150 lines
2.4 KiB
C
150 lines
2.4 KiB
C
/* Hilbert curve drawing program
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* by Josh Holtrop
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*/
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/* includes */
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#include <SDL/SDL.h>
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#include <GL/gl.h>
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#include <GL/glu.h>
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/* constants */
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#define SEGMENTS 16
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#define WIDTH 800
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#define HEIGHT 600
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/* functions */
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void usage(void);
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void initgl(void);
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void display(void);
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void mainloop(void);
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void drawHilbert();
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/* global variables */
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int level = 2;
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float size = 0.4;
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SDL_Surface * sdlScreen;
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int winWidth = WIDTH;
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int winHeight = HEIGHT;
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int displayList = -1;
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int main(int argc, char *argv[])
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{
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int i;
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for (i = 1; i < argc; i++)
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{
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if (!strncmp("-l", argv[i], 2))
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{
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sscanf(argv[i] + 2, "%d", &level);
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if (level < 1)
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usage();
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}
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else if (!strncmp("-s", argv[i], 2))
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{
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sscanf(argv[i] + 2, "%f", &size);
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if (size < 0.01 || size > 0.99)
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usage();
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}
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else
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{
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usage();
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}
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}
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if (SDL_Init(SDL_INIT_VIDEO))
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{
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printf("Failed to initialize SDL!\n");
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return 1;
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}
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atexit(SDL_Quit);
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SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
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if (!(sdlScreen = SDL_SetVideoMode(WIDTH, HEIGHT, 16, SDL_OPENGL | SDL_RESIZABLE)))
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{
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printf("Failed to set video mode!\n");
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SDL_Quit();
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return 2;
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}
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SDL_WM_SetCaption(argv[0], argv[0]);
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initgl();
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mainloop();
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return 0;
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}
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void mainloop(void)
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{
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SDL_Event event;
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display();
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while (SDL_WaitEvent(&event))
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{
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switch (event.type)
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{
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case SDL_QUIT:
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return;
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case SDL_KEYDOWN:
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switch (event.key.keysym.sym)
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{
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case SDLK_ESCAPE:
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return;
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default:
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break;
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}
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break;
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case SDL_VIDEORESIZE:
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break;
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}
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}
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}
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void initgl(void)
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{
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glClearColor (0.0, 0.0, 0.0, 0.0);
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glEnable(GL_DEPTH_TEST);
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glShadeModel(GL_SMOOTH);
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glViewport(0, 0, winWidth, winHeight);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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gluPerspective(60.0, (GLfloat)winHeight/(GLfloat)winWidth, 1.0, 30.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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glTranslatef(0.0, 0.0, -3.6);
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}
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void display(void)
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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if (displayList >= 0)
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{
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glCallList(displayList);
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}
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else
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{
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displayList = glGenLists(1);
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if (displayList < 0)
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{
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fprintf(stderr, "Error allocating display list!\n");
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exit(132);
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}
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glNewList(displayList, GL_COMPILE_AND_EXECUTE);
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drawHilbert();
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glEndList();
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}
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SDL_GL_SwapBuffers();
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}
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void drawHilbert()
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{
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}
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void usage(void)
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{
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printf("Options:\n"
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" -l<level> level of Hilbert curve to draw (1-?)\n"
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" -s<size> radius of Hilbert curve (0.01-0.99)\n");
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exit(42);
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}
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