commit 4fecc146a3b1a70830a7aafad2097fdcd4e5081a
parent 01eaf683a4811b49a6e7645d036e15ec8bdc9d54
Author: amin <dev@aminmesbah.com>
Date: Fri, 24 Mar 2017 02:31:29 +0000
Add gravity related physics.
FossilOrigin-Name: ad88a31f80fd65e0b4e32ed5e6f25b8e4232c89a1376f0093da93b337bf7d3f5
Diffstat:
| M | .gitignore | | | 2 | +- |
| M | Makefile | | | 4 | ++-- |
| A | main.cpp | | | 355 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | star.h | | | 64 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| D | stars.cpp | | | 355 | ------------------------------------------------------------------------------- |
5 files changed, 422 insertions(+), 358 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -1,2 +1,2 @@
-stars
+star-garden
*.swp
diff --git a/Makefile b/Makefile
@@ -1,7 +1,7 @@
build:
- g++ -std=c++11 -Wall -Wextra -g stars.cpp -o stars `sdl2-config --cflags --libs`
+ g++ -std=c++11 -Wall -Wextra -g main.cpp -o star-garden `sdl2-config --cflags --libs`
run:
- ./stars
+ ./star-garden
test: build run
diff --git a/main.cpp b/main.cpp
@@ -0,0 +1,355 @@
+#include <cmath>
+#include <inttypes.h>
+#include <SDL.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <time.h>
+#include "star.h"
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#define TITLE "Stars"
+#define SCREEN_WIDTH 640
+#define SCREEN_HEIGHT 480
+#define BYTES_PER_PIXEL 4
+#define NUM_STARS 200
+#define DRAG 0.9999
+
+#define SECOND 1000.0f
+#define FPS 60
+#define MS_PER_FRAME (SECOND / FPS)
+#define UPDATES_PER_SECOND 120
+#define MS_PER_UPDATE (SECOND / UPDATES_PER_SECOND)
+
+#define COLOR_WHITE 0xFFFFFF
+#define COLOR_BLACK 0x000000
+#define COLOR_SOL_BG 0x002B36
+#define COLOR_YELLOW 0xB58900
+#define COLOR_ORANGE 0xCB4B16
+#define COLOR_RED 0xDC322F
+#define COLOR_MAGENTA 0xD33682
+#define COLOR_VIOLET 0x6C71C4
+#define COLOR_BLUE 0x268bD2
+#define COLOR_CYAN 0x2AA198
+#define COLOR_GREEN 0x859900
+#define COLOR_BACKGROUND COLOR_BLACK
+
+enum color_t
+{
+ YELLOW,
+ ORANGE,
+ RED,
+ MAGENTA,
+ VIOLET,
+ BLUE,
+ CYAN,
+ GREEN,
+ NUM_COLORS,
+};
+
+struct SDLOffscreenBuffer
+{
+ // NOTE(amin): pixels are always 32-bits wide. Memory order: BB GG RR XX.
+ SDL_Texture *texture;
+ void *memory;
+ int width;
+ int height;
+ int pitch;
+};
+
+struct SDLWindowDimension
+{
+ int width;
+ int height;
+};
+
+
+static SDLOffscreenBuffer global_back_buffer;
+
+
+SDLWindowDimension sdl_get_window_dimension(SDL_Window *window)
+{
+ SDLWindowDimension result;
+ SDL_GetWindowSize(window, &result.width, &result.height);
+ return(result);
+}
+
+
+void sdl_resize_texture(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_Window *window, SDL_Renderer *renderer, 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);
+}
+
+
+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_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(window, renderer, global_back_buffer);
+ } break;
+ }
+ } break;
+ }
+ return(should_quit);
+}
+
+
+// TODO: change buffer to a pointer
+void set_pixel(SDLOffscreenBuffer buffer, uint32_t x, uint32_t y, uint32_t color)
+{
+ /* Origin is (0, 0) on the upper left.
+ * To go one pixel right, increment by 32 bits.
+ * To go one pixel down, increment by (buffer.width * 32) bits.
+ */
+ if (x < buffer.width && y < buffer.height)
+ {
+ uint8_t *pixel_pos = (uint8_t *)buffer.memory;
+ pixel_pos += ((BYTES_PER_PIXEL*x) + (buffer.pitch * y));
+ uint32_t *pixel = (uint32_t *)pixel_pos;
+ *pixel = color;
+ }
+}
+
+// TODO: change buffer to a pointer
+void clear_screen(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);
+}
+
+
+void update(Star stars[], int num_stars, SDLWindowDimension* dimension)
+{
+ for (int i = 0; i < num_stars; ++i)
+ {
+ for (int j = i + 1; j < num_stars; ++j)
+ {
+ star_attract(&stars[i], &stars[j]);
+ }
+ stars[i].x += sinf(stars[i].angle) * stars[i].speed;
+ stars[i].y -= cosf(stars[i].angle) * stars[i].speed;
+ //printf("%d: (%f, %f)\n", i, stars[i].x, stars[i].y);
+
+ stars[i].speed *= DRAG;
+ if (stars[i].x > dimension->width)
+ {
+ stars[i].x = 0;
+ }
+ else if (stars[i].x < 0)
+ {
+ stars[i].x = dimension->width;
+ }
+
+ if (stars[i].y > dimension->height)
+ {
+ stars[i].y = 0;
+ }
+ else if (stars[i].y < 0)
+ {
+ stars[i].y = dimension->height;
+ }
+ }
+}
+
+void render(SDLOffscreenBuffer buffer, float dt, Star stars[], int num_stars)
+{
+ //printf("%f\n", dt);
+ for (int i = 0; i < num_stars; ++i)
+ {
+ set_pixel(
+ buffer,
+ stars[i].x + (sinf(stars[i].angle) * stars[i].speed) * dt,
+ stars[i].y + (cosf(stars[i].angle) * stars[i].speed) * dt,
+ stars[i].color);
+ }
+}
+
+
+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);
+ //SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN_DESKTOP);
+
+ if (window)
+ {
+ SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, 0);
+
+ if (renderer)
+ {
+ SDLWindowDimension dimension = sdl_get_window_dimension(window);
+ sdl_resize_texture(&global_back_buffer, renderer, dimension.width, dimension.height);
+
+ bool running = true;
+ srand((uint32_t)time(NULL));
+
+ uint64_t lag = 0;
+ uint64_t previous_ms = (SDL_GetPerformanceCounter() * SECOND) / SDL_GetPerformanceFrequency();
+ Star stars[NUM_STARS];
+ for (int i = 0; i < NUM_STARS; ++i)
+ {
+ stars[i].x = rand() % dimension.width;
+ stars[i].y = rand() % dimension.height;
+ stars[i].angle = ((float)rand()/(float)(RAND_MAX)) * 2 * M_PI;
+ stars[i].speed = 0.1;
+ stars[i].mass = 1;
+ stars[i].size = star_calc_size(stars[i].mass);
+ stars[i].color = COLOR_WHITE;
+
+ //enum color_t color = (color_t)(rand() % NUM_COLORS);
+ //switch(color)
+ //{
+ // case YELLOW:
+ // stars[i].color = COLOR_YELLOW;
+ // break;
+ // case ORANGE:
+ // stars[i].color = COLOR_ORANGE;
+ // break;
+ // case RED:
+ // stars[i].color = COLOR_RED;
+ // break;
+ // case MAGENTA:
+ // stars[i].color = COLOR_MAGENTA;
+ // break;
+ // case VIOLET:
+ // stars[i].color = COLOR_VIOLET;
+ // break;
+ // case BLUE:
+ // stars[i].color = COLOR_BLUE;
+ // break;
+ // case CYAN:
+ // stars[i].color = COLOR_CYAN;
+ // break;
+ // case GREEN:
+ // stars[i].color = COLOR_GREEN;
+ // break;
+ // default:
+ // stars[i].color = COLOR_WHITE;
+ // break;
+ //}
+ //printf("%f, %f, %f, %f, %f\n", stars[i].angle, sinf(stars[i].angle), cosf(stars[i].angle), stars[i].speed, stars[i].mass);
+ }
+
+ 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("Lag: %d\n", lag);
+ //printf("%" PRIu64 ", %f\n", lag, MS_PER_UPDATE);
+
+ SDL_Event event;
+
+ while (SDL_PollEvent(&event))
+ {
+ running = !handle_event(&event);
+ }
+
+ SDL_PumpEvents();
+
+ dimension = sdl_get_window_dimension(window);
+
+ while (lag >= MS_PER_UPDATE)
+ {
+ update(stars, NUM_STARS, &dimension);
+ //printf("\t%" PRIu64 ", %f\n", lag, MS_PER_UPDATE);
+ lag -= MS_PER_UPDATE;
+ }
+ clear_screen(global_back_buffer, COLOR_BACKGROUND);
+ render(global_back_buffer, lag/SECOND, stars, NUM_STARS);
+ sdl_update_window(window, renderer, global_back_buffer);
+ if (elapsed_ms <= MS_PER_FRAME)
+ {
+ SDL_Delay(MS_PER_FRAME - elapsed_ms);
+ }
+ }
+ }
+ else
+ {
+ // TODO(amin): log SDL_Renderer error
+ }
+ }
+ else
+ {
+ // TODO(amin): log SDL_Window error
+ }
+
+ SDL_Quit();
+ return(0);
+}
diff --git a/star.h b/star.h
@@ -0,0 +1,64 @@
+#ifndef STAR_H
+#define STAR_H
+
+#include <math.h>
+#include <stdint.h>
+
+#define GRAVITATION 0.1f
+
+struct Star
+{
+ float angle;
+ float speed;
+ float mass;
+ float size;
+ double x;
+ double y;
+ uint32_t color;
+};
+
+struct Vec2d
+{
+ float angle;
+ float length;
+};
+
+Vec2d *vec2d_add(float angle1, float length1, float angle2, float length2)
+{
+ float x = sinf(angle1) * length1 + sinf(angle2) * length2;
+ float y = cosf(angle1) * length1 + cosf(angle2) * length2;
+
+ Vec2d *new_vec = (Vec2d*)malloc(sizeof(Vec2d));
+ new_vec->angle = 0.5 * M_PI - atan2f(y, x);
+ new_vec->length = hypotf(x, y);
+ return new_vec;
+}
+
+void star_accelerate(Star *s, float angle, float acceleration)
+{
+ Vec2d *new_vec = vec2d_add(s->angle, s->speed, angle, acceleration);
+ s->angle = new_vec->angle;
+ s->speed = new_vec->length;
+ free(new_vec);
+}
+
+float star_calc_size(float mass)
+{
+ return 0.5 * (powf(mass, 0.5));
+}
+
+void star_attract(Star *s1, Star *s2)
+{
+ float dx = s1->x - s2->x;
+ float dy = s1->y - s2->y;
+ float distance = hypotf(dx, dy);
+
+ if (distance > s1->size + s2->size)
+ {
+ float theta = atan2f(dy, dx);
+ float force = GRAVITATION * (s1->mass * s2->mass / powf(distance, 2));
+ star_accelerate(s1, theta - (0.5 * M_PI), force / s1->mass);
+ star_accelerate(s2, theta + (0.5 * M_PI), force / s2->mass);
+ }
+}
+#endif
diff --git a/stars.cpp b/stars.cpp
@@ -1,355 +0,0 @@
-#include <cmath>
-#include <inttypes.h>
-#include <SDL.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <string.h>
-#include <time.h>
-
-#ifndef MAP_ANONYMOUS
-#define MAP_ANONYMOUS MAP_ANON
-#endif
-
-#define TITLE "Stars"
-#define SCREEN_WIDTH 640
-#define SCREEN_HEIGHT 480
-#define BYTES_PER_PIXEL 4
-#define NUM_STARS 10000
-
-#define SECOND 1000.0f
-#define FPS 60
-#define MS_PER_FRAME (SECOND / FPS)
-#define UPDATES_PER_SECOND 120
-#define MS_PER_UPDATE (SECOND / UPDATES_PER_SECOND)
-
-#define COLOR_WHITE 0xFFFFFF
-#define COLOR_BLACK 0x000000
-#define COLOR_SOL_BG 0x002B36
-#define COLOR_YELLOW 0xB58900
-#define COLOR_ORANGE 0xCB4B16
-#define COLOR_RED 0xDC322F
-#define COLOR_MAGENTA 0xD33682
-#define COLOR_VIOLET 0x6C71C4
-#define COLOR_BLUE 0x268bD2
-#define COLOR_CYAN 0x2AA198
-#define COLOR_GREEN 0x859900
-#define COLOR_BACKGROUND COLOR_BLACK
-
-enum color_t
-{
- YELLOW,
- ORANGE,
- RED,
- MAGENTA,
- VIOLET,
- BLUE,
- CYAN,
- GREEN,
- NUM_COLORS,
-};
-
-struct SDLOffscreenBuffer
-{
- // NOTE(amin): pixels are always 32-bits wide. Memory order: BB GG RR XX.
- SDL_Texture *texture;
- void *memory;
- int width;
- int height;
- int pitch;
-};
-
-struct SDLWindowDimension
-{
- int width;
- int height;
-};
-
-struct Star
-{
- float angle;
- float speed;
- float mass;
- double x;
- double y;
- uint32_t color;
-};
-
-static SDLOffscreenBuffer global_back_buffer;
-
-
-SDLWindowDimension sdl_get_window_dimension(SDL_Window *window)
-{
- SDLWindowDimension result;
- SDL_GetWindowSize(window, &result.width, &result.height);
- return(result);
-}
-
-
-void sdl_resize_texture(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_Window *window, SDL_Renderer *renderer, 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);
-}
-
-
-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_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(window, renderer, global_back_buffer);
- } break;
- }
- } break;
- }
- return(should_quit);
-}
-
-
-// TODO: change buffer to a pointer
-void set_pixel(SDLOffscreenBuffer buffer, uint32_t x, uint32_t y, uint32_t color)
-{
- /* Origin is (0, 0) on the upper left.
- * To go one pixel right, increment by 32 bits.
- * To go one pixel down, increment by (buffer.width * 32) bits.
- */
- if (x < buffer.width && y < buffer.height)
- {
- uint8_t *pixel_pos = (uint8_t *)buffer.memory;
- pixel_pos += ((BYTES_PER_PIXEL*x) + (buffer.pitch * y));
- uint32_t *pixel = (uint32_t *)pixel_pos;
- *pixel = color;
- }
-}
-
-// TODO: change buffer to a pointer
-void clear_screen(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);
-}
-
-
-void update(Star stars[], int num_stars, SDLWindowDimension* dimension)
-{
- for (int i = 0; i < num_stars; ++i)
- {
- stars[i].x += sinf(stars[i].angle) * stars[i].speed;
- stars[i].y += cosf(stars[i].angle) * stars[i].speed;
-
- if (stars[i].x > dimension->width)
- {
- stars[i].x = 0;
- }
- else if (stars[i].x < 0)
- {
- stars[i].x = dimension->width;
- }
-
- if (stars[i].y > dimension->height)
- {
- stars[i].y = 0;
- }
- else if (stars[i].y < 0)
- {
- stars[i].y = dimension->height;
- }
- }
-}
-
-void render(SDLOffscreenBuffer buffer, float dt, Star stars[], int num_stars)
-{
- //printf("%f\n", dt);
- for (int i = 0; i < num_stars; ++i)
- {
- set_pixel(
- buffer,
- stars[i].x + (sinf(stars[i].angle) * stars[i].speed) * dt,
- stars[i].y + (cosf(stars[i].angle) * stars[i].speed) * dt,
- stars[i].color);
- }
-}
-
-
-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);
- //SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN_DESKTOP);
-
- if (window)
- {
- SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, 0);
-
- if (renderer)
- {
- SDLWindowDimension dimension = sdl_get_window_dimension(window);
- sdl_resize_texture(&global_back_buffer, renderer, dimension.width, dimension.height);
-
- bool running = true;
- srand((uint32_t)time(NULL));
-
- uint64_t lag = 0;
- uint64_t previous_ms = (SDL_GetPerformanceCounter() * SECOND) / SDL_GetPerformanceFrequency();
- Star stars[NUM_STARS];
- for (int i = 0; i < NUM_STARS; ++i)
- {
- stars[i].x = rand() % dimension.width;
- stars[i].y = rand() % dimension.height;
- stars[i].angle = ((float)rand()/(float)(RAND_MAX)) * 2 * M_PI;
- stars[i].speed = 0.1;
- stars[i].mass = 10;
- stars[i].color = COLOR_WHITE;
-
- //enum color_t color = (color_t)(rand() % NUM_COLORS);
- //switch(color)
- //{
- // case YELLOW:
- // stars[i].color = COLOR_YELLOW;
- // break;
- // case ORANGE:
- // stars[i].color = COLOR_ORANGE;
- // break;
- // case RED:
- // stars[i].color = COLOR_RED;
- // break;
- // case MAGENTA:
- // stars[i].color = COLOR_MAGENTA;
- // break;
- // case VIOLET:
- // stars[i].color = COLOR_VIOLET;
- // break;
- // case BLUE:
- // stars[i].color = COLOR_BLUE;
- // break;
- // case CYAN:
- // stars[i].color = COLOR_CYAN;
- // break;
- // case GREEN:
- // stars[i].color = COLOR_GREEN;
- // break;
- // default:
- // stars[i].color = COLOR_WHITE;
- // break;
- //}
- //printf("%f, %f, %f, %f, %f\n", stars[i].angle, sinf(stars[i].angle), cosf(stars[i].angle), stars[i].speed, stars[i].mass);
- }
-
- 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("Lag: %d\n", lag);
- //printf("%" PRIu64 ", %f\n", lag, MS_PER_UPDATE);
-
- SDL_Event event;
-
- while (SDL_PollEvent(&event))
- {
- running = !handle_event(&event);
- }
-
- SDL_PumpEvents();
-
- dimension = sdl_get_window_dimension(window);
-
- while (lag >= MS_PER_UPDATE)
- {
- update(stars, NUM_STARS, &dimension);
- //printf("\t%" PRIu64 ", %f\n", lag, MS_PER_UPDATE);
- lag -= MS_PER_UPDATE;
- }
- clear_screen(global_back_buffer, COLOR_BACKGROUND);
- render(global_back_buffer, lag/SECOND, stars, NUM_STARS);
- sdl_update_window(window, renderer, global_back_buffer);
- if (elapsed_ms <= MS_PER_FRAME)
- {
- SDL_Delay(MS_PER_FRAME - elapsed_ms);
- }
- }
- }
- else
- {
- // TODO(amin): log SDL_Renderer error
- }
- }
- else
- {
- // TODO(amin): log SDL_Window error
- }
-
- SDL_Quit();
- return(0);
-}
