State stores the window size and the domain where to look the set

4 files changed, 43 insertions, 29 deletions

diff --git a/graphics.c b/graphics.c
index e36fee0..dd146d2 100644
--- a/graphics.c
+++ b/graphics.c
@@ -1,8 +1,17 @@
+#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 500
+#define WINDOW_H 500
+#define REFRESH_RATE 3
+
+#define BRIGHTNESS_LO 0
+#define BRIGHTNESS_HI 20
 
 static void update(GState *state);
 static void event_handler(GState *state);
@@ -10,7 +19,7 @@ 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(GConf *conf)
+GState *graphics_init(void)
 {
     GState *state = (GState*)malloc(sizeof(GState));
     if (state == NULL)
@@ -25,6 +34,12 @@ GState *graphics_init(GConf *conf)
     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;
 }
 
@@ -40,24 +55,27 @@ void graphics_run(GState *state)
     {
         event_handler(state);
         update(state);
-        SDL_Delay(3);
+        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 < WINDOW_W; x++)
+    for (int x = 0; x < state->window_w; x++)
     {
-        for (int y = 0; y < WINDOW_H; y++)
+        for (int y = 0; y < state->window_h; y++)
         {
-            double complex mapped_z = map_range((double)x, 0, WINDOW_W, LO, HI)
-                                      + map_range((double)y, 0, WINDOW_H, LO, HI) * I;
+            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;
-            double brightness = map_range(steps, LO, HI, 0, 20);
+            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);
diff --git a/header.h b/header.h
index 8873077..3f86f46 100644
--- a/header.h
+++ b/header.h
@@ -5,37 +5,33 @@
 # include <complex.h>
 # include <SDL2/SDL.h>
 
-# define WINDOW_W 500
-# define WINDOW_H 500
-
-# define LO -1.5
-# define HI 1.5
-# define AXIS_DIV 46.0
-# define AXIS_STEP ((HI - LO) / AXIS_DIV)
+# define REAL_LO -2.0
+# define REAL_HI 2.0
+# define IMAG_LO -2.0
+# define IMAG_HI 2.0
 
 # define MAX_ITERATION 30
 # define _INFINITY 4
 
-
 typedef struct
 {
     SDL_Window *window;
     SDL_Renderer *renderer;
     bool running;
+    int window_w;
+    int window_h;
+    double real_lo;
+    double real_hi;
+    double imag_lo;
+    double imag_hi;
 } GState;
 
-typedef struct
-{
-    int window_width;
-    int window_height;
-} GConf;
-
 // mandelbrot.c
 int mandelbrot_in_set(double _Complex c);
 void mandelbrot_print(void);
 
 // graphics.c
-GState *graphics_init(GConf *conf);
+GState *graphics_init(void);
 void graphics_quit(GState *state);
 void graphics_run(GState *state);
 
diff --git a/main.c b/main.c
index 494ee2c..7757243 100644
--- a/main.c
+++ b/main.c
@@ -3,11 +3,7 @@
 int main(void)
 {
     /* mandelbrot_print(); */
-    GConf gconf = {
-        .window_width = 300,
-        .window_height = 300
-    };
-    GState *gstate = graphics_init(&gconf);
+    GState *gstate = graphics_init();
     graphics_run(gstate);
     graphics_quit(gstate);
     return 0;
diff --git a/mandelbrot.c b/mandelbrot.c
index 48d893d..fcbb765 100644
--- a/mandelbrot.c
+++ b/mandelbrot.c
@@ -3,6 +3,10 @@
 #include <complex.h>
 #include "header.h"
 
+#define AXIS_DIV 46.0
+#define REAL_AXIS_STEP ((REAL_HI - REAL_LO) / AXIS_DIV)
+#define IMAG_AXIS_STEP ((IMAG_HI - IMAG_LO) / AXIS_DIV)
+
 #define IN_CHAR '*'
 #define OUT_CHAR ' '
 
@@ -21,9 +25,9 @@ int mandelbrot_in_set(double complex c)
 
 void mandelbrot_print(void)
 {
-    for (double i = LO; i < HI; i += AXIS_STEP)
+    for (double i = IMAG_LO; i < IMAG_HI; i += IMAG_AXIS_STEP)
     {
-        for (double r = LO; r < HI; r += AXIS_STEP)
+        for (double r = REAL_LO; r < REAL_HI; r += REAL_AXIS_STEP)
         {
             if (mandelbrot_in_set(r + i * I))
                 putchar(IN_CHAR);