src/SDL2_particles.c

   1 #include "SDL2_particles.h"
   2
   3 void basic_particle_init(particle_t *p)
   4 {
   5         p->x = 0;
   6         p->y = 0;
   7 }
   8
   9 void basic_particle_move(particle_t *p)
  10 {
  11         float x = p->x;
  12         float y = p->y;
  13         Sint32 ttl = p->ttl--;
  14         Uint8 size = p->size;
  15         float spd = p->spd;
  16         float a = p->ang;
  17         float c = cosf(a * M_PI / 180);
  18         float s = sinf(a * M_PI / 180);
  19         float nx = x + spd * c;
  20         float ny = y + spd * s;
  21         p->x = nx;
  22         p->y = ny;
  23         x = nx;
  24         y = ny;
  25 }
  26 void basic_particle_reset(particle_t *p)
  27 {
  28 #if 0
  29                 p->x = rand() % 120;
  30                 p->y = rand() % 120;
  31                 p->ttl = 20 + rand() % 100;
  32                 p->spd = 1;
  33                 p->ang = 45 + rand() % 90 ;
  34                 p->size = 2;
  35 #else
  36                 p->x = 0;
  37                 p->y = 0;
  38                 p->ttl = rand() % 80 ;//+ rand() % 20;
  39                 p->spd = 1;
  40                 p->ang = rand() % 30 - 90 - 15;
  41                 p->size = 2;
  42 #endif
  43 }
  44
  45 void PS_Update(particle_system *ps) {
  46         int i;
  47         int done = 0;
  48         for (i = 0; i < PARTICLES_PER_SYSTEM; i++) {
  49                 ps->move(&ps->particle[i]);
  50                 if (ps->particle[i].ttl <= 0) {
  51                         if (ps->spawn < ps->limit) {
  52                                 ps->reset(&ps->particle[i]);
  53                                 ps->spawn++;
  54                         } else done++;
  55                 }
  56         }
  57         if (done >= PARTICLES_PER_SYSTEM) {
  58                 ps->limit = 0;
  59         }
  60 }
  61
  62 void PS_Render(SDL_Renderer *target, particle_system *ps, SDL_Color *colors, int num_colors, Uint32 bx, Uint32 by) {
  63
  64         int i, j;
  65         int colorquant = PARTICLES_PER_SYSTEM / num_colors;
  66         for (i = 0; i < PARTICLES_PER_SYSTEM; i++) {
  67                 Uint32 x = ps->particle[i].x;
  68                 Uint32 y = ps->particle[i].y;
  69                 Sint32 ttl = ps->particle[i].ttl--;
  70                 Uint8 size = ps->particle[i].size;
  71                 if (ttl <= 0) continue;
  72                 j = i % colorquant;
  73                 //Uint32 color = SDL_MapRGB(surface->format, reds[j].r, reds[j].g, reds[j].b);
  74                 //-//SDL_AlphaFill(surface, bx + x, by + y, size, size, color);
  75                 //-SDL_PutPixel(surface, bx + x, by + y, color+ttl);
  76         SDL_SetRenderDrawColor(target, colors[j].r, colors[j].g, colors[j].b, 0);
  77                 SDL_RenderDrawPoint(target, bx + x, by + y);
  78         }
  79 }