Data commit

Task/Fractal-tree/C/fractal-tree.c

@@ -0,0 +1,101 @@
+#include <SDL/SDL.h>
+#ifdef WITH_CAIRO
+#include <cairo.h>
+#else
+#include <SDL/sge.h>
+#endif
+#include <cairo.h>
+#include <stdlib.h>
+#include <time.h>
+#include <math.h>
+
+#ifdef WITH_CAIRO
+#define PI 3.1415926535
+#endif
+
+#define SIZE           800   // determines size of window
+#define SCALE          5     // determines how quickly branches shrink (higher value means faster shrinking)
+#define BRANCHES       14    // number of branches
+#define ROTATION_SCALE 0.75  // determines how slowly the angle between branches shrinks (higher value means slower shrinking)
+#define INITIAL_LENGTH 50    // length of first branch
+
+double rand_fl(){
+  return (double)rand() / (double)RAND_MAX;
+}
+
+void draw_tree(SDL_Surface * surface, double offsetx, double offsety,
+               double directionx, double directiony, double size,
+               double rotation, int depth) {
+#ifdef WITH_CAIRO
+  cairo_surface_t *surf = cairo_image_surface_create_for_data( surface->pixels,
+                                                               CAIRO_FORMAT_RGB24,
+							       surface->w, surface->h,
+							       surface->pitch );
+  cairo_t *ct = cairo_create(surf);
+
+  cairo_set_line_width(ct, 1);
+  cairo_set_source_rgba(ct, 0,0,0,1);
+  cairo_move_to(ct, (int)offsetx, (int)offsety);
+  cairo_line_to(ct, (int)(offsetx + directionx * size), (int)(offsety + directiony * size));
+  cairo_stroke(ct);
+#else
+  sge_AALine(surface,
+      (int)offsetx, (int)offsety,
+      (int)(offsetx + directionx * size), (int)(offsety + directiony * size),
+      SDL_MapRGB(surface->format, 0, 0, 0));
+#endif
+  if (depth > 0){
+    // draw left branch
+    draw_tree(surface,
+        offsetx + directionx * size,
+        offsety + directiony * size,
+        directionx * cos(rotation) + directiony * sin(rotation),
+        directionx * -sin(rotation) + directiony * cos(rotation),
+        size * rand_fl() / SCALE + size * (SCALE - 1) / SCALE,
+        rotation * ROTATION_SCALE,
+        depth - 1);
+
+    // draw right branch
+    draw_tree(surface,
+        offsetx + directionx * size,
+        offsety + directiony * size,
+        directionx * cos(-rotation) + directiony * sin(-rotation),
+        directionx * -sin(-rotation) + directiony * cos(-rotation),
+        size * rand_fl() / SCALE + size * (SCALE - 1) / SCALE,
+        rotation * ROTATION_SCALE,
+        depth - 1);
+  }
+}
+
+void render(SDL_Surface * surface){
+  SDL_FillRect(surface, NULL, SDL_MapRGB(surface->format, 255, 255, 255));
+  draw_tree(surface,
+      surface->w / 2.0,
+      surface->h - 10.0,
+      0.0, -1.0,
+      INITIAL_LENGTH,
+      PI / 8,
+      BRANCHES);
+  SDL_UpdateRect(surface, 0, 0, 0, 0);
+}
+
+int main(){
+  SDL_Surface * screen;
+  SDL_Event evt;
+
+  SDL_Init(SDL_INIT_VIDEO);
+
+  srand((unsigned)time(NULL));
+
+  screen = SDL_SetVideoMode(SIZE, SIZE, 32, SDL_HWSURFACE);
+
+  render(screen);
+  while(1){
+    if (SDL_PollEvent(&evt)){
+      if(evt.type == SDL_QUIT) break;
+    }
+    SDL_Delay(1);
+  }
+  SDL_Quit();
+  return 0;
+}