/* -*- Mode: C; tab-width: 4 -*- */
-/* glplanet --- 3D rotating planet, e.g., Earth. */
-
-#if !defined( lint ) && !defined( SABER )
-static const char sccsid[] = "@(#)plate.c 4.07 97/11/24 xlockmore";
-
-#endif
-
-/*-
+/* glplanet --- 3D rotating planet, e.g., Earth.
+ *
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appear in all copies and that
* other special, indirect and consequential damages.
*
* Revision History:
+ * 21-Mar-01: jwz@jwz.org Broke sphere routine out into its own file.
+ *
* 9-Oct-98: dek@cgl.ucsf.edu Added stars.
*
* 8-Oct-98: jwz@jwz.org Made the 512x512x1 xearth image be built in.
#ifdef USE_GL /* whole file */
+#include "sphere.h"
+
#ifdef HAVE_XPM
# include <X11/xpm.h>
# ifndef PIXEL_ALREADY_TYPEDEFED
}
+#if 0
/* Function for determining points on the surface of the sphere */
static void inline ParametricSphere(float theta, float rho, GLfloat *vector)
{
return;
}
+#endif
/* lame way to generate some random stars */
void generate_stars(int width, int height)
{
- int i;
-/* GLfloat size_range[2], size;*/
- GLfloat x, y;
+ int i, j;
+ int max_size = 3;
+ GLfloat inc = 0.5;
+ int steps = max_size / inc;
planetstruct *gp = &planets[MI_SCREEN(mi)];
-/* glGetFloatv(GL_POINT_SIZE_RANGE, size_range); */
-
-/* printf("size range: %f\t%f\n", size_range[0], size_range[1]); */
gp->starlist = glGenLists(1);
glNewList(gp->starlist, GL_COMPILE);
/* disable depth testing for the stars, so they don't obscure the planet */
glDisable(GL_DEPTH_TEST);
- glEnable(GL_POINT_SMOOTH);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
- glBegin(GL_POINTS);
- for(i = 0 ; i < NUM_STARS ; i++)
- {
-/* size = ((random()%size_range[0])) * size_range[1]/2.; */
-/* glPointSize(size); */
- x = random() % width;
- y = random() % height;
- glVertex2f(x,y);
- }
- glEnd();
+ glColor3f(1,1,1);
+
+ glEnable(GL_POINT_SMOOTH);
+
+ for (j = 1; j <= steps; j++)
+ {
+ glPointSize(inc * j);
+ glBegin(GL_POINTS);
+ for(i = 0 ; i < NUM_STARS / steps; i++)
+ {
+ glColor3f (0.6 + frand(0.3),
+ 0.6 + frand(0.3),
+ 0.6 + frand(0.3));
+ glVertex2f ((GLfloat) (random() % width),
+ (GLfloat) (random() % height));
+ }
+ glEnd();
+ }
/* return to original PROJECT and MODELVIEW */
glMatrixMode(GL_PROJECTION);
}
+/* Set up lighting */
+static void
+init_sun (ModeInfo * mi)
+{
+ GLfloat light[4];
+ light[0] = frand(2.0) - 1.0;
+ light[1] = frand(2.0) - 1.0;
+ light[2] = 1.0;
+ light[3] = 0;
+
+ glLightfv(GL_LIGHT0, GL_POSITION, light);
+}
+
+
/* Initialization function for screen saver */
static void
pinit(ModeInfo * mi)
{
Bool wire = MI_IS_WIREFRAME(mi);
planetstruct *gp = &planets[MI_SCREEN(mi)];
- int i, j;
- int stacks=STACKS, slices=SLICES;
- float radius=RADIUS;
-
- float drho, dtheta;
- float rho, theta;
- GLfloat vector[3];
- GLfloat ds, dt, t, s;;
if (wire) {
glEnable(GL_LINE_SMOOTH);
generate_stars(MI_WIDTH(mi), MI_HEIGHT(mi));
}
-
- /*-
- * Generate a sphere with quadrilaterals.
- * Quad vertices are determined using a parametric sphere function.
- * For fun, you could generate practically any parameteric surface and
- * map an image onto it.
- */
-
- drho = M_PI / stacks;
- dtheta = 2.0 * M_PI / slices;
- ds = 1.0 / slices;
- dt = 1.0 / stacks;
-
-
gp->platelist=glGenLists(1);
glNewList(gp->platelist, GL_COMPILE);
-
- glColor3f(1,1,1);
- glBegin( wire ? GL_LINE_LOOP : GL_QUADS );
-
- t = 0.0;
- for(i=0; i<stacks; i++) {
- rho = i * drho;
- s = 0.0;
- for(j=0; j<slices; j++) {
- theta = j * dtheta;
-
-
- glTexCoord2f(s,t);
- ParametricSphere(theta, rho, vector);
- normalize(vector);
- glNormal3fv(vector);
- ParametricSphere(theta, rho, vector);
- glVertex3f( vector[0]*radius, vector[1]*radius, vector[2]*radius );
-
- glTexCoord2f(s,t+dt);
- ParametricSphere(theta, rho+drho, vector);
- normalize(vector);
- glNormal3fv(vector);
- ParametricSphere(theta, rho+drho, vector);
- glVertex3f( vector[0]*radius, vector[1]*radius, vector[2]*radius );
-
- glTexCoord2f(s+ds,t+dt);
- ParametricSphere(theta + dtheta, rho+drho, vector);
- normalize(vector);
- glNormal3fv(vector);
- ParametricSphere(theta + dtheta, rho+drho, vector);
- glVertex3f( vector[0]*radius, vector[1]*radius, vector[2]*radius );
-
- glTexCoord2f(s+ds, t);
- ParametricSphere(theta + dtheta, rho, vector);
- normalize(vector);
- glNormal3fv(vector);
- ParametricSphere(theta + dtheta, rho, vector);
- glVertex3f( vector[0]*radius, vector[1]*radius, vector[2]*radius );
-
- s = s + ds;
-
- }
- t = t + dt;
- }
- glEnd();
+ glPushMatrix ();
+ glScalef (RADIUS, RADIUS, RADIUS);
+ unit_sphere (STACKS, SLICES, wire);
+ glPopMatrix ();
glEndList();
-
- }
+ init_sun (mi);
+}
static void
draw_sphere(ModeInfo * mi)
void
reshape_planet(ModeInfo *mi, int width, int height)
{
- GLfloat light[4];
GLfloat h = (GLfloat) height / (GLfloat) width;
- light[0] = -1;
- light[1] = (int) (((random() % 3) & 0xFF) - 1);
- light[2] = (int) (((random() % 3) & 0xFF) - 1);
- light[3] = 0;
-
glViewport(0, 0, (GLint) width, (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -h, h, 5.0, 100.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
- glTranslatef(0.0, 0.0, -DIST);
- glLightfv(GL_LIGHT0, GL_POSITION, light);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
+ glTranslatef(0.0, 0.0, -DIST);
}
if (do_stars) {
/* protect our modelview matrix and attributes */
glPushMatrix();
- glPushAttrib(GL_ALL_ATTRIB_BITS);
- {
- glColor3f(1,1,1);
- /* draw the star field. */
- glCallList(gp->starlist);
-
- }
+ glCallList(gp->starlist);
glPopMatrix();
- glPopAttrib();
}
/* protect our modelview matrix and attributes */
projects / xscreensaver / blobdiff