fractals.c
上传用户:xk288cn
上传日期:2007-05-28
资源大小:4876k
文件大小:19k
- /*
- * To compile: cc -o fractals fractals.c -lGL -lGLU -lX11 -lglut -lXmu -lm
- *
- * Usage: fractals
- *
- * Homework 6, Part 2: fractal mountains and fractal trees
- * (Pretty Late)
- *
- * Draws fractal mountains and trees -- and an island of mountains in water
- * (I tried having trees on the island but it didn't work too well.)
- *
- * Two viewer modes: polar and flying (both restrained to y>0 for up vector).
- * Keyboard 0->9 and +/- control speed when flying.
- *
- * Only keyboard commands are 0-9 and +/- for speed in flying mode.
- *
- * Fog would make the island look much better, but I couldn't get it to work
- * correctly. Would line up on -z axis not from eye.
- *
- * Philip Winston - 3/4/95
- * pwinston@hmc.edu
- * http://www.cs.hmc.edu/people/pwinston
- *
- */
- #include <GL/glut.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <math.h>
- #include <limits.h> /* ULONG_MAX is defined here */
- #include <float.h> /* FLT_MAX is atleast defined here */
- #include <time.h> /* for random seed */
- #include "fracviewer.h"
- #ifdef _WIN32
- #define drand48() (((float) rand())/((float) RAND_MAX))
- #define srand48(x) (srand((x)))
- #endif
- typedef enum { NOTALLOWED, MOUNTAIN, TREE, ISLAND, BIGMTN, STEM, LEAF,
- MOUNTAIN_MAT, WATER_MAT, LEAF_MAT, TREE_MAT, STEMANDLEAVES,
- AXES } DisplayLists;
- #define MAXLEVEL 8
- int Rebuild = 1, /* Rebuild display list in next display? */
- Fract = TREE, /* What fractal are we building */
- Level = 4; /* levels of recursion for fractals */
- int DrawAxes = 0;
- /***************************************************************/
- /************************* VECTOR JUNK *************************/
- /***************************************************************/
- /* print vertex to stderr */
- void printvert(float v[3])
- {
- fprintf(stderr, "(%f, %f, %f)n", v[0], v[1], v[2]);
- }
- /* normalizes v */
- void normalize(GLfloat v[3])
- {
- GLfloat d = sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
- if (d == 0)
- fprintf(stderr, "Zero length vector in normalizen");
- else
- v[0] /= d; v[1] /= d; v[2] /= d;
- }
- /* calculates a normalized crossproduct to v1, v2 */
- void ncrossprod(float v1[3], float v2[3], float cp[3])
- {
- cp[0] = v1[1]*v2[2] - v1[2]*v2[1];
- cp[1] = v1[2]*v2[0] - v1[0]*v2[2];
- cp[2] = v1[0]*v2[1] - v1[1]*v2[0];
- normalize(cp);
- }
- /* calculates normal to the triangle designated by v1, v2, v3 */
- void triagnormal(float v1[3], float v2[3], float v3[3], float norm[3])
- {
- float vec1[3], vec2[3];
- vec1[0] = v3[0] - v1[0]; vec2[0] = v2[0] - v1[0];
- vec1[1] = v3[1] - v1[1]; vec2[1] = v2[1] - v1[1];
- vec1[2] = v3[2] - v1[2]; vec2[2] = v2[2] - v1[2];
- ncrossprod(vec2, vec1, norm);
- }
- float xzlength(float v1[3], float v2[3])
- {
- return sqrt((v1[0] - v2[0])*(v1[0] - v2[0]) +
- (v1[2] - v2[2])*(v1[2] - v2[2]));
- }
- float xzslope(float v1[3], float v2[3])
- {
- return ((v1[0] != v2[0]) ? ((v1[2] - v2[2]) / (v1[0] - v2[0]))
- : FLT_MAX);
- }
- /***************************************************************/
- /************************ MOUNTAIN STUFF ***********************/
- /***************************************************************/
- GLfloat DispFactor[MAXLEVEL]; /* Array of what to multiply random number
- by for a given level to get midpoint
- displacement */
- GLfloat DispBias[MAXLEVEL]; /* Array of what to add to random number
- before multiplying it by DispFactor */
- #define NUMRANDS 191
- float RandTable[NUMRANDS]; /* hash table of random numbers so we can
- raise the same midpoints by the same amount */
- /* The following are for permitting an edge of a moutain to be */
- /* pegged so it won't be displaced up or down. This makes it */
- /* easier to setup scenes and makes a single moutain look better */
- GLfloat Verts[3][3], /* Vertices of outside edges of mountain */
- Slopes[3]; /* Slopes between these outside edges */
- int Pegged[3]; /* Is this edge pegged or not */
- /*
- * Comes up with a new table of random numbers [0,1)
- */
- void InitRandTable(unsigned int seed)
- {
- int i;
- srand48((long) seed);
- for (i = 0; i < NUMRANDS; i++)
- RandTable[i] = drand48() - 0.5;
- }
- /* calculate midpoint and displace it if required */
- void Midpoint(GLfloat mid[3], GLfloat v1[3], GLfloat v2[3],
- int edge, int level)
- {
- unsigned hash;
- mid[0] = (v1[0] + v2[0]) / 2;
- mid[1] = (v1[1] + v2[1]) / 2;
- mid[2] = (v1[2] + v2[2]) / 2;
- if (!Pegged[edge] || (fabs(xzslope(Verts[edge], mid)
- - Slopes[edge]) > 0.00001)) {
- srand48((int)((v1[0]+v2[0])*23344));
- hash = drand48() * 7334334;
- srand48((int)((v2[2]+v1[2])*43433));
- hash = (unsigned)(drand48() * 634344 + hash) % NUMRANDS;
- mid[1] += ((RandTable[hash] + DispBias[level]) * DispFactor[level]);
- }
- }
- /*
- * Recursive moutain drawing routine -- from lecture with addition of
- * allowing an edge to be pegged. This function requires the above
- * globals to be set, as well as the Level global for fractal level
- */
- void FMR(GLfloat v1[3], GLfloat v2[3], GLfloat v3[3], int level)
- {
- if (level == Level) {
- GLfloat norm[3];
- triagnormal(v1, v2, v3, norm);
- glNormal3fv(norm);
- glVertex3fv(v1);
- glVertex3fv(v2);
- glVertex3fv(v3);
- } else {
- GLfloat m1[3], m2[3], m3[3];
- Midpoint(m1, v1, v2, 0, level);
- Midpoint(m2, v2, v3, 1, level);
- Midpoint(m3, v3, v1, 2, level);
- FMR(v1, m1, m3, level + 1);
- FMR(m1, v2, m2, level + 1);
- FMR(m3, m2, v3, level + 1);
- FMR(m1, m2, m3, level + 1);
- }
- }
- /*
- * sets up lookup tables and calls recursive mountain function
- */
- void FractalMountain(GLfloat v1[3], GLfloat v2[3], GLfloat v3[3],
- int pegged[3])
- {
- GLfloat lengths[MAXLEVEL];
- GLfloat fraction[8] = { 0.3, 0.3, 0.4, 0.2, 0.3, 0.2, 0.4, 0.4 };
- GLfloat bias[8] = { 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1 };
- int i;
- float avglen = (xzlength(v1, v2) +
- xzlength(v2, v3) +
- xzlength(v3, v1) / 3);
- for (i = 0; i < 3; i++) {
- Verts[0][i] = v1[i]; /* set mountain vertex globals */
- Verts[1][i] = v2[i];
- Verts[2][i] = v3[i];
- Pegged[i] = pegged[i];
- }
- Slopes[0] = xzslope(Verts[0], Verts[1]); /* set edge slope globals */
- Slopes[1] = xzslope(Verts[1], Verts[2]);
- Slopes[2] = xzslope(Verts[2], Verts[0]);
- lengths[0] = avglen;
- for (i = 1; i < Level; i++) {
- lengths[i] = lengths[i-1]/2; /* compute edge length for each level */
- }
- for (i = 0; i < Level; i++) { /* DispFactor and DispBias arrays */
- DispFactor[i] = (lengths[i] * ((i <= 7) ? fraction[i] : fraction[7]));
- DispBias[i] = ((i <= 7) ? bias[i] : bias[7]);
- }
- glBegin(GL_TRIANGLES);
- FMR(v1, v2, v3, 0); /* issues no GL but vertex calls */
- glEnd();
- }
- /*
- * draw a mountain and build the display list
- */
- void CreateMountain(void)
- {
- GLfloat v1[3] = { 0, 0, -1 }, v2[3] = { -1, 0, 1 }, v3[3] = { 1, 0, 1 };
- int pegged[3] = { 1, 1, 1 };
- glNewList(MOUNTAIN, GL_COMPILE);
- glPushAttrib(GL_LIGHTING_BIT);
- glCallList(MOUNTAIN_MAT);
- FractalMountain(v1, v2, v3, pegged);
- glPopAttrib();
- glEndList();
- }
- /*
- * new random numbers to make a different moutain
- */
- void NewMountain(void)
- {
- InitRandTable(time(NULL));
- }
- /***************************************************************/
- /***************************** TREE ****************************/
- /***************************************************************/
- long TreeSeed; /* for srand48 - remember so we can build "same tree"
- at a different level */
- /*
- * recursive tree drawing thing, fleshed out from class notes pseudocode
- */
- void FractalTree(int level)
- {
- long savedseed; /* need to save seeds while building tree too */
- if (level == Level) {
- glPushMatrix();
- glRotatef(drand48()*180, 0, 1, 0);
- glCallList(STEMANDLEAVES);
- glPopMatrix();
- } else {
- glCallList(STEM);
- glPushMatrix();
- glRotatef(drand48()*180, 0, 1, 0);
- glTranslatef(0, 1, 0);
- glScalef(0.7, 0.7, 0.7);
- savedseed = (long) drand48()*ULONG_MAX; /* recurse on a 3-way branching */
- glPushMatrix();
- glRotatef(110 + drand48()*40, 0, 1, 0);
- glRotatef(30 + drand48()*20, 0, 0, 1);
- FractalTree(level + 1);
- glPopMatrix();
- srand48(savedseed);
- savedseed = (long) drand48()*ULONG_MAX;
- glPushMatrix();
- glRotatef(-130 + drand48()*40, 0, 1, 0);
- glRotatef(30 + drand48()*20, 0, 0, 1);
- FractalTree(level + 1);
- glPopMatrix();
- srand48(savedseed);
- glPushMatrix();
- glRotatef(-20 + drand48()*40, 0, 1, 0);
- glRotatef(30 + drand48()*20, 0, 0, 1);
- FractalTree(level + 1);
- glPopMatrix();
- glPopMatrix();
- }
- }
- /*
- * Create display lists for a leaf, a set of leaves, and a stem
- */
- void CreateTreeLists(void)
- {
- GLUquadricObj *cylquad = gluNewQuadric();
- int i;
- glNewList(STEM, GL_COMPILE);
- glPushMatrix();
- glRotatef(-90, 1, 0, 0);
- gluCylinder(cylquad, 0.1, 0.08, 1, 10, 2 );
- glPopMatrix();
- glEndList();
- glNewList(LEAF, GL_COMPILE); /* I think this was jeff allen's leaf idea */
- glBegin(GL_TRIANGLES);
- glNormal3f(-0.1, 0, 0.25); /* not normalized */
- glVertex3f(0, 0, 0);
- glVertex3f(0.25, 0.25, 0.1);
- glVertex3f(0, 0.5, 0);
- glNormal3f(0.1, 0, 0.25);
- glVertex3f(0, 0, 0);
- glVertex3f(0, 0.5, 0);
- glVertex3f(-0.25, 0.25, 0.1);
- glEnd();
- glEndList();
- glNewList(STEMANDLEAVES, GL_COMPILE);
- glPushMatrix();
- glPushAttrib(GL_LIGHTING_BIT);
- glCallList(STEM);
- glCallList(LEAF_MAT);
- for(i = 0; i < 3; i++) {
- glTranslatef(0, 0.333, 0);
- glRotatef(90, 0, 1, 0);
- glPushMatrix();
- glRotatef(0, 0, 1, 0);
- glRotatef(50, 1, 0, 0);
- glCallList(LEAF);
- glPopMatrix();
- glPushMatrix();
- glRotatef(180, 0, 1, 0);
- glRotatef(60, 1, 0, 0);
- glCallList(LEAF);
- glPopMatrix();
- }
- glPopAttrib();
- glPopMatrix();
- glEndList();
- }
- /*
- * draw and build display list for tree
- */
- void CreateTree(void)
- {
- srand48(TreeSeed);
- glNewList(TREE, GL_COMPILE);
- glPushMatrix();
- glPushAttrib(GL_LIGHTING_BIT);
- glCallList(TREE_MAT);
- glTranslatef(0, -1, 0);
- FractalTree(0);
- glPopAttrib();
- glPopMatrix();
- glEndList();
- }
- /*
- * new seed for a new tree (groan)
- */
- void NewTree(void)
- {
- TreeSeed = time(NULL);
- }
- /***************************************************************/
- /*********************** FRACTAL PLANET ************************/
- /***************************************************************/
- void CreateIsland(void)
- {
- CreateMountain();
- glNewList(ISLAND, GL_COMPILE);
- glPushAttrib(GL_LIGHTING_BIT);
- glMatrixMode(GL_MODELVIEW);
- glPushMatrix();
- glCallList(WATER_MAT);
- glBegin(GL_QUADS);
- glNormal3f(0, 1, 0);
- glVertex3f(100, 0.01, 100);
- glVertex3f(100, 0.01, -100);
- glVertex3f(-100, 0.01, -100);
- glVertex3f(-100, 0.01, 100);
- glEnd();
- glPushMatrix();
- glTranslatef(0, -0.1, 0);
- glCallList(MOUNTAIN);
- glPopMatrix();
- glPushMatrix();
- glRotatef(135, 0, 1, 0);
- glTranslatef(0.2, -0.15, -0.4);
- glCallList(MOUNTAIN);
- glPopMatrix();
- glPushMatrix();
- glRotatef(-60, 0, 1, 0);
- glTranslatef(0.7, -0.07, 0.5);
- glCallList(MOUNTAIN);
- glPopMatrix();
- glPushMatrix();
- glRotatef(-175, 0, 1, 0);
- glTranslatef(-0.7, -0.05, -0.5);
- glCallList(MOUNTAIN);
- glPopMatrix();
- glPushMatrix();
- glRotatef(165, 0, 1, 0);
- glTranslatef(-0.9, -0.12, 0.0);
- glCallList(MOUNTAIN);
- glPopMatrix();
- glPopMatrix();
- glPopAttrib();
- glEndList();
- }
- void NewFractals(void)
- {
- NewMountain();
- NewTree();
- }
- void Create(int fract)
- {
- switch(fract) {
- case MOUNTAIN:
- CreateMountain();
- break;
- case TREE:
- CreateTree();
- break;
- case ISLAND:
- CreateIsland();
- break;
- }
- }
- /***************************************************************/
- /**************************** OPENGL ***************************/
- /***************************************************************/
- void SetupMaterials(void)
- {
- GLfloat mtn_ambuse[] = { 0.426, 0.256, 0.108, 1.0 };
- GLfloat mtn_specular[] = { 0.394, 0.272, 0.167, 1.0 };
- GLfloat mtn_shininess[] = { 10 };
- GLfloat water_ambuse[] = { 0.0, 0.1, 0.5, 1.0 };
- GLfloat water_specular[] = { 0.0, 0.1, 0.5, 1.0 };
- GLfloat water_shininess[] = { 10 };
- GLfloat tree_ambuse[] = { 0.4, 0.25, 0.1, 1.0 };
- GLfloat tree_specular[] = { 0.0, 0.0, 0.0, 1.0 };
- GLfloat tree_shininess[] = { 0 };
- GLfloat leaf_ambuse[] = { 0.0, 0.8, 0.0, 1.0 };
- GLfloat leaf_specular[] = { 0.0, 0.8, 0.0, 1.0 };
- GLfloat leaf_shininess[] = { 10 };
- glNewList(MOUNTAIN_MAT, GL_COMPILE);
- glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mtn_ambuse);
- glMaterialfv(GL_FRONT, GL_SPECULAR, mtn_specular);
- glMaterialfv(GL_FRONT, GL_SHININESS, mtn_shininess);
- glEndList();
- glNewList(WATER_MAT, GL_COMPILE);
- glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, water_ambuse);
- glMaterialfv(GL_FRONT, GL_SPECULAR, water_specular);
- glMaterialfv(GL_FRONT, GL_SHININESS, water_shininess);
- glEndList();
- glNewList(TREE_MAT, GL_COMPILE);
- glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, tree_ambuse);
- glMaterialfv(GL_FRONT, GL_SPECULAR, tree_specular);
- glMaterialfv(GL_FRONT, GL_SHININESS, tree_shininess);
- glEndList();
- glNewList(LEAF_MAT, GL_COMPILE);
- glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, leaf_ambuse);
- glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, leaf_specular);
- glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, leaf_shininess);
- glEndList();
- }
- void myGLInit(void)
- {
- GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
- GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
- GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
- GLfloat light_position[] = { 0.0, 0.3, 0.3, 0.0 };
- GLfloat lmodel_ambient[] = { 0.4, 0.4, 0.4, 1.0 };
- glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
- glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
- glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
- glLightfv(GL_LIGHT0, GL_POSITION, light_position);
-
- glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
- glEnable(GL_LIGHTING);
- glEnable(GL_LIGHT0);
- glDepthFunc(GL_LEQUAL);
- glEnable(GL_DEPTH_TEST);
- glEnable(GL_NORMALIZE);
- #if 0
- glEnable(GL_CULL_FACE);
- glCullFace(GL_BACK);
- #endif
- glShadeModel(GL_SMOOTH);
- #if 0
- glEnable(GL_BLEND);
- glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
- #endif
- SetupMaterials();
- CreateTreeLists();
- glFlush();
- }
- /***************************************************************/
- /************************ GLUT STUFF ***************************/
- /***************************************************************/
- void reshape(GLsizei w, GLsizei h)
- {
- glViewport(0,0,w,h);
- glMatrixMode(GL_PROJECTION);
- glLoadIdentity();
- gluPerspective(60.0, (GLdouble)w/h, 0.01, 100);
- glPushMatrix();
- glMatrixMode(GL_MODELVIEW);
- glFlush();
- }
- void display(void)
- {
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
- glFlush();
- glMatrixMode(GL_PROJECTION);
- glPopMatrix();
- glPushMatrix(); /* clear of last viewing xform, leaving perspective */
- agvViewTransform();
- glMatrixMode(GL_MODELVIEW);
- glLoadIdentity();
- if (Rebuild) {
- Create(Fract);
- Rebuild = 0;
- }
- glCallList(Fract);
- if (DrawAxes)
- glCallList(AXES);
- glutSwapBuffers();
- glFlush();
- }
- void visible(int v)
- {
- if (v == GLUT_VISIBLE)
- agvSetAllowIdle(1);
- else {
- glutIdleFunc(NULL);
- agvSetAllowIdle(0);
- }
- }
- void menuuse(int v)
- {
- if (v == GLUT_MENU_NOT_IN_USE)
- agvSetAllowIdle(1);
- else {
- glutIdleFunc(NULL);
- agvSetAllowIdle(0);
- }
- }
- /***************************************************************/
- /******************* MENU SETUP & HANDLING *********************/
- /***************************************************************/
- typedef enum { MENU_QUIT, MENU_RAND, MENU_MOVE, MENU_AXES } MenuChoices;
- void setlevel(int value)
- {
- Level = value;
- Rebuild = 1;
- glutPostRedisplay();
- }
- void choosefract(int value)
- {
- Fract = value;
- Rebuild = 1;
- glutPostRedisplay();
- }
- void handlemenu(int value)
- {
- switch (value) {
- case MENU_QUIT:
- exit(0);
- break;
- case MENU_RAND:
- NewFractals();
- Rebuild = 1;
- glutPostRedisplay();
- break;
- case MENU_AXES:
- DrawAxes = !DrawAxes;
- glutPostRedisplay();
- break;
- }
- }
- void MenuInit(void)
- {
- int submenu3, submenu2, submenu1;
- submenu1 = glutCreateMenu(setlevel);
- glutAddMenuEntry("0", 0); glutAddMenuEntry("1", 1);
- glutAddMenuEntry("2", 2); glutAddMenuEntry("3", 3);
- glutAddMenuEntry("4", 4); glutAddMenuEntry("5", 5);
- glutAddMenuEntry("6", 6); glutAddMenuEntry("7", 7);
- glutAddMenuEntry("8", 8);
- submenu2 = glutCreateMenu(choosefract);
- glutAddMenuEntry("Moutain", MOUNTAIN);
- glutAddMenuEntry("Tree", TREE);
- glutAddMenuEntry("Island", ISLAND);
- submenu3 = glutCreateMenu(agvSwitchMoveMode);
- glutAddMenuEntry("Flying", FLYING);
- glutAddMenuEntry("Polar", POLAR);
- glutCreateMenu(handlemenu);
- glutAddSubMenu("Level", submenu1);
- glutAddSubMenu("Fractal", submenu2);
- glutAddSubMenu("Movement", submenu3);
- glutAddMenuEntry("New Fractal", MENU_RAND);
- glutAddMenuEntry("Toggle Axes", MENU_AXES);
- glutAddMenuEntry("Quit", MENU_QUIT);
- glutAttachMenu(GLUT_RIGHT_BUTTON);
- }
- /***************************************************************/
- /**************************** MAIN *****************************/
- /***************************************************************/
- int main(int argc, char** argv)
- {
- glutInit(&argc, argv);
- glutInitWindowSize(512, 512);
- glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_MULTISAMPLE);
- glutCreateWindow("Fractal Planet?");
- agvInit(1); /* 1 cause we don't have our own idle */
- glutReshapeFunc(reshape);
- glutDisplayFunc(display);
- glutVisibilityFunc(visible);
- glutMenuStateFunc(menuuse);
- NewFractals();
- agvMakeAxesList(AXES);
- myGLInit();
- MenuInit();
- glutMainLoop();
- return 0; /* ANSI C requires main to return int. */
- }