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/* main.c
* Created: 2023-08-25
* Author: Aryadev Chavali
* Description: Entry point of program
*/
#include <malloc.h>
#include <stdbool.h>
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <raylib.h>
#include <raymath.h>
#include "./lib.h"
struct StepArg
{
state_t *state;
size_t x_min, x_max, y_min, y_max;
};
pthread_mutex_t mutex;
void step(struct StepArg arg)
{
state_t *state = arg.state;
for (size_t i = arg.x_min; i < arg.x_max; ++i)
for (size_t j = arg.y_min; j < arg.y_max; ++j)
if (state->data[(i * state->dwidth) + j] >= 4)
{
pthread_mutex_lock(&mutex);
uint64_t *references[] = {
(j == 0) ? NULL : &state->data[((i)*state->dwidth) + j - 1],
(i == state->dwidth - 1)
? NULL
: &state->data[((i + 1) * state->dwidth) + j],
(j == state->dwidth - 1)
? NULL
: &state->data[(i * state->dwidth) + j + 1],
(i == 0) ? NULL : &state->data[((i - 1) * state->dwidth) + j]};
for (size_t k = 0; k < 4; ++k)
if (references[k])
*references[k] += state->data[(i * state->dwidth) + j] / 4;
state->data[(i * state->dwidth) + j] %= 4;
pthread_mutex_unlock(&mutex);
}
}
void *compute_thread(void *input)
{
struct StepArg *arg = input;
while (arg->state->thread_alive)
step(*arg);
return NULL;
}
bool completed_avalanche(state_t *state)
{
for (size_t i = 0; i < state->dwidth; ++i)
for (size_t j = 0; j < state->dwidth; ++j)
if (state->data[(i * state->dwidth) + j] >= 4)
return false;
return true;
}
int main(int argc, char *argv[])
{
// Setup "default" state
state_t state = {NULL, 512, 512, 0, true, pow(2, 16)};
state.data = calloc(state.dwidth * state.dwidth, sizeof(*state.data));
state.multiplier = state.window_len / state.dwidth;
state.data[(state.dwidth * state.dwidth / 2) + (state.dwidth / 2)] =
state.payload;
const float zoom = 0.125f;
Camera2D camera = {0};
camera.zoom = 1.0f;
// Initialise mutex for threads to use
pthread_mutex_init(&mutex, NULL);
// Setup quadrants (for threads)
struct StepArg a = {&state, 0, state.dwidth / 2, 0, state.dwidth / 2};
struct StepArg b = {&state, 0, state.dwidth / 2, state.dwidth / 2,
state.dwidth};
struct StepArg c = {&state, state.dwidth / 2, state.dwidth, 0,
state.dwidth / 2};
struct StepArg d = {&state, state.dwidth / 2, state.dwidth, state.dwidth / 2,
state.dwidth};
// Setup threads
pthread_t thread_a, thread_b, thread_c, thread_d;
pthread_create(&thread_a, NULL, &compute_thread, &a);
pthread_create(&thread_b, NULL, &compute_thread, &b);
pthread_create(&thread_c, NULL, &compute_thread, &c);
pthread_create(&thread_d, NULL, &compute_thread, &d);
InitWindow(state.window_len, state.window_len, "Abelian sand pile");
SetTargetFPS(60);
const int DELTA = 100;
bool done = false;
for (uint64_t ticks = 0, prev_ticks = 0; !WindowShouldClose(); ++ticks)
{
if (IsKeyPressed(KEY_UP) || IsKeyDown(KEY_UP))
{
Vector2 centre = {state.window_len / 2, state.window_len / 2};
Vector2 world_pos = GetScreenToWorld2D(centre, camera);
camera.offset = centre;
camera.target = world_pos;
camera.zoom += zoom;
if (camera.zoom < zoom)
camera.zoom = zoom;
}
if (IsKeyPressed(KEY_DOWN) || IsKeyDown(KEY_DOWN))
{
Vector2 centre = {state.window_len / 2, state.window_len / 2};
Vector2 world_pos = GetScreenToWorld2D(centre, camera);
camera.offset = centre;
camera.target = world_pos;
camera.zoom -= zoom;
if (camera.zoom < zoom)
camera.zoom = zoom;
}
if (ticks - prev_ticks > DELTA && !done)
{
printf("Checking if avalanche is complete!\n");
if (completed_avalanche(&state))
{
state.thread_alive = false;
pthread_join(thread_a, NULL);
pthread_join(thread_b, NULL);
pthread_join(thread_c, NULL);
pthread_join(thread_d, NULL);
done = true;
}
prev_ticks = ticks;
}
if (IsMouseButtonDown(MOUSE_BUTTON_LEFT))
{
Vector2 delta = Vector2Scale(GetMouseDelta(), -1.0f / camera.zoom);
camera.target = Vector2Add(camera.target, delta);
}
BeginDrawing();
ClearBackground(BLACK);
BeginMode2D(camera);
for (size_t i = 0; i < state.dwidth; ++i)
for (size_t j = 0; j < state.dwidth; ++j)
{
Color c = {0};
uint64_t sandpile = state.data[(i * state.dwidth) + j];
if (sandpile == 0)
c = BLACK;
else if (sandpile == 1)
c = MAGENTA;
else if (sandpile == 2)
c = RED;
else if (sandpile == 3)
c = BLUE;
DrawRectangle(i * state.multiplier, j * state.multiplier,
state.multiplier, state.multiplier, c);
}
EndMode2D();
EndDrawing();
}
if (state.thread_alive)
{
state.thread_alive = false;
pthread_join(thread_a, NULL);
pthread_join(thread_b, NULL);
pthread_join(thread_c, NULL);
pthread_join(thread_d, NULL);
}
CloseWindow();
write_to_png(&state, "data.png");
free(state.data);
return 0;
}
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