commit 1fda0881eb5d297cb202289501b27734f7151ac6
parent 0ac5616992d1fd7b57126b531072ef2c89e5dce7
Author: amin <dev@aminmesbah.com>
Date: Sun, 30 Jul 2017 00:56:06 +0000
Move sim state related code out of platform layer.
The `SimState` struct encapsulates all the state information necessary
for updating and rendering. The platform layer just needs to declare a
`SimState` and call various functions on it. It doesn't need to know
about stars or quadtrees or any other simulated entity.
FossilOrigin-Name: 86127fbe437d62ad2ddda4bef66a97f2e909d43b847148fc33dd7fd82b4e04d3
Diffstat:
3 files changed, 101 insertions(+), 43 deletions(-)
diff --git a/src/platform_sdl.c b/src/platform_sdl.c
@@ -188,20 +188,9 @@ int main(void)
uint64_t lag = 0;
uint64_t previous_ms = (SDL_GetPerformanceCounter() * SECOND) / SDL_GetPerformanceFrequency();
- struct 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;
- stars[i].mass = 5;
- stars[i].size = star_calc_size(stars[i].mass);
- stars[i].color = COLOR_WHITE;
- //printf("%f, %f, %f\n", stars[i].angle, stars[i].speed, stars[i].mass);
- }
- struct QuadTree *qt = quad_tree_init();
+ struct SimState sim_state;
+ sim_init(&sim_state, dimension.width, dimension.height);
while (running)
{
@@ -222,7 +211,8 @@ int main(void)
dimension = sdl_get_window_dimension(window);
struct OffscreenBuffer buffer;
- // these pointers are now aliased
+ // 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;
@@ -236,7 +226,7 @@ int main(void)
{
while (lag >= MS_PER_UPDATE)
{
- update(buffer.width, buffer.height, stars, NUM_STARS, qt);
+ sim_update(&sim_state, buffer.width, buffer.height);
//printf("\t%" PRIu64 ", %f\n", lag, MS_PER_UPDATE);
lag -= MS_PER_UPDATE;
}
@@ -247,7 +237,7 @@ int main(void)
clear_screen(&global_back_buffer, COLOR_BACKGROUND);
}
- render(&buffer, lag/SECOND, stars, NUM_STARS, qt);
+ sim_render(&buffer, lag/SECOND, &sim_state);
sdl_update_window(renderer, &global_back_buffer);
if (elapsed_ms <= MS_PER_FRAME)
{
@@ -255,7 +245,7 @@ int main(void)
}
}
- quad_tree_free(qt);
+ sim_cleanup(&sim_state);
}
else
{
diff --git a/src/star_garden.c b/src/star_garden.c
@@ -5,12 +5,40 @@ bool BRUTE_FORCE = false;
bool RENDER_GRID = false;
bool RENDER_TRAILS = false;
-void update(int field_width,
- int field_height,
- struct Star stars[],
- int num_stars,
- struct QuadTree *qt)
+
+void sim_init(struct SimState *sim_state, int field_width, int field_height)
{
+ if (!sim_state)
+ {
+ // TODO: handle invalid pointer error
+ return;
+ }
+
+ sim_state->num_stars = NUM_STARS;
+ for (int i = 0; i < sim_state->num_stars; ++i)
+ {
+ struct Star *star = &sim_state->stars[i];
+ star->x = rand() % field_width;
+ star->y = rand() % field_height;
+ star->angle = ((float)rand()/(float)(RAND_MAX)) * 2 * M_PI;
+ star->speed = 0;
+ star->mass = 5;
+ star->size = star_calc_size(star->mass);
+ star->color = COLOR_WHITE;
+ //printf("%f, %f, %f\n", star->angle, star->speed, star->mass);
+ }
+ sim_state->qt = quad_tree_init();
+}
+
+
+void sim_update(struct SimState *sim_state, int field_width, int field_height)
+{
+ if (!sim_state)
+ {
+ // TODO: handle invalid pointer error
+ return;
+ }
+
// TODO: either limit the bounds of the simulation, or base these values on
// the smallest bounding rectangle
int center_x = field_width / 2;
@@ -18,6 +46,10 @@ void update(int field_width,
int dist_x = field_width / 2;
int dist_y = field_height / 2;
+ int num_stars = sim_state->num_stars;
+ struct Star *stars = sim_state->stars;
+ struct QuadTree *qt = sim_state->qt;
+
if (BRUTE_FORCE)
{
for (int i = 0; i < num_stars; ++i)
@@ -62,19 +94,23 @@ void update(int field_width,
}
-void render(
- struct OffscreenBuffer *buffer,
- float dt,
- struct Star stars[],
- int num_stars,
- struct QuadTree *qt)
+void sim_render(struct OffscreenBuffer *buffer, float dt, struct SimState *sim_state)
{
+ if (!buffer || !sim_state)
+ {
+ // TODO: handle invalid pointer error
+ return;
+ }
+
+ int num_stars = sim_state->num_stars;
+ struct Star *stars = sim_state->stars;
+ struct QuadTree *qt = sim_state->qt;
//printf("%f\n", dt);
if (BRUTE_FORCE)
{
for (int i = 0; i < num_stars; ++i)
{
- set_pixel(
+ sim_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,
@@ -85,7 +121,7 @@ void render(
{
for (int i = 0; i < num_stars; ++i)
{
- set_pixel(
+ sim_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,
@@ -95,13 +131,19 @@ void render(
if (RENDER_GRID)
{
- draw_grid(buffer, qt->root, COLOR_GREEN);
+ sim_render_grid(buffer, qt->root, COLOR_GREEN);
}
}
-void set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t color)
+void sim_set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t color)
{
+ if (!buffer)
+ {
+ // TODO: handle invalid pointer error
+ return;
+ }
+
/* 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.
@@ -116,27 +158,45 @@ void set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t
}
-void draw_grid(struct OffscreenBuffer *buffer, struct QuadTreeNode *node, uint32_t color)
+void sim_render_grid(struct OffscreenBuffer *buffer, struct QuadTreeNode *node, uint32_t color)
{
+ if (!buffer)
+ {
+ // TODO: handle invalid pointer error
+ return;
+ }
+
if (node && node->ne && node->nw && node->sw && node->se)
{
for (int x = (node->cell->center_x - node->cell->distance_x);
x <= (node->cell->center_x + node->cell->distance_x);
++x)
{
- set_pixel(buffer, x, node->cell->center_y, color);
+ sim_set_pixel(buffer, x, node->cell->center_y, color);
}
for (int y = (node->cell->center_y - node->cell->distance_y);
y <= (node->cell->center_y + node->cell->distance_y);
++y)
{
- set_pixel(buffer, node->cell->center_x, y, color);
+ sim_set_pixel(buffer, node->cell->center_x, y, color);
}
- draw_grid(buffer, node->ne, color);
- draw_grid(buffer, node->nw, color);
- draw_grid(buffer, node->sw, color);
- draw_grid(buffer, node->se, color);
+ sim_render_grid(buffer, node->ne, color);
+ sim_render_grid(buffer, node->nw, color);
+ sim_render_grid(buffer, node->sw, color);
+ sim_render_grid(buffer, node->se, color);
}
}
+
+
+void sim_cleanup(struct SimState *sim_state)
+{
+ if (!sim_state)
+ {
+ // TODO: handle invalid pointer error
+ return;
+ }
+
+ quad_tree_free(sim_state->qt);
+}
diff --git a/src/star_garden.h b/src/star_garden.h
@@ -56,6 +56,12 @@ typedef enum color_t
NUM_COLORS,
} color_t;
+struct SimState
+{
+ struct Star stars[NUM_STARS];
+ struct QuadTree *qt;
+ int num_stars;
+};
struct OffscreenBuffer
{
@@ -66,10 +72,12 @@ struct OffscreenBuffer
unsigned int pitch;
};
-void update(int buffer_width, int buffer_height, struct Star stars[], int num_stars, struct QuadTree *qt);
-void render(struct OffscreenBuffer *buffer, float dt, struct Star stars[], int num_stars, struct QuadTree *qt);
-void set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t color);
-void draw_grid(struct OffscreenBuffer *buffer, struct QuadTreeNode *node, uint32_t color);
+void sim_init(struct SimState *sim_state, int field_width, int field_height);
+void sim_update(struct SimState *sim_state, int field_width, int field_height);
+void sim_render(struct OffscreenBuffer *buffer, float dt, struct SimState *sim_state);
+void sim_set_pixel(struct OffscreenBuffer *buffer, uint32_t x, uint32_t y, uint32_t color);
+void sim_render_grid(struct OffscreenBuffer *buffer, struct QuadTreeNode *node, uint32_t color);
+void sim_cleanup(struct SimState *sim_state);
#define STAR_GARDEN_H
#endif
