breakhack/src/particle_engine.c

377 lines
8.0 KiB
C

/*
* BreakHack - A dungeone crawler RPG
* Copyright (C) 2018 Linus Probert <linus.probert@gmail.com>
*
* 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 3 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdarg.h>
#include "particle_engine.h"
#include "linkedlist.h"
#include "util.h"
#include "defines.h"
#include "vector2d.h"
#include "random.h"
typedef struct Particle_t {
Position pos;
Vector2d velocity;
Dimension dim;
unsigned int movetime;
unsigned int lifetime;
bool fixed;
Uint8 blend_mode;
SDL_Color color;
} Particle;
typedef struct Engine_t {
LinkedList *global_particles;
LinkedList *game_particles;
} Engine;
static Engine *engine = NULL;
static Particle*
create_particle(void)
{
Particle *p = ec_malloc(sizeof(Particle));
p->pos = (Position) { 0, 0 };
p->dim = (Dimension) { 1, 1 };
p->velocity = VECTOR2D_NODIR;
p->movetime = 100;
p->lifetime = 100;
p->fixed = false;
p->blend_mode = SDL_BLENDMODE_MOD;
p->color = (SDL_Color) { 255, 255, 255, 255 };
return p;
}
static void
check_engine(void)
{
if (!engine)
fatal("Particle engine not initiated");
}
void
particle_engine_init(void)
{
if (engine != NULL)
fatal("Engine already initiated");
engine = ec_malloc(sizeof(Engine));
engine->game_particles = linkedlist_create();
engine->global_particles = linkedlist_create();
}
void
particle_engine_bloodspray(Position pos, Dimension dim, unsigned int count)
{
check_engine();
if (count > 100)
count = 100;
for (unsigned int i = 0; i < count; ++i) {
int x, y, xv, yv, w, h;
unsigned int mt, lt;
Particle *p;
x = get_random(dim.width) + pos.x;
y = get_random(dim.height) + pos.y;
xv = get_random(200) - 100;
yv = get_random(200) - 100;
mt = get_random(10) + 10;
lt = get_random(120) + 60;
w = get_random(3) + 2;
h = get_random(3) + 2;
p = create_particle();
p->pos = (Position) { x, y };
p->velocity = (Vector2d) { (float) xv, (float) yv };
p->movetime = mt;
p->lifetime = lt;
p->dim = (Dimension) { w, h };
p->color = (SDL_Color) { 255, 0, 0, 255 };
linkedlist_append(&engine->game_particles, p);
}
}
static void
create_explosion(Position pos, Dimension dim, unsigned int c_count, ...)
{
SDL_Color *colors = ec_malloc(c_count * sizeof(SDL_Color));
va_list(args);
va_start(args, c_count);
for (size_t i = 0; i < c_count; ++i) {
colors[i] = va_arg(args, SDL_Color);
}
va_end(args);
for (unsigned int i = 0; i < 150; ++i) {
int x, y, xv, yv;
unsigned int lt;
Particle *p;
x = get_random(dim.width) + pos.x;
y = get_random(dim.height) + pos.y;
xv = get_random(600) - 300;
yv = get_random(600) - 300;
lt = get_random(10);
p = create_particle();
p->pos = (Position) { x, y };
p->velocity = (Vector2d) { (float) xv, (float) yv };
p->movetime = lt;
p->lifetime = lt;
p->dim = (Dimension) { 2, 2 };
p->color = colors[get_random((unsigned int) c_count-1)];
linkedlist_append(&engine->game_particles, p);
}
free(colors);
}
void
particle_engine_fire_explosion(Position pos, Dimension dim)
{
check_engine();
create_explosion(pos, dim, 3, C_YELLOW, C_YELLOW, C_RED);
}
void
particle_engine_eldritch_explosion(Position pos, Dimension dim)
{
check_engine();
create_explosion(pos, dim, 1, C_GREEN);
}
void
particle_engine_speed_lines(Position pos, Dimension dim, bool horizontal)
{
static SDL_Color color = { 0, 0, 255, 200 };
unsigned int count = (unsigned int) (dim.width + dim.height) / 2;
if (dim.width == 0 || dim.height == 0)
return;
for (unsigned int i = 0; i < count; ++i) {
int x, y;
unsigned int lt;
Particle *p;
x = get_random(dim.width) + pos.x;
y = get_random(dim.height) + pos.y;
lt = get_random(10);
p = create_particle();
p->pos = (Position) { x, y };
p->velocity = (Vector2d) { 0, 0 };
p->movetime = lt;
p->lifetime = lt;
if (horizontal)
p->dim = (Dimension) { 20, 1 };
else
p->dim = (Dimension) { 2, 20 };
p->color = color;
linkedlist_append(&engine->game_particles, p);
}
}
void
particle_engine_sparkle(Position pos, Dimension dim)
{
for (unsigned int i = 0; i < 10; ++i) {
int x, y, yv, alpha;
unsigned int lt;
Particle *p;
x = get_random(dim.width) + pos.x;
y = get_random(dim.height) + pos.y;
alpha = get_random(155) + 100;
yv = (get_random(100) + 100) * -1;
lt = get_random(20);
p = create_particle();
p->pos = (Position) { x, y };
p->velocity = (Vector2d) { (float) 0, (float) yv };
p->movetime = lt;
p->lifetime = lt;
p->blend_mode = SDL_BLENDMODE_BLEND;
p->dim = (Dimension) { 2, 2 };
p->color = C_WHITE;
p->color.a = (Uint8) alpha;
p->fixed = true;
linkedlist_append(&engine->global_particles, p);
}
}
void
particle_engine_wind(Vector2d direction)
{
unsigned int count = 5;
Position pos = { 0, 0 };
Dimension dim = { GAME_VIEW_WIDTH, GAME_VIEW_HEIGHT };
if (dim.width == 0 || dim.height == 0)
return;
for (unsigned int i = 0; i < count; ++i) {
int x, y;
int w, h;
unsigned int lt;
Particle *p;
int velocity;
x = get_random(dim.width) + pos.x;
y = get_random(dim.height) + pos.y;
w = get_random(2) + 2;
h = get_random(2) + 2;
velocity = get_random(500) + 500;
lt = get_random(500);
p = create_particle();
p->pos = (Position) { x, y };
p->velocity = (Vector2d) { direction.x * (float) velocity, direction.y * (float) velocity };
p->movetime = lt;
p->lifetime = lt;
p->dim = (Dimension) { w, h };
p->color = C_BLUE;
p->fixed = true;
linkedlist_append(&engine->game_particles, p);
}
}
static void
move_particle(Particle *particle, float deltaTime)
{
if (!particle->movetime)
return;
particle->pos.x += (int) (particle->velocity.x * deltaTime);
particle->pos.y += (int) (particle->velocity.y * deltaTime);
}
static void
update_particles(LinkedList **particles, float deltaTime)
{
LinkedList *cleared = linkedlist_create();
while (*particles) {
Particle *particle = linkedlist_pop(particles);
if (particle->movetime)
particle->movetime--;
if (particle->lifetime > 0) {
particle->lifetime--;
move_particle(particle, deltaTime);
linkedlist_push(&cleared, particle);
} else {
free(particle);
}
}
*particles = cleared;
}
void
particle_engine_update(float deltaTime)
{
check_engine();
update_particles(&engine->global_particles, deltaTime);
update_particles(&engine->game_particles, deltaTime);
}
static void
render_particle(Particle *p, Camera *cam)
{
Position pos;
if (p->fixed)
pos = p->pos;
else
pos = camera_to_camera_position(cam, &p->pos);
SDL_SetRenderDrawBlendMode(cam->renderer, p->blend_mode);
SDL_Rect box = { pos.x, pos.y, p->dim.width, p->dim.height };
SDL_SetRenderDrawColor(cam->renderer,
p->color.r,
p->color.g,
p->color.b,
p->color.a);
SDL_RenderFillRect(cam->renderer, &box);
// Reset the blend mode
SDL_SetRenderDrawBlendMode(cam->renderer, SDL_BLENDMODE_BLEND);
}
static void
render_particles(LinkedList *particles, Camera *cam)
{
check_engine();
LinkedList *render_list = particles;
while (render_list) {
render_particle(render_list->data, cam);
render_list = render_list->next;
}
}
void
particle_engine_render_game(Camera *cam)
{
render_particles(engine->game_particles, cam);
}
void
particle_engine_render_global(Camera *cam)
{
render_particles(engine->global_particles, cam);
}
void
particle_engine_clear(void)
{
check_engine();
while (engine->game_particles)
free(linkedlist_pop(&engine->game_particles));
}
void
particle_engine_close(void)
{
check_engine();
while (engine->game_particles)
free(linkedlist_pop(&engine->game_particles));
free(engine);
engine = NULL;
}