvoid )
{
/* These are to calculate our fps */
static GLint T0 = 0;
static GLint Frames = 0;
/* Clear The Screen And The Depth Buffer */
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
/* Move Left 1.5 Units And Into The Screen 6.0 */
glLoadIdentity();
glTranslatef( -1.5f, 0.0f, -6.0f );
glBegin( GL_TRIANGLES ); /* Drawing Using Triangles */
glVertex3f( 0.0f, 1.0f, 0.0f ); /* Top */
glVertex3f( -1.0f, -1.0f, 0.0f ); /* Bottom Left */
glVertex3f( 1.0f, -1.0f, 0.0f ); /* Bottom Right */
glEnd( ); /* Finished Drawing The Triangle */
/* Move Right 3 Units */
glTranslatef( 3.0f, 0.0f, 0.0f );
glBegin( GL_QUADS ); /* Draw A Quad */
glVertex3f( -1.0f, 1.0f, 0.0f ); /* Top Left */
glVertex3f( 1.0f, 1.0f, 0.0f ); /* Top Right */
glVertex3f( 1.0f, -1.0f, 0.0f ); /* Bottom Right */
glVertex3f( -1.0f, -1.0f, 0.0f ); /* Bottom Left */
glEnd( ); /* Done Drawing The Quad */
/* Draw it to the screen */
SDL_GL_SwapBuffers( );
/* Gather our frames per second */
Frames++;
{
GLint t = SDL_GetTicks();
if (t - T0 >= 5000) {
GLfloat seconds = (t - T0) / 1000.0;
GLfloat fps = Frames / seconds;
printf("%d frames in %g seconds = %g FPS\n", Frames, seconds, fps);
T0 = t;
Frames = 0;
}
}
return( TRUE );
}
int main( int argc, char **argv )
{
/* Flags to pass to SDL_SetVideoMode */
int videoFlags;
/* main loop variable */
int done = FALSE;
/* used to collect events */
SDL_Event event;
/* this holds some info about our display */
const SDL_VideoInfo *videoInfo;
/* whether or not the window is active */
int isActive = TRUE;
/* initialize SDL */
if ( SDL_Init( SDL_INIT_VIDEO ) < 0 )
{
fprintf( stderr, "Video initialization failed: %s\n",
SDL_GetError( ) );
Quit( 1 );
}
/* Fetch the video info */
videoInfo = SDL_GetVideoInfo( );
if ( !videoInfo )
{
fprintf( stderr, "Video query failed: %s\n",
SDL_GetError( ) );
Quit( 1 );
}
/* the flags to pass to SDL_SetVideoMode */
videoFlags = SDL_OPENGL; /* Enable OpenGL in SDL */
videoFlags |= SDL_GL_DOUBLEBUFFER; /* Enable double buffering */
videoFlags |= SDL_HWPALETTE; /* Store the palette in hardware */
videoFlags |= SDL_RESIZABLE; /* Enable window resizing */
/* This checks to see if surfaces can be stored in memory */
if ( videoInfo->hw_available )
videoFlags |= SDL_HWSURFACE;
else
videoFlags |= SDL_SWSURFACE;
/* This checks if hardware blits can be done */
if ( videoInfo->blit_hw )
videoFlags |= SDL_HWACCEL;
/* Sets up OpenGL double buffering */
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
/* get a SDL surface */
surface = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP,
videoFlags );
/* Verify there is a surface */
if ( !surface )
{
fprintf( stderr, "Video mode set failed: %s\n", SDL_GetError( ) );
Quit( 1 );
}
/* initialize OpenGL */
initGL( );
/* resize the initial window */
resizeWindow( SCREEN_WIDTH, SCREEN_HEIGHT );
/* wait for events */
while ( !done )
{
/* handle the events in the queue */
while ( SDL_PollEvent( &event ) )
{
switch( event.type )
{
case SDL_ACTIVEEVENT:
/* Something's happend with our focus
* If we lost focus or we are iconified, we
* shouldn't draw the screen
*/
if ( event.active.gain == 0 )
isActive = FALSE;
else
isActive = TRUE;
break;
case SDL_VIDEORESIZE:
/* handle resize event */
surface = SDL_SetVideoMode( event.resize.w,
event.resize.h,
16, videoFlags );
if ( !surface )
{
fprintf( stderr, "Could not get a surface after resize: %s\n", SDL_GetError( ) );
Quit( 1 );
}
resizeWindow( event.resize.w, event.resize.h );
break;
case SDL_KEYDOWN:
/* handle key presses */
handleKeyPress( &event.key.keysym );
break;
case SDL_QUIT:
/* handle quit requests */
done = TRUE;
break;
default:
break;
}
}
/* draw the scene */
if ( isActive )
drawGLScene( );
}
/* clean ourselves up and exit */
Quit( 0 );
/* Should never get here */
return( 0 );
}
Nun habe ich diese Zeilen auskommentiert:
glBegin( GL_TRIANGLES ); /* Drawing Using Triangles */
glVertex3f( 0.0f, 1.0f, 0.0f ); /* Top */
glVertex3f( -1.0f, -1.0f, 0.0f ); /* Bottom Left */
glVertex3f( 1.0f, -1.0f, 0.0f ); /* Bottom Right */
glEnd( ); /* Finished Drawing The Triangle */
Dann hab ich erwartet, dass das Dreieck verschwindet. Aber es ist immer noch ein Dreieck und ein Viereck zu sehen. Zwischendurch hab ich mal glxgears ausprobiert, bei dem die Zahnräder etwas unrund liefen, und dann hat mein Programm plötzlich Spuren von glxgears enthalten.
Kann mir jemand weiterhelfen?
Für eine Hilfe wäre ich sehr dankbar!
Nicolas