OpenGL 分形入门

/***************************************************************************** Copyright: 2012, ustc All rights reserved. contact:k283228391@126.com File name: main3D.c Description:Sierpinski 3D. Author:Silang Quan Version: 1.0 Date: 2012.12.02 *****************************************************************************/ #include <SDL/SDL.h> #include <GL/gl.h> #include <GL/glu.h> #include <stdio.h> #include <stdlib.h> SDL_Surface *screen; GLfloat colors[4][3]={{1.0,0.0,0.0},{0.0,1.0,0.0},{0.0,0.0,1.0},{0.0,1.0,1.0}}; typedef struct Point3f { GLfloat x; GLfloat y; GLfloat z; }point; typedef struct squa2d { int isBlack; point pos[4]; }squa; void quit( int code ) { SDL_Quit( ); /* Exit program. */ exit( code ); } void handleKeyEvent( SDL_keysym* keysym ) { switch( keysym->sym ) { case SDLK_ESCAPE: quit( 0 ); break; case SDLK_SPACE: break; default: break; } } void resizeGL(int width,int height) { if ( height == 0 ) { height = 1; } //Reset View glViewport( 0, 0, (GLint)width, (GLint)height ); //Choose the Matrix mode glMatrixMode( GL_PROJECTION ); //reset projection glLoadIdentity(); //set perspection gluPerspective( 45.0, (GLfloat)width/(GLfloat)height, 0.1, 100.0 ); //choose Matrix mode glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); } void handleEvents() { // Our SDL event placeholder. SDL_Event event; //Grab all the events off the queue. while( SDL_PollEvent( &event ) ) { switch( event.type ) { case SDL_KEYDOWN: // Handle key Event handleKeyEvent( &event.key.keysym ); break; case SDL_QUIT: // Handle quit requests (like Ctrl-c). quit( 0 ); break; case SDL_VIDEORESIZE: //Handle resize event screen = SDL_SetVideoMode(event.resize.w, event.resize.h, 16, SDL_OPENGL|SDL_RESIZABLE); if ( screen ) { resizeGL(screen->w, screen->h); } break; } } } void initSDL(int width,int height,int bpp,int flags) { // First, initialize SDL's video subsystem. if( SDL_Init( SDL_INIT_VIDEO ) < 0 ) { fprintf( stderr, "Video initialization failed: %s\n", SDL_GetError( ) ); quit( 1 ); } atexit(SDL_Quit); //Set some Attribute of OpenGL in SDL SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 ); SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 ); SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 ); SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 ); SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); //Set the video mode screen= SDL_SetVideoMode( width, height, bpp,flags); if(!screen ) { fprintf( stderr, "Video mode set failed: %s\n",SDL_GetError( ) ); quit( 1 ); } resizeGL(screen->w, screen->h); //Set caption SDL_WM_SetCaption( "Cantuo", NULL ); } void drawSquar(squa *s) { int i; if(s->isBlack) { for(i=0;i<4;i++) glVertex3f(s->pos[i].x,s->pos[i].y,s->pos[i].z); } //glVertex3fv(); //glVertex3fv(vc); } void cantuo2(GLfloat *a, GLfloat *b,GLfloat *c,GLfloat *d ) { static int i=0; glBegin(GL_QUADS); glColor3fv(colors[i++%4]); glVertex3fv(a); glVertex3fv(b); glVertex3fv(c); glVertex3fv(d); glEnd(); } void divide_cantuo2(GLfloat *a, GLfloat *b,GLfloat *c,GLfloat *d,int m) { GLfloat mid[12][3]; if(m>0) { // compute 12 points mid[0][0]=a[0]+(b[0]-a[0])/3.0; mid[0][1]=a[1]+(b[1]-a[1])/3.0; mid[0][2]=0.0; mid[1][0]=a[0]+2.0*(b[0]-a[0])/3.0; mid[1][1]=a[1]+2.0*(b[1]-a[1])/3.0; mid[1][2]=0.0; mid[2][0]=d[0]+1.0*(a[0]-d[0])/3.0; mid[2][1]=d[1]+2.0*(a[1]-d[1])/3.0; mid[2][2]=0.0; mid[3][0]=a[0]+(b[0]-a[0])/3.0; mid[3][1]=d[1]+2.0*(a[1]-d[1])/3.0; mid[3][2]=0.0; mid[4][0]=a[0]+2.0*(b[0]-a[0])/3.0; mid[4][1]=d[1]+2.0*(a[1]-d[1])/3.0; mid[4][2]=0.0; mid[5][0]=c[0]+2.0*(b[0]-c[0])/3.0; mid[5][1]=c[1]+2.0*(a[1]-d[1])/3.0; mid[5][2]=0.0; mid[6][0]=d[0]+(a[0]-d[0])/3.0; mid[6][1]=d[1]+(a[1]-d[1])/3.0; mid[6][2]=0.0; mid[7][0]=a[0]+(b[0]-a[0])/3.0; mid[7][1]=d[1]+(a[1]-d[1])/3.0; mid[7][2]=0.0; mid[8][0]=a[0]+2.0*(b[0]-a[0])/3.0; mid[8][1]=d[1]+(a[1]-d[1])/3.0; mid[8][2]=0.0; mid[9][0]=c[0]+2.0*(b[0]-c[0])/3.0; mid[9][1]=d[1]+(a[1]-d[1])/3.0; mid[9][2]=0.0; mid[10][0]=a[0]+(b[0]-a[0])/3.0; mid[10][1]=d[1]+(c[1]-d[1])/3.0; mid[10][2]=0.0; mid[11][0]=a[0]+2.0*(b[0]-a[0])/3.0; mid[11][1]=d[1]+2.0*(c[1]-d[1])/3.0; mid[11][2]=0.0; /* create 9 part by subdivision */ divide_cantuo2(a,mid[0],mid[3],mid[2], m-1); divide_cantuo2(mid[0],mid[1],mid[4],mid[3],m-1); divide_cantuo2(mid[1],b,mid[5],mid[4],m-1); divide_cantuo2(mid[2],mid[3],mid[7],mid[6],m-1); //divide_cantuo2(mid[3],mid[4],mid[8],mid[7],m-1); divide_cantuo2(mid[4],mid[5],mid[9],mid[8],m-1); divide_cantuo2(mid[6],mid[7],mid[10],d,m-1); divide_cantuo2(mid[7],mid[8],mid[11],mid[10],m-1); divide_cantuo2(mid[8],mid[9],c,mid[11],m-1); printf("m:%d\n",m); } else cantuo2(a,b,c,d); } void renderGL() { //Define a triangle in space //GLfloat v[4][3]={{0.0, 0.0, 1.0},{0.0, 0.942809, -0.33333},{-0.816497, -0.471405, -0.333333},{0.816497, -0.471405, -0.333333}}; GLfloat a[4][3]={{-3.0, 3.0, 0.0},{3.0, 3.0, 0},{3.0, -3.0, 0.0},{-3.0, -3.0, 0}}; // Clear the color and depth buffers. glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); // We don't want to modify the projection matrix. */ glMatrixMode( GL_MODELVIEW ); glLoadIdentity( ); // Move down the z-axis. glTranslatef( 0.0, 0.0, -6.0 ); glClear(GL_COLOR_BUFFER_BIT); /* clear the window */ divide_cantuo2(a[0],a[1],a[2],a[3],2); SDL_GL_SwapBuffers( ); } void initGL( int width, int height ) { float ratio = (float) width / (float) height; // Our shading model--Gouraud (smooth). glShadeModel( GL_SMOOTH ); // Set the clear color. glClearColor( 0, 0, 0, 0 ); // Setup our viewport. glViewport( 0, 0, width, height ); //Change to the projection matrix and set our viewing volume. glMatrixMode( GL_PROJECTION ); glLoadIdentity(); gluPerspective( 60.0, ratio, 1.0, 100.0 ); } int main( int argc, char* argv[] ) { // Dimensions of our window. int width = 640; int height = 480; // Color depth in bits of our window. int bpp = 32; int flags= SDL_OPENGL|SDL_RESIZABLE; //Set the SDL initSDL(width, height, bpp,flags); //Set the OpenGL initGL( width, height ); renderGL( ); //main loop while(1) { /* Process incoming events. */ handleEvents( ); /* Draw the screen. */ } return 0; }