#include #include #include /* Include non-standard libraries here */ #include #include #include "SDL.h" /* screen width, height, and bit depth */ #define SCREEN_WIDTH 640 #define SCREEN_HEIGHT 480 #define SCREEN_BPP 16 /* Set up some booleans */ #define TRUE 1 #define FALSE 0 /* Global variables. This is our SDL surface */ SDL_Surface *surface; GLfloat xrot; /* X Rotation */ GLfloat yrot; /* Y Rotation */ GLfloat xspeed; /* X Rotation Speed */ GLfloat yspeed; /* Y Rotation Speed */ GLfloat z_depth = -15.0f; /* Depth Into The Screen */ /* Here is our drawing code for lab 7. */ void myfunction(void) { float x,y,z; glColor3f(1.0f, 1.0f, 1.0f); glBegin(GL_LINES); /* draw axes */ /* Draw coordinate axes */ /* write six lines of code, 2 for each line */ /* see step 1. */ glEnd(); /* Stop drawing axes */ /* Plot your function with points */ glBegin(GL_POINTS); /* Draw points */ for(x = -10.0; x <= 10.0 ; x = x+ .2) for(y = -6.0; y <= 6.0; y = y+ .2) { /* your single line of code goes here to use glColor3f to shade plot see step 4. */ /* your line of code goes here to compute z see step 2. */ /* your single line of code goes here to plot the point (x,y,z) see step 3. */ /* remember in using glVertex3f( y coordinate , z coordinate , x coordinate */ } glEnd(); /* Stop drawing points */ } /* End LAB 7 code */ /* Function drawGLScene */ int drawGLScene( GLvoid ) { /* Clear The Screen And The Depth Buffer */ glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); /* Reset the view */ glLoadIdentity( ); /* Translate Into/Out Of The Screen By z_depth */ glTranslatef( 0.0f, -5.0f, -20.0f); glRotatef( xrot, 1.0f, 0.0f, 0.0f); /* Rotate On The X Axis By xrot */ glRotatef( yrot, 0.0f, 1.0f, 0.0f); /* Rotate On The Y Axis By yrot */ myfunction(); /* Draw it to the screen */ SDL_GL_SwapBuffers( ); xrot += xspeed; /* Add xspeed To xrot */ yrot += yspeed; /* Add yspeed To yrot */ return( TRUE ); } /* 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, ( GLint )width, ( GLint )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_UP: /* Up arrow key was pressed * this affects the x rotation */ xspeed -= 0.01f; break; case SDLK_DOWN: /* Down arrow key was pressed * this affects the x rotation */ xspeed += 0.01f; break; case SDLK_RIGHT: /* Right arrow key was pressed * this affects the y rotation */ yspeed += 0.01f; break; case SDLK_LEFT: /* Left arrow key was pressed * this affects the y rotation */ yspeed -= 0.01f; 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 ); } 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 = 1; break; default: break; } } /* draw the scene */ if ( isActive ) drawGLScene( ); } /* clean ourselves up and exit */ Quit( 0 ); /* Should never get here */ return( 0 ); }