/*
* (c) Copyright 1993, Silicon Graphics, Inc.
* ALL RIGHTS RESERVED
* Permission to use, copy, modify, and distribute this software for
* any purpose and without fee is hereby granted, provided that the above
* copyright notice appear in all copies and that both the copyright notice
* and this permission notice appear in supporting documentation, and that
* the name of Silicon Graphics, Inc. not be used in advertising
* or publicity pertaining to distribution of the software without specific,
* written prior permission.
*
* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
* AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
*
* US Government Users Restricted Rights
* Use, duplication, or disclosure by the Government is subject to
* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
* (c)(1)(ii) of the Rights in Technical Data and Computer Software
* clause at DFARS 252.227-7013 and/or in similar or successor
* clauses in the FAR or the DOD or NASA FAR Supplement.
* Unpublished-- rights reserved under the copyright laws of the
* United States. Contractor/manufacturer is Silicon Graphics,
* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
*
* OpenGL(TM) is a trademark of Silicon Graphics, Inc.
*/
#include "windows.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "GL/gl.h"
#include "GL/glu.h"
#include "tk.h"
#define PI 3.141592657
enum {
NORMAL = 0,
WEIRD = 1
};
enum {
STREAK = 0,
CIRCLE = 1
};
#define MAXSTARS 400
#define MAXPOS 10000
#define MAXWARP 10
#define MAXANGLES 6000
typedef struct _starRec {
GLint type;
float x[2], y[2], z[2];
float offsetX, offsetY, offsetR, rotation;
} starRec;
GLenum doubleBuffer, directRender;
GLint windW, windH;
GLenum flag = NORMAL;
GLint starCount = MAXSTARS / 2;
float speed = 1.0;
GLint nitro = 0;
starRec stars[MAXSTARS];
float sinTable[MAXANGLES];
float Sin(float angle)
{
return (sinTable[(GLint)angle]);
}
float Cos(float angle)
{
return (sinTable[((GLint)angle+(MAXANGLES/4))%MAXANGLES]);
}
void NewStar(GLint n, GLint d)
{
if (rand()%4 == 0) {
stars[n].type = CIRCLE;
} else {
stars[n].type = STREAK;
}
stars[n].x[0] = (float)(rand() % MAXPOS - MAXPOS / 2);
stars[n].y[0] = (float)(rand() % MAXPOS - MAXPOS / 2);
stars[n].z[0] = (float)(rand() % MAXPOS + d);
if (rand()%4 == 0 && flag == WEIRD) {
stars[n].offsetX = (float)(rand() % 100 - 100 / 2);
stars[n].offsetY = (float)(rand() % 100 - 100 / 2);
stars[n].offsetR = (float)(rand() % 25 - 25 / 2);
} else {
stars[n].offsetX = 0.0;
stars[n].offsetY = 0.0;
stars[n].offsetR = 0.0;
}
}
void RotatePoint(float *x, float *y, float rotation)
{
float tmpX, tmpY;
tmpX = *x * Cos(rotation) - *y * Sin(rotation);
tmpY = *y * Cos(rotation) + *x * Sin(rotation);
*x = tmpX;
*y = tmpY;
}
void MoveStars(void)
{
float offset;
GLint n;
offset = speed * 60.0;
for (n = 0; n < starCount; n++) {
stars[n].x[1] = stars[n].x[0];
stars[n].y[1] = stars[n].y[0];
stars[n].z[1] = stars[n].z[0];
stars[n].x[0] += stars[n].offsetX;
stars[n].y[0] += stars[n].offsetY;
stars[n].z[0] -= offset;
stars[n].rotation += stars[n].offsetR;
if (stars[n].rotation > MAXANGLES) {
stars[n].rotation = 0.0;
}
}
}
GLenum StarPoint(GLint n)
{
float x0, y0, x1, y1, width;
GLint i;
x0 = stars[n].x[0] * windW / stars[n].z[0];
y0 = stars[n].y[0] * windH / stars[n].z[0];
RotatePoint(&x0, &y0, stars[n].rotation);
x0 += windW / 2.0;
y0 += windH / 2.0;
if (x0 >= 0.0 && x0 < windW && y0 >= 0.0 && y0 < windH) {
if (stars[n].type == STREAK) {
x1 = stars[n].x[1] * windW / stars[n].z[1];
y1 = stars[n].y[1] * windH / stars[n].z[1];
RotatePoint(&x1, &y1, stars[n].rotation);
x1 += windW / 2.0;
y1 += windH / 2.0;
glLineWidth(MAXPOS/100.0/stars[n].z[0]+1.0);
glColor3f(1.0, (MAXWARP-speed)/MAXWARP, (MAXWARP-speed)/MAXWARP);
if (fabs(x0-x1) < 1.0 && fabs(y0-y1) < 1.0) {
glBegin(GL_POINTS);
glVertex2f(x0, y0);
glEnd();
} else {
glBegin(GL_LINES);
glVertex2f(x0, y0);
glVertex2f(x1, y1);
glEnd();
}
} else {
width = MAXPOS / 10.0 / stars[n].z[0] + 1.0;
glColor3f(1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
for (i = 0; i < 8; i++) {
float x = x0 + width * Cos((float)i*MAXANGLES/8.0);
float y = y0 + width * Sin((float)i*MAXANGLES/8.0);
glVertex2f(x, y);
};
glEnd();
}
return GL_TRUE;
} else {
return GL_FALSE;
}
}
void ShowStars(void)
{
GLint n;
glClear(GL_COLOR_BUFFER_BIT);
for (n = 0; n < starCount; n++) {
if (stars[n].z[0] > speed || (stars[n].z[0] > 0.0 && speed < MAXWARP)) {
if (StarPoint(n) == GL_FALSE) {
NewStar(n, MAXPOS);
}
} else {
NewStar(n, MAXPOS);
}
}
}
static void Init(void)
{
float angle;
GLint n;
srand((unsigned int)time(NULL));
for (n = 0; n < MAXSTARS; n++) {
NewStar(n, 100);
}
angle = 0.0;
for (n = 0; n < MAXANGLES ; n++) {
sinTable[n] = sin(angle);
angle += PI / (MAXANGLES / 2.0);
}
glClearColor(0.0, 0.0, 0.0, 0.0);
glDisable(GL_DITHER);
}
void Reshape(int width, int height)
{
windW = (GLint)width;
windH = (GLint)height;
glViewport(0, 0, windW, windH);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(-0.5, windW+0.5, -0.5, windH+0.5);
glMatrixMode(GL_MODELVIEW);
}
static GLenum Key(int key, GLenum mask)
{
switch (key) {
case TK_ESCAPE:
tkQuit();
case TK_SPACE:
flag = (flag == NORMAL) ? WEIRD : NORMAL;
break;
case TK_t:
nitro = 1;
break;
default:
return GL_FALSE;
}
return GL_TRUE;
}
void Idle(void)
{
MoveStars();
ShowStars();
if (nitro > 0) {
speed = (float)(nitro / 10) + 1.0;
if (speed > MAXWARP) {
speed = MAXWARP;
}
if (++nitro > MAXWARP*10) {
nitro = -nitro;
}
} else if (nitro < 0) {
nitro++;
speed = (float)(-nitro / 10) + 1.0;
if (speed > MAXWARP) {
speed = MAXWARP;
}
}
glFlush();
if (doubleBuffer) {
tkSwapBuffers();
}
}
static GLenum Args(int argc, char **argv)
{
GLint i;
doubleBuffer = GL_FALSE;
directRender = GL_FALSE;
for (i = 1; i < argc; i++) {
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;
}
}
return GL_TRUE;
}
void main(int argc, char **argv)
{
GLenum type;
if (Args(argc, argv) == GL_FALSE) {
tkQuit();
}
windW = 300;
windH = 300;
tkInitPosition(0, 0, 300, 300);
type = TK_RGB;
type |= (doubleBuffer) ? TK_DOUBLE : TK_SINGLE;
type |= (directRender) ? TK_DIRECT : TK_INDIRECT;
tkInitDisplayMode(type);
if (tkInitWindow("Stars") == GL_FALSE) {
tkQuit();
}
Init();
tkExposeFunc(Reshape);
tkReshapeFunc(Reshape);
tkKeyDownFunc(Key);
tkIdleFunc(Idle);
tkExec();
}