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Diffstat (limited to 'progs/samples/overlay.c')
| -rw-r--r-- | progs/samples/overlay.c | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/progs/samples/overlay.c b/progs/samples/overlay.c new file mode 100644 index 00000000000..23b5a4793ba --- /dev/null +++ b/progs/samples/overlay.c @@ -0,0 +1,378 @@ +/* + * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc. + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation for any purpose is hereby granted without fee, provided + * that (i) the above copyright notices and this permission notice appear in + * all copies of the software and related documentation, and (ii) the name of + * Silicon Graphics may not be used in any advertising or + * publicity relating to the software without the specific, prior written + * permission of Silicon Graphics. + * + * THE SOFTWARE IS PROVIDED "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 BE LIABLE FOR + * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, + * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, + * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF + * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <math.h> +#include <time.h> +#include <GL/glut.h> + + +#ifndef PI +#define PI 3.141592657 +#endif + + +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; +GLint windW, windH; + +GLenum flag = NORMAL, overlayInit = GL_FALSE; +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; + + glutUseLayer(GLUT_OVERLAY); + + glViewport(0, 0, windW, windH); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + gluOrtho2D(-0.5, windW+0.5, -0.5, windH+0.5); + glMatrixMode(GL_MODELVIEW); + overlayInit = GL_FALSE; + + glutUseLayer(GLUT_NORMAL); + + glViewport(0, 0, windW, windH); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + gluOrtho2D(-0.5, windW+0.5, -0.5, windH+0.5); + glMatrixMode(GL_MODELVIEW); +} + +static void Key(unsigned char key, int x, int y) +{ + + switch (key) { + case 27: + exit(1); + case 32: + flag = (flag == NORMAL) ? WEIRD : NORMAL; + break; + case 't': + nitro = 1; + break; + default: + return; + } +} + +void Idle(void) +{ + + if (overlayInit == GL_FALSE) { + glutUseLayer(GLUT_OVERLAY); + glClear(GL_COLOR_BUFFER_BIT); +/* glColor3f(1.0, 0.0, 0.0);*/ + + glIndexf( 2.0 ); + glBegin(GL_POLYGON); + glVertex2i(windW/4-10, windH/4-10); + glVertex2i(windW/2-10, windH/4-10); + glVertex2i(windW/2-10, windH/2-10); + glVertex2i(windW/4-10, windH/2-10); + glEnd(); + + glIndexf( 0.0 ); + glBegin(GL_POLYGON); + glVertex2i(windW/4, windH/4); + glVertex2i(windW/2, windH/4); + glVertex2i(windW/2, windH/2); + glVertex2i(windW/4, windH/2); + glEnd(); + + glIndexf( 1.0 ); + glBegin(GL_POLYGON); + glVertex2i(windW/4+10, windH/4+10); + glVertex2i(windW/2+10, windH/4+10); + glVertex2i(windW/2+10, windH/2+10); + glVertex2i(windW/4+10, windH/2+10); + glEnd(); + + glutUseLayer(GLUT_NORMAL); + overlayInit = GL_TRUE; + } + + 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) { + glutSwapBuffers(); + } +} + +static GLenum Args(int argc, char **argv) +{ + GLint i; + + doubleBuffer = GL_TRUE; + + 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; + } + } + return GL_TRUE; +} + +int main(int argc, char **argv) +{ + GLenum type; + + glutInit(&argc, argv); + + if (!glutLayerGet(GLUT_OVERLAY_POSSIBLE)) + { + fprintf(stderr, "Overlay not available\n"); + return(1); + } + + if (Args(argc, argv) == GL_FALSE) { + return(1); + } + + windW = 300; + windH = 300; + glutInitWindowPosition(0, 0); glutInitWindowSize( 300, 300); + + type = GLUT_RGB; + type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE; + glutInitDisplayMode(type); + + if (glutCreateWindow("Overlay Test") == GL_FALSE) { + return(1); + } + + glutEstablishOverlay(); + + Init(); + + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutIdleFunc(Idle); + glutMainLoop(); + return 0; +} |