massive overhaul, see new keyboard options

1 files changed, 587 insertions, 465 deletions

diff --git a/progs/demos/stex3d.c b/progs/demos/stex3d.c
index 56ec49ca62a..427d1f3a50c 100644
--- a/progs/demos/stex3d.c
+++ b/progs/demos/stex3d.c
@@ -1,4 +1,4 @@
-/* $Id: stex3d.c,v 1.6 2002/04/22 16:03:37 brianp Exp $ */
+/* $Id: stex3d.c,v 1.7 2002/10/23 14:00:01 brianp Exp $ */
 
 /*----------------------------- 
  * stex3d.c GL example of the mesa 3d-texture extention to simulate procedural
@@ -9,6 +9,7 @@
  *           [email protected]
  *
  * Converted to GLUT by brianp on 1/1/98
+ * Massive clean-up on 2002/10/23 by brianp
  *
  *      
  * cc stex3d.c -o stex3d -lglut -lMesaGLU -lMesaGL -lX11 -lXext -lm 
@@ -21,529 +22,650 @@
 #include <math.h>
 #include <GL/gl.h>
 #include <GL/glut.h>
-/* function declarations */
+
+
 #ifndef M_PI
 #define M_PI            3.14159265358979323846
 #endif
- 
-void init(void),
-     printHelp(void),
-     create3Dtexture(void),
-     setDefaults(void),
-     drawScene(void),
-     resize(int w, int h),
-     buildFigure(void),
-     initNoise(void);
-float turbulence(float point[3], float lofreq, float hifreq);
-
-void KeyHandler( unsigned char key, int x, int y );
-GLenum parseCmdLine(int argc, char **argv);
-float noise3(float vec[3]);
-      
-/* global variables */
-GLenum rgb, doubleBuffer, directRender, windType; /* visualization state*/
-float tex_width,tex_height,tex_depth;        /* texture volume dimensions  */
-unsigned char *voxels;                       /* texture data ptr */
-int angx,angy,angz;
-GLuint figure;
-
-/*function definitions */
-int main(int argc, char **argv)
-{
 
- if (parseCmdLine(argc, argv) == GL_FALSE) {
-    exit(0);
- }
-
- glutInitWindowPosition(0, 0);
- glutInitWindowSize(400, 400);
- windType = (rgb) ? GLUT_RGB : GLUT_INDEX;
- windType |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
- windType |= GLUT_DEPTH;
- glutInitDisplayMode(windType);
-
- if (glutCreateWindow("stex3d") <= 0) {
-    exit(0);
- }
- /* init all */
- init();
-
- glutReshapeFunc(resize);
- glutKeyboardFunc(KeyHandler);
- glutDisplayFunc(drawScene);
- glutMainLoop();
- return 0;
+#define NOISE_TEXTURE 1
+#define GRADIENT_TEXTURE 2
+
+#define TORUS 1
+#define SPHERE 2
+
+static int tex_width=64, tex_height=64, tex_depth=64;
+static float angx=0, angy=0, angz=0;
+static GLuint DList;
+static int texgen = 2, animate = 1, smooth = 1;
+static int CurTexture = NOISE_TEXTURE, CurObject = TORUS;
+
+
+static void
+BuildTorus(void)
+{
+   GLint i, j;
+   float theta1, phi1, theta2, phi2, rings, sides;
+   float v0[03], v1[3], v2[3], v3[3];
+   float t0[03], t1[3], t2[3], t3[3];
+   float n0[3], n1[3], n2[3], n3[3];
+   float innerRadius = 0.25;
+   float outerRadius = 0.5;
+   float scalFac;
+
+   rings = 16;
+   sides = 12;
+   scalFac = 1 / (outerRadius * 2);
+
+   glNewList(TORUS, GL_COMPILE);
+   for (i = 0; i < rings; i++) {
+      theta1 = (float) i *2.0 * M_PI / rings;
+      theta2 = (float) (i + 1) * 2.0 * M_PI / rings;
+      for (j = 0; j < sides; j++) {
+	 phi1 = (float) j *2.0 * M_PI / sides;
+	 phi2 = (float) (j + 1) * 2.0 * M_PI / sides;
+
+	 v0[0] = cos(theta1) * (outerRadius + innerRadius * cos(phi1));
+	 v0[1] = -sin(theta1) * (outerRadius + innerRadius * cos(phi1));
+	 v0[2] = innerRadius * sin(phi1);
+
+	 v1[0] = cos(theta2) * (outerRadius + innerRadius * cos(phi1));
+	 v1[1] = -sin(theta2) * (outerRadius + innerRadius * cos(phi1));
+	 v1[2] = innerRadius * sin(phi1);
+	 v2[0] = cos(theta2) * (outerRadius + innerRadius * cos(phi2));
+	 v2[1] = -sin(theta2) * (outerRadius + innerRadius * cos(phi2));
+	 v2[2] = innerRadius * sin(phi2);
+
+	 v3[0] = cos(theta1) * (outerRadius + innerRadius * cos(phi2));
+	 v3[1] = -sin(theta1) * (outerRadius + innerRadius * cos(phi2));
+	 v3[2] = innerRadius * sin(phi2);
+
+	 n0[0] = cos(theta1) * (cos(phi1));
+	 n0[1] = -sin(theta1) * (cos(phi1));
+	 n0[2] = sin(phi1);
+
+	 n1[0] = cos(theta2) * (cos(phi1));
+	 n1[1] = -sin(theta2) * (cos(phi1));
+	 n1[2] = sin(phi1);
+
+	 n2[0] = cos(theta2) * (cos(phi2));
+	 n2[1] = -sin(theta2) * (cos(phi2));
+	 n2[2] = sin(phi2);
+
+	 n3[0] = cos(theta1) * (cos(phi2));
+	 n3[1] = -sin(theta1) * (cos(phi2));
+	 n3[2] = sin(phi2);
+
+	 t0[0] = v0[0] * scalFac + 0.5;
+	 t0[1] = v0[1] * scalFac + 0.5;
+	 t0[2] = v0[2] * scalFac + 0.5;
+
+	 t1[0] = v1[0] * scalFac + 0.5;
+	 t1[1] = v1[1] * scalFac + 0.5;
+	 t1[2] = v1[2] * scalFac + 0.5;
+
+	 t2[0] = v2[0] * scalFac + 0.5;
+	 t2[1] = v2[1] * scalFac + 0.5;
+	 t2[2] = v2[2] * scalFac + 0.5;
+
+	 t3[0] = v3[0] * scalFac + 0.5;
+	 t3[1] = v3[1] * scalFac + 0.5;
+	 t3[2] = v3[2] * scalFac + 0.5;
+
+	 glBegin(GL_POLYGON);
+	 glNormal3fv(n3);
+	 glTexCoord3fv(t3);
+	 glVertex3fv(v3);
+	 glNormal3fv(n2);
+	 glTexCoord3fv(t2);
+	 glVertex3fv(v2);
+	 glNormal3fv(n1);
+	 glTexCoord3fv(t1);
+	 glVertex3fv(v1);
+	 glNormal3fv(n0);
+	 glTexCoord3fv(t0);
+	 glVertex3fv(v0);
+	 glEnd();
+      }
+   }
+   glEndList();
 }
 
-void init()
-{ 
- /* init light */
- GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
- GLfloat mat_shininess[] = { 25.0 };
- GLfloat gray[] = { 0.6, 0.6, 0.6, 0.0 };
- GLfloat white[] = { 1.0, 1.0, 1.0, 0.0 };
- GLfloat light_position[] = { 0.0, 1.0, 1.0, 0.0 };
-
- glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
- glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
- glLightfv(GL_LIGHT1, GL_POSITION, light_position);
- glLightfv(GL_LIGHT1, GL_AMBIENT, gray);
- glLightfv(GL_LIGHT1, GL_DIFFUSE, white);
- glLightfv(GL_LIGHT1, GL_SPECULAR, white);
- glColorMaterial(GL_FRONT, GL_DIFFUSE);
- glEnable(GL_COLOR_MATERIAL);
- glEnable(GL_LIGHTING);
- glEnable(GL_LIGHT1);
-
- /* create torus for texturing */
- figure=glGenLists(1); 
- buildFigure();
-/* tkSolidTorus(figure,0.3,1.2);*/
-
- /* start the noise function variables */
- initNoise();
- 
- /* see if we have OpenGL 1.2 or later, for 3D texturing */
- {
-    const char *version = (const char *) glGetString(GL_VERSION);
-    if (strncmp(version, "1.0", 3) == 0 ||
-        strncmp(version, "1.1", 3) == 0) {
-       printf("Sorry, OpenGL 1.2 or later is required\n");
-       exit(1);
-    }
- }
- 
- /* if texture is supported then generate the texture */
- create3Dtexture(); 
-
- glEnable(GL_TEXTURE_3D); 
- /*
- glBlendFunc(GL_SRC_COLOR, GL_SRC_ALPHA);
- glEnable(GL_BLEND); 
- */
- glEnable(GL_DEPTH_TEST);
-
- glShadeModel(GL_FLAT);
- glColor3f(0.6,0.7,0.8);
+
+/*--------------------------------------------------------------------
+ noise function over R3 - implemented by a pseudorandom tricubic spline 
+              EXCERPTED FROM SIGGRAPH 92, COURSE 23
+                        PROCEDURAL MODELING
+                             Ken Perlin
+                           New York University
+----------------------------------------------------------------------*/
+
+
+#define DOT(a,b) (a[0] * b[0] + a[1] * b[1] + a[2] * b[2])
+#define B 128
+static int p[B + B + 2];
+static float g[B + B + 2][3];
+#define setup(i,b0,b1,r0,r1) \
+        t = vec[i] + 10000.; \
+        b0 = ((int)t) & (B-1); \
+        b1 = (b0+1) & (B-1); \
+        r0 = t - (int)t; \
+        r1 = r0 - 1.;
+
+static float
+noise3(float vec[3])
+{
+   int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11;
+   float rx0, rx1, ry0, ry1, rz0, rz1, *q, sx, sy, sz, a, b, c, d, t, u, v;
+   register int i, j;
+
+   setup(0, bx0, bx1, rx0, rx1);
+   setup(1, by0, by1, ry0, ry1);
+   setup(2, bz0, bz1, rz0, rz1);
+
+   i = p[bx0];
+   j = p[bx1];
+
+   b00 = p[i + by0];
+   b10 = p[j + by0];
+   b01 = p[i + by1];
+   b11 = p[j + by1];
+
+#define at(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] )
+#define surve(t) ( t * t * (3. - 2. * t) )
+#define lerp(t, a, b) ( a + t * (b - a) )
+
+   sx = surve(rx0);
+   sy = surve(ry0);
+   sz = surve(rz0);
+
+   q = g[b00 + bz0];
+   u = at(rx0, ry0, rz0);
+   q = g[b10 + bz0];
+   v = at(rx1, ry0, rz0);
+   a = lerp(sx, u, v);
+
+   q = g[b01 + bz0];
+   u = at(rx0, ry1, rz0);
+   q = g[b11 + bz0];
+   v = at(rx1, ry1, rz0);
+   b = lerp(sx, u, v);
+
+   c = lerp(sy, a, b);		/* interpolate in y at lo x */
+
+   q = g[b00 + bz1];
+   u = at(rx0, ry0, rz1);
+   q = g[b10 + bz1];
+   v = at(rx1, ry0, rz1);
+   a = lerp(sx, u, v);
+
+   q = g[b01 + bz1];
+   u = at(rx0, ry1, rz1);
+   q = g[b11 + bz1];
+   v = at(rx1, ry1, rz1);
+   b = lerp(sx, u, v);
+
+   d = lerp(sy, a, b);		/* interpolate in y at hi x */
+
+   return 1.5 * lerp(sz, c, d);	/* interpolate in z */
 }
 
-void buildFigure(void)
-{   GLint i, j;
-    float theta1, phi1, theta2, phi2, rings, sides;
-    float v0[03], v1[3], v2[3], v3[3];
-    float t0[03], t1[3], t2[3], t3[3];
-    float n0[3], n1[3], n2[3], n3[3];
-    float innerRadius=0.4;
-    float outerRadius=0.8;
-    float scalFac;
-
-    rings = 8;
-    sides = 10;
-    scalFac=1/(outerRadius*2);
-
-    glNewList(figure, GL_COMPILE);
-    for (i = 0; i < rings; i++) {
-        theta1 = (float)i * 2.0 * M_PI / rings;
-        theta2 = (float)(i + 1) * 2.0 * M_PI / rings;
-        for (j = 0; j < sides; j++) {
-            phi1 = (float)j * 2.0 * M_PI / sides;
-            phi2 = (float)(j + 1) * 2.0 * M_PI / sides;
-
-            v0[0] = cos(theta1) * (outerRadius + innerRadius * cos(phi1));
-            v0[1] = -sin(theta1) * (outerRadius + innerRadius * cos(phi1));
-            v0[2] = innerRadius * sin(phi1);
-
-            v1[0] = cos(theta2) * (outerRadius + innerRadius * cos(phi1));
-            v1[1] = -sin(theta2) * (outerRadius + innerRadius * cos(phi1));
-            v1[2] = innerRadius * sin(phi1);
-            v2[0] = cos(theta2) * (outerRadius + innerRadius * cos(phi2));
-            v2[1] = -sin(theta2) * (outerRadius + innerRadius * cos(phi2));
-            v2[2] = innerRadius * sin(phi2);
-
-            v3[0] = cos(theta1) * (outerRadius + innerRadius * cos(phi2));
-            v3[1] = -sin(theta1) * (outerRadius + innerRadius * cos(phi2));
-            v3[2] = innerRadius * sin(phi2);
-
-            n0[0] = cos(theta1) * (cos(phi1));
-            n0[1] = -sin(theta1) * (cos(phi1));
-            n0[2] = sin(phi1);
-
-            n1[0] = cos(theta2) * (cos(phi1));
-            n1[1] = -sin(theta2) * (cos(phi1));
-            n1[2] = sin(phi1);
-
-            n2[0] = cos(theta2) * (cos(phi2));
-            n2[1] = -sin(theta2) * (cos(phi2));
-            n2[2] = sin(phi2);
-
-            n3[0] = cos(theta1) * (cos(phi2));
-            n3[1] = -sin(theta1) * (cos(phi2));
-            n3[2] = sin(phi2);
-
-            t0[0] = v0[0]*scalFac + 0.5;
-            t0[1] = v0[1]*scalFac + 0.5;
-            t0[2] = v0[2]*scalFac + 0.5;
-
-            t1[0] = v1[0]*scalFac + 0.5;
-            t1[1] = v1[1]*scalFac + 0.5;
-            t1[2] = v1[2]*scalFac + 0.5;
-
-            t2[0] = v2[0]*scalFac + 0.5;
-            t2[1] = v2[1]*scalFac + 0.5;
-            t2[2] = v2[2]*scalFac + 0.5;
-
-            t3[0] = v3[0]*scalFac + 0.5;
-            t3[1] = v3[1]*scalFac + 0.5;
-            t3[2] = v3[2]*scalFac + 0.5;
-
-            glBegin(GL_POLYGON);
-                glNormal3fv(n3); glTexCoord3fv(t3); glVertex3fv(v3);
-                glNormal3fv(n2); glTexCoord3fv(t2); glVertex3fv(v2);
-                glNormal3fv(n1); glTexCoord3fv(t1); glVertex3fv(v1);
-                glNormal3fv(n0); glTexCoord3fv(t0); glVertex3fv(v0);
-            glEnd();
-        }
-    }
-    glEndList();
+static void
+initNoise(void)
+{
+   /*long random(); */
+   int i, j, k;
+   float v[3], s;
+
+   /* Create an array of random gradient vectors uniformly on the unit sphere */
+   /*srandom(1); */
+   srand(1);
+   for (i = 0; i < B; i++) {
+      do {			/* Choose uniformly in a cube */
+	 for (j = 0; j < 3; j++)
+	    v[j] = (float) ((rand() % (B + B)) - B) / B;
+	 s = DOT(v, v);
+      } while (s > 1.0);	/* If not in sphere try again */
+      s = sqrt(s);
+      for (j = 0; j < 3; j++)	/* Else normalize */
+	 g[i][j] = v[j] / s;
+   }
+
+   /* Create a pseudorandom permutation of [1..B] */
+   for (i = 0; i < B; i++)
+      p[i] = i;
+   for (i = B; i > 0; i -= 2) {
+      k = p[i];
+      p[i] = p[j = rand() % B];
+      p[j] = k;
+   }
+
+   /* Extend g and p arrays to allow for faster indexing */
+   for (i = 0; i < B + 2; i++) {
+      p[B + i] = p[i];
+      for (j = 0; j < 3; j++)
+	 g[B + i][j] = g[i][j];
+   }
 }
 
-void create3Dtexture()
+
+static float
+turbulence(float point[3], float lofreq, float hifreq)
 {
- int i,j,k;
- unsigned char *vp;
- float vec[3];
- int tmp;
-
- printf("creating 3d textures...\n");
- voxels = (unsigned char  *) malloc((size_t)(4*tex_width*tex_height*tex_depth));
- vp=voxels;
- for (i=0;i<tex_width;i++){
-    vec[0]=i;
-    for (j=0;j<tex_height;j++) {
-      vec[1]=j;
-       for (k=0;k<tex_depth;k++) {
-           vec[2]=k;
-           tmp=(sin(k*i*j+turbulence(vec,0.01,1))+1)*127.5; 
-           *vp++=0;
-           *vp++=0;
-           *vp++=tmp; 
-           *vp++=tmp+128; 
-       }
-     }
- }
-
- printf("setting up 3d texture...\n");
- glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
- glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
- glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
- glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S,     GL_REPEAT);
- glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T,     GL_REPEAT);
- glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R,     GL_REPEAT);
- glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
-
- glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA,
-              tex_width, tex_height, tex_depth,
-              0, GL_RGBA, GL_UNSIGNED_BYTE, voxels);
- 
- printf("finished setting up 3d texture image...\n");
+   float freq, t, p[3];
+
+   p[0] = point[0] + 123.456;
+   p[1] = point[1];
+   p[2] = point[2];
+
+   t = 0;
+   for (freq = lofreq; freq < hifreq; freq *= 2.) {
+      t += fabs(noise3(p)) / freq;
+      p[0] *= 2.;
+      p[1] *= 2.;
+      p[2] *= 2.;
+   }
+   return t - 0.3;		/* readjust to make mean value = 0.0 */
 }
 
-void printHelp()
+
+static void
+create3Dtexture(void)
 {
-  printf("\nUsage: stex3d  <cmd line options>\n"); 
-  printf(" cmd line options:\n");
-  printf("      -help   print this help!\n");
-  printf("      -rgb     RGBA mode. (Default)\n");
-  printf("      -ci     Color index mode.\n");
-  printf("      -sb     Single buffer mode. (Default)\n");
-  printf("      -db     Double buffer mode. \n");
-  printf("      -dr     Direct render mode.\n");
-  printf("      -ir     Indirect render mode. (Default)\n");
-  printf("      -wxxx   Width of the texture (Default=64)\n");
-  printf("      -hxxx   Height of the texture (Default=64)\n");
-  printf("      -dxxx   Depth of the texture (Default=64)\n");
-  printf(" Keyboard Options:\n");
-  printf("       1      Object Texture coordinates (Default)\n");
-  printf("       2      Eye Texture coordinates \n");
-  printf("       x      rotate around x clockwise\n");
-  printf("       X      rotate around x counter clockwise\n");
-  printf("       y      rotate around y clockwise\n");
-  printf("       Y      rotate around y counter clockwise\n");
-  printf("       z      rotate around z clockwise\n");
-  printf("       Z      rotate around z counter clockwise\n");
-  printf("       t      enable 3-D texuring (Default)\n");
-  printf("       T      disable 3-D texuring\n");
-  printf("       s      smooth shading \n");
-  printf("       S      flat shading (Default)\n");
+   unsigned char *voxels = NULL;
+   int i, j, k;
+   unsigned char *vp;
+   float vec[3];
+   int tmp;
+
+   printf("creating 3d textures...\n");
+   voxels =
+      (unsigned char *)
+      malloc((size_t) (4 * tex_width * tex_height * tex_depth));
+   vp = voxels;
+   for (i = 0; i < tex_width; i++) {
+      vec[0] = i;
+      for (j = 0; j < tex_height; j++) {
+	 vec[1] = j;
+	 for (k = 0; k < tex_depth; k++) {
+	    vec[2] = k;
+	    tmp = (sin(k * i * j + turbulence(vec, 0.01, 1)) + 1) * 127.5;
+	    *vp++ = 0;
+	    *vp++ = 0;
+	    *vp++ = tmp;
+	    *vp++ = tmp + 128;
+	 }
+      }
+   }
+
+   printf("setting up 3d texture...\n");
+
+   glBindTexture(GL_TEXTURE_3D, NOISE_TEXTURE);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
+   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
+
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+   glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA,
+		tex_width, tex_height, tex_depth,
+		0, GL_RGBA, GL_UNSIGNED_BYTE, voxels);
+
+   free(voxels);
+
+   printf("finished setting up 3d texture image.\n");
 }
 
-void setDefaults()
+
+static void
+printHelp(void)
 {
- /* visualization defaults */
-  rgb = GL_TRUE;
-  doubleBuffer = GL_FALSE;
-  directRender = GL_TRUE;
-  angx=130;
-  angy=30;
-  angz=0; 
- /* texture values */
- tex_width=64;
- tex_height=64;
- tex_depth=64;
+   printf("\nUsage: stex3d  <cmd line options>\n");
+   printf(" cmd line options:\n");
+   printf("      -wxxx   Width of the texture (Default=64)\n");
+   printf("      -hxxx   Height of the texture (Default=64)\n");
+   printf("      -dxxx   Depth of the texture (Default=64)\n");
+   printf(" Keyboard Options:\n");
+   printf("    up/down   rotate around X\n");
+   printf("  left/right  rotate around Y\n");
+   printf("      z/Z     rotate around Z\n");
+   printf("       a      toggle animation\n");
+   printf("       s      toggle smooth shading\n");
+   printf("       t      toggle texgen mode\n");
+   printf("       o      toggle object: torus/sphere\n");
+   printf("       i      toggle texture image: noise/gradient\n");
 }
 
-GLenum parseCmdLine(int argc, char **argv)
+
+static GLenum
+parseCmdLine(int argc, char **argv)
 {
-  GLint i;
- 
-  setDefaults();
-
-  for (i = 1; i < argc; i++) {
-      if (strcmp(argv[i], "-ci") == 0) {
-          rgb = GL_FALSE;
-      } else if (strcmp(argv[i], "-rgb") == 0) {
-          rgb = GL_TRUE;
-      } else if (strcmp(argv[i], "-sb") == 0) {
-          doubleBuffer = GL_FALSE;
-      } else if (strcmp(argv[i], "-db") == 0) {
-          doubleBuffer = GL_TRUE;
-      } else if (strcmp(argv[i], "-dr") == 0) {
-          directRender = GL_TRUE;
-      } else if (strcmp(argv[i], "-ir") == 0) {
-          directRender = GL_FALSE;
-      } else if (strstr(argv[i], "-w") == 0) {
-          tex_width=atoi((argv[i])+2);
-      } else if (strstr(argv[i], "-h") == 0) {
-          tex_height=atoi((argv[i])+2);
-      } else if (strstr(argv[i], "-d") == 0) {
-          tex_depth=atoi((argv[i])+2);
-      } else if (strcmp(argv[i], "-help") == 0) {
-          printHelp();
-          return GL_FALSE;
-      } else {
-          printf("%s (Bad option).\n", argv[i]);
-          printHelp();
-          return GL_FALSE;
+   GLint i;
+
+   for (i = 1; i < argc; i++) {
+      if (strstr(argv[i], "-w") == 0) {
+	 tex_width = atoi((argv[i]) + 2);
       }
-  }
- if(tex_width==0 || tex_height==0 || tex_depth==0) {
-   printf("%s (Bad option).\n", "size parameters can't be 0");
-   printHelp();
-   return GL_FALSE;
- }
-  return GL_TRUE;
+      else if (strstr(argv[i], "-h") == 0) {
+	 tex_height = atoi((argv[i]) + 2);
+      }
+      else if (strstr(argv[i], "-d") == 0) {
+	 tex_depth = atoi((argv[i]) + 2);
+      }
+      else if (strcmp(argv[i], "-help") == 0) {
+	 printHelp();
+	 return GL_FALSE;
+      }
+      else {
+	 printf("%s (Bad option).\n", argv[i]);
+	 printHelp();
+	 return GL_FALSE;
+      }
+   }
+   if (tex_width == 0 || tex_height == 0 || tex_depth == 0) {
+      printf("%s (Bad option).\n", "size parameters can't be 0");
+      printHelp();
+      return GL_FALSE;
+   }
+   return GL_TRUE;
+}
+
+
+static void
+drawScene(void)
+{
+   static const GLfloat sPlane[4] = { 0.5, 0, 0, -.5 };
+   static const GLfloat tPlane[4] = { 0, 0.5, 0, -.5 };
+   static const GLfloat rPlane[4] = { 0, 0, 0.5, -.5 };
+
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+   glPushMatrix();
+   if (texgen == 2) {
+      glTexGenfv(GL_S, GL_EYE_PLANE, sPlane);
+      glTexGenfv(GL_T, GL_EYE_PLANE, tPlane);
+      glTexGenfv(GL_R, GL_EYE_PLANE, rPlane);
+   }
+
+   glRotatef(angx, 1.0, 0.0, 0.0);
+   glRotatef(angy, 0.0, 1.0, 0.0);
+   glRotatef(angz, 0.0, 0.0, 1.0);
+
+   if (texgen == 1) {
+      glTexGenfv(GL_S, GL_EYE_PLANE, sPlane);
+      glTexGenfv(GL_T, GL_EYE_PLANE, tPlane);
+      glTexGenfv(GL_R, GL_EYE_PLANE, rPlane);
+   }
+
+   if (texgen) {
+      glEnable(GL_TEXTURE_GEN_S);
+      glEnable(GL_TEXTURE_GEN_T);
+      glEnable(GL_TEXTURE_GEN_R);
+   }
+   else {
+      glDisable(GL_TEXTURE_GEN_S);
+      glDisable(GL_TEXTURE_GEN_T);
+      glDisable(GL_TEXTURE_GEN_R);
+   }
+
+   glCallList(CurObject);
+   glPopMatrix();
+
+   glutSwapBuffers();
 }
 
-void drawScene()
+
+static void
+resize(int w, int h)
 {
- /* clear background, z buffer etc */
- glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
- glPushMatrix();
- glRotatef(angx,1.0,0.0,0.0);
- glRotatef(angy,0.0,1.0,0.0);
- glRotatef(angz,0.0,0.0,1.0);
-
- glCallList(figure);     
- glPopMatrix();
- glFlush();
- if(doubleBuffer)
-    glutSwapBuffers();
- ;
+   float ar = (float) w / (float) h;
+   float ax = 0.6 * ar;
+   float ay = 0.6;
+   glViewport(0, 0, (GLint) w, (GLint) h);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-ax, ax, -ay, ay, 2, 20);
+   /*glOrtho(-2, 2, -2, 2, -10, 10);*/
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef(0, 0, -4);
 }
 
-void resize(int w, int h)
-{ 
- glViewport(0, 0, (GLint)w, (GLint)h);
- glMatrixMode(GL_PROJECTION);
- glLoadIdentity();
- glOrtho(-2,2,-2,2,-5,10);
- glMatrixMode(GL_MODELVIEW);
- glLoadIdentity();
- glTranslatef(0,0,-5);
+
+static void
+Idle(void)
+{
+   float t = glutGet(GLUT_ELAPSED_TIME);
+   angx = 0.01 * t;
+   angy = 0.03 * t;
+   angz += 0;
+   glutPostRedisplay();
 }
 
-static void cleanEverything(void)
+
+static void
+SpecialKey(int k, int x, int y)
 {
-/*  free(voxels); */
+  switch (k) {
+  case GLUT_KEY_UP:
+    angx += 5.0;
+    break;
+  case GLUT_KEY_DOWN:
+    angx -= 5.0;
+    break;
+  case GLUT_KEY_LEFT:
+    angy += 5.0;
+    break;
+  case GLUT_KEY_RIGHT:
+    angy -= 5.0;
+    break;
+  default:
+    return;
+  }
+  glutPostRedisplay();
 }
 
 
-void KeyHandler( unsigned char key, int x, int y )
+static void
+KeyHandler(unsigned char key, int x, int y)
 {
+   static const char *mode[] = {
+      "glTexCoord3f (no texgen)",
+      "texgen fixed to eye coords",
+      "texgen fixed to object coords"
+   };
    (void) x;
    (void) y;
-   switch(key) {
-      case 27:
-      case 'q':
-      case 'Q': /* quit game. */
-         cleanEverything();
-         exit(0);
-         break;
-      case 'x':
-         angx+=10;
-         break;
-      case 'X': 
-         angx-=10; 
-         break;
-      case 'y':
-         angy+=10;
-         break;
-      case 'Y': 
-         angy-=10; 
-         break;
-      case 'z':
-         angz+=10;
-         break;
-      case 'Z': 
-         angz-=10; 
-         break;
-      case 't':
-         glEnable(GL_TEXTURE_3D); 
-         break;
-      case 'T':
-         glDisable(GL_TEXTURE_3D);
-         break;
-      case 's':
+   switch (key) {
+   case 27:
+   case 'q':
+   case 'Q':			/* quit game. */
+      exit(0);
+      break;
+   case 'z':
+      angz += 10;
+      break;
+   case 'Z':
+      angz -= 10;
+      break;
+   case 's':
+      smooth = !smooth;
+      if (smooth)
          glShadeModel(GL_SMOOTH);
-         break;
-      case 'S':
+      else
          glShadeModel(GL_FLAT);
-         break;
-      case '1':
-         glDisable(GL_TEXTURE_GEN_S);
-         glDisable(GL_TEXTURE_GEN_T);
-         glDisable(GL_TEXTURE_GEN_R);
-         break;
-      case '2':
-         glEnable(GL_TEXTURE_GEN_S);
-         glEnable(GL_TEXTURE_GEN_T);
-         glEnable(GL_TEXTURE_GEN_R);
-         break;
-      default:
-         break;
+      break;
+   case 't':
+      texgen++;
+      if (texgen > 2)
+         texgen = 0;
+      printf("Texgen: %s\n", mode[texgen]);
+      break;
+   case 'o':
+      if (CurObject == TORUS)
+         CurObject = SPHERE;
+      else
+         CurObject = TORUS;
+      break;
+   case 'i':
+      if (CurTexture == NOISE_TEXTURE)
+         CurTexture = GRADIENT_TEXTURE;
+      else
+         CurTexture = NOISE_TEXTURE;
+      glBindTexture(GL_TEXTURE_3D, CurTexture);
+      break;
+   case 'a':
+      animate = !animate;
+      if (animate)
+         glutIdleFunc(Idle);
+      else
+         glutIdleFunc(NULL);
+      break;
+   default:
+      break;
    }
    glutPostRedisplay();
 }
 
-/*--------------------------------------------------------------------
- noise function over R3 - implemented by a pseudorandom tricubic spline 
-              EXCERPTED FROM SIGGRAPH 92, COURSE 23
-                        PROCEDURAL MODELING
-                             Ken Perlin
-                           New York University
-----------------------------------------------------------------------*/
 
+void
+create3Dgradient(void)
+{
+   unsigned char *v;
+   int i, j, k;
+   unsigned char *voxels = NULL;
+
+   voxels = (unsigned char *) malloc(4 * tex_width * tex_height * tex_depth);
+   v = voxels;
+
+   for (i = 0; i < tex_depth; i++) {
+      for (j = 0; j < tex_height; j++) {
+	 for (k = 0; k < tex_width; k++) {
+	    GLint r = (255 * i) / (tex_depth - 1);
+	    GLint g = (255 * j) / (tex_height - 1);
+	    GLint b = (255 * k) / (tex_width - 1);
+	    *v++ = r;
+	    *v++ = g;
+	    *v++ = b;
+	    *v++ = 255;
+	 }
+      }
+   }
 
-#define DOT(a,b) (a[0] * b[0] + a[1] * b[1] + a[2] * b[2])
-#define B 256
-static int p[B + B + 2];
-static float g[B + B + 2][3];
-#define setup(i,b0,b1,r0,r1) \
-        t = vec[i] + 10000.; \
-        b0 = ((int)t) & (B-1); \
-        b1 = (b0+1) & (B-1); \
-        r0 = t - (int)t; \
-        r1 = r0 - 1.;
 
-float noise3(float vec[3])
-{
-        int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11;
-        float rx0, rx1, ry0, ry1, rz0, rz1, *q, sx, sy, sz, a, b, c, d, t, u, v;
-        register int i, j;
+   glBindTexture(GL_TEXTURE_3D, GRADIENT_TEXTURE);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+   glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
+   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 
-        setup(0, bx0,bx1, rx0,rx1);
-        setup(1, by0,by1, ry0,ry1);
-        setup(2, bz0,bz1, rz0,rz1);
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+   glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA,
+		tex_width, tex_height, tex_depth,
+		0, GL_RGBA, GL_UNSIGNED_BYTE, voxels);
 
-        i = p[ bx0 ];
-        j = p[ bx1 ];
+   free(voxels);
+}
 
-        b00 = p[ i + by0 ];
-        b10 = p[ j + by0 ];
-        b01 = p[ i + by1 ];
-        b11 = p[ j + by1 ];
 
-#define at(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] )
-#define surve(t) ( t * t * (3. - 2. * t) )
-#define lerp(t, a, b) ( a + t * (b - a) )
 
-        sx = surve(rx0);
-        sy = surve(ry0);
-        sz = surve(rz0);
+static void
+init(void)
+{
+   static const GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
+   static const GLfloat mat_shininess[] = { 25.0 };
+   static const GLfloat gray[] = { 0.6, 0.6, 0.6, 0.0 };
+   static const GLfloat white[] = { 1.0, 1.0, 1.0, 0.0 };
+   static const GLfloat light_position[] = { 0.0, 1.0, 1.0, 0.0 };
+
+   int max;
+
+   /* see if we have OpenGL 1.2 or later, for 3D texturing */
+   {
+      const char *version = (const char *) glGetString(GL_VERSION);
+      if (strncmp(version, "1.0", 3) == 0 || strncmp(version, "1.1", 3) == 0) {
+	 printf("Sorry, OpenGL 1.2 or later is required\n");
+	 exit(1);
+      }
+   }
+   printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER));
+   glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE, &max);
+   printf("GL_MAX_3D_TEXTURE_SIZE: %d\n", max);
+   printf("Current 3D texture size: %d x %d x %d\n",
+          tex_width, tex_height, tex_depth);
 
-        q = g[ b00 + bz0 ] ; u = at(rx0,ry0,rz0);
-        q = g[ b10 + bz0 ] ; v = at(rx1,ry0,rz0);
-        a = lerp(sx, u, v);
+   /* init light */
+   glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
+   glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
+   glLightfv(GL_LIGHT1, GL_POSITION, light_position);
+   glLightfv(GL_LIGHT1, GL_AMBIENT, gray);
+   glLightfv(GL_LIGHT1, GL_DIFFUSE, white);
+   glLightfv(GL_LIGHT1, GL_SPECULAR, white);
+   glColorMaterial(GL_FRONT, GL_DIFFUSE);
+   glEnable(GL_COLOR_MATERIAL);
+   glEnable(GL_LIGHTING);
+   glEnable(GL_LIGHT1);
 
-        q = g[ b01 + bz0 ] ; u = at(rx0,ry1,rz0);
-        q = g[ b11 + bz0 ] ; v = at(rx1,ry1,rz0);
-        b = lerp(sx, u, v);
+   glClearColor(.5, .5, .5, 0);
 
-        c = lerp(sy, a, b);          /* interpolate in y at lo x */
+   /* create torus for texturing */
+   DList = glGenLists(1);
 
-        q = g[ b00 + bz1 ] ; u = at(rx0,ry0,rz1);
-        q = g[ b10 + bz1 ] ; v = at(rx1,ry0,rz1);
-        a = lerp(sx, u, v);
+   glNewList(SPHERE, GL_COMPILE);
+   glutSolidSphere(0.95, 30, 15);
+   glEndList();
 
-        q = g[ b01 + bz1 ] ; u = at(rx0,ry1,rz1);
-        q = g[ b11 + bz1 ] ; v = at(rx1,ry1,rz1);
-        b = lerp(sx, u, v);
+   BuildTorus();
 
-        d = lerp(sy, a, b);          /* interpolate in y at hi x */
 
-        return 1.5 * lerp(sz, c, d); /* interpolate in z */
-}
+   create3Dgradient();
 
-void initNoise()
-{
-        /*long random();*/
-        int i, j, k;
-        float v[3], s;
-
-/* Create an array of random gradient vectors uniformly on the unit sphere */
-        /*srandom(1);*/
-        srand(1);
-        for (i = 0 ; i < B ; i++) {
-                do {                            /* Choose uniformly in a cube */                        for (j=0 ; j<3 ; j++)
-                                v[j] = (float)((rand() % (B + B)) - B) / B;
-                        s = DOT(v,v);
-                } while (s > 1.0);              /* If not in sphere try again */                s = sqrt(s);
-                for (j = 0 ; j < 3 ; j++)       /* Else normalize */
-                        g[i][j] = v[j] / s;
-        }
-
-/* Create a pseudorandom permutation of [1..B] */
-        for (i = 0 ; i < B ; i++)
-                p[i] = i;
-        for (i = B ; i > 0 ; i -= 2) {
-                k = p[i];
-                p[i] = p[j = rand() % B];
-                p[j] = k;
-        }
-
-/* Extend g and p arrays to allow for faster indexing */
-        for (i = 0 ; i < B + 2 ; i++) {
-                p[B + i] = p[i];
-                for (j = 0 ; j < 3 ; j++)
-                        g[B + i][j] = g[i][j];
-        }
+   initNoise();
+   create3Dtexture();
+
+   glEnable(GL_TEXTURE_3D);
+
+   /*
+      glBlendFunc(GL_SRC_COLOR, GL_SRC_ALPHA);
+      glEnable(GL_BLEND); 
+    */
+   glEnable(GL_DEPTH_TEST);
+
+   glColor3f(0.6, 0.7, 0.8);
 }
 
-float turbulence(float point[3], float lofreq, float hifreq)
+
+int
+main(int argc, char **argv)
 {
-        float freq, t, p[3];
-
-        p[0] = point[0] + 123.456;
-        p[1] = point[1];
-        p[2] = point[2];
-
-        t = 0;
-        for (freq = lofreq ; freq < hifreq ; freq *= 2.) {
-                t += fabs(noise3(p)) / freq;
-                p[0] *= 2.;
-                p[1] *= 2.;
-                p[2] *= 2.;
-        }
-        return t - 0.3; /* readjust to make mean value = 0.0 */
+   glutInit(&argc, argv);
+
+   if (parseCmdLine(argc, argv) == GL_FALSE) {
+      exit(0);
+   }
+
+   glutInitWindowPosition(0, 0);
+   glutInitWindowSize(400, 400);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+
+   if (glutCreateWindow("stex3d") <= 0) {
+      exit(0);
+   }
+
+   init();
+
+   printHelp();
+
+   glutReshapeFunc(resize);
+   glutKeyboardFunc(KeyHandler);
+   glutSpecialFunc(SpecialKey);
+   glutDisplayFunc(drawScene);
+   if (animate)
+      glutIdleFunc(Idle);
+   glutMainLoop();
+   return 0;
 }