/* Copyright (C) 2002 W.P. van Paassen - peter@paassen.tmfweb.nl 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. You should have received a copy of the GNU General Public License along with this program; see the file COPYING. If not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /*note that the code has not been fully optimized*/ #include #include #include #include #include "tdec.h" #define NUMBER_OF_PARTICLES 500 #define SCREEN_WIDTH 480 #define SCREEN_HEIGHT 360 static Uint8 fire[SCREEN_WIDTH * SCREEN_HEIGHT]; static SDL_Color colors[256]; /*particle structure*/ typedef struct { Uint16 xpos,ypos,xdir,ydir; Uint8 colorindex; Uint8 dead; } PARTICLE; static PARTICLE particles[NUMBER_OF_PARTICLES]; void quit( int code ) { /* * Quit SDL so we can release the fullscreen * mode and restore the previous video settings, * etc. */ SDL_Quit( ); TDEC_print_fps(); /* Exit program. */ exit( code ); } void init_particle(PARTICLE* particle) { /* randomly init particles, generate them in the center of the screen */ particle->xpos = (SCREEN_WIDTH >> 1) - 20 + (int)(40.0 * (rand()/(RAND_MAX+1.0))); particle->ypos = (SCREEN_HEIGHT >> 1) - 20 + (int)(40.0 * (rand()/(RAND_MAX+1.0))); particle->xdir = -10 + (int)(20.0 * (rand()/(RAND_MAX+1.0))); particle->ydir = -17 + (int)(19.0 * (rand()/(RAND_MAX+1.0))); particle->colorindex = 255; particle->dead = 0; } void handle_key_down( SDL_keysym* keysym ) { int i; switch( keysym->sym ) { case SDLK_ESCAPE: quit( 0 ); break; case SDLK_SPACE: /* randomly init particles, generate them in the center of the screen */ for (i = 0; i < NUMBER_OF_PARTICLES; i++) { init_particle(particles + i); } break; default: break; } } void process_events( void ) { /* Our SDL event placeholder. */ SDL_Event event; /* Grab all the events off the queue. */ while( SDL_PollEvent( &event ) ) { switch( event.type ) { case SDL_KEYDOWN: /* Handle key presses. */ handle_key_down( &event.key.keysym ); break; case SDL_QUIT: /* Handle quit requests*/ quit( 0 ); break; } } } void init() { Uint32 i; /* create a suitable fire palette, this is crucial for a good effect */ /* black to blue, blue to red, red to yellow, yellow to white*/ for (i = 0; i < 32; ++i) { /* black to blue, 32 values*/ colors[i].b = i << 1; /* blue to red, 32 values*/ colors[i + 32].r = i << 3; colors[i + 32].b = 64 - (i << 1); /*red to yellow, 32 values*/ colors[i + 64].r = 255; colors[i + 64].g = i << 3; /* yellow to white, 162 */ colors[i + 96].r = 255; colors[i + 96].g = 255; colors[i + 96].b = i << 2; colors[i + 128].r = 255; colors[i + 128].g = 255; colors[i + 128].b = 64 + (i << 2); colors[i + 160].r = 255; colors[i + 160].g = 255; colors[i + 160].b = 128 + (i << 2); colors[i + 192].r = 255; colors[i + 192].g = 255; colors[i + 192].b = 192 + i; colors[i + 224].r = 255; colors[i + 224].g = 255; colors[i + 224].b = 224 + i; } SDL_SetPalette(screen, SDL_LOGPAL | SDL_PHYSPAL, colors, 0, 256); for (i = 0; i < NUMBER_OF_PARTICLES; i++) { init_particle(particles + i); } /*disable events */ for (i = 0; i < SDL_NUMEVENTS; ++i) { if (i != SDL_KEYDOWN && i != SDL_QUIT) { SDL_EventState(i, SDL_IGNORE); } } SDL_ShowCursor(SDL_DISABLE); } int main( int argc, char* argv[] ) { Uint8* image, *image_start; Uint32 buf, index, temp; int i, j; printf("\nPress Space to relive the experience!!\n"); if (argc > 1) { printf("Retro Particle Explosion Effect - W.P. van Paassen - 2002\n"); return -1; } if (!TDEC_set_video(SCREEN_WIDTH, SCREEN_HEIGHT, 8, SDL_SWSURFACE | SDL_HWPALETTE | SDL_DOUBLEBUF/* | SDL_FULLSCREEN;*/)) quit(1); TDEC_init_timer(); SDL_WM_SetCaption("Retro - Particle Explosion - ", ""); init(); /* Lock the screen for direct access to the pixels */ SDL_LockSurface(screen); image_start = (Uint8*)screen->pixels + (screen->pitch * SCREEN_HEIGHT); /*start in the right bottom corner*/ /* fill fire array with black */ memset(fire, 0, SCREEN_WIDTH * SCREEN_HEIGHT * sizeof(Uint8)); /* time based demo loop */ while( 1 ) { TDEC_new_time(); process_events(); /* move and draw particles into fire array */ for (i = 0; i < NUMBER_OF_PARTICLES; i++) { if (!particles[i].dead) { particles[i].xpos += particles[i].xdir; particles[i].ypos += particles[i].ydir; /* is particle dead? */ if ((particles[i].ypos >= SCREEN_HEIGHT - 3) || particles[i].colorindex == 0 || particles[i].xpos <= 1 || particles[i].xpos >= SCREEN_WIDTH - 3) { particles[i].dead = 1; continue; } /* gravity takes over */ particles[i].ydir++; /* particle cools off */ particles[i].colorindex--; /* draw particle */ temp = particles[i].ypos * SCREEN_WIDTH + particles[i].xpos; fire[temp] = particles[i].colorindex; fire[temp - 1] = particles[i].colorindex; fire[temp + SCREEN_WIDTH] = particles[i].colorindex; fire[temp - SCREEN_WIDTH] = particles[i].colorindex; fire[temp + 1] = particles[i].colorindex; } } /* create fire effect */ for (i = 1; i < SCREEN_HEIGHT - 2; i++) { index = (i - 1) * SCREEN_WIDTH; for (j = 1; j < SCREEN_WIDTH - 2; j++) { buf = index + j; temp = fire[buf]; temp += fire[buf + 1]; temp += fire[buf - 1]; buf += SCREEN_WIDTH; temp += fire[buf - 1]; temp += fire[buf + 1]; buf += SCREEN_WIDTH; temp += fire[buf]; temp += fire[buf + 1]; temp += fire[buf - 1]; temp >>= 3; if (temp > 4) { temp -= 4; } else { temp = 0; } fire[buf - SCREEN_WIDTH] = temp; } } image = image_start; /* draw fire array to screen from bottom to top*/ for (i = SCREEN_HEIGHT - 1; i >= 0; --i) { temp = i * SCREEN_WIDTH; for (j = SCREEN_WIDTH - 1; j >= 0; --j) { *image= fire[temp + j]; image --; } } if (TDEC_fps_ok()) SDL_Flip(screen); } return 0; /* never reached */ }