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#include <stdbool.h>
#include <SDL2/SDL.h>
#include "header.h"
#define WINDOW_TITLE "Mandelbrot"
#define WINDOW_X 20
#define WINDOW_Y 20
#define REFRESH_RATE 2
#define MOVE_RATIO 10
#define ZOOM_RATIO 1.1
#define REAL_LO(state) (state->center.x - state->real_range / 2)
#define REAL_HI(state) (state->center.x + state->real_range / 2)
#define IMAG_LO(state) (state->center.y - state->imag_range / 2)
#define IMAG_HI(state) (state->center.y + state->imag_range / 2)
#define IN_SET_COLOR 0x050505
#define PALETTE_START 0x000022
#define PALETTE_END 0xd62f2f
#define SET_DRAW_COLOR(renderer, c) ( \
SDL_SetRenderDrawColor(renderer, c.rgb.r, c.rgb.g, c.rgb.b, SDL_ALPHA_OPAQUE));
static void update(GState *state);
static void event_handler(GState *state);
/* static Color *create_palette(Color start, Color end); */
/* static void move_center(GState *state, int motion_x, int motion_y); */
static void recenter(GState *state, int x, int y);
static void recenter_x(GState *state, int x);
static void recenter_y(GState *state, int y);
static void zoom_in(GState *state, double ratio);
static void zoom_out(GState *state, double ratio);
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(Config *config)
{
Color start, end;
if (SDL_Init(SDL_INIT_VIDEO) < 0)
error_exit("unable to init SDL");
GState *state = (GState*)malloc(sizeof(GState));
if (state == NULL)
error_exit("state allocation failed");
state->window = SDL_CreateWindow(WINDOW_TITLE, WINDOW_X, WINDOW_Y,
config->window_w, config->window_h, 0);
if (state->window == NULL)
error_exit_state(state, "unable to create window");
state->renderer = SDL_CreateRenderer(state->window, -1, 0);
if (state->renderer == NULL)
error_exit_state(state, "unable to create renderer");
start.hexcode = PALETTE_START;
end.hexcode = PALETTE_END;
state->palette = create_palette(start, end);
if (state->palette == NULL)
error_exit_state(state, "unable to create color palette");
state->running = true;
state->window_w = config->window_w;
state->window_h = config->window_h;
state->real_range = config->real_range;
state->imag_range = config->imag_range;
state->center.x = config->center_x;
state->center.y = config->center_y;
state->in_set_color.hexcode = IN_SET_COLOR;
state->moving = false;
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;
Color color;
SET_DRAW_COLOR(state->renderer, state->in_set_color);
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, REAL_LO(state), REAL_HI(state));
b = map_range((double)y, 0, state->window_h, IMAG_LO(state), IMAG_HI(state));
int frac_steps = mandelbrot_in_set(a, b);
if (frac_steps == -1)
continue;
color = state->palette[frac_steps];
/* color.rgb.r = 100 * frac_steps; */
/* color.rgb.g = 100 * frac_steps; */
/* color.rgb.b = 100 * frac_steps; */
SET_DRAW_COLOR(state->renderer, color);
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_KEYDOWN:
switch (e.key.keysym.sym)
{
case SDLK_UP:
case SDLK_k:
state->center.y -= state->imag_range / MOVE_RATIO;
break;
case SDLK_DOWN:
case SDLK_j:
state->center.y += state->imag_range / MOVE_RATIO;
break;
case SDLK_LEFT:
case SDLK_h:
state->center.x -= state->real_range / MOVE_RATIO;
break;
case SDLK_RIGHT:
case SDLK_l:
state->center.x += state->real_range / MOVE_RATIO;
break;
case SDLK_PLUS:
case SDLK_p:
zoom_in(state, ZOOM_RATIO);
break;
case SDLK_MINUS:
case SDLK_m:
zoom_out(state, ZOOM_RATIO);
break;
case SDLK_q:
state->running = false;
}
break;
case SDL_MOUSEWHEEL:
if (e.wheel.y == -1)
zoom_in(state, ZOOM_RATIO);
else if (e.wheel.y == 1)
zoom_out(state, ZOOM_RATIO);
break;
case SDL_MOUSEBUTTONDOWN:
printf("> %d, %d\n", e.button.x, e.button.y);
if (e.button.button == SDL_BUTTON_RIGHT)
recenter(state, e.button.x, e.button.y);
// TODO
/* case SDL_MOUSEBUTTONUP: */
/* if (e.button.button == SDL_BUTTON_LEFT) */
/* { */
/* if (!state->moving && e.button.state == SDL_PRESSED) */
/* state->moving = true; */
/* else if (state->moving && e.button.state == SDL_RELEASED) */
/* state->moving = false; */
/* printf("%d %d\n", state->moving, e.button.state); */
/* } */
/* break; */
/* case SDL_MOUSEMOTION: */
/* if (state->moving) */
/* { */
/* printf("%d, %d\n", e.motion.x, e.motion.y); */
/* move_center(state, e.motion.xrel, e.motion.yrel); */
/* printf("%f, %f\n", state->center.x, state->center.y); */
/* } */
}
}
}
Color *create_palette(Color start, Color end)
{
int red_step = abs(end.rgb.r - start.rgb.r) / MAX_ITERATION;
int green_step = abs(end.rgb.g - start.rgb.g) / MAX_ITERATION;
int blue_step = abs(end.rgb.b - start.rgb.b) / MAX_ITERATION;
Color *palette = (Color*)malloc(sizeof(Color) * MAX_ITERATION);
if (palette == NULL)
return NULL;
for (int i = 0; i < MAX_ITERATION; i++)
{
palette[i].rgb.r = i * red_step + start.rgb.r;
palette[i].rgb.g = i * green_step + start.rgb.g;
palette[i].rgb.b = i * blue_step + start.rgb.b;
}
return palette;
}
// TODO
/* static void move_center(GState *state, int motion_x, int motion_y) */
/* { */
/* printf("%d, %d\n", motion_x, motion_y); */
/* if (motion_x != 0) */
/* state->center.x -= map_range(150 - motion_x, 0, state->window_w, */
/* REAL_LO(state), REAL_HI(state)); */
/* if (motion_y != 0) */
/* state->center.y -= map_range(150 - motion_y, 0, state->window_h, */
/* IMAG_LO(state), IMAG_HI(state)); */
/* printf(">> %f, %f\n", state->center.x, state->center.y); */
/* } */
static void recenter(GState *state, int x, int y)
{
recenter_x(state, x);
recenter_y(state, y);
}
static void recenter_x(GState *state, int x)
{
state->center.x = map_range(x, 0, state->window_w,
REAL_LO(state), REAL_HI(state));
}
static void recenter_y(GState *state, int y)
{
state->center.y = map_range(y, 0, state->window_w,
IMAG_LO(state), IMAG_HI(state));
}
static void zoom_in(GState *state, double ratio)
{
state->real_range /= ratio;
state->imag_range /= ratio;
}
static void zoom_out(GState *state, double ratio)
{
state->real_range *= ratio;
state->imag_range *= ratio;
}
static void destroy_state(GState *state)
{
if (state == NULL)
return;
free(state->palette);
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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