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1fec301126
flying-balls/balls.c
Antonio Carzaniga 1fec301126 (window) removed global variable for game window.
2021-12-11 18:05:13 +01:00

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <math.h>
#include <time.h>
#include <gdk/gdkkeysyms.h>
#include <gtk/gtk.h>
#define DEFAULT_WIDTH 800
#define DEFAULT_HEIGHT 800
#include "balls.h"
#include "c_index.h"
double delta = 0.01; /* seconds */
unsigned int width = DEFAULT_WIDTH;
unsigned int height = DEFAULT_HEIGHT;
unsigned int radius_min = 5;
unsigned int radius_max = 10;
unsigned int v_max = 100;
unsigned int v_min = 0;
unsigned int v_angle_min = 0;
unsigned int v_angle_max = 100;
struct ball * balls = 0;
unsigned int n_balls = 50;
double g_y = 20;
double g_x = 0;
void random_velocity(struct ball * p) {
double r2;
do {
p->v_x = v_min + rand() % (v_max + 1 - v_min);
p->v_y = v_min + rand() % (v_max + 1 - v_min);
r2 = p->v_x*p->v_x + p->v_y*p->v_y;
} while (r2 > v_max*v_max || r2 < v_min*v_min);
}
struct ball spaceship;
double spaceship_thrust = 0;
int spaceship_thrust_countdown = 0;
int spaceship_thrust_init = 50;
void spaceship_init_state () {
spaceship.x = width/2;
spaceship.y = height/2;
spaceship.radius = 30;
spaceship.v_x = 0;
spaceship.v_y = 0;
spaceship.angle = 0;
spaceship.v_angle = 0;
}
void balls_init_state () {
srand(time(NULL));
static const unsigned int border = 10;
unsigned int w = width < 2*border ? 1 : width - 2*border;
unsigned int h = height < 2*border ? 1 : height - 2*border;
for (unsigned int i = 0; i < n_balls; ++i) {
balls[i].x = border + rand() % w;
balls[i].y = border + rand() % h;
random_velocity(balls + i);
if (rand() % 2)
balls[i].v_x = -balls[i].v_x;
if (rand() % 2)
balls[i].v_y = -balls[i].v_y;
balls[i].radius = radius_min + rand() % (radius_max + 1 - radius_min);
unsigned int v_angle_360 = (v_angle_min + rand() % (v_angle_max + 1 - v_angle_min)) % 360;
balls[i].v_angle = 2*M_PI*v_angle_360/360;
balls[i].angle = (rand() % 360)*2*M_PI/360;
}
}
void ball_elastic_collision (struct ball * p, struct ball * q) {
double dx = q->x - p->x;
double dy = q->y - p->y;
double d2 = dx*dx + dy*dy;
double r = p->radius + q->radius;
if (d2 <= r*r) {
double dv_x = q->v_x - p->v_x;
double dv_y = q->v_y - p->v_y;
double mp = p->radius * p->radius;
double mq = q->radius * q->radius;
double f = dv_x*dx + dv_y*dy;
if (f < 0) {
f /= d2*(mp + mq);
p->v_x += 2*mq*f*dx;
p->v_y += 2*mq*f*dy;
q->v_x -= 2*mp*f*dx;
q->v_y -= 2*mp*f*dy;
}
}
}
void ball_update_state (struct ball * p) {
p->x += delta*p->v_x + delta*delta*g_x/2.0;
p->v_x += delta*g_x;
p->y += delta*p->v_y + delta*delta*g_y/2.0;
p->v_y += delta*g_y;
if (p->x + p->radius > width) { /* right wall */
if (p->v_x > 0) {
p->x -= p->x + p->radius - width;
p->v_x = -p->v_x;
}
} else if (p->x < p->radius) { /* left wall */
if (p->v_x < 0) {
p->x += p->radius - p->x;
p->v_x = -p->v_x;
}
}
if (p->y + p->radius > height) { /* bottom wall */
if (p->v_y > 0) {
p->y -= p->y + p->radius - height;
p->v_y = -p->v_y;
}
} else if (p->y < p->radius) { /* top wall */
if (p->v_y < 0) {
p->y += p->radius - p->y;
p->v_y = -p->v_y;
}
}
p->angle += delta*p->v_angle;
while (p->angle >= 2*M_PI)
p->angle -= 2*M_PI;
while (p->angle < 0)
p->angle += 2*M_PI;
}
void spaceship_update_state () {
if (spaceship_thrust > 0) {
double fx = cos(spaceship.angle)*spaceship_thrust*4.0;
double fy = sin(spaceship.angle)*spaceship_thrust*4.0;
spaceship.x += delta*delta*fx/2.0;
spaceship.v_x += delta*fx;
spaceship.y += delta*delta*fy/2.0;
spaceship.v_y += delta*fy;
if (spaceship_thrust_countdown > 0)
--spaceship_thrust_countdown;
else
spaceship_thrust = 0;
}
ball_update_state(&spaceship);
}
void reposition_within_borders () {
for(int i = 0; i < n_balls; ++i) {
struct ball * p = balls + i;
if (p->x < p->radius)
p->x = p->radius;
else if (p->x + p->radius > width)
p->x = width - p->radius;
if (p->y < p->radius)
p->y = p->radius;
else if (p->y + p->radius > height)
p->y = height - p->radius;
}
}
void movement_and_borders () {
for(int i = 0; i < n_balls; ++i)
ball_update_state(balls + i);
spaceship_update_state();
}
/* Trivial collision check
*/
void check_collisions_simple () {
for(int i = 0; i < n_balls; ++i)
for(int j = i + 1; j < n_balls; ++j)
ball_elastic_collision(balls + i, balls + j);
for(int j = 0; j < n_balls; ++j)
ball_elastic_collision(&spaceship, balls + j);
}
void check_collisions_with_index () {
c_index_build();
c_index_check_collisions(ball_elastic_collision);
}
void (*check_collisions)() = 0;
void update_state () {
if (check_collisions)
check_collisions();
movement_and_borders();
}
/* Graphics System
*/
GtkWidget * canvas;
int gravity_vector_countdown = 0;
int gravity_vector_init = 300;
void draw_gravity_vector(cairo_t * cr) {
if (gravity_vector_countdown != 0) {
cairo_save(cr);
cairo_new_path(cr);
cairo_move_to(cr, width/2, height/2);
cairo_line_to(cr, width/2 + g_x, height/2 + g_y);
cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
cairo_set_line_width(cr, 1.0);
cairo_stroke(cr);
cairo_arc(cr, width/2 + g_x, height/2 + g_y, 3, 0, 2*M_PI);
cairo_fill(cr);
if (gravity_vector_countdown > 0)
--gravity_vector_countdown;
cairo_restore(cr);
}
}
const char * face_filename = 0;
int face_rotation = 0;
static const double linear_rotation_unit = 2.0;
unsigned int faces_count;
struct ball_face ** faces;
struct ball_face {
unsigned int rotations;
cairo_surface_t ** c_faces;
};
static double random_color_component() {
return 1.0*(rand() % 200 + 56)/255;
};
struct ball_face * new_ball_face(unsigned int radius, cairo_surface_t * face, int rotation) {
struct ball_face * f = malloc(sizeof(struct ball_face));
if (!f)
return 0;
if (face && rotation) {
f->rotations = 2*M_PI * radius / linear_rotation_unit;
} else {
f->rotations = 1;
}
f->c_faces = malloc(sizeof(cairo_surface_t *)*f->rotations);
if (!f->c_faces) {
free(f);
return 0;
}
for (int i = 0; i < f->rotations; ++i) {
f->c_faces[i] = gdk_window_create_similar_surface(gtk_widget_get_window(canvas),
CAIRO_CONTENT_COLOR_ALPHA,
2*radius, 2*radius);
assert(f->c_faces[i]);
cairo_t * ball_cr = cairo_create(f->c_faces[i]);
cairo_translate(ball_cr, radius, radius);
cairo_arc(ball_cr, 0.0, 0.0, radius, 0, 2 * M_PI);
cairo_clip(ball_cr);
if (face) {
int face_x_offset = cairo_image_surface_get_width (face) / 2;
int face_y_offset = cairo_image_surface_get_height (face) / 2;
cairo_rotate(ball_cr, i*2*M_PI/f->rotations);
cairo_scale (ball_cr, 1.0 * radius / face_x_offset, 1.0 * radius / face_y_offset);
cairo_set_source_surface(ball_cr, face, -face_x_offset, -face_y_offset);
cairo_paint(ball_cr);
} else {
cairo_pattern_t *pat;
pat = cairo_pattern_create_radial (-0.2*radius, -0.2*radius, 0.2*radius,
-0.2*radius, -0.2*radius, 1.3*radius);
double col_r = random_color_component();
double col_g = random_color_component();
double col_b = random_color_component();
cairo_pattern_add_color_stop_rgba (pat, 0, col_r, col_g, col_b, 1);
cairo_pattern_add_color_stop_rgba (pat, 1, col_r/3, col_g/3, col_b/3, 1);
cairo_set_source (ball_cr, pat);
cairo_arc (ball_cr, 0.0, 0.0, radius, 0, 2 * M_PI);
cairo_fill (ball_cr);
}
cairo_surface_flush(f->c_faces[i]);
cairo_destroy(ball_cr);
}
return f;
}
void init_graphics() {
cairo_surface_t * face_surface = 0;
if (face_filename) {
face_surface = cairo_image_surface_create_from_png (face_filename);
if (cairo_surface_status(face_surface) != CAIRO_STATUS_SUCCESS) {
cairo_surface_destroy (face_surface);
face_surface = 0;
fprintf(stderr, "could not create surface from PNG file %s\n", face_filename);
}
}
if (face_surface) {
faces_count = radius_max + 1 - radius_min;
faces = malloc(sizeof(struct ball_face *)*faces_count);
for (unsigned int i = 0; i < faces_count; ++i)
faces[i] = 0;
for(struct ball * b = balls; b != balls + n_balls; ++b) {
unsigned int r_idx = b->radius - radius_min;
if (!faces[r_idx])
faces[r_idx] = new_ball_face(b->radius, face_surface, face_rotation);
b->face = faces[r_idx];
}
cairo_surface_destroy (face_surface);
} else {
faces_count = n_balls;
faces = malloc(sizeof(struct ball_face *)*faces_count);
for (unsigned int i = 0; i < n_balls; ++i)
balls[i].face = faces[i] = new_ball_face(balls[i].radius, 0, face_rotation);
}
}
void destroy_graphics() {
if (!faces)
return;
for (int i = 0; i < faces_count; ++i) {
if (faces[i]) {
if (faces[i]->c_faces) {
for (unsigned int j = 0; j < faces[i]->rotations; ++j)
cairo_surface_destroy(faces[i]->c_faces[j]);
free(faces[i]->c_faces);
}
free(faces[i]);
}
}
free(faces);
faces = 0;
faces_count = 0;
}
void draw_space_ship (cairo_t * cr) {
static const double one_over_sqrt_2 = 0.70710678118654752440;
cairo_save(cr);
cairo_set_source_rgba(cr, 0.0, 0.0, 1.0, 1.0);
cairo_translate(cr, spaceship.x, spaceship.y);
cairo_rotate(cr, spaceship.angle);
cairo_arc(cr, 0, 0, spaceship.radius, 0, 2*M_PI);
cairo_stroke(cr);
cairo_set_source_rgba(cr, 0.0, 1.0, 0.0, 1.0);
cairo_move_to (cr, 0, 0);
cairo_line_to (cr, -one_over_sqrt_2*spaceship.radius, one_over_sqrt_2*spaceship.radius);
cairo_line_to (cr, spaceship.radius, 0);
cairo_line_to (cr, -one_over_sqrt_2*spaceship.radius, -one_over_sqrt_2*spaceship.radius);
cairo_line_to (cr, 0, 0);
cairo_stroke(cr);
for (unsigned int i = 0; i < spaceship_thrust; i += 5) {
cairo_arc(cr, 0, 0, spaceship.radius + i, 0.7*M_PI, 1.3*M_PI);
cairo_stroke(cr);
}
cairo_restore(cr);
}
void draw_balls (cairo_t * cr) {
for (const struct ball * b = balls; b != balls + n_balls; ++b) {
cairo_save(cr);
cairo_translate(cr, b->x - b->radius, b->y - b->radius);
unsigned int face_id;
if (b->face->rotations == 1)
face_id = 0;
else {
face_id = b->face->rotations*b->angle/(2*M_PI);
assert(face_id < b->face->rotations);
if (face_id >= b->face->rotations)
face_id %= b->face->rotations;
}
cairo_set_source_surface(cr, b->face->c_faces[face_id], 0, 0);
cairo_paint(cr);
cairo_restore(cr);
}
}
gboolean draw_frame (GtkWidget * widget, cairo_t *cr, gpointer data) {
cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
cairo_paint(cr);
draw_gravity_vector(cr);
draw_balls(cr);
draw_space_ship(cr);
return FALSE;
}
gint configure_event (GtkWidget *widget, GdkEventConfigure * event) {
if (width == gtk_widget_get_allocated_width(widget) && height == gtk_widget_get_allocated_height(widget))
return FALSE;
width = gtk_widget_get_allocated_width(widget);
height = gtk_widget_get_allocated_height(widget);
reposition_within_borders();
return TRUE;
}
gint keyboard_input (GtkWidget *widget, GdkEventKey *event) {
if (event->type != GDK_KEY_PRESS)
return FALSE;
switch(event->keyval) {
case GDK_KEY_Up:
g_y -= 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_KEY_Down:
g_y += 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_KEY_Left:
g_x -= 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_KEY_Right:
g_x += 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_KEY_G:
case GDK_KEY_g:
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_KEY_Q:
case GDK_KEY_q:
gtk_main_quit();
break;
default:
return FALSE;
}
return TRUE;
}
gboolean mouse_scroll (GtkWidget *widget, GdkEvent *event, gpointer user_data) {
if (event->type == GDK_SCROLL) {
GdkEventScroll * e = (GdkEventScroll*) event;
switch (e->direction) {
case GDK_SCROLL_SMOOTH: {
double dx, dy;
gdk_event_get_scroll_deltas (event, &dx, &dy);
spaceship.angle -= dx/4;
if (spaceship.angle < 0)
spaceship.angle += 2*M_PI;
else if (spaceship.angle > 2*M_PI)
spaceship.angle -= 2*M_PI;
spaceship_thrust += dy;
if (spaceship_thrust > 0)
spaceship_thrust_countdown = spaceship_thrust_init;
else
spaceship_thrust = 0;
break;
}
case GDK_SCROLL_LEFT:
g_x -= 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_SCROLL_RIGHT:
g_x += 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_SCROLL_UP:
g_y += 10;
gravity_vector_countdown = gravity_vector_init;
break;
case GDK_SCROLL_DOWN:
g_y -= 10;
gravity_vector_countdown = gravity_vector_init;
break;
}
}
return TRUE;
}
void destroy_window (void) {
gtk_main_quit();
}
void print_usage (const char * progname) {
fprintf(stderr,
"usage: %s [options...]\n"
"options:\n"
"\t<width>x<height>\n"
"\tn=<number of balls>\n"
"\tfx=<x-force>\n"
"\tfy=<y-force>\n"
"\tradius=<min-radius>-<max-radius>\n"
"\tv=<min-velocity>-<max-velocity>\n"
"\tdelta=<frame-delta-time> (in seconds)\n"
"\tface=<filename>\n"
"\tstats=<sample-count> :: rendering timing statitstics (0=disabled, default)\n"
"\tcollisions=<C> :: n=no collisions, s=simple, i=index\n"
"\t-r :: activate face rotation\n",
progname);
}
static unsigned int stats_sampling = 0;
static guint64 stats_update_usec = 0;
static unsigned int stats_update_samples = 0;
static guint64 stats_draw_usec = 0;
static unsigned int stats_draw_samples = 0;
gboolean draw_event (GtkWidget *widget, cairo_t * cr, gpointer data) {
if (stats_sampling > 0) {
guint64 start = g_get_monotonic_time ();
draw_frame (widget, cr, data);
stats_draw_usec += g_get_monotonic_time () - start;
++stats_draw_samples;
} else
draw_frame (widget, cr, data);
return FALSE;
}
gboolean timeout (gpointer user_data) {
if (stats_sampling > 0) {
guint64 start = g_get_monotonic_time ();
update_state();
stats_update_usec += g_get_monotonic_time () - start;
if (++stats_update_samples == stats_sampling) {
float uavg = 1.0*stats_update_usec / stats_update_samples;
float davg = 1.0*stats_draw_usec / stats_draw_samples;
printf("\rupdate = %.0f us, draw = %.0f us, load = %.0f%% (%u update, %u draw) ",
uavg, davg, (uavg+davg)/(10000.0*delta),
stats_update_samples, stats_draw_samples);
fflush(stdout);
stats_update_usec = 0;
stats_update_samples = 0;
stats_draw_usec = 0;
stats_draw_samples = 0;
}
} else {
update_state();
}
gtk_widget_queue_draw(canvas);
return TRUE;
}
int main (int argc, const char *argv[]) {
int w = DEFAULT_WIDTH;
int h = DEFAULT_HEIGHT;
for (int i = 1; i < argc; ++i) {
if (sscanf(argv[i], "%dx%d", &w, &h) == 2)
continue;
if (sscanf(argv[i], "n=%u", &n_balls) == 1)
continue;
if (sscanf(argv[i], "fx=%lf", &g_x) == 1)
continue;
if (sscanf(argv[i], "fy=%lf", &g_y) == 1)
continue;
if (sscanf(argv[i], "radius=%u-%u", &radius_min, &radius_max) == 2)
continue;
if (sscanf(argv[i], "v=%u-%u", &v_min, &v_max) == 2)
continue;
if (sscanf(argv[i], "delta=%lf", &delta) == 1)
continue;
if (strncmp(argv[i], "face=", 5) == 0) {
face_filename = argv[i] + 5;
continue;
}
if (sscanf(argv[i], "stats=%u", &stats_sampling) == 1)
continue;
char collisions;
if (sscanf(argv[i], "collisions=%c", &collisions) == 1) {
switch (collisions) {
case 'i':
case 'I':
check_collisions = check_collisions_with_index;
continue;
case '0':
case 'N':
case 'n':
check_collisions = 0;
continue;
case 's':
case 'S':
check_collisions = check_collisions_simple;
continue;
}
}
if (strcmp(argv[i], "-r") == 0) {
face_rotation = 1;
continue;
}
print_usage(argv[0]);
return 1;
}
balls = malloc(sizeof(struct ball)*n_balls);
assert(balls);
assert(c_index_init());
balls_init_state();
spaceship_init_state();
gtk_init(0, 0);
GtkWidget * window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size(GTK_WINDOW(window), width, height);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_set_title(GTK_WINDOW(window), "Game");
g_signal_connect(window, "destroy", G_CALLBACK(destroy_window), NULL);
g_signal_connect (G_OBJECT (window), "delete-event", G_CALLBACK(destroy_window), NULL);
g_signal_connect(G_OBJECT (window), "key-press-event", G_CALLBACK(keyboard_input), NULL);
gtk_widget_set_events (window, GDK_EXPOSURE_MASK | GDK_SCROLL_MASK | GDK_SMOOTH_SCROLL_MASK | GDK_KEY_PRESS_MASK);
canvas = gtk_drawing_area_new ();
g_signal_connect (G_OBJECT (canvas), "configure-event", G_CALLBACK(configure_event), NULL);
g_signal_connect (G_OBJECT (canvas), "draw", G_CALLBACK (draw_event), NULL);
g_signal_connect (G_OBJECT (canvas), "scroll-event",G_CALLBACK(mouse_scroll), NULL);
gtk_widget_set_events (canvas, GDK_SCROLL_MASK | GDK_SMOOTH_SCROLL_MASK);
gtk_container_add (GTK_CONTAINER (window), canvas);
g_timeout_add (delta * 1000, timeout, canvas);
gtk_widget_show_all(window);
init_graphics();
gtk_main();
if (stats_sampling > 0)
printf("\n");
destroy_graphics();
c_index_destroy();
free(balls);
return 0;
}
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