cocos2d slot machine animation - objective-c

Question

I am trying to create an application that simulates a slot machine.
Now, I have all the images ready, with the vertical png file and the plist file. My question is, how do I simulate the spinning (when the user presses a button), and then the stopping of the slot machine (after around 1-2 seconds)?
Note that the png file has to wrap around somehow.
Everything else is all a matter of NSArrays and checking, what I want to figure out is the animation. I hope some can share some code or references to do this.
Thanks!

Answer 1

This is relatively straightforward: just repeat the png file as many times as you need to simulate the spinning action. So it's basically a vertical variation on parallax scrolling. If you have Steffan Itterheim's book, he talks about this type of thing in chapter 7 "Scrolling With Joy". You may also find some help here: Cocos2D vertically scrolling background
Hope this helps!
Mike

Answer 2

I am doing something like this:
#include <ctime>
#include <vector>
#include <cstdlib>
#include <iostream>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
using namespace std;
static int last[5]={0, 0, 0, 0, 0};
static int stops[5];
static int reels[5][63] = {
{9,7,12,5,7,3,4,11,9,7,12,6,7,4,11,10,4,3,11,12,7,5,10,9,7,5,9,10,8,9,7,4,9,10,11,5,10,3,9,10,3,9,4,8,7,5,11,9,12,6,3,5,7,9,11,10,6,7,3,5,10,8,4,},
{11,5,4,7,6,8,4,9,7,8,3,11,6,5,11,7,12,5,8,6,10,9,5,6,8,7,12,11,5,6,10,3,4,5,9,12,8,9,6,5,12,8,9,12,7,8,5,10,12,7,11,3,4,8,7,4,5,9,8,6,12,4,6,},
{10,4,5,8,6,7,5,9,6,7,8,4,6,5,11,3,9,8,7,11,12,6,8,5,4,8,6,12,9,6,5,11,3,7,4,8,7,3,10,9,5,6,4,3,9,12,10,8,9,6,3,9,10,6,7,5,6,8,4,11,9,7,8,},
{9,3,6,5,3,10,6,9,5,12,4,8,11,10,7,6,5,9,7,3,8,6,12,4,5,7,3,12,10,6,9,7,8,5,6,4,9,6,11,5,8,12,6,7,3,6,10,3,7,5,10,8,9,6,12,4,7,9,5,6,8,3,10,},
{5,3,9,4,6,12,10,5,11,4,8,7,10,5,9,11,4,6,7,3,6,4,8,5,11,8,5,10,8,11,5,10,8,3,7,4,10,11,5,7,8,9,5,11,6,8,10,3,7,9,3,8,10,12,6,8,10,11,7,10,8,11,6,},
};
static SDL_Window *window = NULL;
static SDL_Surface *canvas = NULL;
static const SDL_Surface *backgroundSurface = IMG_Load("./Background.png");
static SDL_Rect backgroundCoordinates = { 0, 0, 0, 0 };
static const SDL_Surface *symbolsSurface[] = {
NULL,
NULL,
NULL,
IMG_Load("./Symbol03.png"),
IMG_Load("./Symbol04.png"),
IMG_Load("./Symbol05.png"),
IMG_Load("./Symbol06.png"),
IMG_Load("./Symbol07.png"),
IMG_Load("./Symbol08.png"),
IMG_Load("./Symbol09.png"),
IMG_Load("./Symbol10.png"),
IMG_Load("./Symbol11.png"),
IMG_Load("./Symbol12.png"),
NULL,
NULL,
NULL,
NULL,
};
static const SDL_Surface *reelsSurface[5] = {NULL, NULL, NULL, NULL, NULL};
static SDL_Rect symbolsCoordinates[5][3] = {
{ { 298, 118, 0, 0 }, { 298, 266, 0, 0 }, { 298, 414, 0, 0 } },
{ { 474, 118, 0, 0 }, { 474, 266, 0, 0 }, { 474, 414, 0, 0 } },
{ { 651, 118, 0, 0 }, { 651, 266, 0, 0 }, { 651, 414, 0, 0 } },
{ { 827, 118, 0, 0 }, { 827, 266, 0, 0 }, { 827, 414, 0, 0 } },
{ { 1003, 118, 0, 0 }, { 1003, 266, 0, 0 }, {1003, 414, 0, 0 } },
};
static unsigned long animationStart = 0;
static unsigned long animationEnd = 0;
static bool stopped[5] = {false, false, false, false, false};
void draw() {
static double y0 = 0;
static double v0[5] = {-9.5, -9.6, -9.7, -9.8, -9.9};
static long t = 0;
static double a = 0.0005;
static int y = 0;
SDL_BlitSurface((SDL_Surface*) backgroundSurface, NULL, canvas, &backgroundCoordinates);
for (int i = 0; i < 5 && animationStart!=animationEnd; i++) {
/*
* y = y0 + v0*t + 1/2*at^2
*/
y0 = last[i] * 140;
t = (1000 * clock() / CLOCKS_PER_SEC) - animationStart;
y = (int)(y0 + v0[i]*t + a*t*t/2) % (63*140);
if(y < 0) {
y += 63*140;
}
/*
* Stop near to the target position.
*/
if(i==0 && abs(y-stops[i]*140)<=140) {
last[i] = stops[i];
stopped[i] = true;
}else if(stopped[i-1] == true && stopped[i] == false && abs(y-stops[i]*140)<=140) {
last[i] = stops[i];
stopped[i] = true;
}
if(stopped[i] == true) {
SDL_SetSurfaceAlphaMod((SDL_Surface*) reelsSurface[i], 255);
y = stops[i] * 140;
} else {
SDL_SetSurfaceAlphaMod((SDL_Surface*) reelsSurface[i], 191);
}
const SDL_Rect frame = {0, y, 140, 3*140};
SDL_BlitSurface((SDL_Surface*) reelsSurface[i], &frame, canvas, &symbolsCoordinates[i][0]);
}
SDL_UpdateWindowSurface(window);
}
int main() {
SDL_Init(SDL_INIT_EVERYTHING);
/*
* Build long strips (two more images at the end).
*/
for(int i=0, index; i<5; i++) {
reelsSurface[i] = IMG_Load("./Reel.png");
for(int j=0; j<(63+2); j++) {
index = reels[i][j%63];
SDL_Rect coordinates = {0, 140*j, 0, 0};
SDL_BlitSurface((SDL_Surface*) symbolsSurface[index], NULL, (SDL_Surface*)reelsSurface[i], &coordinates);
}
}
//window = SDL_CreateWindow("Slot Reels Animation", 0, 0, 1280, 1024, SDL_WINDOW_FULLSCREEN_DESKTOP);
window = SDL_CreateWindow("Slot Reels Animation", 0, 0, 1440, 900, 0);
canvas = SDL_GetWindowSurface(window);
SDL_Event event;
bool done = false;
while (done == false) {
while (SDL_PollEvent(&event)) {
switch (event.type) {
case SDL_QUIT:
done = true;
break;
case SDL_KEYDOWN:
switch (event.key.keysym.sym) {
case SDLK_ESCAPE:
done = true;
break;
case SDLK_RETURN:
//startAnimation();
memset(stopped, false, 5*sizeof(bool));
animationStart = 1000 * clock() / CLOCKS_PER_SEC;
for (int i = 0, r; i < 5; i++) {
stops[i] = rand() % 63;
}
break;
}
}
}
draw();
}
SDL_DestroyWindow(window);
for(int i=0; i<5; i++) {
SDL_FreeSurface((SDL_Surface*)reelsSurface[i]);
}
SDL_Quit();
return EXIT_SUCCESS;
}