Color Palette, need shortcut

Added color palette instead of brighness level to display the set
boundaries.
Vim-like shortcut to move around.

1 files changed, 51 insertions, 16 deletions

diff --git a/graphics.c b/graphics.c
index 4d29d2f..84aa20d 100644
--- a/graphics.c
+++ b/graphics.c
@@ -6,35 +6,48 @@
 #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 WINDOW_W 500
+#define WINDOW_H 500
+#define REFRESH_RATE 1
 #define MOVE_SIZE 0.1
 #define ZOOM_SIZE 0.1
 
-#define BRIGHTNESS_LO 0
-#define BRIGHTNESS_HI 10
+#define RED_MASK 0xFF0000
+#define GREEN_MASK 0x00FF00
+#define BLUE_MASK 0x0000FF
+#define RED(c) ((c & RED_MASK) >> (8 * 2))
+#define GREEN(c) ((c & GREEN_MASK) >> 8)
+#define BLUE(c) (c & BLUE_MASK)
+#define MERGE_RGB(r, g, b) ((r) << (8 * 2) | (g) << 8 | (b))
+#define PALETTE_START 0x334455
+#define PALETTE_END 0xFFFFFF
+#define SET_DRAW_COLOR_RGB(renderer, c) ( \
+        SDL_SetRenderDrawColor(renderer, RED(c), GREEN(c), BLUE(c), SDL_ALPHA_OPAQUE))
+#define IN_SET_COLOR 0x000000
 
 static void update(GState *state);
 static void event_handler(GState *state);
+static Color *create_palette(Color start, Color end);
 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");
+    GState *state = (GState*)malloc(sizeof(GState));
+    if (state == NULL)
+        error_exit("state allocation failed");
     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");
+        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");
+    if ((state->palette = create_palette(PALETTE_START, PALETTE_END)) == NULL)
+        error_exit_state(state, "unable to create color palette");
     state->running = true;
     state->window_w = WINDOW_W;
     state->window_h = WINDOW_H;
@@ -63,8 +76,8 @@ void graphics_run(GState *state)
 
 static void update(GState *state)
 {
-    double a, b, brightness;
-    SDL_SetRenderDrawColor(state->renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
+    double a, b;
+    SET_DRAW_COLOR_RGB(state->renderer, IN_SET_COLOR);
     SDL_RenderClear(state->renderer);
     for (int x = 0; x < state->window_w; x++)
     {
@@ -76,10 +89,7 @@ static void update(GState *state)
             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);
+            SET_DRAW_COLOR_RGB(state->renderer, state->palette[steps]);
             SDL_RenderDrawPoint(state->renderer, x, y);
         }
     }
@@ -96,42 +106,67 @@ static void event_handler(GState *state)
             case SDL_QUIT:
                 state->running = false;
                 break;
-            case SDL_KEYUP:
+            case SDL_KEYDOWN:
                 switch (e.key.keysym.sym)
                 {
                     case SDLK_UP:
+                    case SDLK_k:
                         state->imag_lo -= MOVE_SIZE;
                         state->imag_hi -= MOVE_SIZE;
                         break;
                     case SDLK_DOWN:
+                    case SDLK_j:
                         state->imag_lo += MOVE_SIZE;
                         state->imag_hi += MOVE_SIZE;
                         break;
                     case SDLK_LEFT:
+                    case SDLK_h:
                         state->real_lo -= MOVE_SIZE;
                         state->real_hi -= MOVE_SIZE;
                         break;
                     case SDLK_RIGHT:
+                    case SDLK_l:
                         state->real_lo += MOVE_SIZE;
                         state->real_hi += MOVE_SIZE;
                         break;
+                    case SDLK_PLUS:
                     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_MINUS:
                     case SDLK_m:
                         state->real_lo -= ZOOM_SIZE;
                         state->real_hi += ZOOM_SIZE;
                         state->imag_lo -= ZOOM_SIZE;
                         state->imag_hi += ZOOM_SIZE;
                         break;
+                    case SDLK_q:
+                        state->running = false;
+                        break;
                 }
         }
     }
 }
 
+static Color *create_palette(Color start, Color end)
+{
+    Color red_step = abs(RED(end) - RED(start)) / MAX_ITERATION;
+    Color green_step = abs(GREEN(end) - GREEN(start)) / MAX_ITERATION;
+    Color blue_step = abs(BLUE(end) - BLUE(start)) / 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] = MERGE_RGB(i * red_step + RED(start),
+                               i * green_step + GREEN(start),
+                               i * blue_step + BLUE(start));
+    return palette;
+}
+
 static void destroy_state(GState *state)
 {
     if (state == NULL)