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