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Diffstat (limited to 'progs/demos/pointblast.c')
-rw-r--r-- | progs/demos/pointblast.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/progs/demos/pointblast.c b/progs/demos/pointblast.c new file mode 100644 index 0000000000..a36046f585 --- /dev/null +++ b/progs/demos/pointblast.c @@ -0,0 +1,506 @@ + +/* Copyright (c) Mark J. Kilgard, 1997. */ + +/* This program is freely distributable without licensing fees + and is provided without guarantee or warrantee expressed or + implied. This program is -not- in the public domain. */ + +/* This example demonstrates how to render particle effects + with OpenGL. A cloud of pinkish/orange particles explodes with the + particles bouncing off the ground. When the EXT_point_parameters + is present , the particle size is attenuated based on eye distance. */ + + +/* + * $Log: pointblast.c,v $ + * Revision 1.1 1999/08/19 00:55:40 jtg + * Initial revision + * + * Revision 3.3 1998/07/26 01:24:27 brianp + * removed include of gl.h + * + * Revision 3.2 1998/02/14 18:51:46 brianp + * fixed a small compiler warning + * + * Revision 3.1 1998/02/14 18:45:25 brianp + * optimized to use flat shading, don't blend ground polygon + * + * Revision 3.0 1998/02/14 18:42:29 brianp + * initial rev + * + */ + + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <math.h> /* for cos(), sin(), and sqrt() */ +#include <GL/glut.h> + +/* Some <math.h> files do not define M_PI... */ +#ifndef M_PI +#define M_PI 3.14159265 +#endif + +#if 0 /* For debugging. */ +#undef GL_EXT_point_parameters +#endif + +static GLfloat angle = -150; /* in degrees */ +static int spin = 0; +static int moving, begin; +static int newModel = 1; +static float theTime; +static int repeat = 1; +static int blend = 1; +int useMipmaps = 1; +int linearFiltering = 1; + +static GLfloat constant[3] = { 1/5.0, 0.0, 0.0 }; +static GLfloat linear[3] = { 0.0, 1/5.0, 0.0 }; +static GLfloat theQuad[3] = { 0.25, 0.0, 1/60.0 }; + +#define MAX_POINTS 2000 + +static int numPoints = 200; + +static GLfloat pointList[MAX_POINTS][3]; +static GLfloat pointTime[MAX_POINTS]; +static GLfloat pointVelocity[MAX_POINTS][2]; +static GLfloat pointDirection[MAX_POINTS][2]; +static int colorList[MAX_POINTS]; +static int animate = 1, motion = 0; + +static GLfloat colorSet[][4] = { + /* Shades of red. */ + { 0.7, 0.2, 0.4, 0.5 }, + { 0.8, 0.0, 0.7, 0.5 }, + { 1.0, 0.0, 0.0, 0.5 }, + { 0.9, 0.3, 0.6, 0.5 }, + { 1.0, 0.4, 0.0, 0.5 }, + { 1.0, 0.0, 0.5, 0.5 }, +}; + +#define NUM_COLORS (sizeof(colorSet)/sizeof(colorSet[0])) + +#define DEAD (NUM_COLORS+1) + + +#if 0 /* drand48 might be better on Unix machines */ +#define RANDOM_RANGE(lo, hi) ((lo) + (hi - lo) * drand48()) +#else +static float float_rand(void) { return rand() / (float) RAND_MAX; } +#define RANDOM_RANGE(lo, hi) ((lo) + (hi - lo) * float_rand()) +#endif + +#define MEAN_VELOCITY 3.0 +#define GRAVITY 2.0 +#define TIME_DELTA 0.025 /* The speed of time. */ + +/* Modeling units of ground extent in each X and Z direction. */ +#define EDGE 12 + +void +makePointList(void) +{ + float angle, velocity, direction; + int i; + + motion = 1; + for (i=0; i<numPoints; i++) { + pointList[i][0] = 0.0; + pointList[i][1] = 0.0; + pointList[i][2] = 0.0; + pointTime[i] = 0.0; + angle = (RANDOM_RANGE(60.0, 70.0)) * M_PI/180.0; + direction = RANDOM_RANGE(0.0, 360.0) * M_PI/180.0; + pointDirection[i][0] = cos(direction); + pointDirection[i][1] = sin(direction); + velocity = MEAN_VELOCITY + RANDOM_RANGE(-0.8, 1.0); + pointVelocity[i][0] = velocity * cos(angle); + pointVelocity[i][1] = velocity * sin(angle); + colorList[i] = rand() % NUM_COLORS; + } + theTime = 0.0; +} + +void +updatePointList(void) +{ + float distance; + int i; + + motion = 0; + for (i=0; i<numPoints; i++) { + distance = pointVelocity[i][0] * theTime; + + /* X and Z */ + pointList[i][0] = pointDirection[i][0] * distance; + pointList[i][2] = pointDirection[i][1] * distance; + + /* Z */ + pointList[i][1] = + (pointVelocity[i][1] - 0.5 * GRAVITY * pointTime[i])*pointTime[i]; + + /* If we hit the ground, bounce the point upward again. */ + if (pointList[i][1] <= 0.0) { + if (distance > EDGE) { + /* Particle has hit ground past the distance duration of + the particles. Mark particle as dead. */ + colorList[i] = NUM_COLORS; /* Not moving. */ + continue; + } + + pointVelocity[i][1] *= 0.8; /* 80% of previous up velocity. */ + pointTime[i] = 0.0; /* Reset the particles sense of up time. */ + } + motion = 1; + pointTime[i] += TIME_DELTA; + } + theTime += TIME_DELTA; + if (!motion && !spin) { + if (repeat) { + makePointList(); + } else { + glutIdleFunc(NULL); + } + } +} + +void +idle(void) +{ + updatePointList(); + if (spin) { + angle += 0.3; + newModel = 1; + } + glutPostRedisplay(); +} + +void +visible(int vis) +{ + if (vis == GLUT_VISIBLE) { + if (animate && (motion || spin)) { + glutIdleFunc(idle); + } + } else { + glutIdleFunc(NULL); + } +} + +void +recalcModelView(void) +{ + glPopMatrix(); + glPushMatrix(); + glRotatef(angle, 0.0, 1.0, 0.0); + newModel = 0; +} + +void +redraw(void) +{ + int i; + + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); + if (newModel) + recalcModelView(); + + glDepthMask(GL_FALSE); + + /* Draw the floor. */ +/* glEnable(GL_TEXTURE_2D);*/ + glColor3f(0.5, 1.0, 0.5); + glBegin(GL_QUADS); + glTexCoord2f(0.0, 0.0); + glVertex3f(-EDGE, -0.05, -EDGE); + glTexCoord2f(20.0, 0.0); + glVertex3f(EDGE, -0.05, -EDGE); + glTexCoord2f(20.0, 20.0); + glVertex3f(EDGE, -0.05, EDGE); + glTexCoord2f(0.0, 20.0); + glVertex3f(-EDGE, -0.05, EDGE); + glEnd(); + + /* Allow particles to blend with each other. */ + glDepthMask(GL_TRUE); + + if (blend) + glEnable(GL_BLEND); + + glDisable(GL_TEXTURE_2D); + glBegin(GL_POINTS); + for (i=0; i<numPoints; i++) { + /* Draw alive particles. */ + if (colorList[i] != DEAD) { + glColor4fv(colorSet[colorList[i]]); + glVertex3fv(pointList[i]); + } + } + glEnd(); + + glDisable(GL_BLEND); + + glutSwapBuffers(); +} + +/* ARGSUSED2 */ +void +mouse(int button, int state, int x, int y) +{ + /* Scene can be spun around Y axis using left + mouse button movement. */ + if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) { + moving = 1; + begin = x; + } + if (button == GLUT_LEFT_BUTTON && state == GLUT_UP) { + moving = 0; + } +} + +/* ARGSUSED1 */ +void +mouseMotion(int x, int y) +{ + if (moving) { + angle = angle + (x - begin); + begin = x; + newModel = 1; + glutPostRedisplay(); + } +} + +void +menu(int option) +{ + switch (option) { + case 0: + makePointList(); + break; +#if GL_EXT_point_parameters + case 1: + glPointParameterfvEXT(GL_DISTANCE_ATTENUATION_EXT, constant); + break; + case 2: + glPointParameterfvEXT(GL_DISTANCE_ATTENUATION_EXT, linear); + break; + case 3: + glPointParameterfvEXT(GL_DISTANCE_ATTENUATION_EXT, theQuad); + break; +#endif + case 4: + blend = 1; + break; + case 5: + blend = 0; + break; +#if GL_EXT_point_parameters + case 6: + glPointParameterfEXT(GL_POINT_FADE_THRESHOLD_SIZE_EXT, 1.0); + break; + case 7: + glPointParameterfEXT(GL_POINT_FADE_THRESHOLD_SIZE_EXT, 10.0); + break; +#endif + case 8: + glEnable(GL_POINT_SMOOTH); + break; + case 9: + glDisable(GL_POINT_SMOOTH); + break; + case 10: + glPointSize(2.0); + break; + case 11: + glPointSize(4.0); + break; + case 12: + glPointSize(8.0); + break; + case 13: + spin = 1 - spin; + if (animate && (spin || motion)) { + glutIdleFunc(idle); + } else { + glutIdleFunc(NULL); + } + break; + case 14: + numPoints = 200; + break; + case 15: + numPoints = 500; + break; + case 16: + numPoints = 1000; + break; + case 17: + numPoints = 2000; + break; + case 666: + exit(0); + } + glutPostRedisplay(); +} + +/* ARGSUSED1 */ +void +key(unsigned char c, int x, int y) +{ + switch (c) { + case 13: + animate = 1 - animate; /* toggle. */ + if (animate && (motion || spin)) { + glutIdleFunc(idle); + } else { + glutIdleFunc(NULL); + } + break; + case ' ': + animate = 1; + makePointList(); + glutIdleFunc(idle); + break; + case 27: + exit(0); + } +} + +/* Nice floor texture tiling pattern. */ +static char *circles[] = { + "....xxxx........", + "..xxxxxxxx......", + ".xxxxxxxxxx.....", + ".xxx....xxx.....", + "xxx......xxx....", + "xxx......xxx....", + "xxx......xxx....", + "xxx......xxx....", + ".xxx....xxx.....", + ".xxxxxxxxxx.....", + "..xxxxxxxx......", + "....xxxx........", + "................", + "................", + "................", + "................", +}; + +static void +makeFloorTexture(void) +{ + GLubyte floorTexture[16][16][3]; + GLubyte *loc; + int s, t; + + /* Setup RGB image for the texture. */ + loc = (GLubyte*) floorTexture; + for (t = 0; t < 16; t++) { + for (s = 0; s < 16; s++) { + if (circles[t][s] == 'x') { + /* Nice blue. */ + loc[0] = 0x1f; + loc[1] = 0x1f; + loc[2] = 0x8f; + } else { + /* Light gray. */ + loc[0] = 0xca; + loc[1] = 0xca; + loc[2] = 0xca; + } + loc += 3; + } + } + + glPixelStorei(GL_UNPACK_ALIGNMENT, 1); + + if (useMipmaps) { + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, + GL_LINEAR_MIPMAP_LINEAR); + gluBuild2DMipmaps(GL_TEXTURE_2D, 3, 16, 16, + GL_RGB, GL_UNSIGNED_BYTE, floorTexture); + } else { + if (linearFiltering) { + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); + } else { + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + } + glTexImage2D(GL_TEXTURE_2D, 0, 3, 16, 16, 0, + GL_RGB, GL_UNSIGNED_BYTE, floorTexture); + } +} + +int +main(int argc, char **argv) +{ + int i; + glutInit(&argc, argv); + glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_MULTISAMPLE); + + for (i=1; i<argc; i++) { + if(!strcmp("-noms", argv[i])) { + glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); + printf("forcing no multisampling\n"); + } else if(!strcmp("-nomipmaps", argv[i])) { + useMipmaps = 0; + } else if(!strcmp("-nearest", argv[i])) { + linearFiltering = 0; + } + } + + glutCreateWindow("point burst"); + glutDisplayFunc(redraw); + glutMouseFunc(mouse); + glutMotionFunc(mouseMotion); + glutVisibilityFunc(visible); + glutKeyboardFunc(key); + glutCreateMenu(menu); + glutAddMenuEntry("Reset time", 0); + glutAddMenuEntry("Constant", 1); + glutAddMenuEntry("Linear", 2); + glutAddMenuEntry("Quadratic", 3); + glutAddMenuEntry("Blend on", 4); + glutAddMenuEntry("Blend off", 5); + glutAddMenuEntry("Threshold 1", 6); + glutAddMenuEntry("Threshold 10", 7); + glutAddMenuEntry("Point smooth on", 8); + glutAddMenuEntry("Point smooth off", 9); + glutAddMenuEntry("Point size 2", 10); + glutAddMenuEntry("Point size 4", 11); + glutAddMenuEntry("Point size 8", 12); + glutAddMenuEntry("Toggle spin", 13); + glutAddMenuEntry("200 points ", 14); + glutAddMenuEntry("500 points ", 15); + glutAddMenuEntry("1000 points ", 16); + glutAddMenuEntry("2000 points ", 17); + glutAddMenuEntry("Quit", 666); + glutAttachMenu(GLUT_RIGHT_BUTTON); + + glShadeModel(GL_FLAT); + glEnable(GL_DEPTH_TEST); + glEnable(GL_POINT_SMOOTH); + glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); + glPointSize(8.0); +#if GL_EXT_point_parameters + glPointParameterfvEXT(GL_DISTANCE_ATTENUATION_EXT, theQuad); +#endif + glMatrixMode(GL_PROJECTION); + gluPerspective( /* field of view in degree */ 40.0, + /* aspect ratio */ 1.0, + /* Z near */ 0.5, /* Z far */ 40.0); + glMatrixMode(GL_MODELVIEW); + gluLookAt(0.0, 1.0, 8.0, /* eye location */ + 0.0, 1.0, 0.0, /* center is at (0,0,0) */ + 0.0, 1.0, 0.); /* up is in postivie Y direction */ + glPushMatrix(); /* dummy push so we can pop on model + recalc */ + + makePointList(); + makeFloorTexture(); + + glutMainLoop(); + return 0; /* ANSI C requires main to return int. */ +} |