add scaling

src/camera.h

@@ -64,9 +64,7 @@ private:
       return 0.5 * (rec.normal + Color(1, 1, 1));
     }
 
-    Vec3 unit_direction = unit_vector(r.direction());
-    auto a = 0.5 * (unit_direction.y() + 1.0);
-    return (1.0 - a) * Color(1.0, 1.0, 1.0) + a * Color(0.5, 0.7, 1.0);
+    return Color(0, 0, 0);
   }
 };
 

src/main.cpp

@@ -19,9 +19,13 @@ int main() {
   std::thread render(render_thread, std::ref(buffer), std::ref(canvas));
 
   SDL_Init(SDL_INIT_VIDEO);
-  SDL_Window *window =
-      SDL_CreateWindow("Solar System", SDL_WINDOWPOS_CENTERED,
-                       SDL_WINDOWPOS_CENTERED, canvas.width, canvas.height, 0);
+  int scale = 3;
+  SDL_Window *window = SDL_CreateWindow(
+      "Solar System", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+      canvas.width * scale,  // window width
+      canvas.height * scale, // window height
+      SDL_WINDOW_RESIZABLE   // optional, allows manual resize
+  );
   SDL_Renderer *renderer =
       SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
   SDL_Texture *texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGB24,
@@ -36,7 +40,8 @@ int main() {
     SDL_UnlockTexture(texture);
 
     SDL_RenderClear(renderer);
-    SDL_RenderCopy(renderer, texture, nullptr, nullptr);
+    SDL_Rect dest = {0, 0, canvas.width * scale, canvas.height * scale};
+    SDL_RenderCopy(renderer, texture, nullptr, &dest);
     SDL_RenderPresent(renderer);
 
     SDL_Event e;

src/simulation.cpp

@@ -49,6 +49,7 @@ SimulationState initialize_solar_system() {
  */
 void simulation_thread(RingBuffer<SimulationState> &buffer) {
   SimulationState state = initialize_solar_system();
+  float BIG_G = 6.67e-11; // gravitational constant
   float dt = 0.01; // if we didnt do this it would run too fast for render
   std::chrono::duration<float> elapsed;
 
@@ -59,10 +60,7 @@ void simulation_thread(RingBuffer<SimulationState> &buffer) {
     elapsed = now - last;
 
     if (elapsed.count() >= dt) {
-      float t_0 = 0;
-      float t = t_0;
-      float dt = 86400;
-      float BIG_G = 6.67e-11; // gravitational constant
+      float bdt = 86400;
 
       size_t n_bodies = state.bodies.size();
       for (size_t m1_idx = 0; m1_idx < n_bodies; m1_idx++) {
@@ -95,21 +93,20 @@ void simulation_thread(RingBuffer<SimulationState> &buffer) {
           }
         }
 
-        state.bodies[m1_idx].velocity.x() += a_g.x() * dt;
-        state.bodies[m1_idx].velocity.y() += a_g.y() * dt;
-        state.bodies[m1_idx].velocity.z() += a_g.z() * dt;
+        state.bodies[m1_idx].velocity.x() += a_g.x() * bdt;
+        state.bodies[m1_idx].velocity.y() += a_g.y() * bdt;
+        state.bodies[m1_idx].velocity.z() += a_g.z() * bdt;
       }
 
       for (size_t entity_idx = 0; entity_idx < n_bodies; entity_idx++) {
         state.bodies[entity_idx].position.x() +=
-            state.bodies[entity_idx].velocity.x() * dt;
+            state.bodies[entity_idx].velocity.x() * bdt;
         state.bodies[entity_idx].position.y() +=
-            state.bodies[entity_idx].velocity.y() * dt;
+            state.bodies[entity_idx].velocity.y() * bdt;
         state.bodies[entity_idx].position.z() +=
-            state.bodies[entity_idx].velocity.z() * dt;
+            state.bodies[entity_idx].velocity.z() * bdt;
       }
 
-      t += dt;
       // Try to push it into the buffer
       while (!buffer.push(state)) {
         // Buffer full, drop or wait (e.g. yield or sleep)
@@ -131,7 +128,7 @@ void render_thread(RingBuffer<SimulationState> &buffer, Canvas &canvas) {
   Camera cam;
   cam.aspect_ratio = 16.0 / 9.0;
   cam.image_width = 400;
-  cam.move_to(Point3(0, 0, 100));
+  cam.move_to(Point3(0, 10, 100));
 
   while (running) {
     auto maybe_state = buffer.pop();