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#include <stdbool.h>
#include <complex.h>
#include <SDL2/SDL.h>
#include "header.h"
#define WINDOW_TITLE "Mandelbrot"
#define WINDOW_X 20
#define WINDOW_Y 20
#define WINDOW_W 300
#define WINDOW_H 300
#define REFRESH_RATE 3
#define MOVE_SIZE 0.1
#define ZOOM_SIZE 0.1
#define BRIGHTNESS_LO 0
#define BRIGHTNESS_HI 10
static void update(GState *state);
static void event_handler(GState *state);
static void destroy_state(GState *state);
static void error_exit_state(GState *state, const char *msg);
static void error_exit(const char *msg);
GState *graphics_init(void)
{
GState *state = (GState*)malloc(sizeof(GState));
if (state == NULL)
return NULL;
if (SDL_Init(SDL_INIT_VIDEO) < 0)
error_exit("unable to init SDL");
state->window = SDL_CreateWindow(WINDOW_TITLE, WINDOW_X, WINDOW_Y,
WINDOW_W, WINDOW_H, 0);
if (state->window == NULL)
error_exit("unable to create window");
state->renderer = SDL_CreateRenderer(state->window, -1, 0);
if (state->renderer == NULL)
error_exit_state(state, "unable to create renderer");
state->running = true;
state->window_w = WINDOW_W;
state->window_h = WINDOW_H;
state->real_lo = REAL_LO;
state->real_hi = REAL_HI;
state->imag_lo = IMAG_LO;
state->imag_hi = IMAG_HI;
return state;
}
void graphics_quit(GState *state)
{
destroy_state(state);
SDL_Quit();
}
void graphics_run(GState *state)
{
while (state->running)
{
event_handler(state);
update(state);
SDL_Delay(REFRESH_RATE);
}
}
static void update(GState *state)
{
double a, b, brightness;
SDL_SetRenderDrawColor(state->renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
SDL_RenderClear(state->renderer);
for (int x = 0; x < state->window_w; x++)
{
for (int y = 0; y < state->window_h; y++)
{
a = map_range((double)x, 0, state->window_w, state->real_lo, state->real_hi);
b = map_range((double)y, 0, state->window_h, state->imag_lo, state->imag_hi);
double complex mapped_z = a + b * I;
int steps = mandelbrot_in_set(mapped_z);
if (steps == -1)
continue;
brightness = map_range(steps, state->real_lo, state->real_hi,
BRIGHTNESS_LO, BRIGHTNESS_HI);
SDL_SetRenderDrawColor(state->renderer, brightness, brightness,
brightness, SDL_ALPHA_OPAQUE);
SDL_RenderDrawPoint(state->renderer, x, y);
}
}
SDL_RenderPresent(state->renderer);
}
static void event_handler(GState *state)
{
SDL_Event e;
while (SDL_PollEvent(&e))
{
switch (e.type)
{
case SDL_QUIT:
state->running = false;
break;
case SDL_KEYUP:
switch (e.key.keysym.sym)
{
case SDLK_UP:
state->imag_lo -= MOVE_SIZE;
state->imag_hi -= MOVE_SIZE;
break;
case SDLK_DOWN:
state->imag_lo += MOVE_SIZE;
state->imag_hi += MOVE_SIZE;
break;
case SDLK_LEFT:
state->real_lo -= MOVE_SIZE;
state->real_hi -= MOVE_SIZE;
break;
case SDLK_RIGHT:
state->real_lo += MOVE_SIZE;
state->real_hi += MOVE_SIZE;
break;
case SDLK_p:
state->real_lo += ZOOM_SIZE;
state->real_hi -= ZOOM_SIZE;
state->imag_lo += ZOOM_SIZE;
state->imag_hi -= ZOOM_SIZE;
break;
case SDLK_m:
state->real_lo -= ZOOM_SIZE;
state->real_hi += ZOOM_SIZE;
state->imag_lo -= ZOOM_SIZE;
state->imag_hi += ZOOM_SIZE;
break;
}
}
}
}
static void destroy_state(GState *state)
{
if (state == NULL)
return;
SDL_DestroyRenderer(state->renderer);
SDL_DestroyWindow(state->window);
free(state);
}
static void error_exit_state(GState *state, const char *msg)
{
destroy_state(state);
error_exit(msg);
}
static void error_exit(const char *msg)
{
SDL_Log("ERROR: %s: %s", SDL_GetError(), msg);
SDL_Quit();
exit(EXIT_FAILURE);
}
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