1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/psys.cc	Wed Aug 19 09:13:48 2015 +0300
     1.3 @@ -0,0 +1,358 @@
     1.4 +#include <stdio.h>
     1.5 +#include <stdlib.h>
     1.6 +#include <vector>
     1.7 +#include <algorithm>
     1.8 +#include "opengl.h"
     1.9 +#include "psys.h"
    1.10 +
    1.11 +#define MAX_SPAWNMAP_SAMPLES	2048
    1.12 +
    1.13 +static double frand();
    1.14 +static float rndval(float x, float range);
    1.15 +static Particle *palloc();
    1.16 +static void pfree(Particle *p);
    1.17 +static void pfreelist(Particle *p);
    1.18 +
    1.19 +void psys_default(PSysParam *pp)
    1.20 +{
    1.21 +	// default parameters
    1.22 +	pp->spawn_rate = 10.0;
    1.23 +	pp->spawn_range = 0.0;
    1.24 +	pp->life = 1.0;
    1.25 +	pp->life_range = 0.0;
    1.26 +	pp->size = 1.0;
    1.27 +	pp->size_range = 0.0;
    1.28 +	pp->spawn_map = 0;
    1.29 +	pp->spawn_map_speed = 0.0;
    1.30 +
    1.31 +	pp->gravity = Vector3(0, -9.2, 0);
    1.32 +
    1.33 +	pp->pimg = 0;
    1.34 +	pp->pcolor_start = pp->pcolor_mid = pp->pcolor_end = Vector3(1, 1, 1);
    1.35 +	pp->palpha_start = 1.0;
    1.36 +	pp->palpha_mid = 0.5;
    1.37 +	pp->palpha_end = 0.0;
    1.38 +	pp->pscale_start = pp->pscale_mid = pp->pscale_end = 1.0;
    1.39 +}
    1.40 +
    1.41 +ParticleSystem::ParticleSystem()
    1.42 +{
    1.43 +	active = true;
    1.44 +	active_time = 0.0f;
    1.45 +	spawn_pending = 0.0f;
    1.46 +	plist = 0;
    1.47 +	pcount = 0;
    1.48 +	smcache = 0;
    1.49 +
    1.50 +	expl = false;
    1.51 +	expl_force = expl_dur = 0.0f;
    1.52 +	expl_life = 0.0f;
    1.53 +
    1.54 +	psys_default(&pp);
    1.55 +}
    1.56 +
    1.57 +ParticleSystem::~ParticleSystem()
    1.58 +{
    1.59 +	pfreelist(plist);
    1.60 +	delete [] smcache;
    1.61 +}
    1.62 +
    1.63 +void ParticleSystem::explode(const Vector3 &c, float force, float dur, float life)
    1.64 +{
    1.65 +	expl_dur = dur;
    1.66 +	expl_force = force;
    1.67 +	expl_cent = c;
    1.68 +	expl_life = life;
    1.69 +	expl = true;
    1.70 +}
    1.71 +
    1.72 +bool ParticleSystem::alive() const
    1.73 +{
    1.74 +	return active || pcount > 0;
    1.75 +}
    1.76 +
    1.77 +void ParticleSystem::update(float dt)
    1.78 +{
    1.79 +	if(pp.spawn_map && !smcache) {
    1.80 +		gen_spawnmap(MAX_SPAWNMAP_SAMPLES);
    1.81 +	}
    1.82 +
    1.83 +	if(active) {
    1.84 +		active_time += dt;
    1.85 +	}
    1.86 +
    1.87 +	if(expl) {
    1.88 +		expl = false;
    1.89 +		//active = false;
    1.90 +
    1.91 +		Vector3 cent = expl_cent + pos;
    1.92 +
    1.93 +		Particle *p = plist;
    1.94 +		while(p) {
    1.95 +			p->max_life = expl_dur;
    1.96 +			Vector3 dir = p->pos - cent;
    1.97 +			p->vel += (normalize(dir + Vector3((frand() - 0.5) * 0.5, frand() - 0.5, (frand() - 0.5) * 0.5))) * expl_force;
    1.98 +			p = p->next;
    1.99 +		}
   1.100 +	}
   1.101 +
   1.102 +	if(expl_life > 0.0) {
   1.103 +		expl_life -= dt;
   1.104 +		if(expl_life <= 0.0) {
   1.105 +			expl_life = 0.0;
   1.106 +			active = false;
   1.107 +		}
   1.108 +	}
   1.109 +
   1.110 +	// update active particles
   1.111 +	Particle *p = plist;
   1.112 +	while(p) {
   1.113 +		p->life += dt;
   1.114 +		if(p->life < p->max_life) {
   1.115 +			float t = p->life / p->max_life;
   1.116 +
   1.117 +			p->pos = p->pos + p->vel * dt;
   1.118 +			p->vel = p->vel + pp.gravity * dt;
   1.119 +
   1.120 +			if(t < 0.5) {
   1.121 +				t *= 2.0;
   1.122 +				p->color = lerp(pp.pcolor_start, pp.pcolor_mid, t);
   1.123 +				p->alpha = lerp(pp.palpha_start, pp.palpha_mid, t);
   1.124 +				p->scale = lerp(pp.pscale_start, pp.pscale_mid, t);
   1.125 +			} else {
   1.126 +				t = (t - 0.5) * 2.0;
   1.127 +				p->color = lerp(pp.pcolor_mid, pp.pcolor_end, t);
   1.128 +				p->alpha = lerp(pp.palpha_mid, pp.palpha_end, t);
   1.129 +				p->scale = lerp(pp.pscale_mid, pp.pscale_end, t);
   1.130 +			}
   1.131 +
   1.132 +		} else {
   1.133 +			p->life = -1.0;
   1.134 +		}
   1.135 +		p = p->next;
   1.136 +	}
   1.137 +
   1.138 +	// remove dead particles
   1.139 +	Particle dummy;
   1.140 +	dummy.next = plist;
   1.141 +	p = &dummy;
   1.142 +	while(p->next) {
   1.143 +		if(p->next->life < 0.0) {
   1.144 +			Particle *tmp = p->next;
   1.145 +			p->next = tmp->next;
   1.146 +			pfree(tmp);
   1.147 +			--pcount;
   1.148 +		} else {
   1.149 +			p = p->next;
   1.150 +		}
   1.151 +	}
   1.152 +	plist = dummy.next;
   1.153 +
   1.154 +	float spawn_rate = pp.spawn_rate;
   1.155 +	if(pp.spawn_map && pp.spawn_map_speed > 0.0) {
   1.156 +		float s = active_time * pp.spawn_map_speed;
   1.157 +		if(s > 1.0) s = 1.0;
   1.158 +		spawn_rate *= s;
   1.159 +	}
   1.160 +
   1.161 +	// spawn particles as needed
   1.162 +	if(active) {
   1.163 +		spawn_pending += spawn_rate * dt;
   1.164 +
   1.165 +		while(spawn_pending >= 1.0f) {
   1.166 +			spawn_pending -= 1.0f;
   1.167 +			spawn_particle();
   1.168 +		}
   1.169 +	}
   1.170 +}
   1.171 +
   1.172 +void ParticleSystem::draw() const
   1.173 +{
   1.174 +	int cur_sdr = 0;
   1.175 +	glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
   1.176 +	if(cur_sdr) {
   1.177 +		glUseProgram(0);
   1.178 +	}
   1.179 +
   1.180 +	glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT);
   1.181 +	glDisable(GL_LIGHTING);
   1.182 +	glEnable(GL_BLEND);
   1.183 +	glBlendFunc(GL_SRC_ALPHA, GL_ONE);
   1.184 +
   1.185 +	if(pp.pimg) {
   1.186 +		if(!pp.pimg->texture) {
   1.187 +			pp.pimg->gen_texture();
   1.188 +		}
   1.189 +		glEnable(GL_TEXTURE_2D);
   1.190 +		glBindTexture(GL_TEXTURE_2D, pp.pimg->texture);
   1.191 +	}
   1.192 +
   1.193 +	glBegin(GL_QUADS);
   1.194 +	Particle *p = plist;
   1.195 +	while(p) {
   1.196 +		float hsz = p->size * p->scale * 0.5;
   1.197 +		glColor4f(p->color.x, p->color.y, p->color.z, p->alpha);
   1.198 +		glTexCoord2f(0, 0); glVertex3f(p->pos.x - hsz, p->pos.y - hsz, p->pos.z);
   1.199 +		glTexCoord2f(1, 0); glVertex3f(p->pos.x + hsz, p->pos.y - hsz, p->pos.z);
   1.200 +		glTexCoord2f(1, 1); glVertex3f(p->pos.x + hsz, p->pos.y + hsz, p->pos.z);
   1.201 +		glTexCoord2f(0, 1); glVertex3f(p->pos.x - hsz, p->pos.y + hsz, p->pos.z);
   1.202 +		p = p->next;
   1.203 +	}
   1.204 +	glEnd();
   1.205 +
   1.206 +	glPopAttrib();
   1.207 +
   1.208 +	if(cur_sdr) {
   1.209 +		glUseProgram(cur_sdr);
   1.210 +	}
   1.211 +}
   1.212 +
   1.213 +void ParticleSystem::gen_spawnmap(int count)
   1.214 +{
   1.215 +	Image *img = pp.spawn_map;
   1.216 +	if(!img) return;
   1.217 +
   1.218 +	delete [] smcache;
   1.219 +	smcache = new Vector3[count];
   1.220 +
   1.221 +	float umax = (float)img->width;
   1.222 +	float vmax = (float)img->height;
   1.223 +	float aspect = umax / vmax;
   1.224 +
   1.225 +	// first generate a bunch of random samples by rejection sampling
   1.226 +	printf("generating %d random spawnmap samples\n", count);
   1.227 +	for(int i=0; i<count; i++) {
   1.228 +		float u, v;
   1.229 +		unsigned char val, ord;
   1.230 +
   1.231 +		do {
   1.232 +			u = (double)rand() / (double)RAND_MAX;
   1.233 +			v = (double)rand() / (double)RAND_MAX;
   1.234 +
   1.235 +			int x = (int)(u * umax);
   1.236 +			int y = (int)(v * vmax);
   1.237 +
   1.238 +			unsigned char *pptr = img->pixels + (y * img->width + x) * 3;
   1.239 +			val = pptr[0];
   1.240 +			ord = pptr[1];
   1.241 +		} while(val < 192);
   1.242 +
   1.243 +		smcache[i] = Vector3(u * 2.0 - 1.0, (1.0 - v * 2.0) / aspect, ord / 255.0);
   1.244 +	}
   1.245 +
   1.246 +	// then order by z
   1.247 +	std::sort(smcache, smcache + count,
   1.248 +			[](const Vector3 &a, const Vector3 &b) { return a.z < b.z; });
   1.249 +
   1.250 +	// precalculate the bounds of each slot
   1.251 +	smcache_max[0] = 0;
   1.252 +	for(int i=1; i<255; i++) {
   1.253 +		float maxval = (float)i / 255.0;
   1.254 +
   1.255 +		int idx = smcache_max[i - 1];
   1.256 +		while(++idx < count && smcache[idx].z < maxval);
   1.257 +		smcache_max[i] = idx;
   1.258 +	}
   1.259 +	smcache_max[255] = count;
   1.260 +}
   1.261 +
   1.262 +static double frand()
   1.263 +{
   1.264 +	return (double)rand() / (double)RAND_MAX;
   1.265 +}
   1.266 +
   1.267 +static float rndval(float x, float range)
   1.268 +{
   1.269 +	if(fabs(range) < 1e-6) {
   1.270 +		return x;
   1.271 +	}
   1.272 +	return x + (frand() * range - range * 0.5);
   1.273 +}
   1.274 +
   1.275 +void ParticleSystem::spawn_particle()
   1.276 +{
   1.277 +	Particle *p = palloc();
   1.278 +	p->pos = Vector3(rndval(pos.x, pp.spawn_range),
   1.279 +			rndval(pos.y, pp.spawn_range),
   1.280 +			rndval(pos.z, pp.spawn_range));
   1.281 +	p->vel = Vector3(0, 0, 0);
   1.282 +	p->color = pp.pcolor_start;
   1.283 +	p->alpha = pp.palpha_start;
   1.284 +	p->life = 0.0;
   1.285 +	p->max_life = rndval(pp.life, pp.life_range);
   1.286 +	p->size = rndval(pp.size, pp.size_range);
   1.287 +	p->scale = pp.pscale_start;
   1.288 +
   1.289 +	if(pp.spawn_map) {
   1.290 +		float maxz = pp.spawn_map_speed > 0.0 ? active_time * pp.spawn_map_speed : 1.0;
   1.291 +		int max_idx = (int)(maxz * 255.0);
   1.292 +		if(max_idx > 255) max_idx = 255;
   1.293 +		if(max_idx < 1) max_idx = 1;
   1.294 +
   1.295 +		int idx = rand() % smcache_max[max_idx];
   1.296 +
   1.297 +		p->pos.x += smcache[idx].x;
   1.298 +		p->pos.y += smcache[idx].y;
   1.299 +	}
   1.300 +
   1.301 +	p->next = plist;
   1.302 +	plist = p;
   1.303 +	++pcount;
   1.304 +}
   1.305 +
   1.306 +// particle allocator
   1.307 +#define MAX_POOL_SIZE	8192
   1.308 +static Particle *ppool;
   1.309 +static int ppool_size;
   1.310 +
   1.311 +static Particle *palloc()
   1.312 +{
   1.313 +	if(ppool) {
   1.314 +		Particle *p = ppool;
   1.315 +		ppool = ppool->next;
   1.316 +		--ppool_size;
   1.317 +		return p;
   1.318 +	}
   1.319 +	return new Particle;
   1.320 +}
   1.321 +
   1.322 +static void pfree(Particle *p)
   1.323 +{
   1.324 +	if(!p) return;
   1.325 +
   1.326 +	if(ppool_size < MAX_POOL_SIZE) {
   1.327 +		p->next = ppool;
   1.328 +		ppool = p;
   1.329 +		++ppool_size;
   1.330 +	} else {
   1.331 +		delete p;
   1.332 +	}
   1.333 +}
   1.334 +
   1.335 +static void pfreelist(Particle *p)
   1.336 +{
   1.337 +	if(!p) return;
   1.338 +
   1.339 +	Particle *it = p;
   1.340 +	int new_pool_size = ppool_size;
   1.341 +
   1.342 +	while(it->next && new_pool_size < MAX_POOL_SIZE) {
   1.343 +		it = it->next;
   1.344 +		++new_pool_size;
   1.345 +	}
   1.346 +
   1.347 +	Particle *last = it;
   1.348 +	it = it->next;
   1.349 +
   1.350 +	// add the first lot to the pool
   1.351 +	last->next = ppool;
   1.352 +	ppool = p;
   1.353 +	ppool_size = new_pool_size;
   1.354 +
   1.355 +	// delete the rest;
   1.356 +	while(it) {
   1.357 +		p = it;
   1.358 +		it = it->next;
   1.359 +		delete p;
   1.360 +	}
   1.361 +}