initial hilbert commit

git-svn-id: svn://anubis/misc/hilbert@14 bd8a9e45-a331-0410-811e-c64571078777

Makefile

@@ -0,0 +1,13 @@
+CC := gcc
+CFLAGS := -O3 -ansi -pedantic -Wall `sdl-config --cflags`
+LDFLAGS := -lGL -lGLU `sdl-config --libs`
+TARGET := hilbert
+OBJS := hilbert.o
+
+all:	$(TARGET)
+
+$(TARGET): $(OBJS)
+	gcc -o $@ $^ $(LDFLAGS)
+
+clean:
+	-rm -f $(FILE) *~ *.o

hilbert.c

@@ -0,0 +1,149 @@
+/* Hilbert curve drawing program
+ * by Josh Holtrop
+ */
+
+/* includes */
+#include <SDL/SDL.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+
+/* constants */
+#define SEGMENTS 16
+#define WIDTH	 800
+#define HEIGHT	 600
+
+/* functions */
+void usage(void);
+void initgl(void);
+void display(void);
+void mainloop(void);
+void drawHilbert();
+
+/* global variables */
+int level = 2;
+float size = 0.4;
+SDL_Surface * sdlScreen;
+int winWidth = WIDTH;
+int winHeight = HEIGHT;
+int displayList = -1;
+
+int	main(int argc, char *argv[])
+{
+	int i;
+	for (i = 1; i < argc; i++)
+	{
+		if (!strncmp("-l", argv[i], 2))
+		{
+			sscanf(argv[i] + 2, "%d", &level);
+			if (level < 1)
+				usage();
+		}
+		else if (!strncmp("-s", argv[i], 2))
+		{
+			sscanf(argv[i] + 2, "%f", &size);
+			if (size < 0.01 || size > 0.99)
+				usage();
+		}
+		else
+		{
+			usage();
+		}
+	}
+
+	if (SDL_Init(SDL_INIT_VIDEO))
+	{
+		printf("Failed to initialize SDL!\n");
+		return 1;
+	}
+
+	atexit(SDL_Quit);
+
+	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+	if (!(sdlScreen = SDL_SetVideoMode(WIDTH, HEIGHT, 16, SDL_OPENGL | SDL_RESIZABLE)))
+	{
+		printf("Failed to set video mode!\n");
+		SDL_Quit();
+		return 2;
+	}
+	SDL_WM_SetCaption(argv[0], argv[0]);
+
+	initgl();
+	mainloop();
+
+	return 0;
+}
+
+void mainloop(void)
+{
+	SDL_Event event;
+	display();
+	while (SDL_WaitEvent(&event))
+	{
+		switch (event.type)
+		{
+			case SDL_QUIT:
+				return;
+			case SDL_KEYDOWN:
+				switch (event.key.keysym.sym)
+				{
+					case SDLK_ESCAPE:
+						return;
+					default:
+						break;
+				}
+				break;
+			case SDL_VIDEORESIZE:
+				break;
+		}
+	}
+}
+
+void initgl(void)
+{
+	glClearColor (0.0, 0.0, 0.0, 0.0);
+	glEnable(GL_DEPTH_TEST);
+	glShadeModel(GL_SMOOTH);
+	glViewport(0, 0, winWidth, winHeight);
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	gluPerspective(60.0, (GLfloat)winHeight/(GLfloat)winWidth, 1.0, 30.0);
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glTranslatef(0.0, 0.0, -3.6);
+}
+
+void display(void)
+{
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+	if (displayList >= 0)
+	{
+		glCallList(displayList);
+	}
+	else
+	{
+		displayList = glGenLists(1);
+		if (displayList < 0)
+		{
+			fprintf(stderr, "Error allocating display list!\n");
+			exit(132);
+		}
+		glNewList(displayList, GL_COMPILE_AND_EXECUTE);
+		drawHilbert();
+		glEndList();
+	}
+
+	SDL_GL_SwapBuffers();
+}
+
+void drawHilbert()
+{
+}
+
+void usage(void)
+{
+	printf("Options:\n"
+	       "    -l<level>   level of Hilbert curve to draw (1-?)\n"
+		   "    -s<size>    radius of Hilbert curve (0.01-0.99)\n");
+	exit(42);
+}