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particles.cpp
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particles.cpp
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/* --------------------------------------------------------------------
EXTREME TUXRACER
Copyright (C) 1999-2001 Jasmin F. Patry (Tuxracer)
Copyright (C) 2010 Extreme Tuxracer Team
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
---------------------------------------------------------------------*/
#include "particles.h"
#include "textures.h"
#include "ogl.h"
#include "course.h"
#include "view.h"
#include "env.h"
// ====================================================================
// gui particles 2D
// ====================================================================
#define MAX_num_snowparticles 10000
#define BASE_num_snowparticles 800
#define GRAVITY_FACTOR 0.015
#define BASE_VELOCITY 0.05
#define VELOCITY_RANGE 0.02
#define PUSH_DECAY_TIME_CONSTANT 0.2
#define PUSH_DIST_DECAY 100
#define PUSH_FACTOR 0.5
#define MAX_PUSH_FORCE 5
#define AIR_DRAG 0.4
#define PARTICLE_MIN_SIZE 1
#define PARTICLE_SIZE_RANGE 10
typedef struct {
TVector2 pt;
double size;
TVector2 vel;
TVector2 tex_min;
TVector2 tex_max;
} TGuiParticle;
static TGuiParticle particles[MAX_num_snowparticles];
static int num_snowparticles = BASE_num_snowparticles;
static GLfloat part_col[4] = {1, 1, 1, 0.5 };
static TVector2 push_position = {0, 0};
static TVector2 last_push_position;
static double last_update_time = -1;
static bool push_position_initialized = false;
static double frand () {return (double)rand() / RAND_MAX; }
static void make_particle (int i, double x, double y) {
double p_dist;
int type;
particles[i].pt.x = x;
particles[i].pt.y = y;
p_dist = frand();
particles[i].size = PARTICLE_MIN_SIZE + (1.0 - p_dist) * PARTICLE_SIZE_RANGE;
particles[i].vel.x = 0;
particles[i].vel.y = -BASE_VELOCITY - p_dist * VELOCITY_RANGE;
type = (int) (frand() * (4.0 - EPS));
if (type == 0) {
particles[i].tex_min = MakeVector2 (0.0, 0.0);
particles[i].tex_max = MakeVector2 (0.5, 0.5);
} else if (type == 1) {
particles[i].tex_min = MakeVector2 (0.5, 0.0);
particles[i].tex_max = MakeVector2 (1.0, 0.5);
} else if (type == 2) {
particles[i].tex_min = MakeVector2 (0.5, 0.5);
particles[i].tex_max = MakeVector2 (1.0, 1.0);
} else {
particles[i].tex_min = MakeVector2 (0.0, 0.5);
particles[i].tex_max = MakeVector2 (0.5, 1.0);
}
}
void init_ui_snow (void) {
int i;
for (i=0; i<num_snowparticles; i++) make_particle (i, frand(), frand());
push_position = MakeVector2 (0.0, 0.0);
}
void update_ui_snow (double time_step) {
TVector2 *v, f;
TVector2 *pt;
double size;
double dist_from_push, p_dist;
TVector2 push_vector;
int i;
double push_timestep, time;
time = Winsys.ClockTime ();
push_vector.x = 0;
push_vector.y = 0;
push_timestep = 0;
if (push_position_initialized) {
push_vector.x = push_position.x - last_push_position.x;
push_vector.y = push_position.y - last_push_position.y;
push_timestep = time - last_update_time;
}
last_push_position = push_position;
last_update_time = time;
for (i=0; i<num_snowparticles; i++) {
pt = &particles[i].pt;
v = &particles[i].vel;
size = particles[i].size;
f.x = 0;
f.y = 0;
dist_from_push = (pow((pt->x - push_position.x), 2) +
pow((pt->y - push_position.y), 2));
if (push_timestep > 0) {
f.x = PUSH_FACTOR * push_vector.x / push_timestep;
f.y = PUSH_FACTOR * push_vector.y / push_timestep;
f.x = MIN (MAX_PUSH_FORCE, f.x);
f.x = MAX (-MAX_PUSH_FORCE, f.x);
f.y = MIN (MAX_PUSH_FORCE, f.y);
f.y = MAX (-MAX_PUSH_FORCE, f.y);
f.x *= 1.0/(PUSH_DIST_DECAY*dist_from_push + 1) *
size/PARTICLE_SIZE_RANGE;
f.y *= 1.0/(PUSH_DIST_DECAY*dist_from_push + 1) *
size/PARTICLE_SIZE_RANGE;
}
v->x += (f.x - v->x * AIR_DRAG) * time_step;
v->y += (f.y - GRAVITY_FACTOR - v->y * AIR_DRAG) * time_step;
pt->x += v->x * time_step * (size / PARTICLE_SIZE_RANGE);
pt->y += v->y * time_step * (size / PARTICLE_SIZE_RANGE);
if (pt->x < 0) {
pt->x = 1;
} else if (pt->x > 1) {
pt->x = 0.0;
}
}
for (i=0; i<num_snowparticles; i++) {
TGuiParticle *p = &particles[i];
if (p->pt.y < -0.05) {
if (num_snowparticles > BASE_num_snowparticles && frand() > 0.5) {
*p = particles[num_snowparticles-1];
num_snowparticles -= 1;
} else {
p->pt.x = frand();
p->pt.y = 1+frand()*BASE_VELOCITY;
p_dist = frand();
p->size = PARTICLE_MIN_SIZE + (1.0 - p_dist) * PARTICLE_SIZE_RANGE;
p->vel.x = 0;
p->vel.y = -BASE_VELOCITY-p_dist*VELOCITY_RANGE;
}
}
}
if (time_step < PUSH_DECAY_TIME_CONSTANT) {
push_vector.x *= 1.0 - time_step/PUSH_DECAY_TIME_CONSTANT;
push_vector.y *= 1.0 - time_step/PUSH_DECAY_TIME_CONSTANT;
} else {
push_vector.x = 0.0;
push_vector.y = 0.0;
}
}
void draw_ui_snow (void) {
TVector2 *pt, *tex_min, *tex_max;
double size;
double xres, yres;
int i;
xres = param.x_resolution;
yres = param.y_resolution;
glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
Tex.BindTex (SNOW_PART);
glColor4f(part_col[0], part_col[1], part_col[2], part_col[3]);
part_col[3] = 0.3;
glPushMatrix();
for (i=0; i<num_snowparticles; i++) {
pt = &particles[i].pt;
size = particles[i].size;
tex_min = &particles[i].tex_min;
tex_max = &particles[i].tex_max;
glPushMatrix();
glTranslatef (pt->x * xres, pt->y * yres, 0);
glBegin (GL_QUADS);
glTexCoord2f (tex_min->x, tex_min->y);
glVertex2f (0, 0);
glTexCoord2f (tex_max->x, tex_min->y);
glVertex2f (size, 0);
glTexCoord2f (tex_max->x, tex_max->y);
glVertex2f (size, size);
glTexCoord2f (tex_min->x, tex_max->y);
glVertex2f (0, size);
glEnd();
glPopMatrix();
}
glPopMatrix();
}
void reset_ui_snow_cursor_pos (TVector2 pos) {
double xres, yres;
xres = param.x_resolution;
yres = param.y_resolution;
push_position = MakeVector2 (pos.x/(double)xres, pos.y/(double)yres);
last_push_position = push_position;
push_position_initialized = true;
}
void push_ui_snow (TVector2 pos) {
double xres, yres;
xres = param.x_resolution;
yres = param.y_resolution;
push_position = MakeVector2 (pos.x/(double)xres, pos.y/(double)yres);
if (!push_position_initialized) last_push_position = push_position;
push_position_initialized = true;
}
void make_ui_snow (TVector2 pos) {
double xres, yres;
xres = param.x_resolution;
yres = param.y_resolution;
if (num_snowparticles < MAX_num_snowparticles) {
make_particle (num_snowparticles, pos.x/xres, pos.y/yres);
num_snowparticles++;
}
}
// ====================================================================
// tux particles
// ====================================================================
#define MAX_PARTICLES 500000
#define START_RADIUS 0.04
#define OLD_PART_SIZE 0.12 // orig 0.07
#define NEW_PART_SIZE 0.035 // orig 0.02
#define MIN_AGE -0.2
#define MAX_AGE 1.0
#define VARIANCE_FACTOR 0.8
#define PARTICLE_SHADOW_HEIGHT 0.05
#define PARTICLE_SHADOW_ALPHA 0.1
#define MAX_TURN_PARTICLES 500
#define BRAKE_PARTICLES 2000
#define MAX_ROLL_PARTICLES 3000
#define PARTICLE_SPEED_FACTOR 40
#define MAX_PARTICLE_ANGLE 80
#define MAX_PARTICLE_ANGLE_SPEED 50
#define PARTICLE_SPEED_MULTIPLIER 0.3
#define MAX_PARTICLE_SPEED 2
typedef struct _Particle {
TVector3 pt;
short type;
double base_size;
double cur_size;
double terrain_height;
double age;
double death;
double alpha;
TVector3 vel;
struct _Particle *next;
} Particle;
static Particle* head = NULL;
static int num_particles = 0;
void draw_billboard (CControl *ctrl,
TVector3 center_pt, double width, double height,
bool use_world_y_axis,
TVector2 min_tex_coord, TVector2 max_tex_coord)
{
TVector3 pt;
TVector3 x_vec;
TVector3 y_vec;
TVector3 z_vec;
x_vec.x = ctrl->view_mat[0][0];
x_vec.y = ctrl->view_mat[0][1];
x_vec.z = ctrl->view_mat[0][2];
if (use_world_y_axis) {
y_vec = MakeVector (0, 1, 0);
x_vec = ProjectToPlane (y_vec, x_vec);
NormVector (&x_vec);
z_vec = CrossProduct (x_vec, y_vec);
} else {
y_vec.x = ctrl->view_mat[1][0];
y_vec.y = ctrl->view_mat[1][1];
y_vec.z = ctrl->view_mat[1][2];
z_vec.x = ctrl->view_mat[2][0];
z_vec.y = ctrl->view_mat[2][1];
z_vec.z = ctrl->view_mat[2][2];
}
glBegin (GL_QUADS);
pt = AddVectors (center_pt, ScaleVector (-width/2.0, x_vec));
pt = AddVectors (pt, ScaleVector (-height/2.0, y_vec));
glNormal3f (z_vec.x, z_vec.y, z_vec.z);
glTexCoord2f (min_tex_coord.x, min_tex_coord.y);
glVertex3f (pt.x, pt.y, pt.z);
pt = AddVectors (pt, ScaleVector (width, x_vec));
glTexCoord2f (max_tex_coord.x, min_tex_coord.y);
glVertex3f (pt.x, pt.y, pt.z);
pt = AddVectors (pt, ScaleVector (height, y_vec));
glTexCoord2f (max_tex_coord.x, max_tex_coord.y);
glVertex3f (pt.x, pt.y, pt.z);
pt = AddVectors (pt, ScaleVector (-width, x_vec));
glTexCoord2f (min_tex_coord.x, max_tex_coord.y);
glVertex3f (pt.x, pt.y, pt.z);
glEnd ();
}
void create_new_particles (TVector3 loc, TVector3 vel, int num) {
Particle *newp;
int i;
double speed;
speed = NormVector (&vel);
if (num_particles + num > MAX_PARTICLES) {
Message ("maximum number of particles exceeded", "");
}
for (i=0; i<num; i++) {
newp = (Particle*)malloc (sizeof (Particle));
if (newp == NULL) Message ("out of memory", "");
num_particles += 1;
newp->next = head;
head = newp;
newp->pt.x = loc.x + 2.*(frand() - 0.5) * START_RADIUS;
newp->pt.y = loc.y;
newp->pt.z = loc.z + 2.*(frand() - 0.5) * START_RADIUS;
newp->type = (int) (frand() * (4.0 - EPS));
newp->base_size = (frand() + 0.5) * OLD_PART_SIZE;
newp->cur_size = NEW_PART_SIZE;
newp->age = frand() * MIN_AGE;
newp->death = frand() * MAX_AGE;
newp->vel = AddVectors (
ScaleVector (speed, vel),
MakeVector (VARIANCE_FACTOR * (frand() - 0.5) * speed,
VARIANCE_FACTOR * (frand() - 0.5) * speed,
VARIANCE_FACTOR * (frand() - 0.5) * speed ));
}
}
void update_particles (double time_step) {
Particle **p, *q;
double ycoord;
for (p = &head; *p != NULL;) {
(**p).age += time_step;
if ((**p).age < 0) continue;
(**p).pt = AddVectors ((**p).pt, ScaleVector (time_step, (**p).vel));
ycoord = Course.FindYCoord ((**p).pt.x, (**p).pt.z);
if ((**p).pt.y < ycoord - 3) {(**p).age = (**p).death + 1;}
if ((**p).age >= (**p).death) {
q = *p;
*p = q->next;
free(q);
num_particles -= 1;
continue;
}
(**p).alpha = ((**p).death - (**p).age) / (**p).death;
(**p).cur_size = NEW_PART_SIZE +
(OLD_PART_SIZE - NEW_PART_SIZE) * ((**p).age / (**p).death);
(**p).vel.y += -EARTH_GRAV * time_step;
p = &((**p).next);
}
}
void draw_particles (CControl *ctrl) {
Particle *p;
TVector2 min_tex_coord, max_tex_coord;
set_gl_options (PARTICLES);
Tex.BindTex (SNOW_PART);
glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glColor4f(part_col[0], part_col[1], part_col[2], part_col[3]);
part_col[3] = 0.8; // !!!!!!!!!
for (p=head; p!=NULL; p = p->next) {
if (p->age < 0) continue;
if (p->type == 0 || p->type == 1) {
min_tex_coord.y = 0;
max_tex_coord.y = 0.5;
} else {
min_tex_coord.y = 0.5;
max_tex_coord.y = 1.0;
}
if (p->type == 0 || p->type == 3) {
min_tex_coord.x = 0;
max_tex_coord.x = 0.5;
} else {
min_tex_coord.x = 0.5;
max_tex_coord.x = 1.0;
}
TColor particle_colour = Env.ParticleColor ();
glColor4f (particle_colour.r,
particle_colour.g,
particle_colour.b,
particle_colour.a * p->alpha);
draw_billboard (ctrl, p->pt, p->cur_size, p->cur_size,
false, min_tex_coord, max_tex_coord);
}
}
void clear_particles() {
Particle *p, *q;
p = head;
for (;;) {
if (p == NULL) break;
q=p;
p=p->next;
free(q);
}
head = NULL;
num_particles = 0;
}
double adjust_particle_count (double particles) {
if (particles < 1) {
if (((double) rand()) / RAND_MAX < particles) return 1.0;
else return 0.0;
} else return particles;
}
void generate_particles (CControl *ctrl, double dtime, TVector3 pos, double speed) {
TVector3 left_part_pt, right_part_pt;
double brake_particles;
double turn_particles;
double roll_particles;
double surf_y;
double left_particles, right_particles;
TVector3 left_part_vel, right_part_vel;
TMatrix rot_mat;
TVector3 xvec;
TTerrType *TerrList = Course.TerrList;
surf_y = Course.FindYCoord (pos.x, pos.z);
int id;
id = Course.GetTerrainIdx (pos.x, pos.z, 0.5);
if (id >= 0 && TerrList[id].particles > 0 && pos.y < surf_y) {
xvec = CrossProduct (ctrl->cdirection, ctrl->plane_nml);
right_part_pt = left_part_pt = pos;
right_part_pt = AddVectors (
right_part_pt,
ScaleVector (TUX_WIDTH/2.0, xvec));
left_part_pt = AddVectors (
left_part_pt,
ScaleVector (-TUX_WIDTH/2.0, xvec));
right_part_pt.y = left_part_pt.y = surf_y;
brake_particles = dtime *
BRAKE_PARTICLES * (ctrl->is_braking ? 1.0 : 0.0)
* min (speed / PARTICLE_SPEED_FACTOR, 1.0);
turn_particles = dtime * MAX_TURN_PARTICLES
* min (speed / PARTICLE_SPEED_FACTOR, 1.0);
roll_particles = dtime * MAX_ROLL_PARTICLES
* min (speed / PARTICLE_SPEED_FACTOR, 1.0);
left_particles = turn_particles *
fabs (min(ctrl->turn_fact, 0.)) +
brake_particles +
roll_particles * fabs (min(ctrl->turn_animation, 0.));
right_particles = turn_particles *
fabs (max(ctrl->turn_fact, 0.)) +
brake_particles +
roll_particles * fabs (max(ctrl->turn_animation, 0.));
left_particles = adjust_particle_count (left_particles);
right_particles = adjust_particle_count (right_particles);
RotateAboutVectorMatrix(
rot_mat, ctrl->cdirection,
MAX (-MAX_PARTICLE_ANGLE,
-MAX_PARTICLE_ANGLE * speed / MAX_PARTICLE_ANGLE_SPEED));
left_part_vel = TransformVector (rot_mat, ctrl->plane_nml);
left_part_vel = ScaleVector (MIN (MAX_PARTICLE_SPEED,
speed * PARTICLE_SPEED_MULTIPLIER),left_part_vel);
RotateAboutVectorMatrix(
rot_mat, ctrl->cdirection,
MIN (MAX_PARTICLE_ANGLE,
MAX_PARTICLE_ANGLE * speed / MAX_PARTICLE_ANGLE_SPEED));
right_part_vel = TransformVector (rot_mat, ctrl->plane_nml);
right_part_vel = ScaleVector (MIN (MAX_PARTICLE_SPEED,
speed * PARTICLE_SPEED_MULTIPLIER),right_part_vel);
create_new_particles (left_part_pt, left_part_vel,
(int)left_particles);
create_new_particles (right_part_pt, right_part_vel,
(int)right_particles);
}
}
// --------------------------------------------------------------------
// snow flakes
// --------------------------------------------------------------------
#define SNOW_WIND_DRIFT 0.1
CFlakes::CFlakes () {
for (int i=0; i<MAX_FLAKEAREAS; i++) areas[i].flakes = 0;
numAreas = 0;
}
CFlakes::~CFlakes () {
Reset ();
}
void CFlakes::Reset () {
for (int i=0; i<MAX_FLAKEAREAS; i++) {
if (areas[i].flakes != 0) delete [] areas[i].flakes;
areas[i].flakes = 0;
}
numAreas = 0;
}
static CFlakes Flakes;
void CFlakes::CreateArea (
int num_flakes,
float xrange,
float ytop,
float yrange,
float zback,
float zrange,
float minSize,
float maxSize,
float speed,
bool rotate) {
if (numAreas >= MAX_FLAKEAREAS) return;
areas[numAreas].num_flakes = num_flakes;
areas[numAreas].xrange = xrange;
areas[numAreas].ytop = ytop;
areas[numAreas].yrange = yrange;
areas[numAreas].zback = zback;
areas[numAreas].zrange = zrange;
areas[numAreas].minSize = minSize;
areas[numAreas].maxSize = maxSize;
areas[numAreas].speed = speed;
areas[numAreas].rotate_flake = rotate;
areas[numAreas].flakes = new TFlake[num_flakes];
numAreas++;
}
void CFlakes::MakeSnowFlake (int ar, int i) {
float p_dist;
int type;
areas[ar].flakes[i].pt.x = XRandom (areas[ar].left, areas[ar].right);
areas[ar].flakes[i].pt.y = -XRandom (areas[ar].top, areas[ar].bottom);
areas[ar].flakes[i].pt.z = areas[ar].back - FRandom () * (areas[ar].back - areas[ar].front);
p_dist = FRandom ();
areas[ar].flakes[i].size = XRandom (areas[ar].minSize, areas[ar].maxSize);
areas[ar].flakes[i].vel.x = 0;
areas[ar].flakes[i].vel.z = 0;
areas[ar].flakes[i].vel.y = -areas[ar].flakes[i].size * areas[ar].speed;
type = (int) (FRandom () * 3.9999);
if (type == 0) {
areas[ar].flakes[i].tex_min = MakeVector2 (0.0, 0.875);
areas[ar].flakes[i].tex_max = MakeVector2 (0.125, 1.0);
} else if (type == 1) {
areas[ar].flakes[i].tex_min = MakeVector2 (0.125, 0.875);
areas[ar].flakes[i].tex_max = MakeVector2 (0.25, 1.0);
} else if (type == 2) {
areas[ar].flakes[i].tex_min = MakeVector2 (0.0, 0.75);
areas[ar].flakes[i].tex_max = MakeVector2 (0.125, 0.875);
} else {
areas[ar].flakes[i].tex_min = MakeVector2 (0.125, 0.75);
areas[ar].flakes[i].tex_max = MakeVector2 (0.25, 0.875);
}
}
void CFlakes::GenerateSnowFlakes (CControl *ctrl) {
if (g_game.snow_id < 1) return;
snow_lastpos = ctrl->cpos;
for (int ar=0; ar<numAreas; ar++) {
for (int i=0; i<areas[ar].num_flakes; i++) MakeSnowFlake (ar, i);
}
}
void CFlakes::UpdateAreas (CControl *ctrl) {
for (int ar=0; ar<numAreas; ar++) {
areas[ar].left = ctrl->cpos.x - areas[ar].xrange / 2;
areas[ar].right = areas[ar].left + areas[ar].xrange;
areas[ar].back = ctrl->cpos.z - areas[ar].zback;
areas[ar].front = areas[ar].back - areas[ar].zrange;
areas[ar].top = ctrl->cpos.y + areas[ar].ytop;
areas[ar].bottom = areas[ar].top - areas[ar].yrange;
}
}
#define YDRIFT 0.8
#define ZDRIFT 0.6
void CFlakes::Init (int grade, CControl *ctrl) {
Reset ();
switch (grade) {
case 1:
// CreateArea (400, 5, 4, 4, -2, 4, 0.01, 0.02, 5, true);
// CreateArea (400, 12, 5, 8, 2, 8, 0.03, 0.045, 5, false);
// CreateArea (400, 30, 6, 15, 10, 15, 0.06, 0.12, 5, false);
CreateArea (400, 5, 4, 4, -2, 4, 0.015, 0.03, 5, true);
CreateArea (400, 12, 5, 8, 2, 8, 0.045, 0.07, 5, false);
CreateArea (400, 30, 6, 15, 10, 15, 0.09, 0.18, 5, false);
// CreateArea (400, 5, 4, 4, -2, 4, 0.02, 0.04, 5, true);
// CreateArea (400, 12, 5, 8, 2, 8, 0.06, 0.09, 5, false);
// CreateArea (400, 30, 6, 15, 10, 15, 0.15, 0.25, 5, false);
break;
case 2:
// CreateArea (500, 5, 4, 4, -2, 4, 0.02, 0.03, 5, true);
// CreateArea (500, 12, 5, 8, 2, 8, 0.045, 0.07, 5, false);
// CreateArea (500, 30, 6, 15, 10, 15, 0.1, 0.15, 5, false);
CreateArea (500, 5, 4, 4, -2, 4, 0.03, 0.045, 5, true);
CreateArea (500, 12, 5, 8, 2, 8, 0.07, 0.1, 5, false);
CreateArea (500, 30, 6, 15, 10, 15, 0.15, 0.22, 5, false);
// CreateArea (500, 5, 4, 4, -2, 4, 0.04, 0.06, 5, true);
// CreateArea (500, 12, 5, 8, 2, 8, 0.09, 0.15, 5, false);
// CreateArea (500, 30, 6, 15, 10, 15, 0.2, 0.32, 5, false);
break;
case 3:
// CreateArea (1000, 5, 4, 4, -2, 4, 0.025, 0.04, 5, true);
// CreateArea (1000, 12, 5, 9, 2, 8, 0.06, 0.10, 5, false);
// CreateArea (1000, 30, 6, 15, 10, 15, 0.12, 0.2, 5, false);
CreateArea (1000, 5, 4, 4, -2, 4, 0.037, 0.05, 5, true);
CreateArea (1000, 12, 5, 9, 2, 8, 0.09, 0.15, 5, false);
CreateArea (1000, 30, 6, 15, 10, 15, 0.18, 0.35, 5, false);
// CreateArea (800, 5, 4, 4, -2, 4, 0.05, 0.08, 5, true);
// CreateArea (800, 12, 5, 9, 2, 8, 0.12, 0.20, 5, false);
// CreateArea (800, 30, 6, 15, 10, 15, 0.25, 0.5, 5, false);
break;
default: break;
}
UpdateAreas (ctrl);
GenerateSnowFlakes (ctrl);
}
void CFlakes::Update (double timestep, CControl *ctrl) {
int i;
float ydiff, zdiff;
if (g_game.snow_id < 1) return;
UpdateAreas (ctrl);
zdiff = ctrl->cpos.z - snow_lastpos.z;
if (g_game.mode != GAME_OVER) {
ydiff = ctrl->cpos.y - snow_lastpos.y;
} else ydiff = 0;
TVector3 winddrift = ScaleVector (SNOW_WIND_DRIFT, Wind.WindDrift ());
float xcoeff = winddrift.x * timestep;
float ycoeff = (ydiff * YDRIFT) + (winddrift.z * timestep);
float zcoeff = (zdiff * ZDRIFT) + (winddrift.z * timestep);
for (int ar=0; ar<numAreas; ar++) {
for (i=0; i<areas[ar].num_flakes; i++) {
areas[ar].flakes[i].pt.x += xcoeff;
areas[ar].flakes[i].pt.y += areas[ar].flakes[i].vel.y * timestep + ycoeff;
areas[ar].flakes[i].pt.z += zcoeff;
if (areas[ar].flakes[i].pt.y < areas[ar].bottom) {
areas[ar].flakes[i].pt.y += areas[ar].yrange;
} else if (areas[ar].flakes[i].pt.x < areas[ar].left) {
areas[ar].flakes[i].pt.x += areas[ar].xrange;
} else if (areas[ar].flakes[i].pt.x > areas[ar].right) {
areas[ar].flakes[i].pt.x -= areas[ar].xrange;
} else if (areas[ar].flakes[i].pt.y > areas[ar].top) {
areas[ar].flakes[i].pt.y -= areas[ar].yrange;
} else if (areas[ar].flakes[i].pt.z < areas[ar].front) {
areas[ar].flakes[i].pt.z += areas[ar].zrange;
} else if (areas[ar].flakes[i].pt.z > areas[ar].back) {
areas[ar].flakes[i].pt.z -= areas[ar].zrange;
}
}
}
snow_lastpos = ctrl->cpos;
}
void CFlakes::DrawArea (int ar, CControl *ctrl) {
TVector2 *tex_min, *tex_max;
TVector3 *pt;
float size;
int i;
TFlake flake;
if (g_game.snow_id < 1) return;
TPlane lp = get_left_clip_plane ();
TPlane rp = get_right_clip_plane ();
float dir_angle (atan (ctrl->viewdir.x / ctrl->viewdir.z) * 180 / 3.14159);
set_gl_options (PARTICLES);
glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
Tex.BindTex (T_WIDGETS);
TColor particle_colour = Env.ParticleColor ();
glColor4f (particle_colour.r, particle_colour.g, particle_colour.b, particle_colour.a);
for (i=0; i < areas[ar].num_flakes; i++) {
flake = areas[ar].flakes[i];
pt = &flake.pt;
size = flake.size;
tex_min = &flake.tex_min;
tex_max = &flake.tex_max;
if ((DistanceToPlane (lp, *pt) < 0) && (DistanceToPlane (rp, *pt) < 0)) {
glPushMatrix();
glTranslatef (pt->x, pt->y, pt->z);
if (areas[ar].rotate_flake) glRotatef (dir_angle, 0, 1, 0);
glBegin (GL_QUADS);
glTexCoord2f (tex_min->x, tex_min->y);
glVertex3f (0, 0, 0);
glTexCoord2f (tex_max->x, tex_min->y);
glVertex3f (size, 0, 0);
glTexCoord2f (tex_max->x, tex_max->y);
glVertex3f (size, size, 0);
glTexCoord2f (tex_min->x, tex_max->y);
glVertex3f (0, size, 0);
glEnd();
glPopMatrix();
}
}
}
void CFlakes::Draw (CControl *ctrl) {
for (int ar=0; ar<numAreas; ar++) DrawArea (ar, ctrl);
}
// --------------------------------------------------------------------
// snow curtains
// --------------------------------------------------------------------
#define NUM_CHANGES 6
#define CHANGE_DRIFT 15
#define CHANGE_SPEED 0.05
#define CURTAIN_WINDDRIFT 0.35
typedef struct {
float min;
float max;
float curr;
float step;
bool forward;
} TChange;
TChange changes[NUM_CHANGES];
void InitChanges () {
for (int i=0; i<NUM_CHANGES; i++) {
changes[i].min = XRandom (-0.15, -0.05);
changes[i].max = XRandom (0.05, 0.15);
changes[i].curr = (changes[i].min + changes[i].max) / 2;
changes[i].step = CHANGE_SPEED;
changes[i].forward = true;
}
}
void UpdateChanges (double timestep) {
TChange *ch;
for (int i=0; i<NUM_CHANGES; i++) {
ch = &changes[i];
if (ch->forward) {
ch->curr += ch->step * timestep;
if (ch->curr > ch->max) ch->forward = false;
} else {
ch->curr -= ch->step * timestep;
if (ch->curr < ch->min) ch->forward = true;
}
}
}
static CCurtain Curtain;
CCurtain::CCurtain () {}
CCurtain::~CCurtain () {}
void CCurtain::CurtainVec (float angle, float zdist, float &x, float &z) {
x = zdist * sin (angle * 3.14159 / 180);
if (angle > 90 || angle < -90) z = sqrt (zdist * zdist - x * x);
else z = -sqrt (zdist * zdist - x * x);
}
void CCurtain::Draw (CControl *ctrl) {
TVector3 *pt;
if (g_game.snow_id < 1) return;
set_gl_options (PARTICLES);
glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
TColor particle_colour = Env.ParticleColor ();
glColor4f (particle_colour.r, particle_colour.g, particle_colour.b, 1.0);
// glEnable (GL_NORMALIZE);
for (int i=0; i<MAX_CURTAINS; i++) {
if (enabled[i]) {
Tex.BindTex (texture[i]);
float halfsize = size[i] / 2;
for (int co=0; co<numCols[i]; co++) {
for (int row=0; row<numRows[i]; row++) {
pt = &curtains[i][co][row].pt;
glPushMatrix();
glTranslatef (pt->x, pt->y, pt->z);
glRotatef (-curtains[i][co][row].angle, 0, 1, 0);
// glNormal3f (0, 0, 1);
glBegin (GL_QUADS);
glTexCoord2f (0, 0);
glVertex3f (-halfsize, -halfsize, 0);
glTexCoord2f (1, 0);
glVertex3f (halfsize, -halfsize, 0);
glTexCoord2f (1, 1);
glVertex3f (halfsize, halfsize, 0);
glTexCoord2f (0, 1);
glVertex3f (-halfsize, halfsize, 0);
glEnd();
glPopMatrix();
}
}
}
}
}
void CCurtain::Update (float timestep, CControl *ctrl) {
if (g_game.snow_id < 1) return;
float x, z;
TCurtainElement *curt = 0;
TVector3 drift = Wind.WindDrift ();
UpdateChanges (timestep);
for (int i=0; i<MAX_CURTAINS; i++) {
if (enabled[i]) {
for (int co=0; co<numCols[i]; co++) {
for (int row=0; row<numRows[i]; row++) {
curt = &curtains[i][co][row];
curt->angle += changes[chg[i][row]].curr * timestep * CHANGE_DRIFT;
curt->angle += drift.x * timestep * CURTAIN_WINDDRIFT;
curt->height -= speed[i] * timestep;
if (curt->angle > lastangle[i] + angledist[i]) curt->angle = startangle[i];
if (curt->angle < startangle[i] - angledist[i]) curt->angle = lastangle[i];
CurtainVec (curt->angle, zdist[i], x, z);
curt->pt.x = ctrl->cpos.x + x;
curt->pt.z = ctrl->cpos.z + z ;
curt->pt.y = ctrl->cpos.y + curt->height;
if (curt->height < minheight[i] - size[i]) curt->height += numRows[i] * size[i];
}
}
}
}
Draw (ctrl);
}
void CCurtain::Reset () {
for (int i=0; i<MAX_CURTAINS; i++) enabled[i] = false;
}
void CCurtain::GenerateCurtain (int nr, int num_rows, float z_dist, float tex_size,
float base_speed, float start_angle, float min_height, int dense) {
if (nr < 0 || nr >= MAX_CURTAINS) return;
enabled[nr] = true;
numRows[nr] = num_rows;
zdist[nr] = z_dist;
size[nr] = tex_size;
speed[nr] = base_speed;
startangle[nr] = start_angle;
minheight[nr] = min_height;
switch (dense) {
case 1: texture[nr] = T_SNOW1; break;
case 2: texture[nr] = T_SNOW2; break;
case 3: texture[nr] = T_SNOW3; break;
}
angledist[nr] = atan (size[nr] / 2 / zdist[nr]) * 360 / 3.14159;
numCols[nr] = (int)(-2 * startangle[nr] / angledist[nr]) + 1;
if (numCols[nr] > MAX_CURTAIN_COLS) numCols[nr] = MAX_CURTAIN_COLS;
lastangle[nr] = startangle[nr] + (numCols[nr]-1) * angledist[nr];
for (int i=0; i<numRows[nr]; i++) chg[nr][i] = IRandom (0, 5);
}
void CCurtain::SetStartParams (CControl *ctrl) {
float x, z;
TCurtainElement *curt = 0;
for (int i=0; i<MAX_CURTAINS; i++) {
if (enabled[i]) {
for (int co=0; co<numCols[i]; co++) {
for (int row=0; row<numRows[i]; row++) {
curt = &curtains[i][co][row];
curt->height = minheight[i] + row * size[i];
curt->angle = co * angledist[i] + startangle[i];
CurtainVec (curt->angle, zdist[i], x, z);
curt->pt.x = ctrl->cpos.x + x;
curt->pt.z = ctrl->cpos.z + z;
curt->pt.y = ctrl->cpos.y + curt->height;
}
}
}
}
}
void CCurtain::Init (CControl *ctrl) {
Reset ();
InitChanges ();
switch (g_game.snow_id) {
case 1:
// GenerateCurtain (0, 3, 60, 10, 3, -100, -10, 1);
// GenerateCurtain (1, 3, 50, 13, 3, -100, -10, 1);
// GenerateCurtain (2, 3, 40, 16, 3, -100, -10, 1);
GenerateCurtain (0, 3, 60, 15, 3, -100, -10, 1);
GenerateCurtain (1, 3, 50, 19, 3, -100, -10, 1);
GenerateCurtain (2, 3, 40, 23, 3, -100, -10, 1);
// GenerateCurtain (0, 3, 60, 20, 3, -100, -10, 1);
// GenerateCurtain (1, 3, 50, 25, 3, -100, -10, 1);
// GenerateCurtain (2, 3, 40, 30, 3, -100, -10, 1);
break;
case 2:
// GenerateCurtain (0, 3, 60, 15, 3, -100, -10, 2);
// GenerateCurtain (1, 3, 50, 17, 3, -100, -10, 2);
// GenerateCurtain (2, 3, 40, 20, 3, -100, -10, 2);
GenerateCurtain (0, 3, 60, 22, 3, -100, -10, 2);
GenerateCurtain (1, 3, 50, 25, 3, -100, -10, 2);
GenerateCurtain (2, 3, 40, 30, 3, -100, -10, 2);
// GenerateCurtain (0, 3, 60, 30, 3, -100, -10, 2);
// GenerateCurtain (1, 3, 50, 35, 3, -100, -10, 2);
// GenerateCurtain (2, 3, 40, 40, 3, -100, -10, 2);
break;
case 3:
// GenerateCurtain (0, 3, 60, 20, 3, -100, -10, 3);
// GenerateCurtain (1, 3, 50, 25, 3, -100, -10, 2);
// GenerateCurtain (2, 3, 40, 30, 3, -100, -10, 2);
GenerateCurtain (0, 3, 60, 22, 3, -100, -10, 3);
GenerateCurtain (1, 3, 50, 27, 3, -100, -10, 2);
GenerateCurtain (2, 3, 40, 32, 3, -100, -10, 2);
// GenerateCurtain (0, 3, 60, 25, 3, -100, -10, 3);
// GenerateCurtain (1, 3, 50, 30, 3, -100, -10, 2);
// GenerateCurtain (2, 3, 40, 35, 3, -100, -10, 2);
break;
default: {}
}
SetStartParams (ctrl);
}
// --------------------------------------------------------------------
// wind
// --------------------------------------------------------------------
#define UPDATE_TIME 0.04
CWind Wind;
CWind::CWind () {
windy = false;
CurrTime = 0.0;
WVector = MakeVector (0, 0, 0);
SpeedMode = 0;
AngleMode = 0;
WSpeed = 0;
WAngle = 0;