star-sim

platform_sdl.c (9363B)

---

 #include "platform_sdl.h"
 
 #include "sim.h"
 
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
 
 #ifndef MAP_ANONYMOUS
 #define MAP_ANONYMOUS MAP_ANON
 #endif
 
 extern bool PAUSED;
 extern bool BRUTE_FORCE;
 extern bool RENDER_GRID;
 extern bool RENDER_BOUNDING_BOX;
 extern bool RENDER_TRAILS;
 
 static struct SDLOffscreenBuffer global_back_buffer;
 
 
 struct SDLWindowDimension sdl_get_window_dimension(SDL_Window *window)
 {
     struct SDLWindowDimension result;
     SDL_GetWindowSize(window, &result.width, &result.height);
     return(result);
 }
 
 
 void sdl_resize_texture(struct SDLOffscreenBuffer *buffer, SDL_Renderer *renderer, int width, int height)
 {
     if (buffer->memory)
     {
         free(buffer->memory);
     }
 
     if (buffer->texture)
     {
         SDL_DestroyTexture(buffer->texture);
     }
 
     buffer->texture = SDL_CreateTexture(
             renderer,
             SDL_PIXELFORMAT_ARGB8888,
             SDL_TEXTUREACCESS_STREAMING,
             width, height);
 
     buffer->width = width;
     buffer->height = height;
     buffer->pitch = width * BYTES_PER_PIXEL;
 
     buffer->memory = malloc(width * height * BYTES_PER_PIXEL);
 }
 
 
 void sdl_update_window(SDL_Renderer *renderer, struct SDLOffscreenBuffer *buffer)
 {
     if (SDL_UpdateTexture(buffer->texture, 0, buffer->memory, buffer->pitch))
     {
         // TODO(amin): Handle this error
     }
 
     SDL_RenderCopy(renderer, buffer->texture, 0, 0);
     SDL_RenderPresent(renderer);
 }
 
 
 void clear_screen(struct SDLOffscreenBuffer *buffer, uint32_t pixel_value)
 {
     // NOTE(amin): Memset is faster than nested for loops, but can only set
     // pixels to single byte values
     memset(buffer->memory, pixel_value, buffer->height * buffer->width * BYTES_PER_PIXEL);
 }
 
 
 bool handle_event(SDL_Event *event)
 {
     bool should_quit = false;
 
     switch(event->type)
     {
         case SDL_QUIT:
         {
             printf("SDL_QUIT\n");
             should_quit = true;
         } break;
 
         case SDL_KEYDOWN:
         case SDL_KEYUP:
         {
             SDL_Keycode key_code = event->key.keysym.sym;
             bool is_down = (event->key.state == SDL_PRESSED);
             if (is_down)
             {
                 if (key_code == SDLK_b)
                 {
                     RENDER_BOUNDING_BOX = !RENDER_BOUNDING_BOX;
                 }
                 if (key_code == SDLK_f)
                 {
                     BRUTE_FORCE = !BRUTE_FORCE;
                 }
                 if (key_code == SDLK_g)
                 {
                     RENDER_GRID = !RENDER_GRID;
                 }
                 if (key_code == SDLK_p)
                 {
                     PAUSED = !PAUSED;
                 }
                 if (key_code == SDLK_t)
                 {
                     RENDER_TRAILS = !RENDER_TRAILS;
                     clear_screen(&global_back_buffer, COLOR_BACKGROUND);
                 }
             }
         } break;
         case SDL_WINDOWEVENT:
         {
             switch(event->window.event)
             {
                 case SDL_WINDOWEVENT_SIZE_CHANGED:
                 {
                     SDL_Window *window = SDL_GetWindowFromID(event->window.windowID);
                     SDL_Renderer *renderer = SDL_GetRenderer(window);
                     printf("SDL_WINDOWEVENT_SIZE_CHANGED (%d, %d)\n", event->window.data1, event->window.data2);
                     sdl_resize_texture(&global_back_buffer, renderer, event->window.data1, event->window.data2);
                 } break;
 
                 case SDL_WINDOWEVENT_FOCUS_GAINED:
                 {
                     printf("SDL_WINDOWEVENT_FOCUS_GAINED\n");
                 } break;
 
                 case SDL_WINDOWEVENT_EXPOSED:
                 {
                     SDL_Window *window = SDL_GetWindowFromID(event->window.windowID);
                     SDL_Renderer *renderer = SDL_GetRenderer(window);
                     sdl_update_window(renderer, &global_back_buffer);
                 } break;
             }
         } break;
     }
     return(should_quit);
 }
 
 
 int main(int argc, char *argv[])
 {
     if (SDL_Init(SDL_INIT_VIDEO))
     {
         // TODO(amin): log SDL_Init error
     }
 
     SDL_Window *window = SDL_CreateWindow(
             TITLE,
             SDL_WINDOWPOS_UNDEFINED,
             SDL_WINDOWPOS_UNDEFINED,
             SCREEN_WIDTH,
             SCREEN_HEIGHT,
             SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
 
 #ifdef FULLSCREEN
     SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN_DESKTOP);
 #endif
 
     if (window)
     {
         SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, 0);
 
         if (renderer)
         {
             struct SDLWindowDimension dimension = sdl_get_window_dimension(window);
             sdl_resize_texture(&global_back_buffer, renderer, dimension.width, dimension.height);
 
             bool running = true;
 
 #ifdef USE_TEST_SEED
             srand((uint32_t)0);
 #else
             srand((uint32_t)time(NULL));
 #endif
 
             uint64_t lag = 0;
             uint64_t previous_ms = (SDL_GetPerformanceCounter() * SECOND) / SDL_GetPerformanceFrequency();
 
             struct SimState sim_state;
             sim_init(&sim_state, dimension.width, dimension.height);
 
             while (running)
             {
                 uint64_t current_ms = (SDL_GetPerformanceCounter() * SECOND) / SDL_GetPerformanceFrequency();
                 uint64_t elapsed_ms = current_ms - previous_ms;
                 previous_ms = current_ms;
                 lag += elapsed_ms;
                 //printf("%" PRIu64 ", %" PRIu64 ", %f\n", elapsed_ms, lag, MS_PER_UPDATE);
 
                 SDL_Event event;
 
                 while (SDL_PollEvent(&event))
                 {
                     running = !handle_event(&event);
                 }
 
                 SDL_PumpEvents();
 
                 dimension = sdl_get_window_dimension(window);
 
                 const uint8_t *keystate = SDL_GetKeyboardState(0);
 
                 // TODO: move this to a function
                 if (keystate[SDL_SCANCODE_A] || keystate[SDL_SCANCODE_H])
                 {
                     sim_state.view.dx += 5 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_D] || keystate[SDL_SCANCODE_L])
                 {
                     sim_state.view.dx -= 5 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_W] || keystate[SDL_SCANCODE_K])
                 {
                     sim_state.view.dy += 5 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_S] || keystate[SDL_SCANCODE_J])
                 {
                     sim_state.view.dy -= 5 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_LEFT])
                 {
                     sim_state.view.dx += 1 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_RIGHT])
                 {
                     sim_state.view.dx -= 1 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_UP])
                 {
                     sim_state.view.dy += 1 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_DOWN])
                 {
                     sim_state.view.dy -= 1 / sim_state.view.zoom;
                 }
                 if (keystate[SDL_SCANCODE_EQUALS])
                 {
                     sim_state.view.zoom *= 1.01;
                 }
                 if (keystate[SDL_SCANCODE_MINUS])
                 {
                     sim_state.view.zoom *= 0.99;
                 }
                 if (keystate[SDL_SCANCODE_0])
                 {
                     sim_state.view.zoom = 1;
                 }
                 if (keystate[SDL_SCANCODE_HOME])
                 {
                     sim_state.view.dx = 0;
                     sim_state.view.dy = 0;
                     sim_state.view.zoom = 1;
                 }
 
                 struct OffscreenBuffer buffer;
                 // WARNING: these pointers are aliased until the end of the
                 // loop
                 buffer.memory = global_back_buffer.memory;
                 buffer.width = global_back_buffer.width;
                 buffer.height = global_back_buffer.height;
                 buffer.pitch = global_back_buffer.pitch;
 
                 if (PAUSED)
                 {
                     lag = 0;
                 }
                 else
                 {
                     while (lag >= MS_PER_UPDATE)
                     {
                         sim_update(&sim_state, buffer.width, buffer.height);
                         //printf("\t%" PRIu64 ", %f\n", lag, MS_PER_UPDATE);
                         lag -= MS_PER_UPDATE;
                     }
                 }
 
                 if (!RENDER_TRAILS)
                 {
                     clear_screen(&global_back_buffer, COLOR_BACKGROUND);
                 }
 
                 sim_render(&buffer, lag/SECOND, &sim_state);
                 sdl_update_window(renderer, &global_back_buffer);
                 if (elapsed_ms <= MS_PER_FRAME)
                 {
                     SDL_Delay(MS_PER_FRAME - elapsed_ms);
                 }
             }
 
             sim_cleanup(&sim_state);
         }
         else
         {
             // TODO(amin): log SDL_Renderer error
         }
     }
     else
     {
         // TODO(amin): log SDL_Window error
     }
 
     SDL_Quit();
     return(0);
 }